jackson (exact): 312 papers, Hirsch index 20, Hirsch ratio 0.064.
adsauthor "Jackson, B.V.; Jackson, Bernard V.; Jackson, Bernard" abstract
@--------------------------------------------------------------------
Title: An Analysis of the Origin and Propagation of the
Multiple Coronal Mass Ejections of 2010 August 1
Authors: Harrison, R. A.; Davies, J. A.; Möstl, C.; Liu, Y.;
Temmer, M.; Bisi, M. M.; Eastwood, J. P.;
de Koning, C. A.; Nitta, N.; Rollett, T.;
Farrugia, C. J.; Forsyth, R. J.; Jackson, B. V.;
Jensen, E. A.; Kilpua, E. K. J.; Odstrcil, D.;
Webb, D. F.
Bibliographic Code: 2012ApJ...750...45H
Abstract
On 2010 August 1, the northern solar hemisphere underwent significant
activity that involved a complex set of active regions near central
meridian with, nearby, two large prominences and other more distant
active regions. This activity culminated in the eruption of four major
coronal mass ejections (CMEs), effects of which were detected at Earth
and other solar system bodies. Recognizing the unprecedented wealth of
data from the wide range of spacecraft that were
available---providing the potential for us to explore methods for
CME identification and tracking, and to assess issues regarding onset
and planetary impact---we present a comprehensive analysis of this
sequence of CMEs. We show that, for three of the four major CMEs, onset
is associated with prominence eruption, while the remaining CME appears
to be closely associated with a flare. Using instrumentation on board
the Solar Terrestrial Relations Observatory spacecraft, three of the
CMEs could be tracked out to elongations beyond 50° their directions
and speeds have been determined by various methods, not least to assess
their potential for Earth impact. The analysis techniques that can be
applied to the other CME, the first to erupt, are more limited since
that CME was obscured by the subsequent, much faster event before it had
propagated far from the Sun; we discuss the speculation that these two
CMEs interact. The consistency of the results, derived from the wide
variety of methods applied to such an extraordinarily complete data set,
has allowed us to converge on robust interpretations of the CME onsets
and their arrivals at 1 AU.
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Title: A Snapshot of the Sun Near Solar Minimum: The Whole
Heliosphere Interval
Authors: Thompson, Barbara J.; Gibson, Sarah E.;
Schroeder, Peter C.; Webb, David F.;
Arge, Charles N.; Bisi, Mario M.; de Toma, Giuliana;
Emery, Barbara A.; Galvin, Antoinette B.;
Haber, Deborah A.; Jackson, Bernard V.;
Jensen, Elizabeth A.; Leamon, Robert J.; Lei, Jiuhou;
Manoharan, Periasamy K.; Mays, M. Leila;
McIntosh, Patrick S.; Petrie, Gordon J. D.;
Plunkett, Simon P.; Qian, Liying; Riley, Peter;
Suess, Steven T.; Tokumaru, Munetoshi;
Welsch, Brian T.; Woods, Thomas N.
Bibliographic Code: 2011SoPh..274...29T
Abstract
We present an overview of the data and models collected for the Whole
Heliosphere Interval, an international campaign to study the
three-dimensional solar-heliospheric-planetary connected
system near solar minimum. The data and models correspond to solar
Carrington Rotation 2068 (20 March - 16 April 2008) extending from
below the solar photosphere, through interplanetary space, and down to
Earth's mesosphere. Nearly 200 people participated in aspects of
WHI studies, analyzing and interpreting data from nearly 100 instruments
and models in order to elucidate the physics of fundamental
heliophysical processes. The solar and inner heliospheric data showed
structure consistent with the declining phase of the solar cycle. A
closely spaced cluster of low-latitude active regions was responsible
for an increased level of magnetic activity, while a highly warped
current sheet dominated heliospheric structure. The geospace data
revealed an unusually high level of activity, driven primarily by the
periodic impingement of high-speed streams. The WHI studies traced the
solar activity and structure into the heliosphere and geospace, and
provided new insight into the nature of the interconnected heliophysical
system near solar minimum.
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Title: SMEI and IPS 3-D CME Reconstructions, and What They
Indicate of Heliospheric Solar Wind Acceleration
Authors: Jackson, B. V.; Clover, J. M.; Hick, P. P.;
Buffington, A.; Bisi, M. M.; Tokumaru, M.
Bibliographic Code: 2011AGUFMSH32A..05J
Abstract
The remotely-sensed measurements of coronal mass ejections (CMEs) and
their interplanetary counterparts (ICMEs) from Solar Mass Ejection
Imager (SMEI) white-light brightness and radio interplanetary
scintillation (IPS) data can be used to provide limits on the
acceleration and deceleration of transients in the inner heliosphere. As
an intermediate measurement between the Sun and 1 AU, the limits
provided by remote sensing are convolved with line-of-sight effects and
CME/ICME `evolution' as each feature of the transient moves outward from
the Sun. Here we review a few of the popular events and studies that
have been presented to show how CME propagation proceeds in the inner
heliosphere. Often, the apparent acceleration shown can only be provided
by employing an assumption of the CME three-dimensional (3-D) shape,
which often changes with solar distance and CME visibility along the
line of sight. This assumption can often abrogate the original
acceleration measurement. In particular we concentrate here on the
analysis of two events during periods in 02-04 November 2003, and also
in January 2010 showing how each event provides significantly different
acceleration profiles depending on which structures are identified in
each transient. Finally, we highlight the strange case of polar coronal
jets (that are essentially miniature CMEs) frequently observed to move
outward in the polar coronal fast wind at speeds of over three times
ambient. These small solar wind transients seem to have disappeared by
the time they can be observed in Ulysses in-situ data. Thus, a detailed
study of these jets may provide an understanding of smaller-scale
CME/ICME deceleration processes.
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Title: Comparative Validation of Realtime Solar Wind
Forecasting Using the UCSD Heliospheric Tomography
Model
Authors: MacNeice, P. J.; Taktakishvili, A.; Jackson, B. V.;
Clover, J. M.; Bisi, M. M.; Odstrcil, D.
Bibliographic Code: 2011AGUFMSH31C2026M
Abstract
The University of California, San Diego 3D Heliospheric Tomography Model
reconstructs the evolution of heliospheric structures, and can make
forecasts of solar wind density and velocity up to 72 hours in the
future. The latest model version, installed and running in near
real-time at the Community Coordinated Modeling Center(CCMC), analyzes
scintillations of meter wavelength radio point sources recorded by the
Solar-Terrestrial Environment Laboratory (STELab) together with
real-time measurements of solar wind speed and density recorded by the
Advanced Composition Explorer(ACE) Solar Wind Electron Proton Alpha
Monitor(SWEPAM). The solution is reconstructed using tomographic
techniques and a simple kinematic wind model. Since installation, the
CCMC has been recording the model forecasts and comparing them with ACE
measurements, and with forecasts made using other heliospheric models
hosted by the CCMC. We report the preliminary results of this validation
work and comparison with alternative models.
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Title: UCSD Time-Dependent Tomographic Forecasting with
Interplanetary Scintillation and White-Light
Observations
Authors: Clover, J. M.; Jackson, B. V.; Hick, P. P.;
Buffington, A.; Tokumaru, M.; Fujiki, K.; Hirota, M.;
Bisi, M. M.
Bibliographic Code: 2011AGUFMSH31C2025C
Abstract
The University of California, San Diego (UCSD) time-dependent tomography
program has been used successfully since the beginning of the year 2000
to remotely sense and forecast interplanetary scintillation (IPS)
observations of coronal mass ejections (CMEs). Recently, this program
has included real-time ACE data in the analysis. This more-efficiently
extends velocity and density measurements obtained near Earth in real
time to those derived from remotely-sensed observations, and allows a
far more efficient extrapolation from the present time into the future.
These analyses are now also used with real-time extrapolations of radial
and tangential magnetic fields from the National Solar Observatory. The
time-dependent program is also being adapted to provide similar
forecasts (but at higher spatial and temporal resolutions) of
heliospheric density using Thomson-scattering data from the Solar Mass
Ejection Imager (SMEI). Here, we describe the current state of these IPS
and SMEI real-time data pipelines and show their usefulness. These
demonstrate in near real-time the improved accuracy of the
remote-sensing fits with the inclusion of space-borne in-situ density
and velocity measurements during the current rising phase of the solar
cycle.
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Title: Using Global Heliospheric Reconstructions to
Separate Multiple CME and CIR Flows
Authors: Webb, D. F.; Jackson, B. V.; Bisi, M. M.;
Howard, T. A.
Bibliographic Code: 2011AGUFMSH31C2024W
Abstract
The heliospheric propagation of density structures has been observed and
measured by the heliospheric imagers (HIs) of the Solar Mass Ejection
Imager (SMEI) in Earth orbit since early 2003 and on the twin Solar
TErrestrial RElations Observatory (STEREO) spacecraft in ~1 AU solar
orbits since early 2007. We discuss several three-dimensional (3-D)
reconstruction techniques being used with these HI data sets and their
capabilities for distinguishing and tracking separate CME/ICME flows in
the inner heliosphere during very active periods, and/or separating
CME/ICME and CIR flows. We include heliospheric modeling techniques
based on kinematical solar wind models, MHD models, and the empirical
Tappin-Howard (T-H) model. We focus on two periods of high activity:
January 2010 and July-August 2010. We will also look at events during
the Whole Heliosphere Interval (WHI) Campaign in March-April 2008.
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Title: Current and Planned Solar Wind Observations Using
the EISCAT and LOFAR Radio-Telescope Systems
Authors: Bisi, M. M.; Fallows, R. A.; Jensen, E. A.;
Breen, A.; Xiong, M.; Jackson, B. V.
Bibliographic Code: 2011AGUFMSH31C2020B
Abstract
Remote-sensing observations of the inner heliosphere using the technique
of interplanetary scintillation (IPS) provide essential information on
the velocity and density of developing solar wind structure. For many
years, observations of IPS have been undertaken with the European
Incoherent SCATter (EISCAT) radio telescopes based across Northern
Scandinavia. We are presently developing the IPS experiment for use on
new and upcoming cutting-edge instrumentation. Such instrumentation
includes the LOw Frequency ARray (LOFAR) which is situated primarily in
the Netherlands with additional stations currently sited across central
Europe. Using data sets from various IPS-capable systems, the University
of California, San Diego (UCSD) three-dimensional (3-D)
tomographic-reconstruction and visualisation algorithms can yield
reconstruction results for comparison with multi-point it{in-situ}
measurements from spacecraft. This makes it possible to study the
structure of the inner heliosphere as a whole, including the isolation
of individual features or events such as interplanetary coronal mass
ejections (ICMEs), stream interaction regions (SIRs), or their
interactions with the ambient solar wind as well as the ambient wind
itself. We are also testing the Faraday rotation (FR) response at low
frequencies using LOFAR. Combined, these techniques have large
implications and capabilities for space-weather forecasting. This work
is focused on the global structure of the inner heliosphere during the
minimum and rise phases of the current solar cycle.
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Title: Necessity of 2D image data for determining 3D
configurations of magnetic clouds
Authors: Marubashi, K.; Tokumaru, M.; Jackson, B. V.;
Clover, J. M.
Bibliographic Code: 2011AGUFMSH21A1911M
Abstract
The structure of magnetic cloud (MC) has long been studied by fitting
in-situ magnetic field measurements to magnetic flux rope models. Such
studies generally provide the size and orientation of the model
structure, which are taken to be applicable only locally to the portion
where the cloud passed the spacecraft. The obtained geometry often
changes depending on the models used for the fitting. For example, for a
single observational data set, a cylinder model and a torus model often
give different cloud axis orientations. Thus we need further
consideration about the global configuration to deduce the 3D structure
of the MC. 2D images from heliospheric remote sensing measurements
provide reliable constraints about the global MC structure. With the
above in mind we attempt to study the global structure of MC by
combining the model fitting results and the 3D reconstruction data from
the Solar Mass Ejection Imager (SMEI) and interplanetary scintillations
(IPS). For this purpose, we first select MC events in which the proton
densities are high enough (generally > 20 /cc) in the sheath regions
behind the driven shocks and/or in the regions occupied by MCs. Then we
examine possible 3D configurations which are consistent with the
orientation of the MC axis obtained from model fittings. The global MC
structure is finally obtained by applying the constraints from 2D image
data. Our preliminary examination shows that the above procedure is
helpful for determining the most probable 3D global structures of MCs.
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Title: Imaging Coronal Mass Ejections and Large-Scale Solar
Wind Structure Using Thomson-Scattering Measurements
from SMEI
Authors: Jackson, B. V.; Clover, J. M.; Buffington, A.;
Hick, P. P.; Bisi, M. M.; Marubashi, K.; Webb, D. F.
Bibliographic Code: 2011AGUFMSH21A1909J
Abstract
In January 2010, two coronal mass ejections (CMEs) erupted from near the
solar east limb, the first on late 14 January 2010 and the second on 17
January 2010. Both arrived at the Solar TErrestrial RElations
Observatory Behind spacecraft (STEREO-B) about six days later. We are
able to reconstruct the heliospheric density of both CME events in three
dimensions (3D) using data from the Solar Mass Ejection Imager (SMEI)
and our tomographic analysis. For each event, we isolate the particular
portion of the heliosphere attributed to the transient CME density
structure from the tomographic results, and then estimate its extent.
The structure of these events is shown in detail in the
three-dimensional reconstruction both as pseudo-coronagraph images and
later as density at the locations of STEREO-B and the Earth. The first
of these CMEs was associated with a magnetic cloud that had a density
enhancement near its center. By assuming that this density enhancement
extends along the loop, we can use the three-dimensional density
analysis to map the extent and orientation of this structure in order to
match it to existing magnetic-loop models and to use the remote-sensing
observations to constrain the various flux-rope models determined using
the in-situ measurements of the 14 January 2010 event.
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Title: A Study of Long-Term Heliospheric Brightness Using
SMEI Data
Authors: Buffington, A.; Clover, J. M.; Hick, P. P.;
Jackson, B. V.; Bisi, M. M.
Bibliographic Code: 2011AGUFMSH13B1970B
Abstract
The Solar Mass Ejection Imager (SMEI) has been returning white-light
photometric maps of nearly the entire sky with a 102-minute cadence for
well over eight years. When the usual sidereal and zodiacal backgrounds
are removed, the residual maps are used to study CME/ICME events.
Moreover, the successful sidereal subtraction provides a certification
of SMEI's photometric accuracy over this time period. Further, since the
zodiacal background removal employs a brightness model which does not
vary with time, a search for potential long-term changes in the residue
can show whether the zodiacal cloud's dust distribution varies within
this portion of the present solar cycle. We present results from studies
using SMEI imagery along with a concluded zodiacal-light model.
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Title: Solar Mass Ejection Imager (SMEI) 3-D reconstruction
of density enhancements behind interplanetary
shocks: In-situ comparison near Earth and at STEREO
Authors: Jackson, B. V.; Hamilton, M. S.; Hick, P. P.;
Buffington, A.; Bisi, M. M.; Clover, J. M.;
Tokumaru, M.; Fujiki, K.
Bibliographic Code: 2011JASTP..73.1317J
Abstract
SMEI and IPS remotely observe increased brightness and velocity
enhancements behind interplanetary shocks that are also seen in situ. We
use the UCSD time-dependent 3-D reconstruction technique to map these
enhancements, and compare them with measurements at the SOHO, Wind, ACE,
and STEREO spacecraft. The analyses of these shocks from hour-averaged
in-situ data show that the enhanced density column associated with the
shock response varies considerably between different instruments, even
for in-situ instruments located at L1 near Earth. The
relatively-low-resolution SMEI 3-D reconstructions generally show
density enhancements, and within errors, the column excesses match those
observed in situ. In these SMEI 3-D reconstructions from remotely-sensed
data, the shock density enhancements appear not as continuous broad
fronts, but as segmented structures. This may provide part of the
explanation for the observed discrepancies between the various in-situ
measurements at Earth and STEREO, but not between individual instruments
near L1.
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Title: Three-dimensional reconstruction of heliospheric
structure using iterative tomography: A review
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Bisi, M. M.; Clover, J. M.; Tokumaru, M.; Kojima, M.;
Fujiki, K.
Bibliographic Code: 2011JASTP..73.1214J
Abstract
Current perspective and in-situ analyses using data from NASA's twin
Solar TErrestrial RElations Observatory (STEREO) spacecraft have focused
studies on ways to provide three-dimensional (3-D) reconstructions of
coronal and heliospheric structure. Data from STEREO are proceeded by
and contemporaneous with many other types of data and analysis
techniques; most of the latter have provided 3-D information by relying
on remote-sensing information beyond those of the near corona (outside
10 RS). These include combinations of past data from the
Helios spacecraft and the Solwind coronagraphs and, continuing from the
past to the present, from observations of interplanetary scintillation
(IPS) and the Solar Mass Ejection Imager (SMEI) instrument. In this
article we review past and ongoing analyses that have led to a current
great wealth of 3-D information. When properly utilized, these analyses
can provide not only shapes of CME/ICMEs but also a characterization of
any solar wind structure or global outflow.
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Title: The 3D Reconstruction of Heliospheric Density Using
Thomson-Scattering Observations - Current Progress
and Future Prospects
Authors: Jackson, Bernard V.; Clover, J. M.; Buffington, A.;
Hick, P. P.
Bibliographic Code: 2011SPD....42.1401J
Abstract
Three-dimensional reconstructions using Thomson-scattering observations
from the Air Force/NASA Solar Mass Ejection Imager (SMEI) provide a
determination of density in the inner heliosphere and allow its forecast
from these remote-sensing heliospheric data. Here we describe our recent
progress in providing density from this technique, and our current
success in this endeavor. We would like to provide the best possible
remote determinations of this heliospheric parameter. Here we explore
this possibility with the copious data available from the SMEI imagery
that can now be cleaned of auroral signals such that as many as 10,000
lines of sight can be available on each 102-minute orbit. We speculate
on the degree to which these methods and results could be used on future
heliospheric missions, should such instruments on such missions provide
images as finely-calibrated as those from SMEI.
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Title: The early outburst light curve of the 2011 eruption
of the Recurrent Nova T Pyxidis from Solar Mass
Ejection Imager (SMEI) observations
Authors: Hounsell, R.; Darnley, M. J.; Harman, D. J.;
Bode, M. F.; Clover, J. M.; Hick, P. P.;
Buffington, A.; Jackson, B. V.; Osborne, J.;
Shafter, A. W.
Bibliographic Code: 2011ATel.3373....1H
Abstract
We report white light observations of the 2011 outburst of Recurrent
Nova T Pyxidis obtained using the USAF/NASA Solar Mass Ejection Imager
(SMEI) on board the Coriolis satellite (see Hounsell et
al., 2010 for details, all magnitudes quoted here are native to the
SMEI photometric system). The instrument has a peak quantum efficiency
at approximately 700 nm with a FWHM ~ 300 nm.
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Title: Outburst of Comet 17P/Holmes Observed with the Solar
Mass Ejection Imager
Authors: Li, Jing; Jewitt, David; Clover, John M.;
Jackson, Bernard V.
Bibliographic Code: 2011ApJ...728...31L, eprint = 1012.1570
Abstract
We present time-resolved photometric observations of the Jupiter family
comet 17P/Holmes during its dramatic 2007 outburst. The observations,
from the orbiting Solar Mass Ejection Imager (SMEI), provide the most
complete measure of the whole-coma brightness, free from the effects of
instrumental saturation and with a time resolution well matched to the
rapid brightening of the comet. The light curve is divided into two
distinct parts. A rapid rise between the first SMEI observation on UT
2007 October 24 06h 37m (mid-integration) and UT 2007 October 25 is
followed by a slow decline until the last SMEI observation on UT 2008
April 6 22h 16m (mid-integration). We find that the rate of change of
the brightness is reasonably well described by a Gaussian function
having a central time of UT 2007 October 24.54 ± 0.01 and a full
width at half-maximum of 0.44 ± 0.02 days. The maximum rate of
brightening occurs some 1.2 days after the onset of activity. At the
peak, the scattering cross-section grows at 1070 ± 40
km2 s-1 while the (model-dependent) mass loss
rates inferred from the light curve reach a maximum at 3 ×
105 kg s-1. The integrated mass in the coma lies
in the range (2-90) × 1010 kg, corresponding to
0.2%-10% of the nucleus mass, while the kinetic energy of the ejecta is
(0.7-30) megatonnes TNT. The particulate coma mass could be contained
within a shell on the nucleus of thickness 1-60 m. This is also the
approximate distance traveled by conducted heat in the century since the
previous outburst of 17P/Holmes. This coincidence is consistent with,
but does not prove, the idea that the outburst was triggered by the
action of conducted heat, possibly through the crystallization of buried
amorphous ice.
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Title: Analysis of Epsilon Aurigae light curve from the
Solar Mass Ejection Imager
Authors: Clover, John; Jackson, B. V.; Buffington, A.;
Hick, P. P.; Kloppenborg, B.; Stencel, R.
Bibliographic Code: 2011AAS...21725702C
Abstract
The Solar Mass Ejection Imager (SMEI) was launched aboard the Coriolis
spacecraft in 2003. It is equipped with 3 CCD cameras to measure the
brightness of Thomson-scattered electrons in the heliosphere. Each CCD
images a strip of the sky that is 3°x60°. The three cameras are
mounted on the satellite with their fields of view aligned end-to-end so
that SMEI sweeps nearly the entire sky each 102 minute orbit. SMEI has
now accumulated stellar time series for about 5700 bright stars,
including epsilon Aurigae, for each orbit where data is available. SMEI
data provide nearly year-round coverage of epsilon Aurigae. The baffled
SMEI optics provide more accurate photometric data than ground-based
observations, particularly at mid-eclipse when epsilon Aurigae is close
to the Sun. We present an analysis of the brightness variations of the
epsilon Aurigae system, before and during the eclipse.
The University of Denver participants are grateful for support under
NSFgrant 10-16678 and the bequest of William Hershel Womble in support
of astronomy at the University of Denver.
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Title: SMEI 3D Reconstruction of a Coronal Mass Ejection
Interacting with a Corotating Solar Wind Density
Enhancement: The 2008 April 26 CME
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Clover, J. M.; Bisi, M. M.; Webb, D. F.
Bibliographic Code: 2010ApJ...724..829J
Abstract
The Solar Mass Ejection Imager (SMEI) has recorded the brightness
responses of hundreds of interplanetary coronal mass ejections (CMEs) in
the interplanetary medium. Using a three-dimensional (3D) reconstruction
technique that derives its perspective views from outward-flowing solar
wind, analysis of SMEI data has revealed the shapes, extents, and masses
of CMEs. Here, for the first time, and using SMEI data, we report on the
3D reconstruction of a CME that intersects a corotating region marked by
a curved density enhancement in the ecliptic. Both the CME and the
corotating region are reconstructed and demonstrate that the CME
disrupts the otherwise regular density pattern of the corotating
material. Most of the dense CME material passes north of the ecliptic
and east of the Sun-Earth line: thus, in situ measurements in the
ecliptic near Earth and at the Solar-TErrestrial RElations Observatory
Behind spacecraft show the CME as a minor density increase in the solar
wind. The mass of the dense portion of the CME is consistent with that
measured by the Large Angle Spectrometric Coronagraph on board the Solar
and Heliospheric Observatory spacecraft, and is comparable to the masses
of many other three-dimensionally reconstructed solar wind features at 1
AU observed in SMEI 3D reconstructions.
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Title: Type III Metric Radio-Wave Activity Prior to and
During Active Region Flaring and CMEs (Invited)
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Oberoi, D.; Matthews, L. D.
Bibliographic Code: 2010AGUFMSH54D..03J
Abstract
From the time that type III metric radio-wave activity has been known,
and imaged, there has been a realization that this activity often
increases during, and for some events from a few minutes to several
hours prior to the major manifestations observed for a flare or Coronal
Mass Ejection (CME). We review these analyses from as long ago as the
observations from Culgoora, Australia, and more recently from the French
Nancay radio observatory. We find there can be precursor activity before
a flare or CME as indicated by the increasing numbers of isolated type
III bursts, and that this can be a maximum prior to the most obvious
manifestation of either the surface flare or the most obvious rapid
outward coronal motion of a CME. Current imaging measurements from the
Nancay radio array further clarify the location of this activity for
specific events such as the 26 April 2008 CME that was observed just
following the Whole Heliosphere Interval (WHI) near the time of solar
minimum. A plausible explanation for this precursor activity exists, and
we expect that this idea can be more fully tested using present-day
observations. As solar activity increases and more observations become
available from, for instance, the Murchison Widefield Array (MWA) now
under construction in Western Australia, far better worldwide temporal
coverage for this type of analysis will exist. In conjunction with
current NASA instrumentation such as the Solar TErrestrial RElations
Observatory (STEREO) and SOlar and Heliospheric Observatory (SOHO)
coronagraphs, and the Solar Dynamics Observatory (SDO), we expect a
significant improvement in our understanding of this unique flare and
CME precursor activity.
@--------------------------------------------------------------------
Title: Imaging Coronal Mass Ejections and Large-Scale Solar
Wind Structure Using IPS and Thomson-Scattered
Sunlight (Invited)
Authors: Clover, J. M.; Jackson, B. V.; Buffington, A.;
Hick, P. P.; Bisi, M. M.; Tokumaru, M.; Fujiki, K.
Bibliographic Code: 2010AGUFMSH52B..03C
Abstract
The Solar Mass Ejection Imager (SMEI) observes Thomson-scattered white
light from heliospheric electrons across almost all of the sky nearly
all of the time since early 2003. Interplanetary scintillation (IPS)
observations of velocity and g-level provide similar structure
information but with a less-complete sky-and-time coverage. The Solar
TErrestrial RElations Observatory (STEREO) twin spacecraft outer
Heliospheric Imagers (HI-2) currently image the heliosphere in
Thomson-scattered light near the ecliptic plane far from Earth. The
Solar-Terrestrial Environment Laboratory (STELab) IPS observations
provide IPS velocity and g-level values, which in conjunction with our
tomographic reconstruction program, yield velocities and densities of
the inner heliosphere in three dimensions. The same tomographic program
substitutes SMEI Thomson-scattering brightness information for the
g-level values to derive heliospheric densities from these data alone.
We look at the global structure of the heliosphere concentrating mainly
on three events from 2007 through the rise phase of Solar Cycle 24. The
first event, observed in both the IPS and SMEI defines the
three-dimensional velocity and density structure around the time of the
shock observed at Earth on 02:02 UT 17 December 2007. The second event,
seen only by SMEI, is that of the 23-26 April 2008 coronal mass ejection
(CME) and its interplanetary counterpart. The third event is the CME
(and its interplanetary counterpart) that took place 17 January 2010 and
arrived at STEREO-B about four days later. For each event, we isolate
the particular portion of the heliosphere attributed to the transient
density structure using our tomographic technique, and then estimate its
extent.
@--------------------------------------------------------------------
Title: A Heliospheric Imager for Deep Space: Lessons
Learned from Helios, SMEI, and STEREO
Authors: Buffington, A.; Jackson, B. V.; Hick, P. P.;
Clover, J. M.; Bisi, M. M.
Bibliographic Code: 2010AGUFMSH41A1780B
Abstract
The zodiacal-light photometers on the twin Helios spacecraft, the Solar
Mass Ejection Imager (SMEI) aboard the Coriolis spacecraft, and the
Heliospheric Imagers (HIs) on the twin Solar-TErrestrial RElations
Observatory (STEREO) spacecraft all point the way to optimizing future
remote-sensing Thomson-scattering observations from deep space. In the
future, such data could be provided by wide-angle viewing instruments
deployed on Solar Orbiter, Solar Probe Plus, and other deep-space
missions. Here, we present instrument specifications required for a
successful heliospheric imager, and the calibration measurements and
data-processing steps that enable the best use of these remote-sensing
systems. When properly designed and calibrated, data from these types of
instruments measure zodiacal-dust properties, and are used to provide
three-dimensional reconstructions of heliospheric electron density over
large volumes of the inner heliosphere. Such systems measure fundamental
properties of the inner heliospheric plasma, provide context for the
in-situ monitors on board spacecraft, and perhaps most significantly,
enable physics-based analyses of this important segment of the
Sun-Spacecraft connection.
@--------------------------------------------------------------------
Title: End-to-End Observations and Modeling of the 17-21
January 2010 CME/ICME
Authors: Webb, D. F.; Cliver, E. W.; Nitta, N. V.;
Attrill, G. D.; Marubashi, K.; Howard, T. A.;
Tappin, J.; Jackson, B. V.
Bibliographic Code: 2010AGUFMSH41A1778W
Abstract
On 17 January 2010, before it rotated onto the Earth-facing disk and
produced a series of M-class X-ray flares, active region 11041 was
associated with an energetic CME with a coronal wave and dimming, radio
type II and III emission. During launch the CME revealed an unusual
circular profile viewed from STEREO-B with EUVI and extending into the
COR1 field. It was also observed over the southeast limb from SOHO EIT
and LASCO from which it appeared as a partial halo. The views from
STEREO and SOHO near the Sun and HI-A and SMEI at 1 AU suggest that at
least part of the CME traveled toward STEREO-B, where a small magnetic
cloud was observed on 21 January. The importance of this event lies in
the multiwavelength observations with high time cadences of near-limb
observations of a CME, its manifestations in the low corona, its passage
through the heliosphere and its appearance as an ICME/magnetic cloud
in-situ at STEREO-B 3.5 days later. This event permits us to study the
origin and driving of the wave because the flanks of the CME and its
relationship to the wave can be studied in detail. Our interpretation is
that the wave is initially driven by the CME and then becomes freely
propagating after the CME lateral expansion ends. Several models are
used to understand the 3-D geometry and propagation of the CME, and two
flux rope models are compared with the launch observations and magnetic
field orientations.
@--------------------------------------------------------------------
Title: Remote-Sensing Studies of Heliospheric Solar-Wind
Structure Around Two Solar Minima
Authors: Bisi, M. M.; Clover, J. M.; Breen, A.; Jensen, E. A.;
Fallows, R.; Jackson, B. V.; Hick, P. P.;
Rawlins, A.; Davies, J. A.; Owens, M.; Xiong, M.;
Buffington, A.; Grande, M.
Bibliographic Code: 2010AGUFMSH41A1771B
Abstract
Remote-sensing observations of the inner heliosphere are carried out
routinely using both the interplanetary scintillation (IPS) observations
of astronomical radio sources and also the Thomson-scattered white light
from heliospheric electrons. For these latter observations, we use the
Earth-orbiting Solar Mass Ejection Imager (SMEI: from February 2003)
aboard the Coriolis Satellite, and more recently using the Heliospheric
Imagers (HIs) aboard the Solar TErrestrial RElations Observatory twin
spacecraft (STEREO: from late 2006/early 2007). The data sets from
various IPS-capable systems as well as SMEI are used with the University
of California, San Diego (UCSD) three-dimensional (3-D)
tomographic-reconstruction and visualisation algorithms. We are able to
compare with in-situ measurements from multiple spacecraft with these
reconstruction results. This makes it possible to study the structure of
the inner heliosphere as a whole, including the isolation of individual
features or events such as interplanetary coronal mass ejections (ICMEs)
or stream interaction regions (SIRs). We look at the global structure of
the heliosphere during the current and previous solar minima, and
discuss similarities and differences between the two solar cycles where
possible.
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager (SMEI) 3-D
Reconstructions of CMEs, CIRs and Interplanetary
Shocks, and Comparison with In-situ Data
Authors: Jackson, B. V.; Clover, J. M.; Hick, P. P.;
Buffington, A.; Bisi, M. M.
Bibliographic Code: 2010AGUFMSH31D..05J
Abstract
The Solar Mass Ejection Imager (SMEI) has been operating since February
2003. At the University of California, San Diego (UCSD), a series of
editing steps and a tomography program removes zodiacal light,
high-energy-particle hits, and aurorae the SMEI data; and generates
reconstructed sky-map images and three-dimensional (3-D) volumetric
densities shortly after the SMEI CCD images become available. The
removal of a long-term base allows us to map the 3-D density extents of
coronal mass ejections (CMEs) and co-rotating structures, and measure
the density variations of these structures including estimates of their
continuity and the extent of density enhancements behind interplanetary
shocks. We match our analysis with the in-situ density columns that pass
the spacecraft near Earth as well as near the twin Solar TErrestrial
RElations Observatory (STEREO) spacecraft. Here we concentrate on
Thomson-scattered white-light SMEI observations of the 3 April 2010 halo
CME, contrasting it to the studies of previous CME events that provide
similar Sun-to-Earth analyses.
@--------------------------------------------------------------------
Title: A Summary of 3-D Reconstructions of the Whole
Heliosphere Interval and Comparison with in-Ecliptic
Solar Wind Measurements from STEREO, ACE, and Wind
Instrumentation
Authors: Bisi, Mario M.; Jackson, B. V.; Clover, J. M.;
Hick, P. P.; Buffington, A.; Tokumaru, M.
Bibliographic Code: 2010HiA....15..480B
Abstract
We present a summary of results from simultaneous Solar-Terrestrial
Environment Laboratory (STELab) Interplanetary Scintillation (IPS),
STEREO, ACE, and Wind observations using three-dimensional
reconstructions of the Whole Heliosphere Interval - Carrington rotation
2068. This is part of the world-wide IPS community's International
Heliosphysical Year (IHY) collaboration. We show the global structure of
the inner heliosphere and how our 3-D reconstructions compare with
in-ecliptic spacecraft measurements.
@--------------------------------------------------------------------
Title: Exquisite Nova Light Curves from the Solar Mass
Ejection Imager (SMEI)
Authors: Hounsell, R.; Bode, M. F.; Hick, P. P.;
Buffington, A.; Jackson, B. V.; Clover, J. M.;
Shafter, A. W.; Darnley, M. J.; Mawson, N. R.;
Steele, I. A.; Evans, A.; Eyres, S. P. S.;
O'Brien, T. J.
Bibliographic Code: 2010ApJ...724..480H, eprint = 1009.1737
Abstract
We present light curves of three classical novae (CNe; KT Eridani, V598
Puppis, V1280 Scorpii) and one recurrent nova (RS Ophiuchi) derived from
data obtained by the Solar Mass Ejection Imager (SMEI) on board the
Coriolis satellite. SMEI provides near complete skymap coverage with
precision visible-light photometry at 102 minute cadence. The light
curves derived from these skymaps offer unprecedented temporal
resolution around, and especially before, maximum light, a phase of the
eruption normally not covered by ground-based observations. They allow
us to explore fundamental parameters of individual objects including the
epoch of the initial explosion, the reality and duration of any
pre-maximum halt (found in all three fast novae in our sample), the
presence of secondary maxima, speed of decline of the initial light
curve, plus precise timing of the onset of dust formation (in V1280 Sco)
leading to estimation of the bolometric luminosity, white dwarf mass,
and object distance. For KT Eri, Liverpool Telescope SkyCamT data
confirm important features of the SMEI light curve and overall our
results add weight to the proposed similarities of this object to
recurrent rather than to CNe. In RS Oph, comparison with hard X-ray data
from the 2006 outburst implies that the onset of the outburst coincides
with extensive high-velocity mass loss. It is also noted that two of the
four novae we have detected (V598 Pup and KT Eri) were only discovered
by ground-based observers weeks or months after maximum light, yet these
novae reached peak magnitudes of 3.46 and 5.42, respectively. This
emphasizes the fact that many bright novae per year are still
overlooked, particularly those of the very fast speed class. Coupled
with its ability to observe novae in detail even when relatively close
to the Sun in the sky, we estimate that as many as five novae per year
may be detectable by SMEI.
@--------------------------------------------------------------------
Title: Three-Dimensional (3-D) Reconstruction of Solar-Wind
Structure at the Inner Planets and in the Inner
Heliosphere
Authors: Bisi, M. M.; Jackson, B. V.; Wood, A. G.;
Clover, J. M.; Breen, A. R.; Fallows, R. A.;
Jensen, E. A.; Tokumaru, M.; Fujiki, K.; Hick, P. P.
Bibliographic Code: 2010epsc.conf..882B
Abstract
@--------------------------------------------------------------------
Title: A Heliospheric Imager for Deep Space: Lessons
Learned from Helios, SMEI, and STEREO
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Bisi, M. M.; Clover, J. M.
Bibliographic Code: 2010SoPh..265..257J
Abstract
The zodiacal-light photometers on the twin Helios spacecraft, the Solar
Mass Ejection Imager (SMEI) on the Coriolis spacecraft, and the
Heliospheric Imagers (HIs) on the Solar-TErrestrial RElations
Observatory (STEREO) twin spacecraft all point the way to optimizing
future remote-sensing Thomson-scattering observations from deep space.
Such data could be provided by wide-angle viewing instruments on Solar
Orbiter, Solar Probe, or other deep-space probes. Here, we present
instrument specifications required for a successful heliospheric imager,
and the measurements and data-processing steps that make the best use of
this remote-sensing system. When this type of instrument is properly
designed and calibrated, its data are capable of determining
zodiacal-dust properties, and of three-dimensional reconstructions of
heliospheric electron density over large volumes of the inner
heliosphere. Such systems can measure fundamental properties of the
inner heliospheric plasma, provide context for the in-situ monitors on
board spacecraft, and enable physics-based analyses of this important
segment of the Sun-spacecraft connection.
@--------------------------------------------------------------------
Title: Inclusion of In-Situ Velocity Measurements into the
UCSD Time-Dependent Tomography to Constrain and
Better-Forecast Remote-Sensing Observations
Authors: Jackson, B. V.; Hick, P. P.; Bisi, M. M.;
Clover, J. M.; Buffington, A.
Bibliographic Code: 2010SoPh..265..245J
Abstract
The University of California, San Diego (UCSD) three-dimensional (3-D)
time-dependent tomography program has been used successfully for a
decade to reconstruct and forecast coronal mass ejections from
interplanetary scintillation observations. More recently, we have
extended this tomography technique to use remote-sensing data from the
Solar Mass Ejection Imager (SMEI) on board the Coriolis spacecraft; from
the Ootacamund (Ooty) radio telescope in India; and from the European
Incoherent SCATter (EISCAT) radar telescopes in northern Scandinavia.
Finally, we intend these analyses to be used with observations from the
Murchison Widefield Array (MWA), or the LOw Frequency ARray (LOFAR) now
being developed respectively in Australia and Europe. In this article we
demonstrate how in-situ velocity measurements from the Advanced
Composition Explorer (ACE) space-borne instrumentation can be used in
addition to remote-sensing data to constrain the time-dependent
tomographic solution. Supplementing the remote-sensing observations with
in-situ measurements provides additional information to construct an
iterated solar-wind parameter that is propagated outward from near the
solar surface past the measurement location, and throughout the volume.
While the largest changes within the volume are close to the radial
directions that incorporate the in-situ measurements, their inclusion
significantly reduces the uncertainty in extending these measurements to
global 3-D reconstructions that are distant in time and space from the
spacecraft. At Earth, this can provide a finely-tuned real-time
measurement up to the latest time for which in-situ measurements are
available, and enables more-accurate forecasting beyond this than
remote-sensing observations alone allow.
@--------------------------------------------------------------------
Title: Three-Dimensional (3-D) Reconstructions of EISCAT
IPS Velocity Data in the Declining Phase of Solar
Cycle 23
Authors: Bisi, M. M.; Jackson, B. V.; Breen, A. R.;
Dorrian, G. D.; Fallows, R. A.; Clover, J. M.;
Hick, P. P.
Bibliographic Code: 2010SoPh..265..233B
Abstract
The European Incoherent SCATter (EISCAT) radar has been used for
remote-sensing observations of interplanetary scintillation (IPS) for a
quarter of a century. During the April/May 2007 observing campaign, a
large number of observations of IPS using EISCAT took place to give a
reasonable spatial and temporal coverage of solar wind velocity
structure throughout this time during the declining phase of Solar Cycle
23. Many co-rotating and transient features were observed during this
period. Using the University of California, San Diego three-dimensional
(3-D) time-dependent computer assisted tomography (C.A.T.) solar-wind
reconstruction analysis, we show the velocity structure of the inner
heliosphere in three dimensions throughout the time interval of 20 April
through 20 May 2007. We also compare to white-light remote-sensing
observations of an interplanetary coronal mass ejection (ICME) seen by
the STEREO Ahead spacecraft inner Heliospheric Imager on 16 May 2007, as
well as to in-situ solar-wind measurements taken with near-Earth
spacebourne instrumentation throughout this interval. The
reconstructions show clear co-rotating regions during this period, and
the time-series extraction at spacecraft locations compares well with
measurements made by the STEREO, Wind, and ACE spacecraft. This is the
first time such clear structures have been revealed using this 3-D
technique with EISCAT IPS data as input.
@--------------------------------------------------------------------
Title: From the Sun to the Earth: The 13 May 2005 Coronal
Mass Ejection
Authors: Bisi, M. M.; Breen, A. R.; Jackson, B. V.;
Fallows, R. A.; Walsh, A. P.; Mikic, Z.; Riley, P.;
Owen, C. J.; Gonzalez-Esparza, A.;
Aguilar-Rodriguez, E.; Morgan, H.; Jensen, E. A.;
Wood, A. G.; Owens, M. J.; Tokumaru, M.;
Manoharan, P. K.; Chashei, I. V.; Giunta, A. S.;
Linker, J. A.; Shishov, V. I.; Tyul'Bashev, S. A.;
Agalya, G.; Glubokova, S. K.; Hamilton, M. S.;
Fujiki, K.; Hick, P. P.; Clover, J. M.; Pintér, B.
Bibliographic Code: 2010SoPh..265...49B
Abstract
We report the results of a multi-instrument, multi-technique,
coordinated study of the solar eruptive event of 13 May 2005. We discuss
the resultant Earth-directed (halo) coronal mass ejection (CME), and the
effects on the terrestrial space environment and upper Earth atmosphere.
The interplanetary CME (ICME) impacted the Earth's magnetosphere and
caused the most-intense geomagnetic storm of 2005 with a Disturbed Storm
Time ( Dst) index reaching -263 nT at its peak. The terrestrial
environment responded to the storm on a global scale. We have combined
observations and measurements from coronal and interplanetary
remote-sensing instruments, interplanetary and near-Earth in-situ
measurements, remote-sensing observations and in-situ measurements of
the terrestrial magnetosphere and ionosphere, along with coronal and
heliospheric modelling. These analyses are used to trace the origin,
development, propagation, terrestrial impact, and subsequent
consequences of this event to obtain the most comprehensive view of a
geo-effective solar eruption to date. This particular event is also part
of a NASA-sponsored Living With a Star (LWS) study and an on-going US
NSF-sponsored Solar, Heliospheric, and INterplanetary Environment
(SHINE) community investigation.
@--------------------------------------------------------------------
Title: Faraday Rotation Response to Coronal Mass Ejection
Structure
Authors: Jensen, E. A.; Hick, P. P.; Bisi, M. M.;
Jackson, B. V.; Clover, J.; Mulligan, T.
Bibliographic Code: 2010SoPh..265...31J
Abstract
We present the results from modeling the coronal mass ejection (CME)
properties that have an effect on the Faraday rotation (FR) signatures
that may be measured with an imaging radio antenna array such as the
Murchison Widefield Array (MWA). These include the magnetic flux rope
orientation, handedness, magnetic-field magnitude, velocity, radius,
expansion rate, electron density, and the presence of a shock/sheath
region. We find that simultaneous multiple radio source observations (FR
imaging) can be used to uniquely determine the orientation of the
magnetic field in a CME, increase the advance warning time on the
geoeffectiveness of a CME by an order of magnitude from the warning time
possible from in-situ observations at L 1, and investigate
the extent and structure of the shock/sheath region at the leading edge
of fast CMEs. The magnetic field of the heliosphere is largely
"invisible" with only a fraction of the interplanetary magnetic-field
lines convecting past the Earth; remote sensing the heliospheric
magnetic field through FR imaging from the MWA will advance solar
physics investigations into CME evolution and dynamics.
@--------------------------------------------------------------------
Title: Three-dimensional Reconstructions and Mass
Determination of the 2008 June 2 LASCO Coronal Mass
Ejection Using STELab Interplanetary Scintillation
Observations
Authors: Bisi, M. M.; Jackson, B. V.; Hick, P. P.;
Buffington, A.; Clover, J. M.; Tokumaru, M.;
Fujiki, K.
Bibliographic Code: 2010ApJ...715L.104B
Abstract
We examine and reconstruct the interplanetary coronal mass ejection
(ICME) first seen in space-based coronagraph white-light difference
images on 2008 June 1 and 2. We use observations of interplanetary
scintillation (IPS) taken with the Solar-Terrestrial Environment
Laboratory (STELab), Japan, in our three-dimensional (3D) tomographic
reconstruction of density and velocity. The coronal mass ejection (CME)
was first observed by the LASCO C3 instrument at around 04:17 UT on 2008
June 2. Its motion subsequently moved across the C3 field of view with a
plane-of-the-sky velocity of 192 km s-1. The 3D reconstructed
ICME is consistent with the trajectory and extent of the CME
measurements taken from the CDAW CME catalog. However, excess mass
estimates vary by an order of magnitude from Solar and Heliospheric
Observatory and Solar Terrestrial Relations Observatory coronagraphs to
our 3D IPS reconstructions of the inner heliosphere. We discuss the
discrepancies and give possible explanations for these differences as
well as give an outline for future studies.
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager (SMEI) and Interplanetary
Scintillation (IPS) 3D-Reconstructions of the Inner
Heliosphere
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Bisi, M. M.; Clover, J. M.; Tokumaru, M.
Bibliographic Code: 2010aogs...21..339J
Abstract
@--------------------------------------------------------------------
Title: Solar Wind and CME Studies of the Inner Heliosphere
Using IPS Data from Stelab, ORT, and EISCAT
Authors: Bisi, M. M.; Jackson, B. V.; Fallows, R. A.;
Dorrian, G. D.; Manoharan, P. K.; Clover, J. M.;
Hick, P. P.; Buffington, A.; Breen, A. R.;
Tokumaru, M.
Bibliographic Code: 2010aogs...21...33B
Abstract
@--------------------------------------------------------------------
Title: Solar Wind Speed Inferred from Cometary Plasma Tails
using Observations from STEREO HI-1
Authors: Clover, John M.; Jackson, Bernard V.;
Buffington, Andrew; Hick, P. Paul; Bisi, Mario M.
Bibliographic Code: 2010ApJ...713..394C
Abstract
The high temporal and spatial resolution of heliospheric white-light
imagers enables us to measure the propagation of plasma tails of bright
comets as they travel through the interplanetary medium. Plasma tails of
comets have been recognized for many years as natural probes of the
solar wind. Using a new technique developed at the University of
California, San Diego to measure the radial motion of the plasma tails,
we measure the ambient solar wind speed, for the first time in situ at
comets 2P/Encke and 96P/Machholz. We determine the enhanced solar wind
speeds during an interplanetary coronal mass ejection encounter with
2P/Encke and compare these to previously modeled values, and also
present solar wind speeds covering a range of latitudes for
96P/Machholz. We here apply this technique using images from the
Sun-Earth Connection Coronal and Heliospheric Investigation Heliospheric
Imagers (HI-1) on board the Solar TErrestrial RElations
Observatory-Ahead spacecraft.
@--------------------------------------------------------------------
Title: 3D Reconstruction of Density Enhancements Behind
Interplanetary Shocks from Solar Mass Ejection
Imager White-Light Observations
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Bisi, M. M.; Clover, J. M.; Hamilton, M. S.;
Tokumaru, M.; Fujiki, K.
Bibliographic Code: 2010AIPC.1216..659J
Abstract
The Solar Mass Ejection Imager (SMEI) observes the increased brightness
from the density enhancements behind interplanetary shocks that are also
observed in situ near the Earth. We use the University of California,
San Diego (UCSD) time-dependent three-dimensional (3D) reconstruction
technique to map the extents of these density enhancements. Here, we
examine shock-density enhancements associated with several well-known
interplanetary coronal mass ejections (ICMEs) including those on 30 May
2003 and on 21 January 2005. We compare these densities with
reconstructed velocities from the Solar-Terrestrial Environment
Laboratory (STELab) interplanetary scintillation (IPS) observations for
the 30 May 2003 ICME, and show the shock is present at the front edge of
the reconstructed high speed solar wind. The SMEI analyses certify that
the brightness enhancements observed behind shocks identified and
measured in situ near Earth are a direct response to the plasma density
enhancements that follow the shocked plasma.
@--------------------------------------------------------------------
Title: Large-Scale Heliospheric Structure during
Solar-Minimum Conditions using a 3D Time-Dependent
Reconstruction Solar-Wind Model and STELab IPS
Observations
Authors: Bisi, M. M.; Jackson, B. V.; Hick, P. P.;
Clover, J. M.; Hamilton, S.; Tokumaru, M.;
Fujiki, K.
Bibliographic Code: 2010AIPC.1216..355B
Abstract
Interplanetary scintillation (IPS) observations provide information
about a large portion of the inner heliosphere. We have used
Solar-Terrestrial Environment Laboratory (STELab) IPS velocity and
g-level observations with our three-dimensional (3D) reconstruction
model to determine velocities and densities of the inner heliosphere in
three dimensions. We present these observations using synoptic maps
generated from our time-dependent model that can measure changes with
durations of less than one day. These synopses show large-scale stable
solar-wind structure during solar-minimum conditions in relation to
transients that are present during this period. These are also available
as differences relative to the background. Here, we concentrate
primarily on data covering the 2007-2009 International Heliophysical
Year (IHY).
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager (SMEI) near real time
images and 3-D reconstruction comparisons with
multi-spacecraft observations during the rising
phase of Solar Cycle 24
Authors: Jackson, Bernard; Clover, John; Hick, P.;
Buffington, Andrew; Bisi, Mario
Bibliographic Code: 2010cosp...38.1873J
Abstract
The Solar Mass Ejection Imager (SMEI) has been operating since February
2003. At the University of California, San Diego (UCSD) we are now able
to provide photometric images from SMEI in near real time. These are
available in quick-look form as orbit-to-orbit difference sky maps in a
variety of formats. A series of editing steps and a tomography program
cleans these data sets of aurora and provides three-dimensional (3-D)
volumetric density soon after the images become available, and allows us
to map the 3-D density extents of interplanetary coronal mass ejections
(ICMEs) and co-rotating structures. Here, we report on observations and
3-D reconstructions from SMEI during the current rising phase of Solar
Cycle 24. We match our analyses with in-situ densities from spacecraft
near Earth as well as at the two STEREO spacecraft. These include both
direct in-situ density variation comparisons and measurements of
columnar mass fluxes for different events. These comparisons show the
continuity of the structures that match in-situ density measurements at
each spacecraft, and their extensions beyond the ecliptic plane.
@--------------------------------------------------------------------
Title: Changes in gegenschein brightness with time,
recorded by the solar mass ejection imager (SMEI)
Authors: Buffington, Andrew; Jackson, Bernard; Hick, P.;
Clover, John
Bibliographic Code: 2010cosp...38..708B
Abstract
The Solar Mass Ejection Imager (SMEI), operating since February 2003,
has provided photometric-quality visible-light maps covering nearly the
entire sky, at a rate of roughly 15 per day for more than seven years.
To measure the Gegenschein and characterize other aspects of the
zodiacal light, we combine these maps into daily averages after
subtracting individual bright stars, a residual sidereal background, and
finally an empirical zodiacal-light model. From averages of the yearly
brightness over the seven-year period, we find that the Gegenschein
brightness has been steadily decreasing by about 2 percent per year. To
confirm that this observation does not result from an error in assessing
the change in imager response over this time, we also search for a
potential brightness change of three comparably-bright but presumably
unchanging sidereal objects, the Andromeda Galaxy and the two Magellanic
Clouds. We find the brightness of these remains constant over this
seven-year time period to better than 1 percent.
@--------------------------------------------------------------------
Title: 3-D reconstructions of the early-November 2004 CDAW
geomagnetic storms: analysis of Ooty IPS speed and
density data
Authors: Bisi, M. M.; Jackson, B. V.; Clover, J. M.;
Manoharan, P. K.; Tokumaru, M.; Hick, P. P.;
Buffington, A.
Bibliographic Code: 2009AnGeo..27.4479B
Abstract
Interplanetary scintillation (IPS) remote-sensing observations provide a
view of the solar wind covering a wide range of heliographic latitudes
and heliocentric distances from the Sun between ~0.1 AU and 3.0 AU. Such
observations are used to study the development of solar coronal
transients and the solar wind while propagating out through
interplanetary space. They can also be used to measure the
inner-heliospheric response to the passage of coronal mass ejections
(CMEs) and co-rotating heliospheric structures. IPS observations can, in
general, provide a speed estimate of the heliospheric material crossing
the observing line of site; some radio antennas/arrays can also provide
a radio scintillation level. We use a three-dimensional (3-D)
reconstruction technique which obtains perspective views from
outward-flowing solar wind and co-rotating structure as observed from
Earth by iteratively fitting a kinematic solar wind model to these data.
Using this 3-D modelling technique, we are able to reconstruct the
velocity and density of CMEs as they travel through interplanetary
space. For the time-dependent model used here with IPS data taken from
the Ootacamund (Ooty) Radio Telescope (ORT) in India, the digital
resolution of the tomography is 10° by 10° in both latitude and
longitude with a half-day time cadence. Typically however, the
resolutions range from 10° to 20° in latitude and longitude,
with a half- to one-day time cadence for IPS data dependant upon how
much data are used as input to the tomography. We compare reconstructed
structures during early-November 2004 with in-situ measurements from the
Wind spacecraft orbiting the Sun-Earth L1-Point to validate
the 3-D tomographic reconstruction results and comment on how these
improve upon prior reconstructions.
@--------------------------------------------------------------------
Title: SMEI direct, 3-D-reconstruction sky maps, and
volumetric analyses, and their comparison with SOHO
and STEREO observations
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Bisi, M. M.; Clover, J. M.
Bibliographic Code: 2009AnGeo..27.4097J
Abstract
In this paper we present the results of the analysis of the late January
2007 Coronal Mass Ejection (CME) events recorded by the Solar Mass
Ejection Imager (SMEI), the Solar TErrestrial RElations Observatory
(STEREO), and the SOlar and Heliospheric Observatory (SOHO) spacecraft.
This period occurs when the two STEREO spacecraft views are from close
to Earth, and thus the views from both SMEI and the STEREO outer
Heliospheric Imagers (HI-2s) coincide. Three-dimensional (3-D) analyses
derived from SMEI data show many CMEs that have also been studied by
others using short-term image subtractions (image-differencing
techniques). During this interval we map several CME structures that are
observed in both SMEI and the STEREO-A HI instruments. SMEI brightness
analyses provided by short-term image subtractions ("difference images")
and, alternatively, subtractions of a mean-brightness fit over a
long-time duration, both show the extents of the CMEs travelling outward
above the East limb that erupted from the Sun on 24 and 25 January 2007.
The SMEI 3-D-reconstructions not only enhance distinct features within
the CME events, but also reconcile difference-imaging results with those
where a long-term base has been removed. In the January 2007 example the
structure as mapped by CME difference images traces the sharp intensity
gradients at the front of the CMEs; generally brighter ejected material
follows behind the location of the CME front, but shows poorly in these
because of its larger angular extent. Using the long-duration background
removal enables SMEI's 3-D analysis to determine a mass for this CME
sequence North of the ecliptic.
@--------------------------------------------------------------------
Title: Measurements of the Gegenschein brightness from the
Solar Mass Ejection Imager (SMEI)
Authors: Buffington, Andrew; Bisi, Mario M.; Clover, John M.;
Hick, P. Paul; Jackson, Bernard V.;
Kuchar, Thomas A.; Price, Stephan D.
Bibliographic Code: 2009Icar..203..124B
Abstract
The Gegenschein is viewed by the Solar Mass Ejection Imager (SMEI),
which has provided near-full-sky broadband visible-light photometric
maps for over 5 years. These have an angular resolution of about
0.5° and differential photometric stability of about 1% throughout
this time. When individual bright stars are removed from the maps and an
empirical sidereal background subtracted, the residue is dominated by
the zodiacal light. The unprecedented sky coverage and duration of these
measurements enables a definitive characterization of the Gegenschein.
This article describes the analysis method for these data, presents a
movie with time of the Gegenschein brightness distribution, determines
empirical formulae describing its average shape, and discusses its
variation with time. These measurements unambiguously confirm previous
reports that the Gegenschein surface-brightness distribution has a
decided peak in the antisolar point, which rises above a broader
background.
@--------------------------------------------------------------------
Title: Fabrication and test of a diamond-turned mirror
suitable for a spaceborne photometric heliospheric
imager
Authors: Buffington, Andrew; Bach, Kirk G.; Bach, Bernhard W.;
Bach, Erich K.; Bisi, Mario M.; Hick, P. Paul;
Jackson, Bernard V.; Klupar, Peter D.
Bibliographic Code: 2009SPIE.7438E..17B
Abstract
We have fabricated a diamond-turned low-mass version of a toroidal
mirror which is a key element for a spaceborne visible-light
heliospheric imager. This mirror's virtual image of roughly a hemisphere
of sky is viewed by a conventional photometric camera. The optical
system views close to the edge of an external protective baffle and does
not protrude from the protected volume. The sky-brightness dynamic range
and background-light rejection requires minimal wideangle scattering
from the mirror surface. We describe the manufacturing process for this
mirror, and present preliminary laboratory measurements of its
wide-angle scattering characteristics.
@--------------------------------------------------------------------
Title: Studying geoeffective interplanetary coronal mass
ejections between the Sun and Earth: Space weather
implications of Solar Mass Ejection Imager
observations
Authors: Webb, D. F.; Howard, T. A.; Fry, C. D.;
Kuchar, T. A.; Mizuno, D. R.; Johnston, J. C.;
Jackson, B. V.
Bibliographic Code: 2009SpWea...705002W
Abstract
Interplanetary coronal mass ejections (ICMEs) are the primary cause of
severe space weather at Earth because they drive shocks and trigger
geomagnetic storms that can damage spacecraft and ground-based systems.
The Solar Mass Ejection Imager (SMEI) is a U. S. Air Force experiment
with the ability to track ICMEs in white light from near the Sun to
Earth and beyond, thus providing an extended observational range for
forecasting storms. We summarize several studies of SMEI's detection and
tracking capability, especially of the ICMEs associated with the intense
(peak Dst <= -100 nT) geomagnetic storms that were the focus of the
NASA Living With a Star Geostorm Coordinated Data Analysis Workshop. We
describe the SMEI observations and analyses for the 18 intense storms
observed from May 2003-2007 with adequate SMEI coverage and identified
solar and interplanetary source regions. SMEI observed the associated
ICMEs for 89% of these intense storms. For each event we extracted the
time differences between these sets of times at 1 AU for shock arrival
time, predicted ICME arrival time, onset of high-altitude aurora
observed by SMEI, and storm onset. The mean intervals between successive
pairs of these data were found to each be ˜4 hours. On average,
SMEI first detected the geoeffective ICME about 1 day in advance,
yielding a prediction lead time of ˜18 hours. Finally, the RMS
values for the ICME-shock and storm-ICME time differences were
determined, and provide at least a 1-hour improvement compared to
similar observational and model-dependent studies.
@--------------------------------------------------------------------
Title: Three-Dimensional Reconstructions of the Solar Wind:
During Solar Minimum Conditions
Authors: Bisi, Mario; Jackson, B. V.; Hick, P. P. L.;
Clover, J. M.; Tokumaru, M.; Fujiki, K.;
Fallows, R. A.; Breen, A. R.
Bibliographic Code: 2009SPD....40.3203B
Abstract
Interplanetary scintillation (IPS) observations provide information
about a vast region of the inner heliosphere. We use Solar-Terrestrial
Environment Laboratory (STELab) IPS velocity and g-level observations as
well as IPS velocity observations from the European Incoherent SCATter
(EISCAT) and EISCAT Svalbard Radar (ESR), with our three-dimensional
(3D) reconstruction model to determine velocities and densities of the
inner heliosphere. We present these observations using various forms of
imaging from our time-dependent model that can measure changes with
durations of less than a day and compare these with various spacecraft
in situ measurements. We concentrate on the current solar-minimum period
showing relatively-stable large-scale solar-wind structure during this
time in relation to transients that are also sometimes present. Data
primarily covers the 2007-2009 International Heliophysical Year (IHY)
which includes the Whole Heliosphere Interval (CR2068).
@--------------------------------------------------------------------
Title: CMEs In The Heliosphere Observed With Combined
Imaging And In-situ Data From LASCO, Stereo And SMEI
Authors: Webb, David F.; Biesecker, D.; Howard, T. A.;
Luhmann, J. G.; Li, Y.; Galvin, A.; Howard, R. A.;
Jackson, B. V.
Bibliographic Code: 2009SPD....40.2102W
Abstract
Despite being in solar activity minimum, there have been a number of
events in which a CME observed at the Sun by one or both STEREO
spacecraft has passed over one of them (or the Earth) as detected from
in-situ data. These form a special class of space weather-type events
that can provide information on the characteristics of the geometry,
propagation and internal structure of CMEs. Important to this study are
the remote imaging observations from the SECCHI Heliospheric Imagers
(HIs) and, occasionally, also from the Solar Mass Ejection Imager (SMEI)
in Earth orbit. HI and SMEI observations of ICMEs can provide
complementary information. I will review these types of events and
summarize their characteristics and what they tell us about CMEs.
@--------------------------------------------------------------------
Title: 3D-Reconstruction of Density Enhancements Behind
Interplanetary Shocks from Solar Mass Ejection
White-Light Observations
Authors: Jackson, Bernard V.; Hick, P. P. L.; Buffington, A.;
Bisi, M. M.; Clover, J. M.; Tokumaru, M.; Fujiki, K.
Bibliographic Code: 2009SPD....40.2101J
Abstract
The Solar Mass Ejection Imager (SMEI) observes the increased brightness
from the density enhancements behind interplanetary shocks that are
observed in situ near the Earth. We use the University of California,
San Diego time-dependent three-dimensional-reconstruction technique to
map the extents of these density enhancements. As examples, we examine
the shock density enhancements associated with several well-known
coronal mass ejections including the 28 October 2003 (Halloween storm)
event. We compare these density enhancements with reconstructed velocity
observations from Solar-Terrestrial Environment Laboratory
interplanetary scintillation (IPS) observations when these are
available. Volumetric-differencing techniques available from the SMEI
analyses show that the outer portion of a larger increase in
heliospheric density is often what is observed in short-time image
brightness subtractions from these data.
@--------------------------------------------------------------------
Title: Study of CME Propagation in the Inner Heliosphere:
SOHO LASCO, SMEI and STEREO HI Observations of the
January 2007 Events
Authors: Webb, D. F.; Howard, T. A.; Fry, C. D.;
Kuchar, T. A.; Odstrcil, D.; Jackson, B. V.;
Bisi, M. M.; Harrison, R. A.; Morrill, J. S.;
Howard, R. A.; Johnston, J. C.
Bibliographic Code: 2009SoPh..256..239W
Abstract
We are investigating the geometric and kinematic characteristics of
interplanetary coronal mass ejections (ICMEs) using data obtained by the
LASCO coronagraphs, the Solar Mass Ejection Imager (SMEI), and the
SECCHI imaging experiments on the STEREO spacecraft. The early evolution
of CMEs can be tracked by the LASCO C2 and C3 and SECCHI COR1 and COR2
coronagraphs, and the HI and SMEI instruments can track their ICME
counterparts through the inner heliosphere. The HI fields of view (4 -
90°) overlap with the SMEI field of view (> 20° to all sky)
and, thus, both instrument sets can observe the same ICME. In this paper
we present results for ICMEs observed on 24 - 29 January 2007, when the
STEREO spacecraft were still near Earth so that both the SMEI and STEREO
views of large ICMEs in the inner heliosphere coincided. These results
include measurements of the structural and kinematic evolution of two
ICMEs and comparisons with drive/drag kinematic, 3D tomographic
reconstruction, the HAFv2 kinematic, and the ENLIL MHD models. We find
it encouraging that the four model runs generally were in agreement on
both the kinematic evolution and appearance of the events. Because it is
essential to understand the effects of projection across large
distances, that are not generally crucial for events observed closer to
the Sun, we discuss our analysis procedure in some detail.
@--------------------------------------------------------------------
Title: Low-Resolution STELab IPS 3D Reconstructions of the
Whole Heliosphere Interval and Comparison with
in-Ecliptic Solar Wind Measurements from STEREO and
Wind Instrumentation
Authors: Bisi, M. M.; Jackson, B. V.; Buffington, A.;
Clover, J. M.; Hick, P. P.; Tokumaru, M.
Bibliographic Code: 2009SoPh..256..201B
Abstract
We present initial 3D tomographic reconstructions of the inner
heliosphere during the Whole Heliosphere Interval (WHI) -
Carrington Rotation 2068 (CR2068) - using Solar-Terrestrial
Environment Laboratory (STELab) Interplanetary Scintillation (IPS)
observations. Such observations have been used for over a decade to
visualise and investigate the structure of the solar wind and to study
in detail its various features. These features include co-rotating
structures as well as transient structures moving out from the Sun. We
present global reconstructions of the structure of the inner heliosphere
during this time, and compare density and radial velocity with
multi-point in situ spacecraft measurements in the ecliptic; namely
STEREO and Wind data, as the interplanetary medium passes over the
spacecraft locations.
@--------------------------------------------------------------------
Title: Coronal Mass Ejection Reconstructions from
Interplanetary Scintillation Data Using a Kinematic
Model: A Brief Review
Authors: Bisi, M. M.; Jackson, B. V.; Hick, P. P.;
Buffington, A.; Clover, J. M.
Bibliographic Code: 2009aogs...14..161B
Abstract
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager 3-D reconstruction of the
27-28 May 2003 coronal mass ejection sequence
Authors: Jackson, B. V.; Bisi, M. M.; Hick, P. P.;
Buffington, A.; Clover, J. M.; Sun, W.
Bibliographic Code: 2008JGRA..11300A15J
Abstract
The Solar Mass Ejection Imager (SMEI) has recorded the
inner-heliospheric response in white-light Thomson scattering for many
hundreds of interplanetary coronal mass ejections (ICMEs). Some of these
have been observed by the Solar and Heliospheric Observatory (SOHO)
Large-Angle Spectroscopic Coronagraph (LASCO) instruments and also in
situ by near-Earth spacecraft. This article presents a low-resolution
three-dimensional (3-D) reconstruction of the 27-28 May 2003 halo CME
event sequence observed by LASCO and later using SMEI observations; this
sequence was also observed by all in situ monitors near Earth. The
reconstruction derives its perspective views from outward flowing solar
wind. Analysis results reveal the shape, extent, and mass of this ICME
sequence as it reaches the vicinity of Earth. The extended shape has
considerable detail that is compared with LASCO images and masses for
this event. The 3-D reconstructed density, derived from the
remote-sensed Thomson scattered brightness, is also compared with the
Advanced Composition Explorer (ACE) and Wind spacecraft in situ plasma
measurements. These agree well in peak and integrated total value for
this ICME event sequence when an appropriately enhanced (~20%) electron
number density is assumed to account for elements heavier than hydrogen
in the ionized plasma.
@--------------------------------------------------------------------
Title: Solar Wind 3D Reconstructions of the Whole
Heliospheric Interval
Authors: Bisi, M. M.; Jackson, B. V.; Clover, J. M.;
Hick, P. P.; Buffington, A.; Manoharan, P. K.;
Tokumaru, M.
Bibliographic Code: 2008AGUFMSH23A1617B
Abstract
3D tomographic reconstructions of the inner heliosphere have been used
for over a decade to visualise and investigate the structure of the
solar wind and its various features such as transients and corotating
structures. Interplanetary scintillation (IPS) observations of the solar
wind have been carried out for a much longer period of time revealing
information on the structure of the solar wind and the features within
it. Here we present such 3D reconstructions using IPS observations from
the Solar Terrestrial Environment Laboratory (STELab) and the Ootacamund
(Ooty) Radio Telescope (ORT) of the Whole Heliospheric Interval (WHI)
Carrington Rotation 2068. This is part of the world-wide IPS community's
International Heliosphysical Year (IHY) collaboration. We show the
structure of the inner heliosphere during this time and how our global
reconstructions compare with deep-space spacecraft measurements such as
those taken by Wind, ACE, STEREO, and Ulysses in terms of density and
velocity.
@--------------------------------------------------------------------
Title: Measurements of the Gegenschein brightness from the
Solar Mass Ejection Imager (SMEI)
Authors: Buffington, A.; Bisi, M. M.; Clover, J. M.; Hick, P.;
Jackson, B. V.
Bibliographic Code: 2008AGUFMSH13B1561B
Abstract
The Gegenschein is a faint diffuse component of the zodiacal light
centered upon the antisolar point; this has now been viewed by the
Solar Mass Ejection Imager (SMEI) for over 5 years. SMEI provides
unprecedented near-full-sky photometric maps each 102-minute orbit,
using data from 3 unfiltered CCD cameras. Its 0.1% photometric precision
enables observation over long periods of time, of heliospheric
structures having surface brightness down to several S10's (an S10 is
the equivalent brightness of a 10th magnitude star spread over one
square degree). When individual bright stars are removed from the maps
and an empirical sidereal background subtracted, the residue is
dominated by the zodiacal light. The sky coverage and duration of these
measurements enables a definitive characterization. We describe the
analysis method for these data, characterize the average Gegenschein
brightness distribution, present empirical formulae describing its
shape, and discuss its variation with time.
@--------------------------------------------------------------------
Title: SMEI Remote Sensing and the 3D Reconstruction of
Corotating Heliospheric Structures
Authors: Jackson, B. V.; Bisi, M. M.; Hick, P. P.;
Buffington, A.; Clover, J. M.; Webb, D. F.;
Tokumaru, M.; Manoharan, P. K.
Bibliographic Code: 2008AGUFMSH13B1554J
Abstract
We report observations and 3D reconstructions of corotating heliospheric
structures observed by the Solar Mass Ejection Imager (SMEI).
Observations of the inner heliosphere have been carried out on a routine
basis by SMEI since its launch in early 2003, and these have been used
to measure and map the outward flow of several-hundred CMEs. Most of
these observations use short-term variations of brightness from one SMEI
orbit to the next (every 102 minutes) to track outward motion. The
disadvantage of these orbit-to-orbit analyses is that they cannot
measure features that remain stationary relative to the Sun-Earth line
(or those which corotate with the Sun) and change slowly over time
periods of several days. At UCSD we provide measurements of
heliospheric structures relative to a long-term base and, even in these
observations, there is little evidence of long-term stationary-standing
density structures that corotate. By employing a kinematic model of the
solar wind, we reconstruct three-dimensional (3D) solar wind structures
from multiple observing lines of sight through the outward-flowing solar
wind. By including interplanetary scintillation (IPS) velocity
observations from STELab, Japan or from Ooty, India we can extract both
the solar wind density and velocity from these analyses to compare with
"ground truth" measurements from multi-point, in-situ solar wind
measurements from the STEREO, SOHO, Wind, and ACE spacecraft. We define
the heliospheric structures by these 3D velocity analyses, and they show
that while the velocities map large regions near the ecliptic that
corotate, the dense structures that front and follow these regions are
far more tenuous.
@--------------------------------------------------------------------
Title: Modeling the Corona-Heliosphere Interface in
Anticipation of the Murchison Wide-field Array
Authors: Kasper, J. C.; Oberoi, D.; Salah, J. E.;
Jackson, B. V.; Cairns, I.
Bibliographic Code: 2008AGUFMSH11A..03K
Abstract
The Murchison Widefield Array (MWA) is an 8,000-antenna, 80-300 MHz,
imaging radio array under construction in Western Australia that
features a large field of view, high sensitivity, and accurate
polarization and intensity calibration. An MWA prototype has been
deployed in the field and construction of the full array will begin in
mid-2009 after the performance of the prototype is evaluated.
Understanding the connection between the upper corona and the inner
heliosphere with novel low-frequency radio observations is a primary
objective of the MWA Solar, Heliospheric, and Ionospheric (SHI) science
consortium. This presentation covers progress by the SHI consortium's
theory and modeling effort. We show simulations of how Faraday
rotation, interplanetary scintillation, and radio burst measurements can
track and constrain the transport of magnetic fields, density, and
energetic electrons into the heliosphere.
@--------------------------------------------------------------------
Title: Observation and Modeling of Ion Upwelling Above
Aurora
Authors: Lummerzheim, D.; Otto, A.; Doe, R. A.;
Jackson, B. V.; Mizuno, D.; Webb, D. F.;
Collins, R. L.; Light, A. S.
Bibliographic Code: 2008AGUFMSA21B1542L
Abstract
Auroral electron precipition heats the ionospheric plasma. Especially at
F-region altitudes, this leads to increased plasma pressure and a
pressure gradient force that accelerates plasma away from the heated
region. The resulting upward ion velocities have been observed by the
incoherent scatter radar at Poker Flat (PFISR). The upward moving ions
cause an increased ion density well above typical auroral ionization
altitudes. N2+ ions that are lifted to altitudes above the shadowheight
will resonantly scatter sunlight. This is observed by coincident
overflights of the Solar Mass Ejection Imager (SMEI) on the Coriolis
satellite, looking up from 840 km altitude. We will present a study that
combines modeling and observations by PFISR and SMEI to illustrate and
explain this process.
@--------------------------------------------------------------------
Title: Three-dimensional reconstructions of the early
November 2004 Coordinated Data Analysis Workshop
geomagnetic storms: Analyses of STELab IPS speed and
SMEI density data
Authors: Bisi, M. M.; Jackson, B. V.; Hick, P. P.;
Buffington, A.; Odstrcil, D.; Clover, J. M.
Bibliographic Code: 2008JGRA..11300A11B
Abstract
Combined interplanetary scintillation (IPS) and Solar Mass Ejection
Imager (SMEI) remote-sensing observations provide a view of the solar
wind at almost all heliographic latitudes and covering distances from
the Sun between 0.1 AU and 3.0 AU. They are used to study the
development of the solar wind and coronal transients as they move out
into interplanetary space, and also the inner heliospheric response to
the passage of corotating solar structures and coronal mass ejections
(CMEs). The observations take place in both radio scintillation level
and speed for IPS, and in Thomson-scattered white light brightness for
SMEI. With colleagues at the Solar Terrestrial Environment Laboratory
(STELab), Nagoya University, Japan, we have developed a data analysis
system for the STELab IPS data which can also be applied to SMEI white
light data. This employs a three-dimensional (3-D) reconstruction
technique that obtains perspective views from solar corotating plasma
and outward flowing solar wind as observed from the Earth by iterative
fitting of a kinematic solar wind model to the data. This 3-D modeling
technique permits reconstructions of the density and speed of CMEs and
other interplanetary transients at relatively coarse spatial and
temporal resolutions. For the time-dependent model (used here), these
typically range from 5° to 20° in latitude and longitude, with a
1/2 to 1 day time cadence. For events during early November 2004 we
compare these reconstructed structures with in situ measurements from
the ACE and Wind (near-Earth) spacecraft to validate the 3-D tomographic
reconstruction results and provide input to the ENLIL 3-D
magnetohydrodynamic (MHD) numerical model.
@--------------------------------------------------------------------
Title: The Solar Eruption of 2005 May 13 and Its Effects:
Long-Baseline Interplanetary Scintillation
Observations of the Earth-Directed Coronal Mass
Ejection
Authors: Breen, A. R.; Fallows, R. A.; Bisi, M. M.;
Jones, R. A.; Jackson, B. V.; Kojima, M.;
Dorrian, G. D.; Middleton, H. R.; Thomasson, P.;
Wannberg, G.
Bibliographic Code: 2008ApJ...683L..79B
Abstract
Long-baseline observations of interplanetary scintillation (IPS) provide
a unique source of information on solar wind speed and meridional
direction across the inner regions of the solar system. We report the
results of a series of coordinated IPS observations of an Earth-directed
CME. A significant development in the interpretation of these data is
the use of 3D tomographic reconstructions of solar wind structure
derived from STELab IPS data to better constrain the analysis of
extremely long baseline observations from EISCAT and MERLIN. The
combination of these two approaches leads to a significantly better
understanding of the interaction of the CME with the background solar
wind than would be possible with either technique alone, revealing a
significant rotation in the meridional flow direction of the background
wind associated with the passage of the CME. The CME itself is
decelerated significantly between its emergence through the corona and
its arrival in the IPS ray path, with comparatively little change in
speed from then until arrival at ACE.
@--------------------------------------------------------------------
Title: SMEI Observations of the Heliosphere During WHI
Authors: Jackson, B. V.; Bisi, M. M.; Hick, P. P.;
Buffington, A.; Clover, J. M.; Webb, D. F.
Bibliographic Code: 2008AGUSMSH51A..08J
Abstract
Solar Mass Ejection Imager (SMEI) observations of the inner heliosphere
have been carried out on a routine basis since early 2003. By employing
a kinematic model of the solar wind, we reconstruct three-dimensional
(3D) solar wind structures from multiple observing lines of sight
through the outward-flowing solar wind. These models allow us to
extract solar wind density and to compare these to "ground truth"
measurements from multi- point in-situ solar wind measurements from the
STEREO, SOHO, ACE, and the Wind spacecraft. This aids in improving the
3D reconstruction technique by comparing these reconstructions at
multiple points in the inner heliosphere. Because our observations
reveal the global nature of heliospheric structures, this also leads to
a better understanding of the structure and dynamics of the
interplanetary environment around each spacecraft, and how these
structures are connected back to the Sun. During the Whole Heliosphere
Interval (WHI) SMEI will provide views and 3D reconstructions of the
global heliosphere that can be compared with ground-based and spacecraft
observations.
@--------------------------------------------------------------------
Title: Observations of a comet tail disruption induced by
the passage of a CME
Authors: Kuchar, T. A.; Buffington, A.; Arge, C. N.;
Hick, P. P.; Howard, T. A.; Jackson, B. V.;
Johnston, J. C.; Mizuno, D. R.; Tappin, S. J.;
Webb, D. F.
Bibliographic Code: 2008JGRA..11304101K
Abstract
The Solar Mass Ejection Imager observed an extremely faint
interplanetary coronal mass ejection (ICME) as it passed Comet C/2001 Q4
(NEAT) on 5 May 2004, apparently causing a disruption of its plasma
tail. This is the first time that an ICME has been directly observed
interacting with a comet. SMEI's nearly all-sky coverage and image
cadence afforded unprecedented coverage of this rarely observed event.
The onset first appeared as a ``kink'' moving antisunward that
eventually developed knots within the disturbed tail. These knots
appeared to be swept up in the solar wind flow. We present the SMEI
observations as well as identify a likely SOHO/LASCO progenitor of the
CME. SMEI observed two other comets (C/2002 T7 [LINEAR] and C/2004 F4
[Bradfield]) and at least five similar events during a 35-d period
encompassing this observation. Although these had similar morphologies
to the 5 May NEAT event, SMEI did not observe any ICMEs in these cases.
Three of these were observed close to the heliospheric current sheet
indicating that a magnetic boundary crossing may have contributed to the
disruptions. However, there are no discernable causes in the SMEI
observations for the remaining two events.
@--------------------------------------------------------------------
Title: Numerical Simulations of Solar Wind Disturbances by
Coupled Models
Authors: Odstrcil, D.; Pizzo, V. J.; Arge, C. N.;
Bissi, M. M.; Hick, P. P.; Jackson, B. V.;
Ledvina, S. A.; Luhmann, J. G.; Linker, J. A.;
Mikic, Z.; Riley, P.
Bibliographic Code: 2008ASPC..385..167O
Abstract
Numerical modeling plays a critical role in efforts to understand the
connection between solar eruptive phenomena and their impacts in the
near-Earth space environment and in interplanetary space. Coupling the
heliospheric model with empirical, observational, and numerical coronal
models is described. Results show background solar wind, evolution of
interplanetary transients, connectivity of magnetic field lines, and
interplanetary shocks approaching geospace.
@--------------------------------------------------------------------
Title: Analysis of Plasma-Tail Motions for Comets C/2001 Q4
(NEAT) and C/2002 T7 (LINEAR) Using Observations
from SMEI
Authors: Buffington, A.; Bisi, M. M.; Clover, J. M.;
Hick, P. P.; Jackson, B. V.; Kuchar, T. A.
Bibliographic Code: 2008ApJ...677..798B
Abstract
Comets C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR) passed within ~0.3 AU of
Earth in April and May of 2004. Their tails were observed by the
Earth-orbiting Solar Mass Ejection Imager (SMEI) during this period. A
time series of photometric SMEI sky maps displays the motions and
frequent disruptions of the comet plasma tails. Ephemerides are used to
unfold the observing geometry; the tails are often seen to extend ~0.5
AU from the comet nuclei. Having selected 12 of the more prominent
motions as ``events'' for further study, we introduce a new method for
determining solar wind radial velocities from these SMEI observations.
We find little correlation between these and the changing solar wind
parameters as measured close to Earth, or with coarse three-dimensional
reconstructions using interplanetary scintillation data. A likely
explanation is that the transverse sizes of the solar wind perturbations
responsible for these disruptions are small, <~0.05 AU. We determine
the radial velocities of these events during the disruptions, using a
technique only possible when the observed comet tails extend over a
significant fraction of an AU. We find typical radial velocities during
these events of 50-100 km s-1 lower than before or afterward.
Time durations of such events vary, typically from 3 to 8 hr, and
correspond to comet traversal distances ~106 km (0.007 AU).
We conclude that these large disturbances are primarily due to
ubiquitous solar wind flow variations, of which these measured events
are a subset.
@--------------------------------------------------------------------
Title: Inner-heliosphere SMEI observations and their
comparison with multi-point in-situ measurements
Authors: Jackson, B. V.; Bisi, M. M.; Hick, P. P.;
Buffington, A.; Clover, J. M.; Feynman, J.
Bibliographic Code: 2007AGUFMSH51B..03J
Abstract
Solar Mass Ejection Imager (SMEI) observations of the inner heliosphere
have been carried out on a routine basis since shortly after its launch
on January 6, 2003. By employing a kinematic model of the solar wind,
we reconstruct three-dimensional (3D) solar wind structures from
multiple observing lines of sight through the outward-flowing solar
wind. This model allows us to extract solar wind densities from the
SMEI white-light observations and to compare these to multi-point in
situ "ground truth" solar wind measurements from instruments aboard the
Ulysses, STEREO, ACE, and Wind spacecraft. This facilitates
improvements to our 3D reconstruction technique by comparing these
reconstructions at multiple points in the inner-heliosphere. Our
observations show heliospheric structures globally, and because of this,
our reconstructions provide us with a better understanding of the
structure and dynamics of the interplanetary environment around each
spacecraft, and how these structures are connected back to the Sun.
@--------------------------------------------------------------------
Title: IPS observations of the inner-heliosphere and their
comparison with multi-point in-situ measurements
Authors: Bisi, M. M.; Jackson, B. V.; Breen, A. R.;
Fallows, R. A.; Feynman, J.; Clover, J. M.;
Hick, P. P.; Buffington, A.
Bibliographic Code: 2007AGUFMSH33A1091B
Abstract
Interplanetary scintillation (IPS) observations of the inner-heliosphere
have been carried out on a routine basis for many years using
metre-wavelength radio telescope arrays. By employing a kinematic model
of the solar wind, we reconstruct the three-dimensional (3D) structure
of the inner-heliosphere from multiple observing lines of sight. From
these reconstructions we extract solar wind parameters such as velocity
and density, and compare these to "ground truth" measurements from
multi-point in situ solar wind measurements from ACE, Ulysses, STEREO,
and the Wind spacecraft, particularly during the International
Heliophysical Year (IHY). These multi- point comparisons help us
improve our 3D reconstruction technique. Because our observations show
heliospheric structures globally, this leads to a better understanding
of the structure and dynamics of the interplanetary environment around
these spacecraft.
@--------------------------------------------------------------------
Title: Analysis and Interpretation of Comet Measurements
from SMEI
Authors: Buffington, A.; Bisi, M. M.; Clover, J. M.;
Hick, P. P.; Jackson, B. V.
Bibliographic Code: 2007AGUFMSH33A1080B
Abstract
The Solar Mass Ejection Imager (SMEI) has observed several comets and
traced their plasma tails as far as 108 km from their nucleus. A time
sequence of SMEI orbital sky maps displays considerable tail motion and
disruption for several of these comets. Tracking these motions versus
time, when combined with ephemeris information about their distance
from the Earth allows a determination of solar wind speeds and their
variation with the location of the comet. In the case of comets C/2001
Q4 (NEAT) and C/2002 T7 (LINEAR), which passed within about 0.3 AU of
Earth in April and May of 2004, the SMEI observations show that speeds
during disruptions are typically 50 to 100 km s-1 less than speeds
before and after. Time durations of the disturbances vary between 3 and
8 hours, and correspond to distances traversed by the comets of ~106 km
(0.007 AU). We compare these observations with interplanetary
scintillation (IPS) three-dimensional tomographic reconstructions and
find no evidence that the comet-tail features are due to large-scale
density or velocity structures. We also compare these with near-by
spacecraft measurements such as the Advanced Composition Explorer (ACE),
and find a similar result. This suggests that the comet-tail
disruptions are caused by small-scale changes in the solar wind acting
over distances that are short compared with 1 AU.
@--------------------------------------------------------------------
Title: Comparison of the extent and mass of CME events in
the interplanetary medium using IPS and SMEI Thomson
scattering observations
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Bisi, M. M.; Kojima, M.; Tokumaru, M.
Bibliographic Code: 2007A&AT...26..477J
Abstract
@--------------------------------------------------------------------
Title: IPS tomographic observations of 3D solar wind
structure
Authors: Kojima, M.; Tokumaru, M.; Fujiki, K.; Hayashi, K.;
Jackson, B. V.
Bibliographic Code: 2007A&AT...26..467K
Abstract
@--------------------------------------------------------------------
Title: Combined STELab, EISCAT, ESR, and MERLIN IPS
observations of the solar wind
Authors: Bisi, Mario M.; Jackson, Bernard V.;
Fallows, Richard A.; Breen, Andrew R.; Hick, P. Paul;
Wannberg, Gudmund; Thomasson, Peter;
Jordan, Christine A.; Dorrian, Gareth D.
Bibliographic Code: 2007SPIE.6689E..31B
Abstract
The technique of interplanetary scintillation (IPS) can be used to probe
interplanetary space between the Sun and Earth most-commonly in terms of
speed and also by using the scintillation-level (g-level) as a proxy for
density. We combine the large spatial-scale 3D tomographic techniques
previously only applied to IPS data from the Solar Terrestrial
Environment Laboratory (STELab) array, Nagoya University in Japan, and
the previously operational Cambridge IPS system in England, with the
finer-scale capabilities of the longer baselines between the systems of
the Multi-Element Radio-Linked Interferometer Network (MERLIN) in the
UK, and the European Incoherent SCATter (EISCAT) radar and the EISCAT
Svalbard Radar (ESR) in northern Scandinavia. Using the UCSD 3D
reconstruction technique, we present results of detailed measurements of
speed in the solar wind and also those of solar wind flow-directions,
constrained by the large-scale density tomography through the use of a
kinematic model, as well as applying this tomographic technique for the
first time to the MERLIN, EISCAT, and ESR IPS solar wind speed
observations in terms of velocity.
@--------------------------------------------------------------------
Title: SMEI observations in the STEREO era
Authors: Jackson, Bernard V.; Buffington, Andrew;
Hick, P. Paul; Bisi, Mario M.; Jensen, Elizabeth A.
Bibliographic Code: 2007SPIE.6689E..12J
Abstract
White-light Thomson scattering observations from the Solar Mass Ejection
Imager (SMEI) have recorded the inner heliospheric response to many
CMEs. Some of these are also observed from the LASCO instrumentation
and, most recently, the STEREO spacecraft. Here, we detail several CME
events in SMEI observations that have also been observed by the LASCO
instrumentation and STEREO spacecrafts. We show how SMEI is able to
measure CME events from their first observations as close as 20°
from the solar disk until they fade away in the SMEI 180° field of
view. We employ a 3D reconstruction technique that provides perspective
views as observed from Earth, from outward-flowing solar wind. This is
accomplished by iteratively fitting the parameters of a kinematic solar
wind density model to the SMEI white-light observations and, where
possible, including interplanetary scintillation (IPS) velocity data.
This 3D modeling technique enables separating the true heliospheric
response in SMEI from background noise, and reconstructing the 3D
heliospheric structure as a function of time. These reconstructions
allow both separation of CME structure from other nearby heliospheric
features and a determination of CME mass. Comparisons with LASCO and
STEREO images for individual CMEs or portions of them allow a detailed
view of changes to the CME shape and mass as they propagate outward.
@--------------------------------------------------------------------
Title: A procedure for fitting point sources in SMEI
white-light full-sky maps
Authors: Hick, P.; Buffington, A.; Jackson, B. V.
Bibliographic Code: 2007SPIE.6689E...9H
Abstract
The Solar Mass Ejection Imager (SMEI) instrument consists of three CCD
cameras with individual fields of view of 60° × 3° degrees
that combined sweep a 160° arc of sky. SMEI covers the entire sky in
one spacecraft orbit of 102 minutes. Individual 4-s exposures from each
orbit are assembled into full-sky maps. The primary objective in the
SMEI data reduction is to isolate the Thomson-scattering signal across
the sky from free electrons in the solar wind. One of the steps needed
to achieve the required photometric precision is the individual fitting
and removal of stars brighter than 6th magnitude from the full-sky maps.
The point-spread function of the SMEI optics has several unusual
properties. It has a full width of about one degree, is asymmetric, and
varies in width depending on where in the field of view the image is
formed. Moreover, the orientation of the PSF on the sidereal sky rotates
over 360 degree over the course of a year. We describe the procedure
used to fit and subtract individual stars from the SMEI full-sky maps. A
by-product of this procedure are time series at the orbital time
resolution for stars brighter than 6th magnitude. These results are used
by Buffington et al. (2007) to calibrate the SMEI instrument against the
LASCO C3 coronagraph.
@--------------------------------------------------------------------
Title: Analysis of the comparative responses of SMEI and
LASCO
Authors: Buffington, Andrew; Morrill, Jeff S.; Hick, P. Paul;
Howard, Russell A.; Jackson, Bernard V.;
Webb, David F.
Bibliographic Code: 2007SPIE.6689E...8B
Abstract
Surface-brightness responses of the SOHO-LASCO C3 coronagraph and of the
Solar Mass Ejection Imager (SMEI) are compared, using measurements of a
selection of bright stars that have been observed in both instruments.
Seventeen stars are selected that are brighter than 4.5 magnitudes, are
not known variables, and do not have a neighboring bright star.
Comparing observations of these determines a scaling relationship
between surface-brightness measurements from one instrument to those
from the other. We discuss units of surface brightness for the two
instruments, and estimate a residual uncertainty for the present scaling
relationship.
@--------------------------------------------------------------------
Title: How Does Large Flaring Activity from the Same Active
Region Produce Oppositely Directed Magnetic Clouds?
Authors: Harra, Louise K.; Crooker, Nancy U.;
Mandrini, Cristina H.; van Driel-Gesztelyi, Lidia;
Dasso, Sergio; Wang, Jingxiu; Elliott, Heather;
Attrill, Gemma; Jackson, Bernard V.; Bisi, Mario M.
Bibliographic Code: 2007SoPh..244...95H
Abstract
We describe the interplanetary coronal mass ejections (ICMEs) that
occurred as a result of a series of solar flares and eruptions from 4 to
8 November 2004. Two ICMEs/magnetic clouds occurring from these events
had opposite magnetic orientations. This was despite the fact that the
major flares related to these events occurred within the same active
region that maintained the same magnetic configuration. The solar events
include a wide array of activities: flares, trans-equatorial coronal
loop disappearance and reformation, trans-equatorial filament eruption,
and coronal hole interaction. The first major ICME/magnetic cloud was
predominantly related to the active region 10696 eruption. The second
major ICME/magnetic cloud was found to be consistent with the magnetic
orientation of an erupting trans-equatorial filament or else a rotation
of 160° of a flux rope in the active region. We discuss these
possibilities and emphasize the importance of understanding the magnetic
evolution of the solar source region before we can begin to predict
geoeffective events with any accuracy.
@--------------------------------------------------------------------
Title: The source and propagation of the interplanetary
disturbance associated with the full-halo coronal
mass ejection on 28 October 2003
Authors: Tokumaru, Munetoshi; Kojima, Masayoshi;
Fujiki, Ken'ichi; Yamashita, Masahiro;
Jackson, Bernard V.
Bibliographic Code: 2007JGRA..11205106T
Abstract
Observations of interplanetary scintillations made with the 327-MHz
four-station system of the Solar-Terrestrial Environment Laboratory of
Nagoya University were analyzed to study the three-dimensional
properties of a transient solar wind stream associated with the 28
October 2003 full-halo coronal mass ejection (CME). A loop-shaped
high-density regionregion propagating at a significantly slower speed
than the CME-driven shock was identified. This feature appeared
approximately the same as the structure seen in white-light observations
made simultaneously. The orientation of the loop structure was found in
general agreement with the inclination of the magnetic flux rope
observed at 1 AU. Therefore we propose that the origin of this loop
structure included the high-density plasma ejected from the corona in
association with the 28 October 2003 CME. By comparing this loop
structure with solar wind speed data, we find that the loop structure
had a solar source aligned with a slow-speed solar wind regionregion.
@--------------------------------------------------------------------
Title: CME 3D Reconstructions Using Solar Mass Ejection
Imager and Interplanetary Scintillation Data
Authors: Jackson, Bernard V.; Bisi, M. M.; Hick, P. P.;
Buffington, A.
Bibliographic Code: 2007AAS...210.2923J
Abstract
Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS)
observations provide a view of the solar wind at all solar elongations;
from 180 degrees anti-solar to as close to the Sun as coronagraph fields
of view. They can be used to study the evolution of the solar wind and
solar transients out into interplanetary space. In addition, the inner
heliospheric response to corotating solar structures and coronal mass
ejections (CMEs) can be measured, both in scintillation level and in
velocity when using IPS, and through Thomson Scattering when using SMEI.
We use a 3D reconstruction technique that obtains perspective views from
solar corotating plasma and outward-flowing solar wind as observed from
Earth, by iteratively fitting a kinematic solar wind model to both SMEI
and IPS observations. This 3D modeling technique permits reconstructions
of the density and velocity structures of CMEs and other interplanetary
transients. These reconstructions have a temporal cadence and
heliographic latitudinal and longitudinal resolution predicated by the
amount of data used for time-dependent reconstructions, and can use data
from a variety of IPS instruments distributed around the Earth. We
highlight the 3D analyses of these different data sets using a series of
CME events observed beginning on the Sun 4-7 November 2004. We also
apply this technique to determine solar wind pressure (``ram''
pressure) at Mars. Results are compared with ram pressure observations
derived from Mars Global Surveyor magnetometer data for the years 1999
through 2004, and include a reconstruction of a ``back-side''
event as seen by SOHO/LASCO.
@--------------------------------------------------------------------
Title: Analysis of Solar Wind Events Using Interplanetary
Scintillation Remote Sensing 3D Reconstructions and
Their Comparison at Mars
Authors: Jackson, B. V.; Boyer, J. A.; Hick, P. P.;
Buffington, A.; Bisi, M. M.; Crider, D. H.
Bibliographic Code: 2007SoPh..241..385J
Abstract
Interplanetary Scintillation (IPS) allows observation of the inner
heliospheric response to corotating solar structures and coronal mass
ejections (CMEs) in scintillation level and velocity. With colleagues at
STELab, Nagoya University, Japan, we have developed near-real-time
access of STELab IPS data for use in space-weather forecasting. We use a
3D reconstruction technique that produces perspective views from solar
corotating plasma and outward-flowing solar wind as observed from Earth
by iteratively fitting a kinematic solar wind model to IPS observations.
This 3D modeling technique permits reconstruction of the density and
velocity structure of CMEs and other interplanetary transients at a
relatively coarse resolution: a solar rotational cadence and 10°
latitudinal and longitudinal resolution for the corotational model and a
one-day cadence and 20° latitudinal and longitudinal heliographic
resolution for the time-dependent model. This technique is used to
determine solar-wind pressure (``ram'' pressure) at Mars.
Results are compared with ram-pressure observations derived from Mars
Global Surveyor magnetometer data (Crider et al. 2003, J. Geophys. Res.
108(A12), 1461) for the years 1999 through 2004. We identified 47
independent in situ pressure-pulse events above 3.5 nPa in the Mars
Global Surveyor data in this time period where sufficient IPS data were
available. We detail the large pressure pulse observed at Mars in
association with a CME that erupted from the Sun on 27 May 2003, which
was a halo CME as viewed from Earth. We also detail the response of a
series of West-limb CME events and compare their response observed at
Mars about 160° west of the Sun Earth line by the Mars Global
Surveyor with the response derived from the IPS 3D reconstructions.
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager (SMEI) observations of
coronal mass ejections (CMEs) in the heliosphere
Authors: Webb, D. F.; Mizuno, D. R.; Buffington, A.;
Cooke, M. P.; Eyles, C. J.; Fry, C. D.;
Gentile, L. C.; Hick, P. P.; Holladay, P. E.;
Howard, T. A.; Hewitt, J. G.; Jackson, B. V.;
Johnston, J. C.; Kuchar, T. A.; Mozer, J. B.;
Price, S.; Radick, R. R.; Simnett, G. M.;
Tappin, S. J.
Bibliographic Code: 2006JGRA..11112101W
Abstract
The Solar Mass Ejection Imager (SMEI) on the Coriolis spacecraft has
been obtaining white light images of nearly the full sky every 102
minutes for three years. We present statistical results of analysis of
the SMEI observations of coronal mass ejections (CMEs) traveling through
the inner heliosphere; 139 CMEs were observed during the first 1.5 years
of operations. At least 30 of these CMEs were observed by SMEI to
propagate out to 1 AU and beyond and were associated with major
geomagnetic storms at Earth. Most of these were observed as frontside
halo events by the SOHO LASCO coronagraphs.
@--------------------------------------------------------------------
Title: 3-D Magnetic Field Geometry of the October 28, 2003
ICME: Comparison with SMEI White-Light Observations
Authors: Jensen, E. A.; Mulligan, T.; Jackson, B. V.;
Tokumaru, M.
Bibliographic Code: 2006AGUFMSH33A0397J
Abstract
Multiple reconstructions of the October 28-29, 2003 CME/ICME using
white-light observations, ground-based cosmic-ray and in situ magnetic
field flux rope modeling show two possible flux-rope configurations that
pass Earth on opposite sides of the central symmetry axis of the
disturbance. An analysis of flux rope model geometries initiated over a
wide range in parameter space to test the uniqueness of the single
spacecraft inversion reveals the fit is degenerate over a range of
impact parameters such that two solutions are obtained. In one case (fit
A) the disturbance passes Earth to the west of the rope center with the
rope axis at a low inclination of 20 deg to the ecliptic, similar to the
ground-based flux rope analysis by Kuwabara et al.~(2004). In the second
case (fit B) the disturbance passes Earth to the east of the flux rope
axis, with the rope axis more highly inclined at 42 deg from the
ecliptic, consistent with the SMEI white-light analysis of Jackson et
al.~(2006). The current densities in both solutions indicate a nearly
force-free structure. Multipoint studies of ICMEs show the radius of
curvature in the plane of the rope is between that of a dipole field
line connected to the Sun and that of a circular field line connected to
the Sun. Assuming a dipole field geometry for the large- scale axial
field curvature of the rope results in a 3-D reconstruction for case B
that is consistent with the loop structure and observed speed in the
white-light LASCO images and SMEI density reconstruction, but not for
case A. Multipoint measurements of large-scale solar wind transients is
one of the key objectives of the Stereo mission, allowing more accurate
3-D reconstructions of in situ data for comparison with white-light
observations. Until they become available, the large-scale axial field
orientation and loop geometry of these rope reconstructions provides
another tool to constrain magnetic flux rope fits of ICMEs using single
spacecraft measurements.
@--------------------------------------------------------------------
Title: The 20 January 2005 CME Solar Mass Ejection Imager
(SMEI) Analyses
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.
Bibliographic Code: 2006AGUFMSH33A0396J
Abstract
Solar Mass Ejection Imager (SMEI) brightness measurements are analyzed
to determine 3D volumetric densities for several CMEs including that of
the 20 January 2005 CME. Here we present analyses of these 3D
heliospheric volumetric solar wind density analyses. We use this system
to measure the distribution of structure and provide a 3D mass of the
ejecta associated with the large CMEs viewed in SMEI observations. In
the case of the 20 January 2005 CME, the primary mass moves to the
northwest of the Sun following the event observed earlier in LASCO
coronagraph observations. There are two other very large coronal
responses to the coronal energy input beginning around 6:30 UT near the
time of CME onset. One of these is the large and extremely prompt Solar
Energetic Particle (SEP) proton event observed at Earth beginning about
6:50 UT. Another response is an outward-propagating fast shock that
arrives at Earth 34 hours following the event onset. A response that
may be attributed to this shock is observed slightly more than 5 days
following this at the Ulysses spacecraft situated 5.3 AU from the Sun,
17 degrees south of the ecliptic, and 27 degrees from the Sun-Earth line
to the west. SMEI observes the white-light response of this shock at
Earth in the interplanetary medium around the spacecraft, and limits the
shock extent in 3D.
@--------------------------------------------------------------------
Title: The Evolution of Comets in the Heliosphere as
Observed by SMEI
Authors: Kuchar, T.; Buffington, A.; Howard, T.; Arge, C. N.;
Webb, D.; Jackson, B. V.; Hick, P. P.
Bibliographic Code: 2006AGUFMSH32A..08K
Abstract
Comet observations have been used as in situ probes of the heliospheric
environment since they were used to confirm the existence of the solar
wind. Changes in a comet tail's appearance are attributed to changes in
the solar wind flow. Large scale tail disruptions are usually
associated with boundary crossings of the current sheet or, more rarely,
impacts from coronal mass ejections. The Solar Mass Ejection Imager
(SMEI) observed three bright comets during April-May 2004: Bradfield
(C/2004 F4), LINEAR (C/2002 T7), and NEAT (C/2001 Q4). We had
previously reported several comet tail disconnection events (DEs) for
both NEAT and LINEAR. Investigation of the entire period further
reveals that these two comets showed continual changes in their plasma
tails. These changes are characterized by a "smokestack-like" billowing
effect punctuated by the disconnections. Bradfield however was
remarkably quiescent during this entire period. We present these
extended comet observations and offer an analysis and cause of the
similarities and disparities of these data.
@--------------------------------------------------------------------
Title: An Empirical Description of Zodiacal Light as
Measured by SMEI
Authors: Buffington, A.; Jackson, B. V.; Hick, P.;
Price, S. D.
Bibliographic Code: 2006AGUFMSH32A..06B
Abstract
The SMEI visible-light cameras provide a photometric skymap for each
102-minute orbit with the objective to observe transient Coronal Mass
Ejections (CMEs). Zodiacal light is a significant contributor to these
maps and must be removed in the data-analysis in order to detect and
characterize the much fainter CMEs. We have analyzed over three years of
the SMEI calibration data that were taken at the highest spatial
resolution to derive the yearly averaged global distribution of zodiacal
light between solar elongations of 20 and 180 degrees. Residuals on the
individual sky maps from this global average provide information on the
detailed geometry of the clouds. We present preliminary results of the
analysis, including a characterization of the Gegenschein, possible dust
bands, and annual variations.
@--------------------------------------------------------------------
Title: CME Brightness at Large Elongations: Application to
LASCO and SMEI Observations
Authors: Vourlidas, A.; Webb, D. F.; Morrill, J. S.;
Jackson, B. V.
Bibliographic Code: 2006AGUFMSH32A..03V
Abstract
The traditional analysis of the CME brightness relied on the assumption
that all lines of sight through the CME were parallel due to the large
distance between the observer and the event. However, this assumption is
not correct when CME observations at large distances from the Sun are
concerned. In a recent paper (Vourlidas & Howard 2006) we have
outlined the proper geometry and presented a few theoretical predictions
about the brightness evolution of CME launched at various angles
relative to the Sun-observer line. In this talk, we use LASCO and SMEI
observations of the same events to test our predictions and see how we
can use our theoretical framework to interpret the observed CME
structures.
@--------------------------------------------------------------------
Title: International Colloquium "Scattering and
Scintillation in Radio Astronomy" was held on June
19-23, 2006 in Pushchino, Moscow region, Russia
Authors: Shishov, V. I.; Coles, W. A.; Rickett, B. J.;
Bird, M. K.; Efimov, A. I.; Samoznaev, L. N.;
Rudash, V. K.; Chashei, I. V.; Plettemeier, D.;
Spangler, S. R.; Tokarev, Yu.; Belov, Yu.; Boiko, G.;
Komrakov, G.; Chau, J.; Harmon, J.; Sulzer, M.;
Kojima, M.; Tokumaru, M.; Fujiki, K.; Janardhan, P.;
Jackson, B. V.; Hick, P. P.; Buffington, A.;
Olyak, M. R.; Fallows, R. A.; Nechaeva, M. B.;
Gavrilenko, V. G.; Gorshenkov, Yu. N.; Alimov, V. A.;
Molotov, I. E.; Pushkarev, A. B.; Shanks, R.;
Tuccari, G.; Lotova, N. A.; Vladimirski, K. V.;
Obridko, V. N.; Gubenko, V. N.; Andreev, V. E.;
Stinebring, D.; Gwinn, C.; Lovell, J. E. J.;
Jauncey, D. L.; Senkbeil, C.; Shabala, S.;
Bignall, H. E.; Macquart, J. -P.; Rickett, B. J.;
Kedziora-Chudczer, L.; Smirnova, T. V.;
Rickett, B. J.; Malofeev, V. M.; Malov, O. I.;
Tyulbashev, S. A.; Jessner, A.; Sieber, W.;
Wielebinski, R.
Bibliographic Code: 2006astro.ph..9517S
Abstract
Topics of the Colloquium: a) Interplanetary scintillation b)
Interstellar scintillation c) Modeling and physical origin of the
interplanetary and the interstellar plasma turbulence d) Scintillation
as a tool for investigation of radio sources e) Seeing through
interplanetary and interstellar turbulent media Ppt-presentations are
available on the Web-site: http://www.prao.ru/conf/Colloquium/main.html
@--------------------------------------------------------------------
Title: Preliminary three-dimensional analysis of the
heliospheric response to the 28 October 2003 CME
using SMEI white-light observations
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Wang, X.; Webb, D.
Bibliographic Code: 2006JGRA..11104S91J
Abstract
The Solar Mass Ejection Imager (SMEI) has recorded the inner
heliospheric response in white-light Thomson scattering to the 28
October 2003 coronal mass ejection (CME). This preliminary report shows
the evolution of this particular event in SMEI observations, as we track
it from a first measurement at approximately 20° elongation (angular
distance) from the solar disk until it fades in the antisolar hemisphere
in the SMEI 180° field of view. The large angle and spectrometric
coronagraph (LASCO) images show a CME and an underlying bright ejection
of coronal material that is associated with an erupting prominence. Both
of these are seen by SMEI in the interplanetary medium. We employ a
three-dimensional (3-D) reconstruction technique that derives its
perspective views from outward flowing solar wind to reveal the shape
and extent of the CME. This is accomplished by iteratively fitting the
parameters of a kinematic solar wind density model to both SMEI
white-light observations and Solar-Terrestrial Environment Laboratory
(STELab), interplanetary scintillation (IPS) velocity data. This
modeling technique separates the true heliospheric signal in SMEI
observations from background noise and reconstructs the 3-D heliospheric
structure as a function of time. These reconstructions allow separation
of the 28 October CME from other nearby heliospheric structure and a
determination of its mass. The present results are the first utilizing
this type of 3-D reconstruction with the SMEI data. We determine an
excess-over-ambient mass for the southward moving ejecta associated with
the prominence material of 7.1 × 1016 g and a total
mass of 8.9 × 1016 g. Preliminary SMEI white-light
calibration indicates that the total mass of this CME including possible
associated nearby structures may have been as much as ~2.0 ×
1017 g spread over much of the earthward facing hemisphere.
@--------------------------------------------------------------------
Title: A Search for Early Optical Emission at Gamma-Ray
Burst Locations by the Solar Mass Ejection Imager
(SMEI)
Authors: Buffington, Andrew; Band, David L.;
Jackson, Bernard V.; Hick, P. Paul; Smith, Aaron C.
Bibliographic Code: 2006ApJ...637..880B, eprint = astro-ph/0510159
Abstract
The Solar Mass Ejection Imager (SMEI) views nearly every point on the
sky once every 102 minutes and can detect point sources as faint as R~10
mag. Therefore, SMEI can detect or provide upper limits for the optical
afterglow from gamma-ray bursts in the tens of minutes after the burst,
when different shocked regions may emit optically. Here we provide upper
limits for 58 bursts between 2003 February and 2005 April.
@--------------------------------------------------------------------
Title: SMEI: A Spaceborne Observatory for Heliospheric
Remote Sensing
Authors: Hick, P.; Jackson, B. V.; Buffington, A.; Yu, Y.
Bibliographic Code: 2005AGUFMSH51C1219H
Abstract
The Solar Mass Ejection Imager (SMEI) provides measurements of the
Thomson scattering brightness with near-full sky coverage from Earth
orbit. These observations allow three-dimensional reconstruction of the
solar wind density and velocity throughout the inner heliosphere. We
discuss how these observations provide context for in situ solar wind
observations from other "Great Observatory" satellites near Earth (ACE),
other planets (Mars Orbiter) and in deep space (Ulysses).
@--------------------------------------------------------------------
Title: Global 3-D Solar Wind Analysis of Halo CMEs Using
Interplanetary Scintillation (IPS) Remote Sensing
and its Comparison at Mars
Authors: Boyer, J. A.; Jackson, B. V.; Buffington, A.;
Hick, P. P.; Yu, Y.; Crider, D. H.
Bibliographic Code: 2005AGUFMSH43A1145B
Abstract
The Interplanetary Scintillation (IPS) process allows observation of the
inner heliospheric response to CMEs in scintillation level and
velocity. With the help of our colleagues in STELab, Japan, we have
developed near real time access of these data for use in space weather
forecasting. We use a 3D reconstruction technique that obtains
perspective views from outward-flowing solar wind as observed from Earth
by iteratively fitting a kinematic solar wind model using the IPS
observations. This 3D modeling technique permits us to reconstruct the
density and velocity structure of CMEs, and other interplanetary
transient structure at low resolution (with a one day cadence, and at a
20 deg. latitudinal and longitudinal heliographic resolution). Here we
explore the use of this technique to reproduce the solar wind pressure
observed at Mars following the aftermath of halo (Earth-directed) CMEs.
These CMEs include one that erupted from the Sun on May 27, 2003 and
another on October 28, 2003 both of which produced a large response at
Mars. In addition we explore the response at Mars and our
reconstruction of "backside" (as seen from Earth) halo CMEs.
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager (SMEI) Solar Wind 3-D
Analysis of the January 20, 2005 CME
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.; Yu, Y.;
Webb, D.
Bibliographic Code: 2005AGUFMSH21A..02J
Abstract
The Solar Mass Ejection Imager (SMEI) has observed the inner
heliospheric response in white light from over 200 CMEs. One of these,
on January 20, 2005, produced one of the largest Solar Energetic
Particle events ever recorded. We show SMEI orbital difference images
and the 3D solar wind reconstruction of this well-observed CME, and
demonstrate how we can track its outward motion from approximately 20
deg. from the Sun until it vanishes in the SMEI field of view in the
direction of the Ulysses spacecraft. Our 3D reconstruction technique is
used to obtain perspective views from outward-flowing solar wind as
observed from Earth by iteratively fitting a kinematic solar wind
density model using the SMEI white light observations. This 3D modeling
technique permits us to separate the heliospheric response in SMEI from
background noise, and to estimate the 3D structure and transient
heliospheric components of the CME and its speed and mass. We then
determine the total energy of the CME that can be used as input to
determine the total energy output of the event. More information about
the spatial extent and energetics of this CME event can be determined
by measurements in-situ from the Ulysses spacecraft that was beyond 5 AU
and about 35 degrees west of Earth. Ulysses first detected an extremely
fast CME response at the spacecraft 7 days following the event on the
Sun and the transient flow continued for several days. The SMEI 3D
reconstruction shows the event as it passes Earth to the west and helps
to disentangle the CME structure. This will allow a better
understanding of which portions of the CME intersect Ulysses, and the 3D
trajectories of several CMEs observed earlier in coronagraph and SMEI
data.
@--------------------------------------------------------------------
Title: 3D CME Mass and Energy From Solar Mass Ejection
Imager (SMEI) and Interplanetary Scintillation (IPS)
Data
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.; Yu, Y.
Bibliographic Code: 2005AAS...20711108J
Abstract
White-light Thomson scattering observations from the Solar Mass Ejection
Imager (SMEI) have recorded the inner heliospheric response to several
hundred CMEs including the halo CMEs of May 28, 2003 and October 28,
2003, and numerous other heliospheric structures. We show the extent of
several well-observed CMEs in SMEI observations, and measure these
events from their first observations in SMEI approximately 20 degrees
from the solar disk until they vanish in the SMEI field of view. Several
portions of large CMEs can be observed in the interplanetary medium
associated with the initial coronal response and the underlying erupting
prominence structure observed by the LASCO coronagraphs and other
instruments. To enhance the images and understand the outward
propagation of these structures we use a 3D reconstruction technique
that obtains perspective views from outward-flowing solar wind as
observed from Earth, iteratively fitting a kinematic solar wind density
model to the SMEI white light observations and, when available, also to
the Solar-Terrestrial Environment Laboratory (STELab), Japan
interplanetary scintillation (IPS) velocity data. This 3D modeling
technique allows separating the heliospheric response in SMEI from
background noise, and estimating the 3D structure of the CME and its
mass. Pixel-to-pixel 3D comparison with the IPS velocity structure gives
the outward flow kinetic energy for these events.
@--------------------------------------------------------------------
Title: Coronal mass ejection kinematics deduced from white
light (Solar Mass Ejection Imager) and radio
(Wind/WAVES) observations
Authors: Reiner, M. J.; Jackson, B. V.; Webb, D. F.;
Mizuno, D. R.; Kaiser, M. L.; Bougeret, J.-L.
Bibliographic Code: 2005JGRA..11009S14R
Abstract
White-light and radio observations are combined to deduce the coronal
and interplanetary kinematics of a fast coronal mass ejection (CME) that
was ejected from the Sun at about 1700 UT on 2 November 2003. The CME,
which was associated with an X8.3 solar flare from W56°, was
observed by the Mauna Loa and Solar and Heliospheric Observatory (SOHO)
Large-Angle Spectrometric Coronograph (LASCO) coronagraphs to 14
R$\odot$. The measured plane-of-sky speed of the LASCO CME
was 2600 km s-1. To deduce the kinematics of this CME, we use
the plane-of-sky white light observations from both the Solar Mass
Ejection Imager (SMEI) all-sky camera on board the Coriolis spacecraft
and the SOHO/LASCO coronagraph, as well as the frequency drift rate of
the low-frequency radio data and the results of the radio
direction-finding analysis from the WAVES experiment on the Wind
spacecraft. In agreement with the in situ observations for this event,
we find that both the white light and radio observations indicate that
the CME must have decelerated significantly beginning near the Sun and
continuing well into the interplanetary medium. More specifically, by
requiring self-consistency of all the available remote and in situ data,
together with a simple, but not unreasonable, assumption about the
general characteristic of the CME deceleration, we were able to deduce
the radial speed and distance time profiles for this CME as it
propagated from the Sun to 1 AU. The technique presented here, which is
applicable to mutual SMEI/WAVES CME events, is expected to provide a
more complete description and better quantitative understanding of how
CMEs propagate through interplanetary space, as well as how the radio
emissions, generated by propagating CME/shocks, relate to the shock and
CME. This understanding can potentially lead to more accurate
predictions for the onset times of space weather events, such as those
that were observed during this unique period of intense solar activity.
@--------------------------------------------------------------------
Title: The SMEI real-time data pipeline: from raw CCD
frames to photometrically accurate full-sky maps
Authors: Hick, P.; Buffington, A.; Jackson, B. V.
Bibliographic Code: 2005SPIE.5901..340H
Abstract
The Solar Mass Ejection Imager (SMEI) records a photometric white-light
response of the interplanetary medium from Earth orbit over most of the
sky. We present the techniques required to process the SMEI data in near
real time from the raw CCD images to their final assembly into
photometrically accurate maps of the sky brightness of Thomson scattered
sunlight. Steps in the SMEI data processing include: integration of new
data into the SMEI data base; conditioning to remove from the raw CCD
images an electronic offset (pedestal) and a temperature-dependent dark
current pattern; placement ("indexing") of the CCD images onto a
high-resolution sidereal grid using known spacecraft pointing
information. During the indexing the bulk of high-energy-particle hits
(cosmic rays), space debris inside the field of view, and pixels with a
sudden state change ("flipper pixels") are identified. Once the
high-resolution grid is produced, it is reformatted to a
lower-resolution set of sidereal maps of sky brightness. From these we
remove bright stars, background stars, and a zodiacal cloud model (their
brightnesses are retained as additional data products). The final maps
can be represented in any convenient sky coordinate system, e.g.,
Sun-centered Hammer-Aitoff or "fisheye" projections. Time series at
selected sidereal locations are extracted and processed further to
remove aurorae, variable stars and other unwanted signals. These time
series of the heliospheric Thomson scattering brightness (with a
long-term base removed) are used in 3D tomographic reconstructions.
@--------------------------------------------------------------------
Title: Interactive visualization of solar mass ejection
imager (SMEI) volumetric data
Authors: Yu, Yang; Hick, P. P.; Jackson, Bernard V.
Bibliographic Code: 2005SPIE.5901..335Y
Abstract
We present a volume rendering system developed for the real time
visualization and manipulation of 3D heliospheric volumetric solar wind
density and velocity data obtained from the Solar Mass Ejection Imager
(SMEI) and interplanetary scintillation (IPS) velocities over the same
time period. Our system exploits the capabilities of the VolumePro 1000
board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of
rendering up to a 512-cubed array of volume data in real time at up to
30 frames per second on a standard PC. Many volume-rendering operations
have been implemented with this system such as stereo/perspective views,
animations of time-sequences, and determination of coronal mass ejection
(CME) volumes and masses. In these visualizations we highlight one time
period where a halo CMEs was observed by SMEI to engulf Earth on October
29, 2003. We demonstrate how this system is used to measure the
distribution of structure and provide 3D mass for individual CME
features, including the ejecta associated with the large prominence
viewed moving to the south of Earth following the late October CME.
Comparisons with the IPS velocity volumetric data give pixel by pixel
and total kinetic energies for these events.
@--------------------------------------------------------------------
Title: Space performance of the multistage labyrinthine
SMEI baffle
Authors: Buffington, Andrew; Jackson, Bernard V.; Hick, P. P.
Bibliographic Code: 2005SPIE.5901..325B
Abstract
The Solar Mass Ejection Imager (SMEI) was launched on 6 January 2003,
and shortly thereafter raised to a nearly circular orbit at 840 km.
Three SMEI CCD cameras on the zenith-nadir oriented CORIOLIS spacecraft
cover most of the sky beyond about 20°. from the Sun, each
102-minute orbit. Data from this instrument provide precision
visible-light photometric sky maps. Once starlight and other constant or
slowly varying backgrounds are subtracted, the residue is mostly
sunlight that has been Thomson-scattered from heliospheric electrons.
These maps enable 3-dimensional tomographic reconstruction of
heliospheric density and velocity. This analysis requires 0.1%
photometry and background-light reduction below one S10 (the brightness
equivalent of a 10th magnitude star per square degree). Thus
10-15 of surface-brightness reduction is required relative to
the solar disk. The SMEI labyrinthine baffle provides roughly
10-10 of this reduction; the subsequent optics system
provides the remainder. We analyze data obtained over two years in
space, and evaluate the full system's stray-light rejection performance.
@--------------------------------------------------------------------
Title: Low resolution three dimensional reconstruction of
CMEs using solar mass ejection imager (SMEI) data
Authors: Jackson, Bernard V.; Buffington, Andrew; Hick, P. P.;
Wang, Cindy X.
Bibliographic Code: 2005SPIE.5901....1J
Abstract
White-light Thomson scattering observations from the Solar Mass Ejection
Imager (SMEI) have recorded the inner heliospheric response to many
CMEs. Here we detail how we determine the extent of several CME events
in SMEI observations (including those of 28 May 28 and 28 October,
2003). We show how we are able to measure these events from their first
observations as close as 20° from the solar disk until they fade
away in the SMEI 180° field of view. We employ a 3D reconstruction
technique that provides perspective views from outward-flowing solar
wind as observed at Earth. This is accomplished by iteratively fitting
the parameters of a kinematic solar wind density model to the SMEI white
light observations and to Solar-Terrestrial Environment Laboratory
(STELab), interplanetary scintillation (IPS) velocity data. This 3D
modeling technique enables separating the true heliospheric response in
SMEI from background noise, and reconstructing the 3D heliospheric
structure as a function of time. These reconstructions allow both
separation of the 28 October CME from other nearby heliospheric
structure and a determination of its mass. Comparisons with LASCO for
individual CMEs or portions of them allow a detailed view of changes to
the CME shape and mass as they propagate outward.
@--------------------------------------------------------------------
Title: Very high altitude aurora observations with the
Solar Mass Ejection Imager
Authors: Mizuno, D. R.; Buffington, A.; Cooke, M. P.;
Eyles, C. J.; Hick, P. P.; Holladay, P. E.;
Jackson, B. V.; Johnston, J. C.; Kuchar, T. A.;
Mozer, J. B.; Price, S. D.; Radick, R. R.;
Simnett, G. M.; Sinclair, D.; Tappin, S. J.;
Webb, D. F.
Bibliographic Code: 2005JGRA..11007230M
Abstract
The Solar Mass Ejection Imager (SMEI) is a sensitive scanning instrument
mounted on the Coriolis satellite that assembles an approximately
all-sky image of the heliosphere in red-biased visible light once per
orbit. Its lines of sight pass obliquely through the topside ionosphere
and magnetosphere. We present serendipitous observations of a visual
phenomenon detected at high altitudes (>=840 km) over the auroral
zones and polar caps. The phenomenon is observed in two basic forms. The
first, and more common, are periods of brief (1-3 min), nearly uniform
illumination of the imager's field of view, which we interpret as
transits of the satellite through a luminous medium. The second appear
as localized filamentary structures, which we interpret as columns of
luminous material, viewed from a distance, possibly extending to visible
altitudes of 2000 km or higher. More than 1000 occurrences of these
phenomena were recorded during the first full year of operations. These
observations are well correlated in brightness and frequency with
periods of enhanced geomagnetic activity.
@--------------------------------------------------------------------
Title: Preliminary Three Dimensional CME Mass and Energy
Using Solar Mass Ejection Imager (SMEI) Data
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.; Yu, Y.;
Webb, D.; Mizuno, D.; Kuchar, T.
Bibliographic Code: 2005AGUSMSP44A..05J
Abstract
White-light Thomson scattering observations from the Solar Mass Ejection
Imager (SMEI) have recorded the inner heliospheric response to several
hundred CMEs including the May 28, 2003 halo CME, the October 28, 2003
halo CME, and numerous other heliospheric structures. Here we show the
extent of several well-observed CMEs in SMEI observations, and show how
we are able to track events from their first measurements in SMEI
approximately 20° from the solar disk until they vanish from the
SMEI 180° field of view. Several portions of large CMEs observed by
the LASCO coronagraphs can be tracked into the interplanetary medium
associated with the initial CME response and the underlying erupting
prominence structure. We use a 3D reconstruction technique that obtains
perspective views from outward-flowing solar wind as observed from
Earth, iteratively fitting a kinematic solar wind density model using
the SMEI white light observations and, when available, the
Solar-Terrestrial Environment Laboratory (STELab), Japan interplanetary
scintillation (IPS) velocity data. This 3D modeling technique allows us
to separate the heliospheric response in SMEI from background noise, and
to estimate the 3D structure of the CME and its mass. For instance, the
analysis shows and tracks outward the northward portion of the loop
structure of the October 28, 2003 CME observed as a halo in LASCO images
that passes Earth on October 29. We determine an excess mass for this
structure of 6.7×1016g and a total mass including an ambient
background of 8.3×1016g. The very fast structure compared in a 3D
pixel to pixel comparison with the IPS velocity data gives a kinetic
energy for the northward portion of this event of 2.0×1034erg as
it passes Earth.
@--------------------------------------------------------------------
Title: Comparative Analyses of the CSSS Calculation in the
UCSD Tomographic Solar Observations
Authors: Dunn, T.; Jackson, B. V.; Hick, P. P.;
Buffington, A.; Zhao, X. P.
Bibliographic Code: 2005SoPh..227..339D
Abstract
We describe a new method to derive the interplanetary magnetic field
(IMF) out to 1 AU from photospheric magnetic field measurements. The
method uses photospheric magnetograms to calculate a source surface
magnetic field at 15R&sun;. Specifically, we use Wilcox
Solar Observatory (WSO) magnetograms as input for the Stanford
Current-Sheet Source-Surface (CSSS) model. Beyond the source surface the
magnetic field is convected along velocity flow lines derived by a
tomographic technique developed at UCSD and applied to interplanetary
scintillation (IPS) observations. We compare the results with in situ
data smoothed by an 18-h running mean. Radial and tangential magnetic
field amplitudes fit well for the 20 Carrington rotations studied, which
are largely from the active phase of the solar cycle. We show exemplary
results for Carrington rotation 1965, which includes the Bastille Day
event.
@--------------------------------------------------------------------
Title: Zodiacal Light Analysis and Removal From the Solar
Mass Ejection Imager (SMEI) Data
Authors: Simon, S.; Jackson, B. V.; Buffington, A.;
Hick, P. P.; Smith, A.
Bibliographic Code: 2004AGUFMSH21A0398S
Abstract
The Solar Mass Ejection Imager (SMEI) experiment provides white-light
photometric maps covering most of the sky each orbit of the Coriolis
spacecraft. The SMEI differential photometry specification is 0.1% for
each 1 square degree sky bin, and was designed to provide precise
photometric white light images over most of the sky on each 102-minute
Earth orbit in order to map heliospheric structures. One of the
brightest contaminant signals observed in SMEI is zodiacal light
brightness that must be modeled and subtracted from the data in order to
provide heliospheric sky maps free from large background changes. We
have devised a technique to remove zodiacal dust brightness from the
SMEI maps, and in order to do so accurately measure the asymmetry of the
equatorial dust to the ecliptic plane as well as the Gegenschein
brightness throughout the year. We present preliminary analyses of
these observations for specific intervals during the one and a half year
lifetime of SMEI.
@--------------------------------------------------------------------
Title: The Deceleration of Interplanetary Transients
Between the Sun and 5 AU
Authors: Tappin, J.; Simnett, G. M.; Jackson, B. V.
Bibliographic Code: 2004AGUFMSH21A0394T
Abstract
During the the SMEI mission, Ulysses has been at relatively low
latitudes (less than 25 degrees) and near aphelion (4.8 to 5.4 AU). This
has provided us with an opportunity to trace interplanetary transient
disturbances from near the Sun (with LASCO), around 1AU with SMEI and
ACE and then again near 5AU with Ulysses. We have selected a number of
events where the identification of the disturbance is clear in LASCO,
SMEI and Ulysses and use the propagation of the disturbance through the
heliosphere to draw conclusions regarding the dynamics of these
disturbances. In particular we focus on the duration of the "driving
flow" and on the significance of "swept-up" matter.
@--------------------------------------------------------------------
Title: Comparison of Solar Mass Ejection Imager (SMEI)
White Light Observations with IPS Velocity
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Kojima, M.; Tokumaru, M.
Bibliographic Code: 2004AGUFMSH21A0393J
Abstract
The Solar Mass Ejection Imager (SMEI) experiment is fixed to the
Coriolis spacecraft and views the sky above Earth using
sunlight-rejecting baffles and CCD camera technology. SMEI was designed
to provide precise photometric white light images over most of the sky
on each 102-minute Earth orbit. The brightness sky maps of the inner
heliosphere indicate a rich variety of electron density structures that
are produced by the material that propagates through it and its
interaction with ambient structures. We present some of the
preliminary results of the analysis of these photometric SMEI
observations derived by 3D reconstructions that allow contaminant
signal removal using both interplanetary scintillation (IPS) velocities
and SMEI data. We use these analyses to compare preliminary SMEI
tomographic white-light results with IPS velocity for the same time
intervals.
@--------------------------------------------------------------------
Title: Systematic Error Reduction and Photometric
Calibration for the Solar Mass Ejection Imager
(SMEI)
Authors: Buffington, A.; Jackson, B. V.; Hick, P.
Bibliographic Code: 2004AGUFMSH11A..07B
Abstract
The Solar Mass Ejection Imager (SMEI) instrument provides white-light
photometric maps covering most of the sky each orbit of the Coriolis
spacecraft. The SMEI differential photometry specification is 0.1% for
each 1 square degree sky bin. A labyrinthine baffle reduces scattered
sunlight, but for a portion of the data a background residue must also
be subtracted to finally reach this specification. We describe this
process, and further discuss how bright stars are used to determine an
appropriate conversion from the CCD-camera data units to sky surface
brightness. Also, the CCD in the camera viewing closest to the Sun
operates significantly warmer than expected, which gives rise to a
changing population of "hot pixels". We describe a data-analysis process
which significantly alleviates the photometric impact of this.
@--------------------------------------------------------------------
Title: Wind/WAVES and SMEI Observations of ICMEs
Authors: Reiner, M. J.; Jackson, B. V.; Webb, D. F.;
Kaiser, M. L.; Cliver, E. W.; Bougeret, J. L.
Bibliographic Code: 2004AGUFMSH11A..05R
Abstract
The low-frequency (kilometric) radio observations on Wind/WAVES provide
important spectral and directional information related to the
propagation of ICMEs through interplanetary space. However, up to now
there has been no white-light observations with which to compare these
low-frequency interplanetary radio observations, beyond the 30 Rs limit
of the LASCO field of view. The recently launched Air Force Coriolis
spacecraft that includes the Solar Mass Ejection Imager (SMEI), which is
the first all-sky camera designed to track ICMEs from the Sun to 1 AU,
provides a unique opportunity of simultaneously tracking CMEs, both in
white light and in radio, all the way from the corona to 1 AU. 3D
reconstruction techniques, utilizing multiple perspective views of the
ICME observed by SMEI, represent the propagation and evolution of these
density structures through the 3D heliosphere. There are two general
ways that the Wind/WAVES radio data can be directly related to the SMEI
heliospheric white-light observations. First, since the observed radio
frequency depends on the local plasma density in the radio source region
and since the interplanetary plasma density falls off with the inverse
of the heliocentric distance squared, the observed radio frequency
generated by the CME/shock decreases as the type II radio source
associated with the CME propagates farther from the Sun. Thus the
frequency characteristics of the type II radio emissions provide
information on the radial distance of the ICME. Secondly, the
low-frequency radio receivers on the Wind spacecraft have the unique
capability of providing information on the direction of arrival of the
radio emissions and of the size of the radio-emitting region. Both of
these results, obtained from analyses of the Wind/WAVES radio
observations, will be directly compared with the results from the
analyses of the SMEI white-light data for various ICME events.
@--------------------------------------------------------------------
Title: Heliospheric Photometric Images and 3D
Reconstruction from the Solar Mass Ejection Imager
(SMEI) Data
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.
Bibliographic Code: 2004AGUFMSH11A..02J
Abstract
The Solar Mass Ejection Imager (SMEI) experiment is fixed to the
Coriolis spacecraft and views the sky above Earth using
sunlight-rejecting baffles and CCD camera technology. SMEI was designed
to provide precise photometric white light images over most of the sky
on each 102-minute Earth orbit. The brightness sky maps of the inner
heliosphere indicate a rich variety of electron density structures that
are produced by the material that propagates through it and its
interaction with ambient structures. We present some of the
preliminary results of the analysis of these photometric SMEI
observations derived by modeling the white light observations such that
most of the contaminant signals: stars, the zodiacal cloud and
high-energy particle variations are removed. We will also show some of
the 3D reconstructions that allow this contaminant signal removal using
both interplanetary scintillation (IPS) and SMEI data.
@--------------------------------------------------------------------
Title: Three-dimensional structure of compound
interplanetary transients associated with 27-28 May
2003 coronal mass ejections
Authors: Tokumaru, M.; Kojima, M.; Fujiki, K.; Yamashita, M.;
Jackson, B. V.; Hick, P.
Bibliographic Code: 2004AGUFMSH11A..01T
Abstract
We have investigated the global features of interplanetary (IP)
disturbances associated with 27-28 May coronal mass ejection (CME)
events using interplanetary scintillation (IPS) measurements of the
Solar-Terrestrial Environment Laboratory (STEL). Our IPS data taken
between 2003 May 28 22h UT and May 29 7h UT showed a set of complex
feature of IP disturbances, and most of them are regarded as IP
consequences of two full-halo CMEs which occurred in association with
the X1.3/2B flare on May 27 23:07 UT and the X3.3 flare on May 28 00:27
UT. Some components of the IP disturbances were discriminated from the
IPS data by making the model fitting analysis iteratively. One of the
components was an Earth-directed one, which appears to correspond to the
IP shock observed by ACE on May 29 18:30 UT. Other components were
obliquely propagating ones, which either preceded or followed the
Earth-directed one. The global features deduced here are generally in
agreement with heliospheric reconstructions made from Solar Mass
Ejection Imager (SMEI) measurements.
@--------------------------------------------------------------------
Title: Preliminary Three Dimensional Reconstruction of CMEs
Using Solar Mass Ejection Imager (SMEI) Data
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Wang, X.
Bibliographic Code: 2004AAS...205.4305J
Abstract
White-light Thomson scattering observations from the Solar Mass Ejection
Imager (SMEI) have recorded the inner heliospheric response to the
October 28, 2003 CME. Here we detail the extent of this particular CME
event in SMEI observations, and we show how we are able to track the
event from its first measurement approximately 20o from the
solar disk until it fades away in the SMEI 180o field of
view. Several portions of this CME that can be tracked into the
interplanetary medium are associated with the initial CME response and
the underlying erupting prominence structure. We employ a 3D
reconstruction technique that provides perspective views from
outward-flowing solar wind as observed from Earth. This is accomplished
by iteratively fitting the parameters of a kinematic solar wind density
model to the SMEI white light observations and to Solar-Terrestrial
Environment Laboratory (STELab), interplanetary scintillation (IPS)
velocity data. This 3D modeling technique enables separating the true
heliospheric response in SMEI from background noise, and reconstructing
the 3D heliospheric structure as a function of time. These
reconstructions allow both separation of the 28 October CME from other
nearby heliospheric structure and a determination of its mass. The
preliminary SMEI white light calibration indicates a total mass of 6 X
1016g for the ejecta associated with the prominence eruption.
The total mass of this CME including possible associated nearby
structures may have been as much as 2 X 1017g of inner
heliospheric response spread over much of the Earthward-facing
hemisphere.
@--------------------------------------------------------------------
Title: Photometric Calibration for the Solar Mass Ejection
Imager (SMEI)
Authors: Buffington, A.; Smith, A. C.; Jackson, B. V.;
Hick, P. P.
Bibliographic Code: 2004AAS...205.1007B
Abstract
The Solar Mass Ejection Imager (SMEI) was designed to record a
photometric white-light response of the interplanetary medium from Earth
over most of the sky in near real time, using Thomson scattered
sunlight. In its first two years the instrument has observed several
hundred Coronal Mass Ejections. Quantitative interpretations of these
data requires that the Analog Data Units (ADUs) of the instrument's CCD
responses be converted to an effective stellar brightness. The present
work provides a preliminary report on establishing this relationship.
An appropriate unit here is an "S10", the equivalent brightness of a
10th magnitude star spread over one square degree. The relationship
between ADUs and S10s is established by using the SMEI response to
bright stars having known visual magnitude and spectral type. These
latter are converted to a "SMEI magnitude" by integrating the various
star's spectra over the nominal SMEI bandpass, which extends between 0.4
and 1.1 microns and peaks at 0.7 microns, to obtain a spectral scaling
factor which is set to unity for G-type stars and relates visual
magnitudes to SMEI magnitudes. The final overall conversion factor is
then determined from the ADU measurements of the individual stars.
This work was supported in part by NSF contract ATM0331513 and NASA
grant NAG 5-134543.
@--------------------------------------------------------------------
Title: Near Real-Time Photometric Data Processing for the
Solar Mass Ejection Imager (SMEI)
Authors: Hick, P. P.; Buffington, A.; Jackson, B. V.
Bibliographic Code: 2004AAS...205.1006H
Abstract
The Solar Mass Ejection Imager (SMEI) records a photometric white-light
response of the interplanetary medium from Earth over most of the sky in
near real time. In the first two years of operation the instrument has
recorded the inner heliospheric response to several hundred CMEs,
including the May 28, 2003 and the October 28, 2003 halo CMEs. In this
preliminary work we present the techniques required to process the SMEI
data from the time the raw CCD images become available to their final
assembly in photometrically accurate maps of the sky brightness relative
to a long-term time base.
Processing of the SMEI data includes integration of new data into the
SMEI data base; a conditioning program that removes from the raw CCD
images an electronic offset ("pedestal") and a temperature-dependent
dark current pattern; an "indexing" program that places these CCD images
onto a high-resolution sidereal grid using known spacecraft pointing
information. At this "indexing" stage further conditioning removes the
bulk of the the effects of high-energy-particle hits ("cosmic rays"),
space debris inside the field of view, and pixels with a sudden state
change ("flipper pixels").
Once the high-resolution grid is produced, it is reformatted to a
lower-resolution set of sidereal maps of sky brightness. From these
sidereal maps we remove bright stars, background stars, and a zodiacal
cloud model (their brightnesses are retained as additional data
products). The final maps can be represented in any convenient sky
coordinate system. Common formats are Sun-centered Hammer-Aitoff or
"fisheye" maps. Time series at selected locations on these maps are
extracted and processed further to remove aurorae, variable stars and
other unwanted signals. These time series (with a long-term base
removed) are used in 3D tomographic reconstructions.
The data processing is distributed over multiple PCs running Linux, and,
runs as much as possible automatically using recurring batch jobs
('cronjobs'). The batch scrips are controlled by Python scripts. The
core data processing routines are written in several computer languages:
Fortran, C++ and IDL.
@--------------------------------------------------------------------
Title: Interactive Visualization of Solar Mass Ejection
Imager (SMEI) Volumetric Data
Authors: Wang, X.; Hick, P. P.; Jackson, B. V.
Bibliographic Code: 2004AAS...205.1005W
Abstract
We present a volume rendering system developed for the real time
visualization and manipulation of 3D heliospheric volumetric solar wind
density and velocity data obtained from the Solar Mass Ejection Imager
(SMEI) and interplanetary scintillation (IPS) velocities over the same
time period. Our system exploits the capabilities of the VolumePro 1000
board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of
rendering up to a 512-cubed array of volume data in real time at up to
30 frames per second on a standard PC. Many volume-rendering operations
have been implemented with this system such as stereo/perspective views,
animations of time-sequences, and determination of CME volumes and
masses. In these visualizations we highlight two time periods where halo
CMEs were observed by SMEI to engulf Earth, on May 30, 2003 and on
October 29, 2003. We demonstrate how this system is used to measure the
distribution of structure and provide 3D mass for individual CME
features, including the ejecta associated with the large prominence
viewed moving to the south of Earth following the late October CME.
@--------------------------------------------------------------------
Title: The Solar Mass-Ejection Imager (SMEI) Mission
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Altrock, R. C.; Figueroa, S.; Holladay, P. E.;
Johnston, J. C.; Kahler, S. W.; Mozer, J. B.;
Price, S.; Radick, R. R.; Sagalyn, R.; Sinclair, D.;
Simnett, G. M.; Eyles, C. J.; Cooke, M. P.;
Tappin, S. J.; Kuchar, T.; Mizuno, D.; Webb, D. F.;
Anderson, P. A.; Keil, S. L.; Gold, R. E.;
Waltham, N. R.
Bibliographic Code: 2004SoPh..225..177J
Abstract
We have launched into near-Earth orbit a solar mass-ejection imager
(SMEI) that is capable of measuring sunlight Thomson-scattered from
heliospheric electrons from elongations to as close as
18o to greater than 90o from the Sun. SMEI
is designed to observe time-varying heliospheric brightness of objects
such as coronal mass ejections, co-rotating structures and shock waves.
The instrument evolved from the heliospheric imaging capability
demonstrated by the zodiacal light photometers of the Helios spacecraft.
A near-Earth imager can provide up to three days warning of the arrival
of a mass ejection from the Sun. In combination with other imaging
instruments in deep space, or alone by making some simple assumptions
about the outward flow of the solar wind, SMEI can provide a
three-dimensional reconstruction of the surrounding heliospheric density
structures.
@--------------------------------------------------------------------
Title: Three-Dimensional Tomography of Interplanetary
Disturbances
Authors: Jackson, Bernard V.; Hick, P. Paul
Bibliographic Code: 2004ASSL..314..355J
Abstract
We have developed a Computer Assisted Tomography (CAT) program that
modifies a three-dimensional kinematic heliospheric model to fit
interplanetary scintillation (IPS) or Thomson scattering observations.
The tomography program iteratively changes this global model to
least-squares fit the data. Both a corotating and time-dependent model
can be reconstructed. The short time intervals of the time-dependent
modeling (to shorter than 1 day) force the heliospheric reconstructions
to depend on outward solar wind motion to give perspective views of each
point in space accessible to the observations, allowing reconstruction
of interplanetary Coronal Mass Ejections (CMEs) as well as corotating
structures. We show these models as velocity or density Carrington maps
and remote views. We have studied several events, including the 2000
July 14 Bastille-Day halo CME and several intervals using archival
Cambridge IPS data, and we have also used archival Helios photometer
data to reproduce the heliosphere. We check our results by comparison
with additional remote-sensing observations, and in-situ observations
from near-Earth spacecraft. A comparison of these observations and the
Earth forecasts possible using them is available in real time on the
World Wide Web using IPS data from the Solar Terrestrial Environment
Laboratory, Japan.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager (SMEI) and Its
Potential as a Precision Time-Series Photometer
Authors: Buffington, A.; Jackson, B. V.; Hick, P. P.;
Penny, A.
Bibliographic Code: 2004AAS...204.6910B
Abstract
The Solar Mass Ejection Imager (SMEI) was launched in January 2003 into
Earth orbit. SMEI is designed to observe heliospheric structures
illuminated by Thomson-scattered sunlight. The design specification for
SMEI is 0.1% in differential photometry for bright unresolved objects,
to enable star removal from the heliospheric maps. Such a near-Earth
imager will also provide photometric time-series measurements of these
stars as a by-product of this removal process. For each 101-minute
orbit, SMEI will deliver near complete sky maps having an expected (1
sigma) photometric resolution of about the equivalent of an 11th
magnitude star in a square degree. We will report on progress in
establishing the photometric calibrations for the SMEI cameras, and
discuss SMEI's potential for delivering photometric time-series
measurements, which data can then be applied to the study of variable
stars, eclipsing stellar systems, and to search for extrasolar planets
by the occultation method.
@--------------------------------------------------------------------
Title: Coronal Mass Ejection Masses From CMEs Identified in
Interplanetary Scintillation (IPS) Tomography and
LASCO Coronagraph Images
Authors: Rappoport, S. A.; Jackson, B. V.; Hick, P. P.;
Buffington, A.; Vourlidas, A.
Bibliographic Code: 2004AAS...204.3802R
Abstract
To optimize the information from individual radio source observations of
the sky covering large elongations, we have developed a
Computer-Assisted Tomography (CAT) program. We fit STELab (Nagoya
University, Japan) interplanetary scintillation (IPS) observations to a
time-dependent, three-dimensional heliospheric model. These observations
allow us to create "sky maps" covering 10 to 80 degrees in elongation,
in which we can track CMEs observed earlier in LASCO coronagraph images.
These events have approximately the same shapes and extents as observed
closer to the Sun. Here we map several CMEs in 3-dimensions as they move
outward to 1 AU. Masses for each of the events are determined from the
reconstruction analysis and are compared with plane of the sky masses
obtained from calibrated LASCO coronagraph images.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager (SMEI) Mission
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Kuchar, T.; Mizuno, D.; Webb, D. F.
Bibliographic Code: 2004AAS...204.1809J
Abstract
The Solar Mass Ejection Imager (SMEI) was launched in January 2003 into
Earth orbit. It observes sunlight that has Thomson-scattered from
heliospheric structures of time-varying density. SMEI is designed to
observe heliospheric structures such as coronal mass ejections (CMEs),
corotating structures and shock waves to elongations greater than 90
degrees from the Sun. Such a near-Earth imager can provide up to three
days warning of the arrival of a CME from the Sun. In combination with
other imaging instruments in deep space, or alone by making some simple
assumptions about the outward flow of the solar wind, SMEI can provide
3D reconstructions of the heliospheric structures that it observes. We
show images of several CMEs observed with this instrument and
low-resolution reconstruction analyses using the SMEI data for each
event. The 3D reconstructions and heights for these events are compared
with elongation-time plots of the same CMEs to estimate true speeds and
line-of-sight locations for each CME.
@--------------------------------------------------------------------
Title: Heliospheric tomography: an algorithm for the
reconstruction of the 3D solar wind from remote
sensing observations
Authors: Hick, P. P.; Jackson, Bernard V.
Bibliographic Code: 2004SPIE.5171..287H
Abstract
Over the past years we have developed a tomographic technique for using
heliospheric remote sensing observations (i.e. interplanetary
scintillation and Thomson scattering data) for the reconstruction of the
three-dimensional solar wind density and velocity in the inner
heliosphere. We describe the basic algorithm on which our technique is
based. To highlight the details of the reconstruction algorithm we
specifically emphasize the implementation of corotating tomography using
IPS g-level and IPS velocity observations as proxies for the solar wind
density and velocity, respectively. We provide some insight into the
modifications required to expand the technique into a fully
time-dependent tomography, and to use Thomson scattering brightness
(instead of g-level) as a proxy for the solar wind density.
@--------------------------------------------------------------------
Title: Visualization of remotely sensed heliospheric
plasmas for space weather applications
Authors: Wang, Xin; Hick, P. P.; Jackson, Bernard V.;
Bailey, Mike
Bibliographic Code: 2004SPIE.5171..280W
Abstract
We demonstrate a software application designed for the display and
interactive manipulation of 3D heliospheric volume data, such as solar
wind density, velocity and magnetic field. The Volume Explorer software
exploits the capabilities of the Volume Pro 1000 (from TeraRecon, Inc.),
a low-cost 64-bit PCI board capable of rendering a 512-cubed array of
volume data in real time at up to 30 frames per second on a standard PC.
The application allows stereo and perspective views, and animations of
time-sequences. We show examples of three-dimensional heliospheric
volume data derived from tomographic reconstructions based on
heliospheric remote sensing observations of the heliospheric density and
velocity structure. Currently these reconstructions are based on
archival IPS and Thomson scattering data. In the near future we expect
to add reconstructions based on the all-sky observations from the
recently launched Solar Mass Ejection Imager.
@--------------------------------------------------------------------
Title: Comparative analyses of the CSSS magnetic field
calculation in the Univ. of California/San Diego
tomographic solar wind model with in situ spacecraft
observations
Authors: Dunn, Tamsen; Hick, P. P.; Jackson, Bernard V.;
Buffington, Andrew; Zhao, Xue Pu
Bibliographic Code: 2004SPIE.5171....6D
Abstract
Our tomographic techniques developed over the last few years are based
on kinematic models of the solar wind. This allows us to determine the
large-scale three-dimensional extents of solar wind structures using
interplanetary scintillation (IPS) observations and Thomson scattering
brightness data in order to forecast their arrival at Earth in real
time. We are specifically interested in a technique that can be combined
with observations presently available from IPS velocity data and with
observations which will become available from the Solar Mass Ejection
Imager. In this paper, we introduce magnetic field projections from
solar surface magnetogram data using the Stanford Current-Sheet Source
Surface model at the source surface of our model and extrapolate the
magnetic field out to and beyond Earth. The results are compared with in
situ data. Real time projections of these data are available on our web
site at: http://cassfos02.ucsd.edu/solar/forecast/index_v_n.html and
http://cassfos02.ucsd.edu/solar/forecast/index_br_bt.html
@--------------------------------------------------------------------
Title: SMEI: design and development of an Earth-orbiting
all-sky coronagraph
Authors: Jackson, Bernard V.; Hick, P. P.; Buffington, Andrew;
Gold, Robert E.; Simnett, George M.;
Eyles, Christopher J.; Cooke, Mark P.;
Waltham, Nicholas R.
Bibliographic Code: 2004SPIE.5171....1J
Abstract
The Air Force/NASA Solar Mass Ejection Imager (SMEI) launched January 6,
2003 is now recording whole sky data on each 100-minute orbit. Precise
photometric sky maps of the heliosphere around Earth are expected from
these data. The SMEI instrument extends the heritage of the HELIOS
spacecraft photometer systems that have recorded CMEs and other
heliospheric structures from close to the Sun into the anti-solar
hemisphere. SMEI rotates once per orbit and views the sky away from
Earth using CCD camera technology. To optimize the information derived
from this and similar instruments, a tomographic technique has been
developed for analyzing remote sensing observations of the heliosphere
as observed in Thomson scattering. The technique provides 3-dimensional
reconstructions of heliospheric density. The tomography program has been
refined to analyze time-dependent phenomena such as evolving corotating
heliospheric structures and more discrete events such as coronal mass
ejections (CMEs), and this improved analysis is being applied to the
SMEI data.
@--------------------------------------------------------------------
Title: Tracking a major interplanetary disturbance with
SMEI
Authors: Tappin, S. J.; Buffington, A.; Cooke, M. P.;
Eyles, C. J.; Hick, P. P.; Holladay, P. E.;
Jackson, B. V.; Johnston, J. C.; Kuchar, T.;
Mizuno, D.; Mozer, J. B.; Price, S.; Radick, R. R.;
Simnett, G. M.; Sinclair, D.; Waltham, N. R.;
Webb, D. F.
Bibliographic Code: 2004GeoRL..3102802T
Abstract
We present the first clear observations of an Earth-directed
interplanetary disturbance tracked by the Solar Mass Ejection Imager
(SMEI). We find that this event can be related to two halo CMEs seen at
the Sun about 2 days earlier, and which merged in transit to 1 AU. The
disturbance was seen about 16 hours before it reached Earth,and caused a
severe geomagnetic storm at the time which would have been predicted had
SMEI been operating as a real-time monitor. It is concluded that SMEI is
capable of giving many hours advance warning of the possible arrival of
interplanetary disturbances.
@--------------------------------------------------------------------
Title: Recent Comparative Analyses of the CSSS UCSD
Tomographic Solar Wind Model with in situ Spacecraft
Observations
Authors: Dunn, T.; Hick, P.; Jackson, B. V.; Buffington, A.
Bibliographic Code: 2003AGUFMSH42B0526D
Abstract
Our tomographic techniques developed over the last few years are based
on kinematic models of the solar wind. This allows us to determine the
large-scale three-dimensional extents of solar wind structures using
interplanetary scintillation (IPS) observations and Thomson scattering
brightness data in order to forecast their arrival at Earth in real
time. We are specifically interested in a technique that can be
combined with observations presently available from IPS velocity data
and with observations which are now becoming available from the Solar
Mass Ejection Imager. We use solar surface magnetogram data, and a
source surface provided by the Stanford Current-Sheet Source Surface
model, to provide input to the UCSD tomography program. The UCSD
tomography program extrapolates the magnetic field out to and beyond
Earth. The latest results are compared with in situ data.
@--------------------------------------------------------------------
Title: Stellar Variability Studies with SMEI
Authors: Penny, A. J.; Jackson, B. V.; Buffington, A.;
Hick, P. P.; Kahler, S. W.; Price, S.;
Johnston, J. C.; Holladay, P.; Sinclair, D.;
Radick, R. R.; Mozer, J. C.; Anderson, P.;
Simnett, G. M.; Eyles, C. J.; Cooke, M. P.;
Tappin, J.; Waltham, N. R.; Kuchnar, T.; Mizuno, D.;
Webb, D. F.
Bibliographic Code: 2003AGUFMSH41C..08P
Abstract
The Solar Mass Ejection Imager (SMEI) instrument images most of the sky
every 105 minutes. From this unique dataset, the brightnesses of stars
down to and below the eight magnitude can be measured to investigate
their variability. This paper presents the methods developed to extract
the stellar brightnesses, and the accuracies obtained as a function of
brightness and crowding. Example lightcurves are given.
@--------------------------------------------------------------------
Title: IPS/SMEI potential joint observations
Authors: Tokumaru, M.; Kojima, M.; Fujiki, K.; Jackson, B. V.;
Hick, P.
Bibliographic Code: 2003AGUFMSH41C..05T
Abstract
Interplanetary scintillation (IPS) measurements are known as one of
remote-sensing techniques which enable us to gain access to global
features of the solar wind (e.g. quasi-stationary corotating structures,
transient streams associated with CMEs). We have carried out a long-term
collaboration on the reconstruction of the heliospheric features from
IPS measurements made with the 327 MHz four-station system of the
Solar-Terrestrial Environment Laboratory (STEL), Nagoya University.
Under the collaboration, we have developed the computer-assisted
tomography (CAT) analysis method, which allows us to retrieve the 3D
distribution of the solar wind velocity and density from IPS data. We
also have been making the real-time reconstruction experiment of
heliospheric features using STEL IPS data and the CAT method. Based on
these results, we propose here the joint observations of IPS and SMEI.
The SMEI is a powerful tool to investigate the global heliospheric
features, and its capability is complementary to one of IPS
observations; That is, SMEI observations provide a high-resolution image
of the solar wind density distribution, while IPS observations provide
reliable estimates of the solar wind velocity. Therefore, a combination
of IPS and SMEI observations is essential for achieving a precise
reconstruction of global heliospheric (velocity and density) features by
the CAT analysis.
@--------------------------------------------------------------------
Title: SMEI: First Results and Future Capabilities
Authors: Webb, D. F.; Mozer, J. B.; Radick, R. R.;
Johnston, J. C.; Price, S. D.; Kuchar, T.;
Mizuno, D. R.; Jackson, B. V.; Buffington, A.;
Tappin, S. J.; Simnett, G. M.
Bibliographic Code: 2003AGUFMSH41C..03W
Abstract
The Solar Mass Ejection Imager (SMEI) experiment was launched on the STP
Coriolis mission 6 January 2003 and is now recording all-sky, white
light images on each 101-minute orbit. SMEI is fixed to the spacecraft
and views the sky above Earth using sunlight-rejecting baffles and CCD
camera technology. When fully calibrated, sky maps of structures having
enhanced electron density in the inner heliosphere will be routinely
produced. We will present some preliminary results of the early analysis
of SMEI data. These include observations of several dozen coronal mass
ejections (CMEs) as confirmed by the SOHO LASCO coronagraphs. One of
these was a halo event which propagated to and beyond 1 AU and was
associated with a major geomagnetic storm at Earth. Tomographic
techniques are being developed to analyze the SMEI observations of the
heliospheric plasma, including the transient CMEs and corotating
interaction regions. SMEI also detected Comet NEAT inbound to and
outbound from the Sun and the asteroid Vesta. With SMEI data we also can
study solar and solar wind processes, and the experiment is capable of
observing various other astronomical phenomena, such as variable stars,
the Zodiacal light, near-Earth objects and extrasolar planetary
transits.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager (SMEI)
Authors: Simnett, G. M.; Eyles, C. J.; Cooke, M. P.;
Waltham, N. R.; King, J. M.; Jackson, B. V.;
Buffington, A.; Hick, P. P.; Holladay, P. E.;
Anderson, P. A.
Bibliographic Code: 2003AGUFMSH41C..02S
Abstract
The Solar Mass Ejection Imager (SMEI) has been designed to detect and
forecast the arrival of solar mass ejections and other heliospheric
structures which are moving towards the Earth. We describe the
instrument, which was launched into a Sun-synchronous polar orbit on 6
January, 2003 on board the US DoD Coriolis spacecrafth. SMEI contains
three CCD cameras, sensitive over the optical waveband, each with a
field-of-view of 60 degrees x 3 degrees. The sensitivity is such that it
will detect changes in sky brightness equivalent to a tenth magnitude
star in one square degree of sky. Each camera takes an image every 4s
and the normal telemetry rate is 128 kbits/s. SMEI has a photometric
accuracy of around 0.1%. In addition to solar mass ejections, images of
stars and the zodiacal cloud are measured to this photometric accuracy
once/ orbit (102 minutes).
@--------------------------------------------------------------------
Title: IPS From LOFAR: A Complement to Thomson Scattering
Studies
Authors: Oberoi, D.; Kasper, J. C.; Lonsdale, C. J.;
Salah, J. E.; Lazarus, A. J.; Jackson, B. V.
Bibliographic Code: 2003AGUFMSH41B0463O
Abstract
Information about the large scale physical properties of the inner
heliosphere plasma can only be obtained by employing remote sensing
techniques. The two most useful measurement techniques for this are
Thomson scattering, used by Solar Mass Ejection Imager (SMEI), and
Interplanetary Scintillation (IPS). Both these techniques are sensitive
to the distribution of properties of the solar wind plasma along the
entire line-of-sight through the medium. The two measurement techniques
are sensitive to different properties of the same physical plasma. IPS
is sensitive to the fluctuations in the refractive index of the medium
(~ delta ne2) and their spectral index, the
perpendicular component of velocity of the solar wind, the anisotropy in
electron density fluctuations caused by the magnetic field and their
inner scale. Thomson scattering, on the other hand, is sensitive only to
the distribution of the electron density along the line of sight. The
data from both these techniques are suitable for tomographic
reconstructions, yielding three dimensional visualisations of the inner
heliosphere. Heliospheric tomography will benefit significantly from the
denser sky coverage and the improved signal-to-noise IPS measurements
promised by the upcoming instruments and the simultaneous use of Thomson
scattering data. The unquestionable synergy between the information
obtained from these two techniques should be exploited to arrive at
significantly better constrained tomographic reconstructions. We are now
assessing the potential for space weather applications, including IPS
studies, of the Low Frequency Array (LOFAR), an aperture synthesis radio
interferometer covering the 10-240 MHz range. The unique design of this
instrument allows the possibility of high sensitivity observations of up
to 4000 IPS sources a day. This unprecedented ability will increase the
sampling of the inner heliosphere by ˜2 orders of magnitude
compared to the present IPS instruments and improve the signal-to-noise
of individual measurements. This paper will describe some aspects of the
LOFAR design and outline its potential IPS measurement capabilities.
@--------------------------------------------------------------------
Title: Space Performance of the Multistage Labyrinthine
SMEI Baffle
Authors: Buffington, A.; Jackson, B. V.; Hick, P. P.
Bibliographic Code: 2003AGUFMSH41B0459B
Abstract
The Solar Mass Ejection Imager (SMEI) was launched on 6 January 2003,
and shortly thereafter raised to a nearly circular orbit at 840 km.
Three SMEI CCD cameras on the zenith-oriented CORIOLIS spacecraft cover
most of the sky beyond about 20° from the Sun, each 102-minute
orbit. Data from this instrument will ultimately provide precision
visible-light photometric sky maps. Once starlight and other constant or
slowly varying backgrounds are subtracted, the residue is mostly
sunlight that has been Thomson-scattered from heliospheric electrons.
These maps will enable 3-dimensional tomographic reconstruction of
heliospheric density and velocity. This analysis requires 0.1%
photometry and background-light reduction below one S10 (the brightness
equivalent of a 10th magnitude star per square degree). Thus
10-15 of surface-reduction is required relative to the solar
disk. The SMEI labyrinthine baffle provides roughly 10-10 of
this reduction; the subsequent optics provides the remainder. We analyze
data covering a range of angles between the SMEI optical axis and the
Sun, or the Moon, to evaluate the full system's stray-light rejection
performance.
@--------------------------------------------------------------------
Title: Interactive Visualization of Transient Solar Wind
Phenomena for Space Weather Applications
Authors: Wang, C. X.; Hick, P. P.; Jackson, B. V.
Bibliographic Code: 2003AGUFMSH41B0458W
Abstract
We present a volume rendering system developed for the visualization and
manipulation of 3D heliospheric volume data such as solar wind density,
velocity and magnetic field. Our system exploits the capabilities of the
VolumePro 1000 board from TeraRecon, Inc., a low-cost 64-bit PCI board
capable of rendering a 512-cubed array of volume data in real time at up
to 30 frames per second on a standard PC. Many operations have been
implemented such as stereo/perspective views, animations of
time-sequences, and determination of CME volumes and masses. We will
show examples of three-dimensional heliospheric volumes from
tomographic reconstructions of density and velocity using real-time
interplanetary scintillation (IPS) data. In the near future we expect
to add reconstructions based on the all-sky observations from the
recently launched Solar Mass Ejection Imager and employ our system to
interactively analyze and visualize the abundant information embedded in
these data.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager (SMEI) Mission
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.;
Holladay, P.; Johnston, J. C.; Kahler, S. W.;
Mozer, J.; Price, S.; Radick, R. R.; Sinclair, D.;
Simnett, G. M.; Eyles, C. J.; Cooke, M. P.;
Tappin, J.; Waltham, N. R.; Kuchar, T.; Mizuno, D.;
Webb, D. F.
Bibliographic Code: 2003AGUFMSH41B0457J
Abstract
We have designed, built and launched into near-Earth orbit a Solar Mass
Ejection Imager (SMEI) capable of observing sunlight that has
Thomson-scattered from heliospheric structures of time-varying density.
SMEI is designed to observe heliospheric structures such as coronal mass
ejections, corotating structures and shock waves, to elongations greater
than 90° from the Sun. The instrument was inspired by the
heliospheric imaging capability demonstrated by the zodiacal light
photometers of the Helios spacecraft. The instrument makes effective
use of in situ solar wind data from spacecraft in the vicinity of the
imager by extending observations to the surrounding environment and back
to the Sun. A near-Earth imager can provide up to three days warning of
the arrival of a mass ejection from the Sun. In combination with other
imaging instruments in deep space, or alone by making some simple
assumptions about the outward flow of the solar wind, SMEI can provide a
tomographic analysis of the heliospheric structures surrounding it.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager (Smei)
Authors: Eyles, C. J.; Simnett, G. M.; Cooke, M. P.;
Jackson, B. V.; Buffington, A.; Hick, P. P.;
Waltham, N. R.; King, J. M.; Anderson, P. A.;
Holladay, P. E.
Bibliographic Code: 2003SoPh..217..319E
Abstract
We describe an instrument (SMEI) which has been specifically designed to
detect and forecast the arrival of solar mass ejections and other
heliospheric structures which are moving towards the Earth. Such events
may cause geomagnetic storms, with resulting radiation hazards and
disruption to military and commercial communications; damage to
Earth-orbiting spacecraft; and also terrestrial effects such as surges
in transcontinental power transmission lines. The detectors are
sensitive over the optical wave-band, which is measured using CCD
cameras. SMEI was launched on 6 January 2003 on the Coriolis spacecraft
into a Sun-synchronous polar orbit as part of the US DoD Space Test
Programme. The instrument contains three cameras, each with a field of
view of 60°×3°, which are mounted onto the spacecraft such
that they scan most of the sky every 102-min orbit. The sensitivity is
such that changes in sky brightness equivalent to a tenth magnitude star
in one square degree of sky may be detected. Each camera takes an image
every 4 s. The normal telemetry rate is 128 kbits s-1. In
order to extract the emission from a typical large coronal mass
ejection, stellar images and the signal from the zodiacal dust cloud
must be subtracted. This requires accurate relative photometry to 0.1%.
One consequence is that images of stars and the zodiacal cloud will be
measured to this photometric accuracy once per orbit. This will enable
studies of transient zodiacal cloud phenomena, flare stars, supernovae,
comets, and other varying point-like objects.
@--------------------------------------------------------------------
Title: Time-dependent tomography of heliospheric structures
using IPS and Thomson scattering observations
Authors: Jackson, Bernard V.; Hick, P. P.; Buffington, A.
Bibliographic Code: 2003ESASP.535..823J
Abstract
The Air Force/NASA Solar Mass Ejection Imager (SMEI) launched January 6,
2003 is now recording whole sky data on each 100-minute orbit. Precise
photometric images of the heliosphere around Earth are expected from
these data. To optimize the information available from this and similar
instruments, we are developing a tomographic technique for analyzing
remote sensing observations of the heliosphere using both interplanetary
scintillation (IPS) and Thomson scattering data. The technique provides
a three-dimensional reconstruction of heliospheric velocities and
densities. We have refined our tomography program to analyze
time-dependent phenomena such as evolving corotating heliospheric
structures and more discrete events such as coronal mass ejections
(CMEs).
@--------------------------------------------------------------------
Title: Time-dependent tomography of hemispheric features
using interplanetary scintillation (IPS)
remote-sensing observations
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Kojima, M.; Tokumaru, M.; Fujiki, K.; Ohmi, T.;
Yamashita, M.
Bibliographic Code: 2003AIPC..679...75J
Abstract
We have developed a Computer Assisted Tomography (CAT) program that
modifies a time-dependent three-dimensional kinematic heliospheric model
to fit interplanetary scintillation (IPS) observations. The tomography
program iteratively changes this global model to least-squares fit IPS
data. The short time intervals of the kinematic modeling (~1 day) force
the heliospheric reconstructions to depend on outward solar wind motion
to give perspective views of each point in space accessible to the
observations, allowing reconstruction of interplanetary Coronal Mass
Ejections (CMEs) as well as corotating structures. We show these models
as velocity or density Carrington maps and remote views. We have studied
several events, including the July 14, 2000 Bastille-day halo CME. We
check our results by comparison with additional remote-sensing
observations, and observations from near-Earth spacecraft.
@--------------------------------------------------------------------
Title: Introduction of the CSSS magnetic field calculation
into the UCSD tomographic solar wind model
Authors: Dunn, Tamsen; Hick, Pierre P.; Jackson, Bernard V.;
Zhao, Xuepu
Bibliographic Code: 2003SPIE.4853..504D
Abstract
Tomographic techniques developed at UCSD over the last few years
incorporate a kinematic model of the solar wind to determine and
forecast the large-scale three-dimensional extents of velocity and
density using interplanetary scintillation (IPS) observations or Thomson
scattering brightness data. In this paper, we introduce magnetic field
calculations from the Stanford Current-Sheet Source Surface (CSSS) model
into our kinematic model. The CSSS model is used to extrapolate the
photospheric magnetic field to a source surface at 15 solar radii
(Rs). The UCSD kinematic model convects magnetic field from
15 Rs out to and beyond Earth. We compare the results with in
situ data near Earth. The spatial relationship between the heliospheric
current sheet and coronal mass ejections (CMEs) is shown in remote views
of the inner heliosphere
@--------------------------------------------------------------------
Title: Calculations for and laboratory measurements of a
multistage labyrinthine baffle for SMEI
Authors: Buffington, Andrew; Jackson, Bernard V.;
Hick, Pierre P.
Bibliographic Code: 2003SPIE.4853..490B
Abstract
The spaceborne Solar Mass Ejection Imager (SMEI) is scheduled for launch
into near-earth orbit (>800 km) in early 2003. Three SMEI CCD cameras
on the zenith-oriented CORIOLIS spacecraft cover most of the sky each
100-minute orbit. Data from this instrument will provide precision
visible-light photometric maps. Once starlight and other constant or
slowly varying backgrounds are subtracted, the residue is mostly
sunlight that has Thomson-scattered from heliospheric electrons. These
maps will enable 3-dimensional tomographic reconstruction of
heliospheric density and velocity. The SMEI design provides three
cameras, one of which views to within 18 degrees of the solar disk with
a field of view 60° long by 3° wide. Placed end-to-end, three
fields of view then cover a nearly 180° long strip that sweeps out
the sky over each orbit. The 3-dimensional tomographic analysis requires
0.1% photometry and background-light reduction below one S10 (the
brightness equivalent of a 10th magnitude star per square degree). Thus
10-15 of surface-brightness reduction is required relative to
the solar disk. The SMEI labyrinthine baffle provides roughly 10-10
of this reduction; the subsequent optics provides the remainder.
We describe the baffle design and present laboratory measurements of
prototypes that confirm performance at this level.
@--------------------------------------------------------------------
Title: Time-dependent tomography of heliospheric features
using the three-dimensional reconstruction
techniques developed for the solar mass ejection
imager (SMEI)
Authors: Jackson, Bernard V.; Hick, Pierre P.;
Buffington, Andrew
Bibliographic Code: 2003SPIE.4853...23J
Abstract
Precise photometric images of the heliosphere are expected from the Air
Force/NASA Solar Mass Ejection Imager (SMEI) now scheduled for launch in
February 2003, and the all-sky cameras proposed for other NASA missions.
To optimize the information available from these instruments, we are
developing tomographic techniques for analyzing remote sensing
observations of heliospheric density as observed in Thomson scattering
(e.g. using the Helios photometer data) for eventual use with SMEI. We
have refined the tomography program to enable us to analyze
time-dependent phenomena, such as the evolution of corotating
heliospheric structures and more discrete events such as coronal mass
ejections. Both types of phenomena are discerned in our data, and are
reconstructed in three dimensions. We use our tomography technique to
study the interaction of these phenomena as they move outward from the
Sun for several events that have been studied by multiple spacecraft in
situ observations and other techniques.
@--------------------------------------------------------------------
Title: The 3d Solar Wind Over the Solar Cycle Observed by
IPS
Authors: Kojima, Masayoshi; Jackson, Bernard V.;
Ohmi, Tomoaki; Hick, Paul; Hayashi, Keiji;
Tokumaru, Munetoshi; Fujiki, Ken-Ichi
Bibliographic Code: 2003IAUJD...7E..25K
Abstract
The interplanetary scintillation (IPS) method can observe the dynamics
and structure of the solar wind in three dimensions with a relatively
short time cadence. Because IPS observations are line-of-sight
integrations we have developed an IPS tomography analysis method that
can retrieve three-dimensional solar wind parameters as well as provide
better spatial resolutions than previous IPS techniques. Using the IPS
tomography analysis we have studied the solar cycle dependence of the
solar wind properties such as the velocity of fast solar wind bimodal
structure north-south asymmetry of fast wind and the origin of a compact
slow streamer. Solar wind structure is bimodal not only in the solar
minimum phase but also in the ascending and descending phases; In solar
minimum phase a small coronal hole in vicinity of an active region
emanates slow wind and a polar coronal hole also becomes the source of
slow wind when it shrinks to a small size at solar maximum; the velocity
of the fast wind does not change significantly when a coronal hole
changes its size in the descending and ascending phases. We also
introduce the three-dimensional dynamic nature of interplanetary
transient events that were observed with another new technique:
time-dependent tomography.
@--------------------------------------------------------------------
Title: Tomography of Heliospheric Features Developed for
Smei
Authors: Jackson, Bernard V.; Hick, P. P.; Buffington, Andrew
Bibliographic Code: 2003IAUJD...7E..23J
Abstract
The Air Force/NASA Solar Mass Ejection Imager (SMEI) launched January 6
2003 is now recording whole sky data on each 100-minute orbit. Precise
photometric images of the heliosphere around Earth are expected from
these data. To optimize the information available from this and similar
instruments we are developing a tomographic technique for analyzing
remote sensing observations of the heliosphere as observed in Thomson
scattering. The technique provides three-dimensional reconstructions of
heliospheric density. We have refined our tomography program to analyze
time-dependent phenomena such as evolving corotating heliospheric
structures and more discrete events such as coronal mass ejections
(CMEs).
@--------------------------------------------------------------------
Title: Corotational Tomography of Heliospheric Features
Using Global Thomson Scattering Data
Authors: Jackson, Bernard V.; Hick, P. Paul
Bibliographic Code: 2002SoPh..211..345J
Abstract
The Air Force/NASA Solar Mass Ejection Imager (SMEI) will provide
two-dimensional images of the sky in visible light with high (0.1%)
photometric precision, and unprecedented sky coverage and cadence. To
optimize the information available from these images they must be
interpreted in three dimensions. We have developed a Computer Assisted
Tomography (CAT) technique that fits a three-dimensional kinematic
heliospheric model to remotely-sensed Thomson scattering observations.
This technique is designed specifically to determine the corotating
background solar wind component from data provided by instruments like
SMEI. Here, we present results from this technique applied to the Helios
spacecraft photometer observations. The tomography program iterates to a
least-squares solution of observed brightnesses using solar rotation,
spacecraft motion and solar wind outflow to provide perspective views of
each point in space covered by the observations. The corotational
tomography described here is essentially the same as used by Jackson et
al. (1998) for the analysis of interplanetary scintillation (IPS)
observations. While IPS observations are related indirectly to the solar
wind density through an assumed (and uncertain) relationship between
small-scale density fluctuations and density, Thomson scattering physics
is more straightforward, i.e., the observed brightness depends linearly
on the solar wind density everywhere in the heliosphere. Consequently,
Thomson scattering tomography can use a more direct density-convergence
criterion to match observed Helios photometer brightness to brightness
calculated from the model density. The general similarities between
results based on IPS and Thomson scattering tomography validate both
techniques and confirm that both observe the same type of solar wind
structures. We show results for Carrington rotation 1653 near solar
minimum. We find that longitudinally segmented dense structures corotate
with the Sun and emanate from near the solar equator. We discuss the
locations of these dense structures with respect to the heliospheric
current sheet and regions of activity on the solar surface.
@--------------------------------------------------------------------
Title: Visualization of Remotely-Sensed Heliospheric
Plasmas
Authors: Bailey, M.; Hick, P. P.; Wang, C.; Jackson, B. V.;
Buffington, A.
Bibliographic Code: 2002AGUFMSH21A0511B
Abstract
We demonstrate a software application designed for the display and
real-time manipulation of 3D heliospheric volume data, such as solar
wind density, velocity and magnetic field. The software exploits the
capabilities of the Volume Pro 1000 (from TeraRecon, Inc.), a low-cost
64-bit PCI board capable of rendering a 512-cubed array of volume data
in real time at up to 30 frames per second on a standard PC. The
application allows stereo and perspective views, and animations of
time-sequences. We show several examples of three-dimensional
heliospheric volume data derived from tomographic reconstructions based
on heliospheric remote sensing observations of the heliospheric density
and velocity structure (e.g. Thomson scattering and interplanetary
scintillation observations). This work was supported through NASA grant
NAG5-9423 and Air Force MURI grant F49620-01-0359.
@--------------------------------------------------------------------
Title: Halo CME's - Will They Hit or Miss Earth?
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.
Bibliographic Code: 2002AGUFMSH21A0474J
Abstract
To optimize the information from maps of the sky that cover large
elongations we have developed a Computer Assisted Tomography (CAT)
program that models these using a time-dependent three-dimensional
heliospheric model to fit Thomson scattering or STELab (Nagoya
University) interplanetary scintillation (IPS) observations. The
duration of a CME event (typically several days) imposes the restriction
that the reconstruction model primarily uses outward solar wind motion
to give perspective views of each point in space. The results to date
are commensurate with the observational coverage, temporal and spatial
resolution, and signal to noise available from the original data. We
provide remote observer views of IPS-based reconstructions of halo CMEs
also observed by the LASCO coronagraphs. We practice our modeling
techniques by making these views available in real time to forecast halo
CME Earth-arrival. Here we explore the locations and shapes of a few
select halo CMEs and their three-dimensional velocity structure in order
to determine whether they will hit or miss the Earth. This work is
supported by NASA grant NAG5-8504 and AFOSR grant F49620-01-1-0054.
@--------------------------------------------------------------------
Title: Remote-Sensing of the Solar Wind: A Space Weather
Application
Authors: Hick, P. P.; Rappoport, S. A.; Jackson, B. V.;
Dunn, T.; Wang, C.
Bibliographic Code: 2002AAS...20114102H
Abstract
Remote sensing observations of the solar wind in the inner heliosphere
fill an observational gap between near-Sun remote sensing and near-Earth
in-situ data. We use heliospheric tomography to follow solar
disturbances from Sun to Earth as the basis for a real-time space
weather system. Over the past few years interplanetary scintillation
observations from the Solar-Terrestrial Laboratory at Nagoya University,
Japan, were the main source of data. In the near future Thomson
scattering observations from the recently launched Solar Mass Ejection
Imager (SMEI) will be added.
Here we show some recent developments in the visualization techniques
used to process the volume data sets produced by the tomographic
analyis: solar wind density, velocity and magnetic field. 3D
visualization is based on an image rendering engine written in the IDL
programming language. In addition, we use hardware-based volume
rendering with the Volume Pro PCI board from TeraRecon. This board
renders 4D volume data (three spatial, plus the time dimension) in
real-time, allowing interactive manipulation of evolving
(time-dependent) data sets.
This work was supported through NASA grant NAG5-9423 and Air Force MURI
grant F49620-01-0359.
@--------------------------------------------------------------------
Title: Coronal Mass Ejections Identified in Interplanetary
Scintillation (IPS) Tomography and in LASCO
Coronagraph Images
Authors: Rappoport, S. A.; Hick, P. P.; Jackson, B. V.
Bibliographic Code: 2002AAS...201.8303R
Abstract
Coronal mass ejections (CMEs), including halo CMEs, can be observed in
interplanetary scintillation (IPS) data. To optimize the information
from radio source observations, we model them using a time-dependent
three-dimensional tomography program. We depict this heliospheric model
as a series of "sky map" images that cover elongations extending from 10
to 80 degrees. These IPS maps show CMEs observed earlier in the LASCO
coronagraph images with approximately the same shapes and extents that
were seen closer to the Sun. Here, a series of these CME events,
including halo CMEs, are mapped as they move outward to distances as
great as 1 AU.
@--------------------------------------------------------------------
Title: The Magnetic Structure of CMEs - a Brief
Introduction
Authors: Jackson, B. V.
Bibliographic Code: 2002AAS...200.6501J
Abstract
Coronal magnetic fields are considered a key driver of Coronal Mass
Ejections (CMEs). The interior regions of CMEs, including their
associated prominences, often appear to erupt as ropes of coronal flux.
In situ observations from space reveal that interplanetary CMEs (ICMEs)
can be associated with strong, rotating magnetic fields (clouds) that
can often be modeled as flux ropes. Both the internal fields of CMEs and
their interaction with quasi-steady heliospheric magnetic structures
influence their propagation and structural development. However, there
is only indirect evidence that coronal magnetic fields directly power
the CME eruption, or how or even if solar surface magnetic fields change
in response to a CME. I will briefly review current observations of the
relationship between magnetic fields and CMEs, and show the effects of
their propagation through the interplanetary medium.
@--------------------------------------------------------------------
Title: 3-D Tomography of Interplanetary Disturbances
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.
Bibliographic Code: 2002AAS...200.4910J
Abstract
We are developing tomographic techniques for analyzing remote sensing
observations of heliospheric density and velocity as observed in Thomson
scattering (e.g. by the Helios photometers) and interplanetary
scintillation (IPS) observations. We have refined the program to enable
us to analyze time-dependent phenomena, such as the evolution of
corotating heliospheric structures and rapidly evolving events such as
coronal mass ejections. We intend our analyses to be used with data from
the future Solar Mass Ejection Imager (SMEI) experiment. We currently
provide these analyses in real-time using IPS observations in order to
forecast the arrival of corotating structures and CMEs at Earth. This
work is supported by NASA grant NAG5-9423 and AFOSR grant F49620-01-0054
@--------------------------------------------------------------------
Title: Tomographic Analysis of Solar Wind Structure Using
Interplanetary Scintillation
Authors: Kojima, M.; Fujiki, K.; Tokumaru, M.; Ohmi, T.;
Shimizu, Y.; Yokobe, A.; Jackson, B. V.; Hick, P. L.
Bibliographic Code: 2002swsm.conf...55K
Abstract
@--------------------------------------------------------------------
Title: Introduction of the CSSS Magnetic Field Model into
the UCSD Tomographic Solar Wind Model
Authors: Dunn, T.; Hick, P. P.; Jackson, B. V.;
Buffington, A.
Bibliographic Code: 2001AGUFMSH31A0701D
Abstract
Our time-dependent tomographic technique developed over the last few
years provides a kinematic model of the solar wind. The model, which has
one-day time steps, allows us to determine the large-scale three
dimensional extent of solar disturbances and to forecast their arrival
at Earth in real-time. We introduce magnetic field calculations from the
Stanford Current-Sheet Source Surface model (Zhao and Hoeksema, 1995) at
the source surface of our kinematic model and extrapolate the magnetic
field out beyond Earth. We show an animated version of the convected
magnetic field, and compare results with in situ data near Earth. We
wish to thank Dr. XuePu Zhao for providing software and input data for
the Stanford Current-Sheet Source Surface model. This work is supported
by AFOSR contract F49620-01-1-0360. References: Zhao, X. and J.T.
Hoeksema, Prediction of the interplanetary magnetic field strength, J.
Geophys. Res. 100, 19, 1995.
@--------------------------------------------------------------------
Title: Study of ICME Structure Using LASCO White Light and
STE Lab IPS Observations of Halo CMEs
Authors: Webb, D. F.; Tokumaru, M.; Jackson, B. V.;
Hick, P. P.
Bibliographic Code: 2001AGUFMSH31A0700W
Abstract
As part of a long-term investigation of halo-like coronal mass ejections
(CMEs) well observed in white light by the SOHO LASCO coronagraphs, we
report on a study comparing our catalog of parameters and solar and
solar wind associations of halo CMEs with interplanetary disturbances
observed with the interplanetary scintillation (IPS) radio array of STE
Lab in Japan. We have cataloged over 100 full halo CMEs observed by
LASCO from 1996 through 2000. This period covers the first half of solar
cycle 23 from activity minimum to maximum. Although the STE Lab
observations are limited during each year, nearly all of these CMEs
occurring during STE Lab observations were associated with IPS
disturbances within a day or so following the halo CME onset time. We
will present a summary of these comparisons, and will discuss how the
combined data sets can be used to determine key parameters of the 3D
shape, structure and propagation of ICMEs. At STE Lab a program is used
to find best-fit parameters automatically by matching model calculations
to the observed IPS g-value (proportional to plasma density) data. At
UCSD a tomographic program is used to reconstruct 3D views of ICMEs
using the IPS data in a reconstruction technique based on solar rotation
and outward solar wind motion. This work is also pertinent for
observations that will be available from the Solar Mass Ejection Imager
(SMEI) experiment to be launched next year and, later, from the NASA
STEREO mission.
@--------------------------------------------------------------------
Title: Volume Rendering of Heliospheric Data
Authors: Hick, P. P.; Jackson, B. V.; Bailey, M. J.;
Buffington, A.
Bibliographic Code: 2001AGUFMSH31A0699H
Abstract
We demonstrate some of the techniques we currently use for the
visualization of heliospheric volume data. Our 3D volume data usually
are derived from tomographic reconstructions of the solar wind density
and velocity from remote sensing observations (e.g., Thomson scattering
and interplanetary scintillation observations). We show examples of
hardware-based volume rendering using the Volume Pro PCI board (from
TeraRecon, Inc.). This board updates the display at a rate of up to 30
frames per second using a parallel projection algorithm, allowing the
manipulation of volume data in real-time. In addition, the manipulation
of 4D volume data (the 4th dimension usually representing time) enables
the visualization in real-time of an evolving (time-dependent) data set.
We also show examples of perspective projections using IDL. This work
was supported through NASA grant NAG5-9423.
@--------------------------------------------------------------------
Title: Space Weather Using Remote Sensing Data
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.;
Dunn, T.; Rappoport, S.; Kojima, M.; Tokumaru, M.;
Fujiki, K.; Yokobe, A.; Ohmi, T.
Bibliographic Code: 2001AGUFMSH31A0698J
Abstract
We are developing tomographic techniques for analyzing remote sensing
observations of the coronal and heliospheric density and velocity
structure as observed in Thomson scattering and also using
interplanetary scintillation (IPS) observations. We have refined our
program to enable us to analyze time-dependent phenomena, such as the
evolution of co-rotating heliospheric structures and rapidly evolving
events such as coronal mass ejections, as observed e.g. with the future
Solar Mass Ejection Imager (SMEI) experiment. We currently provide
heliospheric three-dimensional reconstructions in real-time using IPS
observations from STELab, Nagoya University, Japan in order to forecast
the arrival at Earth of CMEs. We compare these reconstructions modeled
at Earth with ACE in-situ spacecraft data and show these analyses along
with a goodness-of-fit criterion designed to certify the reconstructions
and refine our technique. This work is supported by AFOSR contract
F49620-01-1-0054 and NASA contract NAG5-8504. index.html
@--------------------------------------------------------------------
Title: A Study of Interacting Plasma Phenomena Using the
Tomographic 3-Dimensional Reconstruction Techniques
Developed for the Solar Mass Ejection Imager (SMEI)
Authors: Jackson, B. V.; Hick, P. P.
Bibliographic Code: 2001AGUFMSH11D..04J
Abstract
We are developing tomographic techniques for analyzing remote sensing
observations of heliospheric density and velocity structure as observed
in Thomson scattering (e.g. using the Helios photometer data) for
eventual use with Solar Mass Ejection Imager (SMEI) observations. We
have refined the tomography program to enable us to analyze
time-dependent phenomena, such as the evolution of corotating
heliospheric structures and more discrete events such as coronal mass
ejections. Both types of phenomena are discerned in our data, and are
reconstructed in three dimensions. We use our tomography technique to
study the interaction of these phenomena as they move outward from the
Sun for several events that have been studied by multiple spacecraft
in-situ observations and other techniques. This work is supported by
NASA grant NAG5-8504 and AFOSR grant F49620-01-1-0054.
>http://casswww.ucsd.edu/solar/crew/bjackson /index.html
@--------------------------------------------------------------------
Title: Evidence for space weather at Mercury
Authors: Killen, R. M.; Potter, A. E.; Reiff, P.;
Sarantos, M.; Jackson, B. V.; Hick, P.; Giles, B.
Bibliographic Code: 2001JGR...10620509K
Abstract
Mercury's sodium atmosphere is known to be highly variable both
temporally and spatially. During a week-long period from November 13 to
20, 1997, the total sodium content of the Hermean atmosphere increased
by a factor of 3, and the distribution varied daily. We demonstrate a
mechanism whereby these rapid variations could be due to solar
wind-magnetosphere interactions. We assume that photon-stimulated
desorption and meteoritic vaporization are the active source processes
on the first (quietest) day of our observations. Increased ion
sputtering results whenever the magnetosphere opens in response to a
southward interplanetary magnetic field (IMF) or unusually large solar
wind dynamic pressure. The solar wind dynamic pressure at Mercury as
inferred by heliospheric radial tomography increased by a factor of 20
during this week, while the solar EUV flux measured by the scanning
electron microscope (SEM) instrument on board the Solar and Heliospheric
Observatory (SOHO) increased by 20%. While impact vaporization provides
roughly 25% of the source, it is uniformly distributed and varies very
little during the week. The variations seen in our data are not related
to Caloris basin, which remained in the field of view during the entire
week of observations. We conclude that increased ion sputtering
resulting from ions entering the cusp regions is the probable mechanism
leading to large rapid increases in the sodium content of the exosphere.
While both the magnitude and distribution of the observed sodium can be
reproduced by our model, in situ measurements of the solar wind density
and velocity, the magnitude and direction of the interplanetary magnetic
field, and Mercury's magnetic moments are required to confirm the
results.
@--------------------------------------------------------------------
Title: A heliospheric imager for Solar Orbiter
Authors: Jackson, B. V.; Buffington, A.; Hick, P. P.
Bibliographic Code: 2001ESASP.493..251J
Abstract
@--------------------------------------------------------------------
Title: Three-Dimensional Solar Wind Modeling Using
Remote-Sensing Data
Authors: Hick, P. P.; Jackson, B. V.
Bibliographic Code: 2001SSRv...97...35H
Abstract
We have developed a computer-assisted tomography (CAT) technique that
iteratively modifies a kinematic solar wind model to least-squares fit
heliospheric remote sensing observations (interplanetary scintillation
and Thomson-scattering observations). These remote sensing data cover a
large range of solar elongations, and access high-latitude regions over
the solar poles. The technique can be applied to a time-independent
solar wind model, assuming strict co-rotation, or, when sufficient
remote sensing observations are available, to a time-dependent model.
For the time-dependent case the technique depends primarily on outward
motion of structures in the solar wind to provide the perspective views
required for a tomographic reconstruction. We show results of corotating
tomographic reconstructions primarily using IPS velocity observations
from the Solar-Terrestrial Environment Laboratory (STELab, Nagoya,
Japan), and include comparisons with in situ velocity data out of the
ecliptic (Ulysses) and in the ecliptic (ACE).
@--------------------------------------------------------------------
Title: Space Weather Using Remote Sensing Data
Authors: Jackson, B. V.; Hick, P.; Buffington, A.
Bibliographic Code: 2001AGUSM..SH22C05J
Abstract
We are developing tomographic techniques for analyzing remote sensing
observations of the coronal and heliospheric density and velocity
structure as observed in Thomson scattering (e.g. by the SOHO/LASCO
coronagraph and Helios photometers) and interplanetary scintillation
(IPS) observations. We have refined the program to enable us to analyze
time-dependent phenomena, such as the evolution of corotating
heliospheric structures and rapidly evolving events such as coronal mass
ejections, as observed e.g. with the future Solar Mass Ejection Imager
(SMEI) experiment. We currently provide the three-dimensional analyses
in real-time using IPS observations in order to forecast the arrival of
CMEs, and we intend to show these analyses at our display. This work is
supported by AFRL grant F49620-01-1-0054 and NSF grant ATM-9819947.
@--------------------------------------------------------------------
Title: Visualization of Remotely-Sensed Heliospheric
Plasmas
Authors: Hick, P.; Jackson, B. V.; Buffington, A.;
Bailey, M. J.
Bibliographic Code: 2001AGUSM..SH22C04H
Abstract
We are currently developing a tomographic approach for analyzing remote
sensing observations of the coronal and heliospheric density and
velocity structure (e.g. Thomson scattering and interplanetary
scintillation observations). Parallel to the tomographic techniques we
are developing the visualization tools required for displaying and
manipulating the three-dimensional tomographic results. We use a common
graphics interface language (OpenGL, supported through IDL), standard
visual interfaces (pop-up menus, sliders, point-and-click methods) and
standard hardware (PCs). The visualization should be capable of
simultaneously displaying the tomographic density and velocity model and
should allow the user to dynamically view the heliospheric model using
any predefined flight path through the three-dimensional cube covered by
the model. For real-time volume rendering we use a Mitsubishi Volume Pro
PCI board. We present our current progress in this visualization effort.
Further details can be found on
http://casswww.ucsd.edu/solar/index.html. This work was supported
through NASA grant NAG5-9423.
@--------------------------------------------------------------------
Title: Certifying Stray-Light Rejection and Photometric
Performance for "SMEI"
Authors: Buffington, A.; Jackson, B. V.; Hick, P.
Bibliographic Code: 2001AGUSM..SH22C03B
Abstract
The Solar Mass Ejection Imager (SMEI) is a collaborative project between
the Air Force, UCSD/CASS, and the University of Birmingham, England. It
will fly on the CORIOLIS spacecraft, scheduled for launch in September
2002. The platform provides a zenith-pointing, terminator orbit. SMEI's
three CCD cameras, each viewing a 3 x 60 degree swath of sky, will
provide a visible-light map of nearly the entire sky each 100-minute
orbit. The instrument is designed to deliver 0.1% differential
photometry, and 10-15 orders of magnitude scattered-light reduction when
viewing further than 20 degrees from the Sun. We present the results of
laboratory measurements which certify that these specifications are met
by the SMEI flight hardware. We will also present night-sky data taken
with the SMEI prototype optics, and progress on normalizing, flat-field
correcting, and registering the SMEI data into a standard sky coordinate
frame. This work is supported by AFRL contract F19628-00-C-0029.
@--------------------------------------------------------------------
Title: Certifying Stray-Light Rejection and Photometric
Performance for SMEI
Authors: Buffington, A.; Jackson, B. V.; Hick, P. P.;
Kuchar, T. A.
Bibliographic Code: 2000AAS...197.5103B
Abstract
The Solar Mass Ejection Imager (SMEI) is a collaborative project between
the Air Force, UCSD/CASS, and the University of Birmingham, England. It
will fly on the CORIOLIS spacecraft, scheduled for launch at the end of
2001. The platform provides a zenith-pointing, terminator orbit. SMEI's
three CCD cameras, each viewing a 3 x 60 degree swath of sky, will
provide a visible-light map of nearly the entire sky each 100-minute
orbit. The instrument is designed to deliver 0.1% differential
photometry, and 10-15 scattered-light reduction when viewing
further than 20 degrees from the Sun. We present the results of
laboratory measurements which certify that these specifications are met
by the SMEI flight hardware. We will also present night-sky data taken
with the SMEI prototype optics. This work is supported by AFRL contract
F19628-00-C-0029.
@--------------------------------------------------------------------
Title: Visualization of Remotely-Sensed Heliospheric
Plasmas
Authors: Hick, P. P.; Jackson, B. V.; Buffington, A.
Bibliographic Code: 2000AAS...197.5102H
Abstract
We are currently developing a tomographic approach for analyzing remote
sensing observations of the coronal and heliospheric density and
velocity structure (e.g. Thomson scattering and interplanetary
scintillation observations). Parallel to the development of the
tomographic techniques we are developing the visualization tools
required for displaying and manipulating the three-dimensional
tomographic results. We use a common graphics interface language
(OpenGL, supported through IDL), standard visual interfaces (pop-up
menus, sliders, point-and-click methods) and standard hardware (PCs).
The visualization will target a software system capable of
simultaneously displaying the tomographic density and velocity model
(and, when available, magnetic field) and will allow the user to
dynamically view the heliospheric model using any predefined flight path
through the three-dimensional cube covered by the model, possibly using
stereographics to get a better feel for the three-dimensionality of the
model. Results of this ongoing visualization project will be
demonstrated on a dedicated web site accessible through
http://casswww.ucsd.edu/solar/index.html. This work was supported
through NASA grant NAG5-9423.
@--------------------------------------------------------------------
Title: Astronomy with SMEI
Authors: Kuchar, T. A.; Price, S. D.; Buffington, A.;
Hick, P. P.; Jackson, B. V.
Bibliographic Code: 2000AAS...197.5101K
Abstract
The Solar Mass Ejection Imager (SMEI) is comprised of three detectors
capable of imaging coronal mass ejections (CMEs) from the Sun. It will
orbit in an 830 km sun-synchronous orbit and provide a hemispherical
view about the sun approximately every 100 minutes. The bandpass of the
detectors is in the visual and near IR and ranges from 400 to 1100 nm.
The processed images will have a resolution of 1 degree in science data
mode. The detection of CMEs will follow after the stellar background and
other known astronomical phenomena (e.g. planets, asteroids, and
zodiacal emission) have been registered and removed from the SMEI data.
Since CMEs evolve on timescales of hours to days, data from a series of
consecutive orbits can be compared to show their presence. The SMEI
mission is scheduled to last for 5 years and thus has the potential to
reveal variations on annual timescales. The data are uniquely suited to
provide analysis for zodiacal background models over this wavelength
range. In this poster we present the methodology for removing the
stellar contribution from the SMEI data and how this can be used to
track annual changes seen in the zodiacal cloud. We show a test of
concept in this presentation using data taken with a prototype SMEI
camera at the Table Mountain Observatory. SMEI is a collaborative
project between the US Air Force, UCSD/CASS, and the University of
Birmingham, England.
@--------------------------------------------------------------------
Title: Space Weather Using Remote Sensing Data
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.
Bibliographic Code: 2000AAS...197.3108J
Abstract
We are developing tomographic techniques for analyzing remote sensing
observations of the coronal and heliospheric density and velocity
structure as observed in Thomson scattering (e.g. by the SOHO/LASCO
coronagraph and Helios photometers) and interplanetary scintillation
(IPS) observations. We have refined the program to enable us to analyze
time-dependent phenomena, such as the evolution of co-rotating
heliospheric structures and rapidly evolving events such as coronal mass
ejections, as observed e.g. by the Helios photometers, and with the
future Solar Mass Ejection Imager (SMEI) experiment. We currently
provide these analyses in real-time using IPS observations in order to
forecast the arrival of CMEs and other heliospheric structures at Earth.
This work is supported by NASA grant NAG5-9423 and NSF grant
ATM-9819947.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager Optics and Baffles:
Design and Construction
Authors: Jackson, Bernard V.; Buffington, Andrew; Hick, P. P.
Bibliographic Code: 2000STIN...0226912J
Abstract
The purpose of SMEI is a proof-of-concept of the ability to predict
geomagnetic disturbances for Air Force space operations and to establish
the feasibility of tracking interplanetary disturbances from the Sun to
the Earth and beyond. The major subsystems of SMEI are an electronic
Camera Assembly, a Data Handling Unit and interconnection harnesses.
Each electronic Camera component consists of a baffle, radiator, bright
object sensor, strongbox (CCD, mirrors and shutter) and electronics box.
The electronic Camera Assembly is used to observe in visible light mass
ejections from the Sun by sensing sunlight scattered from clouds of
solar-produced interplanetary electrons. Predictions of arrival time at
Earth of this disturbance can be made up to three days in advance.
@--------------------------------------------------------------------
Title: Time-Dependent Tomography Of Heliospheric Features
Using Global Thomson-Scattering Data From the Helios
Spacecraft Photometers
Authors: Jackson, B. V.; Hick, P. P.
Bibliographic Code: 2000SPD....3102103J
Abstract
In the near future white-light, all-sky imagery of the heliosphere will
become available from instruments such as the Air Force/NASA Solar Mass
Ejection Imager (SMEI), and all-sky cameras as currently included in the
instrument complement of the NASA Solar Probe and Solar Polar Sail
missions and the ESA Solar Orbiter mission. To optimize the information
available from these instruments, their 2-dimensional sky images need to
be interpreted in three dimensions. We have developed a Computer
Assisted Tomography (CAT) program that modifies a time-segmented
three-dimensional kinematic heliospheric model to fit Thomson scattering
observations and is designed specifically with observations from the
above instrumentation in mind. Here we apply this technique to the
Helios spacecraft photometer observations. The tomography program
iteratively changes these models to least-squares fit observed global
brightness data. The short time intervals of the kinematic modeling
impose the restriction that the reconstructions primarily use outward
solar wind motion to give perspective views of each point in space
accessible to the observations. We plot these models as density
Carrington maps and remote observer views for the Helios data sets. The
results to date are commensurate with the observational coverage,
temporal and spatial resolution, and signal to noise available from the
original data. At solar maximum, the Helios photometer data show
significant CME activity in the form of dense transient structures at
all heliographic latitudes. We explore the location of these dense
structures with respect to the heliospheric current sheet and regions of
activity on the solar surface.
@--------------------------------------------------------------------
Title: Prediction of Solar Wind Conditions in the Inner
Heliosphere Using IPS Tomography
Authors: Hick, P. P.; Jackson, B. V.; Buffington, A.
Bibliographic Code: 2000SPD....31.0241H
Abstract
The ability to determine the 3D structure of the co-rotating component
of the inner heliosphere, and of the 3D extent and evolution of solar
disturbances superposed on this co-rotating background, are of primary
importance for effective 'space weather' forecasting. We developed a
tomographic technique that uses remote sensing data to reconstruct a
heliospheric solar wind density and velocity model. This enables us to
reconstruct the background solar wind as well as solar disturbances as
they move away from the Sun, and forecast their subsequent arrival at
Earth. Currently we are testing a real-time forecasting system based on
tomographic reconstructions of the solar wind from interplanetary
scintillation (IPS) data, available on a daily basis from the Solar
Terrestrial Environment Laboratory (STE-Lab) near Nagoya, Japan. The IPS
tomography is used to determine velocities at 1 AU where they are
compared with in situ observations from Earth-orbiting spacecraft. The
tomographic solar wind model is also used to passively 'convect'
Stanford magnetic field data from the source outward to 1 AU for
comparison with in situ magnetic field data. We show current results
from this IPS forecasting system. The real-time forecasting data are
available on a dedicated Web site at
http://casswww.ucsd.edu/personal/bjackson/weather.htm. This work was
supported by NSF grant INT-9815377 and AFOSR grant AF49620-97-1-0070.
@--------------------------------------------------------------------
Title: Three Dimensional Tomography of Heliospheric
Features Using Global Thomson Scattering Data
Authors: Jackson, B. V.; Hick, P.
Bibliographic Code: 2000AdSpR..25.1875J
Abstract
Images of the heliosphere will become available from the Air Force/NASA
Solar Mass Ejection Imager (SMEI), and from the all-sky cameras proposed
for the NASA missions STEREO, Solar Probe and Solar Polar Sail. To
optimize the information available from these instruments, their
2-dimensional images need to be interpreted in three dimensions. We have
developed a Computer Assisted Tomography (CAT) program that modifies a
three-dimensional heliospheric model to fit Thomson scattering solar
minimum observations from the Helios spacecraft photometers. The
tomography program iterates to a least-squares solution fit of observed
brightness data using spacecraft and solar wind motion to provide
perspective views of each point in space accessible to the observations.
We plot the optimized models as Carrington maps in density for the
Helios data sets. The results to date are commensurate with resolutions
available from the original data. At solar minimum, longitudinally
segmented dense structures emanate from near the solar equator. We
explore the location of these dense structures with respect to the
heliospheric current sheet and regions of activity on the solar surface
@--------------------------------------------------------------------
Title: Mercury Sodium Atmosphere, Magnetosphere and Solar
Wind
Authors: Killen, R. M.; Giles, B.; Potter, A. E.;
Jackson, B. V.; Linker, J.; Mikic, Z.
Bibliographic Code: 1999DPS....31.1801K
Abstract
Earth-based observations of Mercury's sodium atmosphere have revealed
large-scale spatial variations and rapid temporal variations (e.g.
Potter and Morgan, Adv. Space Res. 19, 1571, 1997; Potter, A.E. et al.,
Planet. Space. Sci., In press, 1999). We show how the observed
brightness variations may be related to the topology of Mercury's
magnetosphere in response to solar wind variations at Mercury's orbit.
Using the Toffoletto-Hill magnetosphere model modified for Mercury (JGR
98, 1339, 1993), we have calculated the structure of the Hermean
magnetosphere for November, 1997, corresponding to dates of our sodium
images obtained at the National Solar Observatory at Kitt Peak, Arizona.
The sodium images are reduced to column abundance using a Chamberlain
type atmosphere with optically thick radiative transfer. Inputs to the
magnetosphere model are solar wind density and velocity, and
interplanetary magnetic field (IMF). Solar wind density and velocity at
the orbit of Mercury are inferred from heliospheric tomography using
radio scintillation measurements (Jackson et al., Adv. Space Res. 20,
23, 1997; Kojima et al., JGR 103, 1981, 1998). The IMF at Mercury's
position is obtained from a model of the inner heliosphere constrained
with the solar magnetic field, in combination with density and
temperature profiles at the sun's surface (Linker et al., JGR 104, 9809,
1999). We use the morphology of the magnetosphere along with solar wind
parameters to infer the rates of ion sputtering of sodium. The total
sodium column is the sum of ion-sputtered sodium and the more slowly
varying sources, photon-stimulated desorption and meteoritic
vaporization. We show that the variations in ion sputtering and
subsequent loss via ioniation may be responsible for rapid changes in
the observed brightness distribution in sodium emissions. Our goal is to
show how solar activity and Mercury's sodium exosphere are related.
@--------------------------------------------------------------------
Title: Mercury sodium atmosphere, magnetosphere and solar
wind.
Authors: Killen, R. M.; Giles, B.; Potter, A. E.;
Jackson, B. V.; Linker, J.; Mikic, Z.
Bibliographic Code: 1999BAAS...31.1102K
Abstract
@--------------------------------------------------------------------
Title: Comparison of solar wind speed with coronagraph data
analyzed by tomography
Authors: Yokobe, Atsushi; Ohmi, Tomoaki; Hakamada, Kazuyuki;
Kojima, Masayoshi; Tokumaru, Munetoshi;
Jackson, Bernard V.; Hick, Paul P.;
Zidowitz, Stephan
Bibliographic Code: 1999AIPC..471..565Y
Abstract
We have analyzed the relation between solar wind speeds observed by
interplanetary scintillation (IPS) and coronal densities derived from
coronagraph observations during the ``Whole Sun Month'' period in 1996.
Since both IPS and coronagraph observations are biased by the effect of
line-of-sight integration, tomography techniques are applied to both
data sets. For this analysis we made a synoptic map of the solar wind
speed at the source surface (2.5 Rsolar) from the IPS
tomography. Each speed region on the source surface was traced to the
height of the coronagraph observations along the magnetic field lines
calculated from the source surface potential field model. This analysis
has obtained clear anti-correlation between the solar wind speed in
interplanetary space and electron density at lower coronal regions. We
have also obtained the radial profiles of coronal densities for both
slow and fast wind flows in the range of 1.3-2.0 Rsolar. We
expect that these provide experimental constraints on solar wind
acceleration models.
@--------------------------------------------------------------------
Title: Quiet solar wind signatures above active regions
observed in X-rays
Authors: Hick, P.; Svestka, Z.; Jackson, B. V.; Farnik, F.;
Hudson, H.
Bibliographic Code: 1999AIPC..471..231H
Abstract
X-ray images from the Yohkoh satellite, obtained following occurrences
of limb flares sometimes show coronal fan-like structures extending
above a growing post-flare loop system. We show one such event observed
in AR 7270 on the east limb of the Sun on 28/29 August 1992. We suggest
that these rays are `ministreamers,' formed as a result of the
re-structuring of the corona following the occurrence of a
flare-associated CME. Synoptic maps of the solar wind density,
constructed from a tomographic analysis of interplanetary scintillation
(IPS) measurements, show enhanced scintillation matching the position of
AR 7270 if we assume a radial outflow at a reasonable slow solar wind
speed of 400 km s-1. From this agreement we argue that outflow of mass
occurs from the active region into interplanetary space.
@--------------------------------------------------------------------
Title: Visible-light All-sky Imagers in Deep Space
Authors: Buffington, A.; Hick, P. P.; Jackson, B. V.
Bibliographic Code: 1999AAS...194.7615B
Abstract
Emerging new techniques for very wide-angle optics and efficient
light-baffling systems permit visible-light imagers capable of viewing
half the sky or more starting within only a few degrees of the Sun.
These instruments provide the 0.1% photometry required for studying
low-contrast heliospheric features such as solar mass ejections and
co-rotating structures. The imagers view sunlight Thomson-scattered from
interplanetary electrons. A typical imager design provides "all-sky"
photometric maps with 1 degree sky bins and a 1-hour cadence. Instrument
weights of only several kilograms and modest power requirements make
these imagers particularly suitable for deployment to deep space.
Tomographic reconstructions of the interplanetary mass density
distribution are enabled by combining data from one or more deep-space
probes, with comparable instruments near Earth. These deep-space images
are also suitable for discovery and study of comets and asteroids, and
for detailed measurements of brightness variations in the zodiacal dust
cloud.
@--------------------------------------------------------------------
Title: Recent UCSD Advances in Tomography for Use with
Heliospheric Remote-Sensing Data
Authors: Jackson, B. V.; Hick, P. P.; Buffington, A.
Bibliographic Code: 1999AAS...194.7614J
Abstract
Solar disturbances produce major effects in the corona, its extension
into the interplanetary medium, and ultimately, the Earth's environment.
The ability to determine the three dimensional extent of these
disturbances and to forecast their arrival at Earth is of primary
scientific and practical interest. We have developed a tomographic
technique for use in mapping these disturbances as they move away from
the Sun. Our technique uses a solar wind density and velocity model and
available remote sensing data and iterates to a least squares fit
solution of these data. This technique provides more contrast between
high and low speed winds and more or less dense solar wind structures
than has been possible with previous techniques. Existing observations
include those from the HELIOS photometers (Thomson scattering data) and
velocity and scintillation-level measurements (from interplanetary
scintillation or IPS data). The latter observations are currently
available on a daily basis from the Solar Terrestrial Environment
Laboratory situated near Nagoya, Japan. We are developing a way to
provide a tomographic reconstruction from IPS data in real time for use
in heliospheric space weather forecasting, and we show our most recent
results on this. We are also in the process of developing this technique
to provide the three dimensional extent of heliospheric features which
vary in shape over short periods of time (i.e., CMEs). The result using
this extension of the technique is commensurate with the quantity,
quality and perspective views present from the remote sensing data, and
with present data is used to explore the extent to which solar
corotating structures are time-variable. As other remote sensing data
become available with high angular and temporal resolution from
spacecraft instruments such as the Solar Mass Ejection Imager (SMEI),
now being developed and constructed for the Air Force, or as proposed
for the NASA STEREO or Solar Probe Missions, the technique should
provide far better heliospheric three dimensional and temporal
resolution (by several orders of magnitude) than now available.
@--------------------------------------------------------------------
Title: Three-dimensional tomography of heliospheric
features using Thomson scattering data
Authors: Hick, P. P.; Jackson, Bernard V.
Bibliographic Code: 1998SPIE.3442...87H
Abstract
All-sky cameras for viewing the heliosphere in white light are included
in the design of several future spacecraft missions. The first of these
to ge put in Earth-orbit will be the solar mass ejection imager, a joint
project of the US Air FOrce, NASA, and the University of Birmingham, UK.
Other missions, including an all-sky imager in their current design, are
STEREO, Solar Probe and Solar Probe Sail. The white-light signal
includes Thomson-scattered light from heliospheric electrons, which can
be used to study the structure and evolution of large-scale heliospheric
features. These studies are the principal reason for putting all-sky
cameras in Earth-orbit or deep space. We discuss a tomographic
technique, which uses the 2D information in the all-sky images provided
by these cameras to reconstruct the heliospheric density structure in
3D. We present preliminary results of this tomographic technique applied
to Thomson scattering data from the photometers onboard the two HELIOS
spacecraft.
@--------------------------------------------------------------------
Title: Corrals, hubcaps, and crystal balls: some new
designs for very-wide-angle visible-light
heliospheric imagers
Authors: Buffington, Andrew; Hick, P. P.; Jackson, Bernard V.;
Korendyke, Clarence M.
Bibliographic Code: 1998SPIE.3442...77B
Abstract
Emerging techniques allow instruments to view very large sky areas, a
hemisphere or more, in visible light. In space, such wide-angle coverage
enables observation of heliospheric features form close to the Sun to
well beyond Earth. Observations from deep-space missions such as Solar
Probe, Stereo, and Solar Polar Sail, coupled with observations near
Earth, permit 3D reconstruction of solar mass ejections and co-rotating
structures, discovery and study of new comets and asteroids, and
detailed measurements of brightness variations in the zodiacal cloud.
Typical heliospheric features have 1 percent or less of ambient
brightness, so visible-light cameras must deliver < 0.1 percent
photometry and be well protected from stray background light. When more
than a hemisphere of viewing area is free of bright background-light
sources, we have shown that corral-like structures with several
vane-like walls reduces background light illuminating to wide-angle
optical system by up to ten orders of magnitude. The optical system
itself typically provides another five orders of surface-brightness
reduction. With CCDs as the light-detection device, images of point-like
sources must cover typically 100 pixels to average down sub-pixel
response gradients and provide the above 0.1 percent photometry. With
present-day CCDs this requires images of order 1 degree in angular size.
Tolerating such large images in turn enables wide-angle sky coverage
using simple reflecting and refracting optical systems such as convex
spherical reflectors, toroids and thick lenses. We show that combining
these with light- reducing corrals yields practical, light-weight
instruments suitable for inclusion on deep-space probes.
@--------------------------------------------------------------------
Title: Solar Polar Sail mission: report of a study to put a
scientific spacecraft in a circular polar orbit
about the sun
Authors: Goldstein, Bruce E.; Buffington, Andrew;
Cummings, Alan C.; Fisher, Richard;
Jackson, Bernard V.; Liewer, Paulett C.;
Mewaldt, Richard A.; Neugebauer, Marcia
Bibliographic Code: 1998SPIE.3442...65G
Abstract
The Solar Polar Sail Mission uses solar-sail propulsion to place a
spacecraft in a circular orbit 0.48 Au from the Sun with an inclination
of 90 degrees. The spacecraft's orbit around the Sun is in 3:1 resonance
with Earth phased such that the Earth-Sun-spacecraft angle range from 30
degrees to 150 degrees. The polar view will further our understanding
of: (1) the global structure and evolution of the corona, (2) the
initiation, evolution, and propagation of coronal mass ejections; (3)
the acceleration of the solar wind; (4) the interactions of rotation,
magnetic fields, and convection within the Sun; (5) the acceleration and
propagation of energetic particles; and (6) the rate of angular momentum
loss by the Sun. Candidate imaging instruments are a coronagraph, an
all-sky imager for following mass ejections and interaction regions from
the Sun to 1 AU, and a disk imager. A lightweight package of fields and
particle instruments is included. A mission using a 158 m square sail
with an effective areal density of 6 g/m(superscript 2) would cost
approximately $LR 250-300M for all mission phases, including the launch
vehicle. This mission depends on the successful development and
demonstration of solar-sail propulsion.
@--------------------------------------------------------------------
Title: Global Solar Wind Changes Over Solar Cycle 21: A
Combination of HELIOS Photometer, In Situ, and
Interplanetary Scintillation Data
Authors: Leinert, Ch.; Jackson, B. V.
Bibliographic Code: 1998ApJ...505..984L
Abstract
We combine Helios spacecraft photometer brightnesses, in situ plasma
densities, and interplanetary scintillation (IPS) velocity data to
obtain a global description of solar wind changes. We find an increase
of solar mass flux at solar maximum from the photometer brightnesses
larger than would be expected from the usual assumption of invariant
momentum flux over solar cycle 21 (1975-1986). A portion of this excess
mass is related to solar mass ejections, which have an occurrence rate
that follows the solar activity cycle.
@--------------------------------------------------------------------
Title: Heliospheric tomography using interplanetary
scintillation observations 1. Combined Nagoya and
Cambridge data
Authors: Jackson, B. V.; Hick, P. L.; Kojima, M.; Yokobe, A.
Bibliographic Code: 1998JGR...10312049J
Abstract
We have produced a computer assisted tomography program that optimizes a
three-dimensional model to fit observational data. We have used this
program with interplanetary scintillation data from Nagoya, Japan, and
Cambridge, England. The program iterates to a least squares solution fit
of observed data using solar rotation and solar wind motion to provide
perspective views of each point in space accessible to the observations.
We plot the optimized model as Carrington maps in velocity V and density
Ne for the two data sets with resolutions of 10° in
heliographic longitude and latitude. We map the model to 1 AU and
compare this to in situ observations from the IMP spacecraft. From this
comparison we find DeltaNe~Ne0.3. We
plot Carrington maps extrapolated to the solar surface to compare with
Yohkoh Soft X ray Telescope (SXT), Sacramento Peak green line, and Mark
III K-coronameter observations. High velocities modeled at the solar
surface for individual rotations trace coronal holes (including polar
ones) observed in SXT data. Regions of high density modeled from the
Cambridge scintillation level data generally show a high correlation
with regions of high solar activity observed as bright in Yohkoh SXT and
green line observations. There is also a general correspondence of the
regions of high density and the areas which are bright in K-coronameter
observations.
@--------------------------------------------------------------------
Title: Heliospheric modeling used to map global solar wind
flows
Authors: Jackson, B. V.; Hick, P.; Leinert, Ch.; Yokobe, A.
Bibliographic Code: 1998AAS...192.1904J
Abstract
In a recent paper Leinert and Jackson (1998) analyzed brightness
observations from the Helios spacecraft photometers, in situ data and
interplanetary scintillation (IPS) velocities, and used these to model
global heliospheric plasma changes over solar cycle no. 21. Our analysis
shows changes in the solar wind flow in terms of mass and velocity over
one Carrington rotation. We model the available IPS velocity
observations using a tomographic least squares fit to determine solar
wind speeds. This technique, crucial to our analysis, provides more
contrast between high speed winds over the solar poles and low speed
winds near the equator than possible with previous techniques. Here, we
confirm the validity of this technique with recent Ulysses spacecraft
measurements and a comparison between Ulysses-measured solar wind speeds
and IPS velocities available from the STELab in Japan. The primary
result of the measurements over solar cycle 21 show the extent to which
the approximation of constant solar wind momentum flux is valid in more
detail than was previously possible. Under this assumption we find that
additional mass at about the 15% level is added to the solar wind at
solar activity maximum, and that this mass is most likely present in the
form of discrete events (Coronal Mass Ejections). This implies that
there are probably two different processes acting to remove solar wind
from the sun - one provided by a constant coronal energization, and one
that is associated with the strongest solar magnetic fields. Leinert,
Ch. and B.V. Jackson, Global Solar Wind Changes Over Solar Cycle 21: a
Combination of Helios Photometer, In-situ and IPS Data, Astrophys. J.,
(accepted), 1998.
@--------------------------------------------------------------------
Title: Fan-Like coronal X-ray Structures as Sources of
Solar Wind
Authors: Hick, P.; Svestka, Z.; Farnik, F.; Hudson, H. S.;
Jackson, B. V.
Bibliographic Code: 1998AAS...192.1503H
Abstract
We show coronal soft X-ray images from the Yohkoh satellite, obtained
following occurrences of limb flares. These images show rising
post-flare loops, which are embedded in hot coronal structures looking
like fans of coronal rays. We analyze the event on 28/29 August 1992,
which occurred in AR 7270 on the east limb of the Sun. We suggest that
these rays are multiple 'ministreamers', which apparently are formed as
a result of the restructuring of the corona following the occurrence of
a flare-associated CME. We argue that this configuration allows outflow
of mass from the active region into interplanetary space. This is
supported by synoptic maps of solar wind sources constructed from
scintillation measurements showing a source of enhanced scintillation at
the position of AR 7270.
@--------------------------------------------------------------------
Title: An All-Sky Coronal Camera on Solar Probe: A Global
View of our Nearest Star's Atmosphere
Authors: Buffington, A.; Jackson, B. V.; Hick, P.
Bibliographic Code: 1998AAS...192.1502B
Abstract
NASA's proposed Solar Probe mission will provide an opportunity to
directly view material in the atmosphere of our nearest star: the Sun.
The Probe is designed to transit both solar poles and approach about as
close as currently feasible: within about 4 solar radii. Onboard
instruments will directly sample the particle composition near the
spacecraft and view the solar poles from its nearby perspective. UCSD's
newly developed lightweight light-baffling and very wide-angle optical
systems permit viewing Thompson-scattered sunlight over nearly the whole
sky around the spacecraft to within a few degrees of the solar disk. The
fly-by's varying perspective will enable a 3-dimensional coronal
reconstruction having unprecedented detail. These observations from
within the acceleration region should greatly refine our understanding
of coronal material propagation.
@--------------------------------------------------------------------
Title: Heliospheric tomography using interplanetary
scintillation observations. III - Correlation
between speed and electron density fluctuations in
the solar wind
Authors: Asai, K.; Kojima, M.; Tokumaru, M.; Yokobe, A.;
Jackson, B. V.; Hick, P. L.; Manoharan, P. K.
Bibliographic Code: 1998JGR...103.1991A
Abstract
We examine the relationship between solar wind speed and electron
density fluctuations on scale sizes around 100 km in the heliocentric
distance range of 0.3 to 0.8 AU using interplanetary scintillation data
obtained at the Solar-Terrestrial Environment Laboratory. The solar wind
properties derived from the IPS data are biased by line of sight
integration through a 3D structured solar wind. Therefore, we apply a
computer-assisted tomography (CAT) method to deconvolve the
line-of-sight integration and reconstruct the solar wind structure. The
analysis was made for the solar wind speed V and electron density
fluctuations delta-Ne in the solar activity minimum phase when
high-speed regions are separated from an equatorial low-speed region by
a sharp velocity gradient. From results of the CAT analysis we derived
the best fit power law relation of delta-Ne varies as V exp -gamma with
gamma = 0.5 +/- 0.15, indicating that fractional density fluctuations
delta-Ne/Ne in the high-speed wind are larger than those in the
low-speed wind. We suggest that the fractional density fluctuation level
of the high-speed wind evolves with heliocentric distance.
@--------------------------------------------------------------------
Title: Heliospheric tomography using interplanetary
scintillation observations 2. Latitude and
heliocentric distance dependence of solar wind
structure at 0.1-1 AU
Authors: Kojima, M.; Tokumaru, M.; Watanabe, H.; Yokobe, A.;
Asai, K.; Jackson, B. V.; Hick, P. L.
Bibliographic Code: 1998JGR...103.1981K
Abstract
Interplanetary scintillation is a useful means to measure the solar wind
in regions inaccessible to in situ observation. However, interplanetary
scintillation measurements involve a line-of-sight integration, which
relates contributions from all locations along the line of sight to the
actual observation. We have developed a computer assisted tomography
(CAT) program to reduce the adverse effects of the line-of-sight
integration. The program uses solar rotation and solar wind motion to
provide three-dimensional perspective views of each point in space
accessible to the interplanetary scintillation observations and
optimizes a three-dimensional solar wind speed distribution to fit the
observations. We analyzed IPS speeds observed at the Solar-Terrestrial
Environment Laboratory and confirmed that (1) the solar wind during the
solar minimum phase has a dominant polar high-speed solar wind region
with speeds of about 800kms-1 and within 30° of the solar
equator speeds decrease to 400kms-1 as observed by Ulysses,
and (2) high-speed winds get their final speed of
750-900kms-1 within 0.1 AU, and consequently, that
acceleration of the solar wind is small above 0.1 AU.
@--------------------------------------------------------------------
Title: Heliospheric tomography using interplanetary
scintillation observations 2. Latitude and
heliocentric distance dependence of solar wind
structure at 0.1-1 AU
Authors: Kojima, M.; Tokumaru, M.; Watanabe, H.; Yokobe, A.;
Asai, K.; Jackson, B. V.; Hick, P. L.
Bibliographic Code: 1998JGR...103.1980K
Abstract
@--------------------------------------------------------------------
Title: Solar Wind Structure at 0.1-1 AU Reconstructed from
IPS Observations Using Tomography
Authors: Kojima, M.; Asai, K.; Jackson, B. V.; Hick, P. L.;
Tokumaru, M.; Watanabe, H.; Yokobe, A.
Bibliographic Code: 1998asct.conf..207K
Abstract
@--------------------------------------------------------------------
Title: The Physics of Remotely-Sensed Heliospheric Plasmas
Authors: Jackson, Bernard V.
Bibliographic Code: 1997ucsd.reptR....J
Abstract
Solar disturbances produce major effects on the corona, the solar wind,
the interplanetary medium, and the Earth along with its magnetosphere.
New techniques have been developed under this grant for studying plasma
disturbances in the inner heliosphere by remotely sensing them. These
techniques have used data from the HELIOS spacecraft zodiacal light
photometers, in situ data and a variety of other spacecraft and
ground-based instruments. The zodiacal-light photometers on board the
two HELIOS spacecraft (data coverage from 1974 to 1986) provided the
first reliable information about the heliospheric masses and shapes of
propagating disturbances. The investigations into the physics of the
disturbances sensed by these techniques, and the ability to forecast
them, have been underway during the contract.
@--------------------------------------------------------------------
Title: The Physics of Remotely-Sensed Heliospheric Plasmas
Authors: Jackson, Bernard V.
Bibliographic Code: 1997ad...rept.....J
Abstract
Solar disturbances produce major effects on the corona, the solar wind,
the interplanetary medium, and the Earth along with its magnetosphere.
New techniques have been developed under this grant for studying plasma
disturbances in the inner heliosphere by remotely sensing them. These
techniques have used data from the HELIOS spacecraft zodiacal light
photometers, in situ data and a variety of other spacecraft and ground
based instruments. The zodiacal light photometers on board the two
HELIOS spacecraft (data coverage from 1974 to 1986) provided the first
reliable information about the heliospheric masses and shapes of
propagating disturbances. The investigations into the physics of the
disturbances sensed by these techniques, and the ability to forecast
them, have been underway during the contract. The data analyses have
used YOHKOH spacecraft observations, Sacramento Peak Observatory and
Mauna Loa (Mark 3) coronagraph data to map solar surface features. In
addition, interplanetary scintillation (IPS) data from the Cambridge,
England, Nagoya, Japan, and Ooty, India radio telescopes plus ULYSSES
and IMP in situ data have been used to determine present day conditions
in the solar wind.
@--------------------------------------------------------------------
Title: Tomography of Heliospheric Structures Using HELIOS
Spacecraft Photometer Data
Authors: Jackson, B. V.; Hick, P. L.
Bibliographic Code: 1997SPD....28.1502J
Abstract
We have produced a Computer Assisted Tomography (CAT) program that
optimizes a three-dimensional heliospheric model to fit observational
data. We have used this program to reconstruct interplanetary
scintillation and Helios photometer Thomson-scattering data. The program
iterates to a least-squares solution fit using solar rotation and solar
wind outward motion to provide perspective views of each point in space
accessible to the observations. We plot the optimized model as
Carrington maps in velocity and density with resolutions commensurate
with the original data sets. Here we concentrate on the Helios
photometer Thomson-scattering measurements and explore the stability of
corotating structures. We map the structures we have reconstructed to
the solar surface and match these with observations from the Sacramento
Peak green line coronagraph. We also map these structures to the Helios
spacecraft where they are compared with data measured in situ.
@--------------------------------------------------------------------
Title: Design for the Solar Mass Ejection Imager (SMEI)
Authors: Keil, S. L.; Altrock, R. C.; Kahler, S. W.;
Jackson, B. V.; Buffington, A.; Hick, P. L.;
Simnett, G.; Eyles, C.; Webb, D. F.; Anderson, P.
Bibliographic Code: 1997SPD....28.0227K
Abstract
The Solar Mass Ejection Imager (SMEI) experiment is designed to detect
and measure transient plasma features in the heliosphere, including
coronal mass ejections (CMEs), shock waves, and structures such as
streamers which corotate with the Sun. SMEI will provide measurements of
the propagation of solar plasma clouds and high-speed streams which can
be used to forecast their arrival at Earth from one to three days in
advance. Data from SMEI will be used to develop models and techniques
that will, for the first time, allow us to predict the onset and
magnitude of geomagnetic storms that disrupt space operations and affect
communications and surveillance activities. We will present the current
design and observational plans for SMEI. SMEI is currently under
construction with instrument completion expected in 1999. We plan to
launch SMEI near the next solar maximum and will make the data available
to the scientific and space weather forecast communities.
@--------------------------------------------------------------------
Title: Solar wind structure at 0.1-1 AU reconstructed from
IPS observations using tomography
Authors: Kojima, M.; Asai, K.; Hick, P. L.; Jackson, B. V.;
Tokumaru, M.; Watanabe, H.; Yokobe, A.
Bibliographic Code: 1997AIPC..385...97K
Abstract
Although interplanetary scintillation (IPS) is a useful means to measure
the solar wind in regions where spacecraft cannot access, the IPS
measurement requires a line of sight integration to relate what is
observed to a location in space. We have produced a Computer Assisted
Tomography (CAT) program that optimizes a three-dimensional solar wind
speed distribution to fit observed interplanetary scintillation data
from STE Lab. Nagoya University. The program uses solar rotation and
solar wind motion to provide 3-dimensional perspective views of each
point in space accessible to the IPS observations and iterates to a
least-square solution fit of the observations. We plot the optimized
result as a Carrington map of solar wind speed at a height of 2.5 Rs and
have confirmed (1) the solar wind near a solar minimum phase has a
bimodal structure near the sun, that is, a low-speed region and a
high-speed region are separated by a sharp speed gradient, (2)
high-speed winds get their final speed of 750-800 km/s within 0.1 AU,
and subsequently the evolution of solar wind structure is small at
0.1-1AU.
@--------------------------------------------------------------------
Title: Heliospheric tomography using interplanetary
scintillation observations
Authors: Jackson, B. V.; Hick, P. L.; Kojima, M.; Yokobe, A.
Bibliographic Code: 1997AdSpR..20...23J
Abstract
A computer-aided tomography program that optimizes a 3D model to fit
observational data has been used with two different sets of
interplanetary scintillation data. Solar rotation and solar wind motion
are iterated by the program to yield perspective views of each point in
space accessible to the observations. The optimized model is plotted as
Carrington maps for the two data sets.
@--------------------------------------------------------------------
Title: Heliospheric Observations of Solar Disturbances and
Their Potential Role in the Origin of Geomagnetic
Storms
Authors: Jackson, Bernard V.
Bibliographic Code: 1997mast.book...59J
Abstract
@--------------------------------------------------------------------
Title: Solar wind structure analyzed by tomography of
interplanetary scintillation
Authors: Yokobe, A.; Asai, K.; Hick, P. L.; Jackson, B. V.;
Kojima, M.; Manoharan, P. K.; Tokumaru, M.;
Watanabe, H.
Bibliographic Code: 1997IAUJD..19E..59Y
Abstract
We have analyzed the global structure of the solar wind in the minimum
phase of the solar cycle using interplanetary scintillation (IPS)
observation data obtained at STE Lab. We examined the relation between
the solar wind velocity V and electron density fluctuations delta
Ne with CAT analysis, and derived the best fit power-low of
delta Ne propto V^{- gamma} with gamma = 0.5 plus or minus
0.15. This result indicates that delta Ne/N in a fast wind is
lager than that of slow wind. We have then analyzed IPS speed data
during Carrington rotations 1894--1896, which matched the passage of the
Ulysses spacecraft of its rapid latitude traversal from southern to
northern hemisphere. As the result, we confirmed that high-speed regions
with speed of about 800 km/s are separated from an equatorial low-speed
region with a sharp velocity gradient at heliographic latitudes of
15circ to 20circ in both hemispheres. This
latitudinal variation is agreed with Ulysses observations very well.
@--------------------------------------------------------------------
Title: Wide-angle stray-light reduction for a spaceborne
optical hemispherical imager
Authors: Buffington, Andrew; Jackson, Bernard V.;
Korendyke, Clarence M.
Bibliographic Code: 1996ApOpt..35.6669B
Abstract
We describe a simple visible-light stray-background-reducing baffle,
suitable for use on a stabilized interplanetary platform. The design is
a corrallike enclosure with five concentric walls. The baffle reduces
direct sunlight and reflections from illuminated portions of the
spacecraft by a factor of 10-12, provided that all these lie
beyond at least a hemisphere centered on the viewing aperture. With this
condition these bright sources do not directly illuminate within the
outermost wall of the corral, and diffraction over the wall tops is the
dominant mechanism by which light reaches the corral interior. We
present design calculations for such a corral, as well as a laboratory
measurement confirming the basic design assumption.
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager (SMEI)
Authors: Keil, Stephen L.; Altrock, Richard C.;
Kahler, Stephen; Jackson, Bernard V.;
Buffington, Andrew; Hick, Paul; Simnett, George M.;
Eyles, Christopher J.; Webb, David; Anderson, Peter
Bibliographic Code: 1996SPIE.2804...78K
Abstract
The Solar Mass Ejection Imager (SMEI) experiment is designed to detect
and measure transient plasma features in the heliosphere, including
coronal mass ejections, shock waves, and structures such as streamers
which corotate with the Sun. SMEI will provide measurements of the
propagation of solar plasma clouds and high-speed streams which can be
used to forecast their arrival at Earth from one to three days in
advance. The white light photometers on the HELIOS spacecraft
demonstrated that visible sunlight scattered from the free electrons of
solar ejecta can be sensed in interplanetary space with an electronic
camera baffled to remove stray background light. SMEI promises a
hundred-fold improvement over the HELIOS data, making possible
quantitative studies of mass ejections. SMEI measurements will help
predict the rate of energy transfer into the Earth's magnetospheric
system. By combining SMEI data with solar, interplanetary and
terrestrial data from other space and ground-based instruments, it will
be possible to establish quantitative relationships between solar
drivers and terrestrial effects. SMEI consists of three cameras, each
imaging a 60 degree(s) X 3 degree(s) field of view for a total image
size of 180 degree(s) X 3 degree(s). As the satellite orbits the earth,
repeated images are used to build up a view of the entire heliosphere.
@--------------------------------------------------------------------
Title: STEREO: a solar terrestrial event observer mission
concept
Authors: Socker, Dennis G.; Antiochos, S. K.;
Brueckner, Guenter E.; Cook, John W.;
Dere, Kenneth P.; Howard, Russell A.; Karpen, J. T.;
Klimchuk, J. A.; Korendyke, Clarence M.;
Michels, Donald J.; Moses, J. Daniel;
Prinz, Dianne K.; Sheely, N. R.; Wu, Shi T.;
Buffington, Andrew; Jackson, Bernard V.;
Labonte, Barry; Lamy, Philippe L.; Rosenbauer, H.;
Schwenn, Rainer; Burlaga, L.; Davila, Joseph M.;
Davis, John M.; Goldstein, Barry; Harris, H.;
Liewer, Paulett C.; Neugebauer, Marcia; Hildner, E.;
Pizzo, Victor J.; Moulton, Norman E.; Linker, J. A.;
Mikic, Z.
Bibliographic Code: 1996SPIE.2804...50S
Abstract
A STEREO mission concept requiring only a single new spacecraft has been
proposed. The mission would place the new spacecraft in a heliocentric
orbit and well off the Sun- Earth line, where it can simultaneously view
both the solar source of heliospheric disturbances and their propagation
through the heliosphere all the way to the earth. Joint observations,
utilizing the new spacecraft and existing solar spacecraft in earth
orbit or L1 orbit would provide a stereographic data set. The new and
unique aspect of this mission lies in the vantage point of the new
spacecraft, which is far enough from Sun-Earth line to allow an entirely
new way of studying the structure of the solar corona, the heliosphere
and solar-terrestrial interactions. The mission science objectives have
been selected to take maximum advantage of this new vantage point. They
fall into two classes: those possible with the new spacecraft alone and
those possible with joint measurements using the new and existing
spacecraft. The instrument complement on the new spacecraft supporting
the mission science objectives includes a soft x-ray imager, a
coronagraph and a sun-earth imager. Telemetry rate appears to be the
main performance determinant. The spacecraft could be launched with the
new Med-Lite system.
@--------------------------------------------------------------------
Title: Comparison of CME masses and kinetic energies near
the sun and in the inner heliosphere
Authors: Webb, D. F.; Howard, R. A.; Jackson, B. V.
Bibliographic Code: 1996AIPC..382..540W
Abstract
Masses have now been determined for many CMEs observed in the inner
heliosphere by the Helios 1 and 2 zodiacal light photometers. The speed
of the brightest material of each CME has also been measured so that,
for events having both mass and speed determinations, their kinetic
energies can be estimated. We compare the excess masses and kinetic
energies of individual CMEs estimated in the inner heliosphere by Helios
and near the Sun from observations by the Solwind (1979-1980) and SMM
coronagraphs (1980). We also compare the speeds of the same CMEs. We
find that the Helios mass and energy estimates are larger by factors of
~3 and 3-8, respectively, than those derived from the coronagraph data.
Possible causes for the mass difference include the extended flow of CME
mass through the corona that is not well measured by coronagraphs, and
an increase of CME mass with height due to compression of ambient solar
wind material. These results provide an important baseline for
observations of CMEs from coronagraphs, from the WIND and Ulysses
spacecraft and in the near future from SOHO.
@--------------------------------------------------------------------
Title: The solar mass ejection imager
Authors: Jackson, B. V.; Buffington, A.; Hick, P. L.;
Kahler, S. W.; Altrock, R. C.; Gold, R. E.;
Webb, D. F.
Bibliographic Code: 1996AIPC..382..536J
Abstract
We are designing a Solar Mass Ejection Imager (SMEI) capable of
observing Thomson-scattered signals from transient density features in
the heliosphere from a spacecraft situated near 1 AU. The imager is
designed to trace these features, which include coronal mass ejections,
corotating structures and shock waves, to elongations greater than
90° from the Sun. The instrument may be regarded as a progeny of the
heliospheric imaging capability shown possible by the zodiacal light
photometers of the HELIOS spacecraft. The instrument we are designing
would make more effective use of in situ solar wind data from spacecraft
in the vicinity of the imager by extending their observations to the
surrounding environment. An imager in Earth orbit could allow up to
three days warning of the arrival of a mass ejection from the Sun.
@--------------------------------------------------------------------
Title: Evidence of active region imprints on the solar wind
structure
Authors: Hick, P.; Jackson, B. V.
Bibliographic Code: 1996AIPC..382..461H
Abstract
A common descriptive framework for discussing the solar wind structure
in the inner heliosphere uses the global magnetic field as a reference:
low density, high velocity solar wind emanates from open magnetic
fields, with high density, low speed solar wind flowing outward near the
current sheet. In this picture, active regions, underlying closed
magnetic field structures in the streamer belt, leave little or no
imprint on the solar wind. We present evidence from interplanetary
scintillation measurements of the `disturbance factor' g that active
regions play a role in modulating the solar wind and possibly contribute
to the solar wind mass output. Hence we find that the traditional view
of the solar wind, though useful in understanding many features of solar
wind structure, is oversimplified and neglects important aspects of
solar wind dynamics.
@--------------------------------------------------------------------
Title: Coronal synoptic temperature maps derived from the
Fe XIV/Fe X intensity ratio
Authors: Hick, P.; Jackson, B. V.; Altrock, R. C.
Bibliographic Code: 1996AIPC..382..169H
Abstract
The large-scale temperature structure of the low corona is investigated
using synoptic temperature maps, derived from the intensity ratio of the
green (Fe XIV) and red (Fe X) coronal lines as observed at the National
Solar Observatory/Sacramento Peak. This intensity ratio is sensitive to
coronal plasma with temperatures of 1-2 MK, a range of temperatures
usually associated with the quiet corona. The synoptic maps indicate an
association between high coronal temperature and the large-scale
magnetic field. A comparison with Stanford `source surface' synoptic
maps shows that, especially when the heliospheric current sheet is
stable over several rotations, the large-scale high-temperature features
follow the current sheet remarkably well. For recent Carrington
rotations, temperature maps are available for four heights between 1.15
and 1.45 Rsolar. For these maps the correspondence with the
current sheet (calculated at 2.5 Rsolar) improves with
height. Discrepancies between temperature structure and magnetic
structure appear to be largest when the magnetic structure changes
rapidly from rotation to rotation.
@--------------------------------------------------------------------
Title: The Solar Coronal Temperature Structure and the
Heliospheric Current Sheet
Authors: Altrock, R. C.; Hick, P.; Jackson, B. V.; Slater, G.;
Henry, T. W.
Bibliographic Code: 1996AAS...188.8004A
Abstract
We explore the large-scale temperature structure of the low corona using
synoptic temperature maps, derived from the intensity ratio of the green
(Fe XIV) and red (Fe X) coronal lines as observed at the National Solar
Observatory/Sacramento Peak, and temperature maps derived from the Al0.1
and AlMgMn filter intensity ratio measured by the Yohkoh/SXT instrument.
The red/green intensity ratio is sensitive to coronal plasma with
temperatures in the range of 1--2 MK and is therefore useful for
studying the `quiet' corona. The Yohkoh/SXT filter ratio covers a much
wider range of coronal temperature (>= 1 MK) and, in particular, is
sensitive to the high temperatures (>= 3 MK) commonly observed above
active regions. We use the temperature maps to study the evolution of
the large-scale coronal temperature distribution, in particular in
relation to the large-scale magnetic field, as given by the `source
surface' maps derived from the Stanford potential field model. We find
that the large-scale high-temperature features follow the heliospheric
current sheet remarkably well, especially when the current sheet is
stable over several rotations.
@--------------------------------------------------------------------
Title: The Influence of Active Regions on IPS measurements
near 1 AU
Authors: Hick, Paul; Jackson, B. V.
Bibliographic Code: 1996ASPC...95..470H
Abstract
@--------------------------------------------------------------------
Title: The Coronal Temperature Structure and the Current
Sheet
Authors: Hick, Paul; Jackson, B. V.; Altrock, R. C.;
Slater, G.; Henry, T.
Bibliographic Code: 1996ASPC...95..358H
Abstract
@--------------------------------------------------------------------
Title: Geomagnetic Storms and Heliospheric CMEs as Viewed
From HELIOS
Authors: Webb, David F.; Jackson, Bernard V.; Hick, Paul
Bibliographic Code: 1996ASPC...95..167W
Abstract
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager (SMEI): Development
and Use in Space Weather Forecasting
Authors: Keil, S. L.; Altrock, R. C.; Kahler, S. W.;
Jackson, B. V.; Buffington, A.; Hick, P. L.;
Simnett, G.; Eyles, C.; Webb, D. F.; Anderson, P.
Bibliographic Code: 1996ASPC...95..158K
Abstract
@--------------------------------------------------------------------
Title: IPS observations of heliospheric density structures
associated with active regions
Authors: Hick, P.; Jackson, B. V.; Altrock, R.; Woan, G.;
Slater, G.
Bibliographic Code: 1996AdSpR..17..311H
Abstract
Interplanetary scintillation (IPS) measurements of the 'disturbance
factor' g, obtained with the Cambridge (UK) array can be used to explore
the heliospheric density structure. We have used these data to construct
synoptic (Carrington) maps, representing the large-scale enhancements of
the g-factor in the inner heliosphere. These maps emphasize the stable
corotating, rather than the transient heliospheric density enhancements.
We have compared these maps with Carrington maps of Fe XIV observations
National Solar Observatory ((NSO), Sacramento Peak) and maps based on
Yohkoh Soft X-Ray Telescope (SXT) X-ray observations. Our results
indicate that the regions of enhanced g tend to map to active regions
rather than the current sheet. The implication is that act ve regions
are the dominant source of the small-scale (approximately equal 200 km)
density variations present in the quiet solar wind.
@--------------------------------------------------------------------
Title: Solar coronal structure: A comparison of NSO/SP
ground-based coronal emission line intensities and
temperatures with YOHKOH SXT and WSO magnetic data
Authors: Altrock, R. C.; Hick, P.; Jackson, B. V.;
Hoeksema, J. T.; Zhao, X. P.; Slater, G.;
Henry, T. W.
Bibliographic Code: 1996AdSpR..17..235A
Abstract
The large-scale structure of the solar corona is investigated using
synoptic maps produced from Fe XIV (530.3 nm), Fe X (637.4 nm) and Ca XV
(569.4 nm) data obtained at National Solar Observatory (NSO/SP),
Yohkoh/Soft X-ray Telescope (SXT) X-ray data and Wilcox Solar
Observatory (WSO) 'source surface' maps. We find that the Fe XIV data
are an excellent proxy for spatially-average Yohkoh/SXT data. Isolated
emission features and large-scale structures are nearly identical in SXT
and Fe XIV maps. In addition, coronal holes and other low-emission
regions are very similar. Synoptic temperature maps, calculated from the
Fe X/Fe XIV ratio, show a tendency for the highest temperatures to occur
where the large-scale magnetic fields change polarity at high latitudes,
while lower-latitude features, including active regions, have lower
apparent tempertures. Regions of enhanced temperature generally follow
the helisopheric current sheet (HCS) as defined by the WSO maps.
Further, emission in Ca XV (formed at T is approximately equal to 3 MK),
generally occurs only over low-latitude regions that are bright in both
FE X (T approximately equal to 1 MK) and Fe XIV (T approximately equal
to 2 MK). Thus, there is evidence for low (approximately equal to 1 MK),
moderate (approximately equal to 2 MK) and high (approximately 3 MK)
temperatures in close proximity in the low corona.
@--------------------------------------------------------------------
Title: Three-dimensional reconstruction of a coronal mass
ejection.
Authors: Jackson, B. V.; Froehling, H. R.
Bibliographic Code: 1995A&A...299..885J
Abstract
We reconstruct the three-dimensional density distribution of a coronal
mass ejection (CME) in the interplanetary medium from data provided by
the Helios spacecraft zodiacal light photometers and by the Solwind
coronagraph. Computer assisted tomography (CAT) techniques can be used
to reconstruct an image from its projections whenever multiple views of
optically thin objects are available. In this case Thomson scattering of
sunlight from electrons is the source of variations in observed
brightness. Polarization measurements from the Helios spacecraft yield
additional information about line of sight electron densities not
normally present in usual CAT-scan techniques. The Helios and
coronagraph views are not simultaneous; the Helios 16deg photometer
observes to within 17Rsun_, whereas the Solwind observations
extend outward to only 10Rsun_. However, if we assume radial
velocities for ejected material, and that as an approximation the
velocity of outward-moving material at a given height is fixed for the
ejection, we obtain a solution. This solution is certified by the
reconstruction of two test structures - a hollow sphere and two spheres
of material analyzed by the same techniques used to deconvolve the CME.
The CAT solution shows that the dense structure of the May 7, 1979 CME
is distributed in two lobes extending over a quarter of a heliospheric
hemisphere. We conclude from the CAT analysis that the CME material must
have accelerated from 100km/s in the Solwind field of view to 600km/s in
the view from Helios.
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager
Authors: Jackson, B. V.; Buffington, A.; Hick, P. L.;
Kahler, S. W.; Altrock, R. C.; Gold, R. E.;
Webb, D. F.
Bibliographic Code: 1995sowi.confR..97J
Abstract
We are designing a Solar Mass Ejection Imager (SMEI) capable of
observing the Thomson-scattered signal from transient density features
in the heliosphere from a spacecraft situated near AU. The imager is
designed to trace these features, which include coronal mass ejections.
corotating structures and shock waves, to elongations greater than 90
deg from the Sun. The instrument may be regarded as a progeny of the
heliospheric imaging capability shown possible by the zodiacal-light
photometers of the HELIOS spacecraft. The instrument we are designing
would make more effective use of in-situ solar wind data from spacecraft
in the vicinity of the imager by extending these observations to the
surrounding environment. The observations from the instrument should
allow deconvolution of these structures from the perspective views
obtained as they pass the spacecraft. An imager at Earth could allow up
to three days warning of the arrival of a mass ejection from the Sun.
@--------------------------------------------------------------------
Title: CME masses measured by the HELIOS spacecraft
photometers
Authors: Jackson, B. V.; Webb, D. F.
Bibliographic Code: 1995sowi.confQ..97J
Abstract
We have cataloged 160 CMEs detected in the HELIOS 1 and 2 90 deg
zodiacal light photometers observed from 1975-1985. The HELIOS 1 and 2
spacecraft orbited from 0.3 to 1.0 AU on 6-month orbits. From the
photometer observations of Thomson-scattered light in the inner
heliosphere, we have determined CME masses for these events using two
methods: (1) by integration over the contours drawn between the three
photometers at a given time; and (2) by integration of the mass flow
over time past a given photometer. The second method, not readily
available using coronagraph observations, is derived from CME speeds
measured by using the timing of the peak CME brightness from the 16 deg
to 31 deg sets of photometers. The two different HELIOS methods of
determining CME mass are consistent with one another for individual
CMEs. We find that the CME mass values range from 1015g to
nearly 1017g. We compare the mass distributions of
HELIOS-measured CMEs with those from coronagraphs and find that CMEs
measured by HELIOS over the same time interval are generally more
massive. The solar cycle variation of the total CME mass present in the
heliosphere varies by over a factor of approximately 15 from solar
minimum to solar maximum. Slightly more massive CMEs carry the bulk of
the CME mass during maximum. The total CME mass at solar maximum is
found to be near 15% of the total solar wind mass.
@--------------------------------------------------------------------
Title: Coronal synoptic temperature maps derived from the
Fe XIV/Fe X intensity ratio
Authors: Hick, P.; Jackson, B. V.; Altrock, R.
Bibliographic Code: 1995sowi.confQ..69H
Abstract
The large-scale temperature structure of the low corona is investigated
using synoptic temperature maps, derived from the intensity ratio of the
green (Fe XIV) and red (Fe X) coronal lines as observed at the National
Solar Observatory/Sacramento Peak. This intensity ratio is sensitive to
coronal plasma with temperatures in the range of 1-2 MK. The synoptic
maps indicate an association between high coronal temperature and the
large-scale magnetic field. A comparison with WSO 'source surface'
synoptic maps shows that especially when the heliospheric current sheet
is stable over several rotations, the large-scale high-temperature
features follow the current sheet remarkably well. For recent Carrington
rotations temperature maps have been constructed for various heights
between 1.15 and 1.45 solar radii. For these maps the correspondence
with the current sheet (calculated at 2.5 solar radii) improves with
height. Deviations between temperature structure and magnetic structure
appears to be largest when the magnetic structure changes rapidly from
rotation to rotation.
@--------------------------------------------------------------------
Title: Comparison of CME masses and kinetic energies near
the Sun and in the inner heliosphere
Authors: Webb, D. F.; Howard, R. A.; Jackson, B. V.
Bibliographic Code: 1995sowi.conf...97W
Abstract
Masses have now been determined for many of the CMEs observed in the
inner heliosphere by the HELIOS 1 and 2 zodiacal light photometers. The
speed of the brightest material of each CME has also been measured so
that, for events having both mass and speed determinations, the kinetic
energies of the CMEs are estimated. We compare the masses and kinetic
energies of the individual CMEs measured in the inner heliosphere by
HELIOS and near the Sun from observations by the SOLWIND (1979-1983) and
SMM coronagraphs (1980). Where feasible we also compare the speeds of
the same CMEs. We find that the HELIOS masses and energies tend to be
somewhat larger by factors of 2-5 than those derived from the
coronagraph data. We also compare the distribution of the masses and
energies of the HELIOS and coronagraph CMEs over the solar cycle. These
results provide an important baseline for observations of CMEs from
coronagraphs, from the ISEE-3/ICE, WIND and Ulysses spacecraft and in
the future from SOHO.
@--------------------------------------------------------------------
Title: Yohkoh/SXT x-ray synoptic maps of coronal brightness
and temperature
Authors: Slater, G. L.; Lemen, J. R.; Hick, P.;
Jackson, B. V.
Bibliographic Code: 1995sowi.conf...68S
Abstract
The Yohkoh soft X-ray telescope (SXT) records on the order of 50 solar
images per day in two different color filters. These provide material
for the generation of synoptic maps, which compress the 3-dimensional
data cube into two dimensions. We are creating synoptic maps from strips
of data both at disk center and at different heights, including limb
maps that are analogous to those produced by ground-based coronagraphs.
The ratios of intensities in images taken in two filters provide
estimates of the electron temperature in the range 1 - 3 x
106 K. These are broad-band temperature maps; rather than
maps created with discrete sampling as in the case of the coronal green
and red lines. We discuss the properties of these maps and their
application to the study of energy release in the corona.
@--------------------------------------------------------------------
Title: Evidence of active region imprints on the solar wind
structure
Authors: Hick, P.; Jackson, B. V.
Bibliographic Code: 1995sowi.conf...48H
Abstract
A common descriptive framework for discussing the solar wind structure
in the inner heliosphere uses the global magnetic field as a reference:
low density, high velocity solar wind emanates from open magnetic
fields, with high density, low speed solar wind flowing outward near the
current sheet. In this picture, active regions, underlying closed
magnetic field structures in the streamer belt, leave little or no
imprint on the solar wind. We present evidence from interplanetary
scintillation measurements of the 'disturbance factor' g that active
regions play a role in modulating the solar wind and possibly contribute
to the solar wind mass output. Hence we find that the traditional view
of the solar wind, though useful in understanding many features of solar
wind structure, is oversimplified and possibly neglects important
aspects of solar wind dynamics
@--------------------------------------------------------------------
Title: Synoptic IPS and YOHKOH soft X-ray observations
Authors: Hick, P.; Jackson, B. V.; Rappoport, S.; Woan, G.;
Slater, G.; Strong, K.; Uchida, Y.
Bibliographic Code: 1995GeoRL..22..643H
Abstract
Interplanetary scintillation measurements of the disturbance factor, g,
from October 1991 to October 1992 are used to construct synoptic
Carrington maps. These maps, which show the structure of the quiet solar
wind, are compared with X-ray Carrington maps from the Yohkoh Soft X-ray
Telescope (SXT) instrument. For the period studied the global structure
outlined by (weakly) enhanced g-values apparent in the interplanetary
scintillation (IPS) maps tend to match the active regions (as shown in
the X-ray maps) significantly better than the heliospheric current
sheet. Contrary to traditional opinion, which views active regions as
magnetically closed structures that do not have any significant impact
on the solar wind flow, our results suggest that density fluctuations in
the solar wind are significantly enhanced over active regions. These
results support the suggestion by Uchida et al. (1992), based on Yohkoh
observations of expanding active regions, that active regions play a
role in feeding mass into the quiet solar wind.
@--------------------------------------------------------------------
Title: Coronagraph Stray Light Analyses (Abstract only)
Authors: Jackson, B. V.; Lones, L. A.
Bibliographic Code: 1995itsa.conf..199J
Abstract
@--------------------------------------------------------------------
Title: Association of Solar Coronal Temperature and
Structure from Ground-Based Emission-Line Data with
Global Magnetic Field Models and Yohkoh SXT Data
(Abstract only)
Authors: Altrock, R. C.; Hick, P.; Jackson, B. V.;
Hoeksema, J. T.; Zhao, X. P.; Slater, G.;
Henry, T. W.
Bibliographic Code: 1995itsa.conf...45A
Abstract
@--------------------------------------------------------------------
Title: The masses of CMEs measured in the inner heliosphere
Authors: Jackson, B. V.
Bibliographic Code: 1994ESASP.373..233J
Abstract
@--------------------------------------------------------------------
Title: Three-dimensional reconstruction of coronal mass
ejections
Authors: Jackson, B. V.; Hick, P.
Bibliographic Code: 1994ESASP.373..199J
Abstract
@--------------------------------------------------------------------
Title: A spaceborne near-Earth asteroid detection system.
Authors: Jackson, B. V.; Buffington, A.; Hick, P. L.;
Kahler, S. W.; Webb, D. F.
Bibliographic Code: 1994A&AS..108..279J
Abstract
We have designed a Solar Mass Ejection Imager (SMEI) to image transient
heliospheric features from Earth orbit over the entire sky every 90
minutes. The instrument is designed to detect changes on this time scale
in the signals from sunlight Thomson-scattered from electrons at a
brightness level of tenth magnitude per square degree of sky. We explore
the possibility of using such an instrument to detect asteroids passing
near the Earth. We estimate that SMEI will detect at least 13 asteroids
per year over ~12m in radius.
@--------------------------------------------------------------------
Title: Solar wind mass and momentum flux variations at 0.3
AU
Authors: Hick, P.; Jackson, B. V.
Bibliographic Code: 1994AdSpR..14..135H
Abstract
In the past we have used electron Thomson scattering brightness
observations, obtained with the zodiacal-light photometers on board the
spacecraft Helios 1 and Helios 2, to study the global density structure
of the quiet corona and inner heliosphere (greater than 17 solar radii).
This was done by means of a comparison of synoptic maps based on these
Thomson scattering observations and synoptic maps based on other
solar/heliospheric data, such as IPS velocity, K-coronameter brightness
and magnetic source surface data. In this paper we continue this
approach by combining the Helios Thomson scattering maps (which provide
density information) with IPS solar wind velocity maps to map out
variations in mass and momentum flux of the solar wind as a function of
latitude and phase of the solar cycle. The method used to construct the
Helios and IPS synoptic maps emphasizes the global, persistent (as
opposed to transient) structures, and thus can be viewed as
approximating conditions in the quiet corona and inner heliosphere.
@--------------------------------------------------------------------
Title: Catalog of HELIOS 90 deg photometer events
Authors: Jackson, Bernard V.; Webb, David F.; Hick, Paul L.;
Nelson, Jessica L.
Bibliographic Code: 1994STIN...9436264J
Abstract
The two Helios spacecraft were launched into solar orbits in December
1974 and January 1976. Each spacecraft contained three zodiacal light
photometers intended to measure the distribution of dust in the
interplanetary medium between the Sun and the Earth. Residual brightness
variations were evident after the zodiacal light and stellar
contributions had been removed from the photometer data. These
variations are now known to have been caused primarily by transient
plasma clouds propagating through the inner heliosphere. About 2/3 of
these were caused by coronal mass ejections and about 1/4 by corotating
structures. We have used specific criteria to select and identify these
plasma events in the data from the Helios photometers which pointed at
the ecliptic poles. This process is now complete and we are making these
data available to the scientific community. This document is a catalog
of the Helios 90 degree photometer events which we have identified. In
the following text we describe the pertinent characteristics of the
zodiacal light experiment, the methods used to select, identify and
classify the 90 degree events, and the details of the catalog structure.
A comprehensive bibliography of all published papers involving analyses
of the Helios photometer plasma observations and the zodiacal light
calibration is also included.
@--------------------------------------------------------------------
Title: A CME Mass Distribution Derived from SOLWIND
Coronagraph Observations
Authors: Jackson, Bernard V.; Howard, Russ A.
Bibliographic Code: 1993SoPh..148..359J
Abstract
Using estimates of the masses of nearly 1000 CMEs observed by SOLWIND
from Howardet al. (1985), we re-plot the numbers of CMEs as a function
of CME mass on a log-linear plot. The plot is significant in that it
shows a linear trend over more than a decade of CME masses. The plot
indicates a simple form for the distribution of the CME masses and
allows an easy determination of the total mass ejected into the solar
wind in the form of CMEs. We find that approximately 16% of the solar
wind at solar maximum can be comprised of CME mass. There is no
indication that the numbers of low-mass CMEs increase in number above
the trend set by the more massive ones. Specifically, there is no
increase in the numbers of small CMEs such that the whole of the solar
wind can be comprised of them.
@--------------------------------------------------------------------
Title: Remote sensing of inner heliospheric plasmas
Authors: Jackson, Bernard V.
Bibliographic Code: 1993ucsd.rept.....J
Abstract
Solar disturbances produce major effects on the corona, the solar wind,
the interplanetary medium, and the earth along with its magnetosphere.
We have developed new techniques for studying plasma disturbances in the
inner heliosphere by remotely sensing them. These techniques use data
from the HELIOS spacecraft zodiacal light photometers and in situ data,
the ISEE-3 spacecraft in situ and kilometer radio wave experiments, and
a variety of other spacecraft and ground-based instruments. We use
interplanetary scintillation (IPS) data from the Cambridge, England,
radio telescope. The zodiacal-light photometers on board the two HELIOS
spacecraft (data coverage from 1974 to 1986) provide the first reliable
information about the heliospheric masses and shapes of propagating
disturbances.
@--------------------------------------------------------------------
Title: Book-Review - Physics of the Inner Heliosphere -
Part Two - Particles Waves and Turbulence
Authors: Schwenn, R.; Marsch, E.; Jackson, B. V.
Bibliographic Code: 1993SoPh..145R.405S
Abstract
@--------------------------------------------------------------------
Title: Book-Review - Physics of the Inner Heliosphere -
Part One - Largescale Phenomena
Authors: Schwenn, R.; Marsch, E.; Jackson, B. V.
Bibliographic Code: 1993SoPh..145Q.405S
Abstract
@--------------------------------------------------------------------
Title: Three Dimensional Reconstruction of Coronal Mass
Ejections
Authors: Jackson, B. V.
Bibliographic Code: 1993BAAS...25R1211J
Abstract
@--------------------------------------------------------------------
Title: Synoptic Interplanetary Scintillation (IPS) Maps for
Use in Heliospheric Data Analysis and Space
Environment Forecasting
Authors: Rappoport, S. A.; Jackson, B. V.; Hick, P. L.;
Davidson, T. E.; Winfield, K. A.
Bibliographic Code: 1993BAAS...25.1211R
Abstract
@--------------------------------------------------------------------
Title: Observations of Solar Wind 'Halo' Electrons
Authors: Hick, P. L.; Jackson, B. V.; Webb, D. F.
Bibliographic Code: 1993BAAS...25.1210H
Abstract
@--------------------------------------------------------------------
Title: The Solar Mass Ejection Imager
Authors: Jackson, B. V.; Buffington, A.; Kahler, S. W.;
Webb, D. F.; Altrock, R.; Gold, R.
Bibliographic Code: 1993BAAS...25.1191J
Abstract
@--------------------------------------------------------------------
Title: A Space-Borne Near-Earth Asteroid Detection System
Authors: Jackson, B. V.; Buffington, A.; Hick, P. L.;
Webb, D. F.
Bibliographic Code: 1993AAS...182.1503J
Abstract
We have designed a Solar Mass Ejection Imager (SMEI) to image transient
heliospheric features from Earth orbit over the entire sky once every 90
minutes. The instrument is designed to detect changes in the signals
from electrons which Thomson-scatter sunlight to a brightness level of
tenth magnitude per square degree of sky. Here, we explore the
additional possibility of using such an instrument to detect asteroids
passing near the Earth. We predict that SMEI will discover about 14
asteroids per year over ~ 12 m in radius and about 10 meteors in the
range 0.5 -- 5.0 m in radius.
@--------------------------------------------------------------------
Title: Book Review: Eruptive solar flares /
Springer-Verlag, 1992
Book Authors: Svestka, Z.; Jackson, B. V.; Machado, M. E.
Review Author: Heinzel, P.
Bibliographic Code: 1993SoPh..143..402H
Abstract
@--------------------------------------------------------------------
Title: Characteristics of CMEs Observed in the Heliosphere
Using HELIOS Photometer and In-Situ Data
Authors: Webb, D. F.; Jackson, B. V.
Bibliographic Code: 1993stp2.conf..381W
Abstract
@--------------------------------------------------------------------
Title: Book-Review - Eruptive Solar Flares
Authors: Svestka, Z.; Jackson, B. V.; Machado, M. E.;
Sylwester, J.
Bibliographic Code: 1993SSRv...65..186S
Abstract
@--------------------------------------------------------------------
Title: Remote sensing of inner heliospheric plasmas
Authors: Jackson, Bernard V.
Bibliographic Code: 1992ucsd.rept.....J
Abstract
Solar disturbances produce major effects on the corona, the solar wind,
the interplanetary medium, and the Earth along with its magnetosphere.
New techniques for studying plasma disturbances in the inner heliosphere
by remotely sensing them were developed. These techniques use data from
the HELIOS spacecraft zodiacal light photometers, the ISEE-3 spacecraft
kilometer radio-wave experiment, and a variety of other spacecraft and
ground-based instruments. Use of interplanetary scintillation (IPS) data
from the Cambridge, England radio telescope was added. The
zodiacal-light photometers on board the two HELIOS spacecraft (data
coverage from 1974 to 1986) provide the first good information about the
heliospheric masses and shapes of propagating disturbances. Metric and
kilometric type 2 and type 3 radiation caused by shock waves and fast
moving electrons respectively are another way to remotely sense the
structures which propagate outward from the Sun. The best kilometric
radio-wave sensing of inner heliospheric plasma is available from the
ISEE-3 spacecraft, and recently these data were used to obtain crude
images of the Earth's magnetosphere. The investigations into the physics
of the disturbances sensed by these techniques and the ability to
forecast them are underway.
@--------------------------------------------------------------------
Title: A model for coronal streamer observations using the
SOHO coronagraph instrumentation
Authors: Jackson, Bernard V.
Bibliographic Code: 1992ESASP.348...97J
Abstract
The SOHO (Solar and Heliospheric Observatory) coronagraphs will offer an
unprecedented opportunity to observe coronal streamer material and
determine its outward motion. The inner C1 and C2 coronagraphs should
enable ready identification of coronal streamers and their surface
manifestations. The outer C3 coronagraph should be able to trace
streamers to nearly interplanetary distances from the Sun. Using a
modeling program designed to determine parameters from co-rotating
heliospheric material viewed by the Helios spacecraft, the locations in
position angle and distance from the Sun of several modeled streamers
are shown. These models demonstrate the expected differences in streamer
location when different assumptions are used for the outward
acceleration of the streamer material.
@--------------------------------------------------------------------
Title: Solar Mass Ejection Imager: A Precision Photometer
for Time-Series Measurements of Stars and Solar
System Objects
Authors: Buffington, A.; Jackson, B. V.
Bibliographic Code: 1992AAS...18110114B
Abstract
@--------------------------------------------------------------------
Title: Display Techniques for use in Interplanetary
Scintillation Analysis and Space Environment
Forecasting
Authors: Winfields, K. A.; Rappo Port, S. A.; Jones, L. A.;
Jones, J.; Jackson, B. V.; Hick, P. L.;
Davidson, T. E.
Bibliographic Code: 1992AAS...181.8114W
Abstract
@--------------------------------------------------------------------
Title: Study of CMES Observed in the Heliosphere Using
HELIOS Photometer, Magnetic Field and Plasma Data
Authors: Webb, D. F.; Jackson, B. V.; Reames, D. V.
Bibliographic Code: 1992AAS...180.1105W
Abstract
The zodiacal light photometers on the two Helios spacecraft have been
used to identify and study the characteristics of solar mass ejections
within 1 AU of the Sun. We have compiled a list of all significant CMEs
detected by the photometers between 1975 and 1985. We examine the
in-situ characteristics of a subset of these CMEs which enveloped the
spacecraft. In particular, we present results of analyses of structures
considered to be manifestations of interplanetary CMEs, such as magnetic
"clouds", shocks and periods of bidirectionally streaming ions at
energies of about 1 MeV. An important advantage of this data set is that
it permits us to make reliable associations in the interplanetary medium
over a long time base between many white light CMEs and their in-situ
proxies.
@--------------------------------------------------------------------
Title: Characteristics of CMEs observed in the heliosphere
using HELIOS photometer data
Authors: Webb, D. F.; Jackson, B. V.
Bibliographic Code: 1992sws..coll..681W
Abstract
The zodiacal light photometers on the two Helios spacecraft have been
used to detect and study mass ejections and other phenomena emanating
from the sun and traversing the heliosphere within 1 AU. We have
recently compiled a complete list of all of the significant white light
transient events detected from the 90-deg photometers on both Helios
spacecraft. This is a preliminary report on the long-term frequency of
occurrence of these events; it emphasizes newly processed data from
Helios-l from 1975 through 1982 and viewed south of the ecliptic. With
the large Helios photometer data base, we will be able to identify the
fraction of the 90 deg events which are heliospheric CMEs and determine
their characteristics.
@--------------------------------------------------------------------
Title: Solar-generated disturbances in the heliosphere
Authors: Jackson, B. V.
Bibliographic Code: 1992sws..coll..623J
Abstract
It has long been known that disturbances can propagate from Sun to Earth
with periods of a few days following large solar flares. Other
disturbances re-occur with the solar rotation rate implying that they
are more or less stably generated by a specific region on the solar
surface. At the Sun some of these disturbances are readily observed in
coronagraphs and against the solar disk. Several techniques have been
used to remotely detect and follow different disturbances in the
interplanetary medium as they propagate outward from the Sun. These
techniques include interplanetary scintillation, kilometric radio and
Helios photometer observations. In situ, spacecraft can mark the passage
of disturbances by direct measurement along the column convected past
the observation point. As probes of the heliospheric magnetic field and
disturbances in themselves, particles above the energy of the thermal
plasma traverse the heliosphere and indicate the extent of its
structures. Both the basic physics, as well as the spatial and temporal
evolution of disturbances, can be confused as they propagate through the
interplanetary medium largely because of the data coverage limitations.
However, as their basic physics becomes better known through more
complete observations and theory, the extent and accuracy of these
disturbances can be better described.
@--------------------------------------------------------------------
Title: Synoptic maps of heliospheric Thomson scattering
brightness from 1974-1985 as observed by the HELIOS
photometers
Authors: Hick, P.; Jackson, B. V.; Schwenn, R.
Bibliographic Code: 1992sws..coll..187H
Abstract
We display the electron Thomson scattering intensity of the inner
heliosphere as observed by the zodiacal light photometers on board the
Helios spacecraft in the form of synoptic maps. The technique
extrapolates the brightness information from each photometer sector near
the Sun and constructs a latitude/longitude map at a given solar height.
These data are unique in that they give a determination of heliospheric
structures out of the ecliptic above the primary region of solar wind
acceleration. The spatial extent of bright, co-rotating heliospheric
structures is readily observed in the data north and south of the
ecliptic plane where the Helios photometer coverage is most complete.
Because the technique has been used on the complete Helios data set from
1974 to 1985, we observe the change in our synoptic maps with solar
cycle. Bright structures are concentrated near the heliospheric equator
at solar minimum, while at solar maximum bright structures are found at
far higher heliographic latitudes. A comparison of these maps with other
forms of synoptic data are shown for two available intervals.
@--------------------------------------------------------------------
Title: Considerations of a Solar Mass Ejection Imager in a
Low Earth Orbit
Authors: Jackson, B. V.; Webb, D. F.; Altrock, R. C.;
Gold, R.
Bibliographic Code: 1992LNP...399..322J
Abstract
@--------------------------------------------------------------------
Title: Remote Sensing Observations of Mass Ejections and
Shocks in Interplanetary Space
Authors: Jackson, B. V.
Bibliographic Code: 1992LNP...399..248J
Abstract
@--------------------------------------------------------------------
Title: Eruptive Solar Flares
Authors: Svestka, Zdenek; Jackson, Bernard V.;
Machado, Marcos E.
Bibliographic Code: 1992LNP...399.....S
Abstract
This is an exhaustive survey of present-day solar research including
both theory and observations. It deals with eruptive flares, filament
eruption in x-rays and radio waves, energy release and transport, and
terrestrial response to solar flares. Details of the most recent SOLAR-A
project (launched shortly after the conference) are also presented.
@--------------------------------------------------------------------
Title: Electron groups traced from the sun to 1 AU
Authors: Jackson, Bernard V.; Leblanc, Yolande
Bibliographic Code: 1991SoPh..136..361J
Abstract
A variety of proxy methods such as solar flare positions and metric and
kilometric type III radio bursts from the sun are used to trace
electrons from the sun until they can be observed in situ as electrons
at the ISEE-3 spacecraft. Timing within the data sets involved is
carefully restricted in order to find a peak in the number of flares
associated with in situ electrons near 60 deg west solar longitude. This
peak shows that type III bursts can be fairly limited in spatial extent,
and that the best connection with the solar surface to the flare is
along the Archimedean magnetic field spiral. This spiral determination
is used to define an 'average' beam shape for an event. The electron
numbers at 2 and 29-45-keV energies combined with this average beam
shape are used to approximate the total numbers of electrons and energy
per burst for individual events. The total number of electrons and total
energy for events are found to vary significantly with flare type; on
average, brighter flares are associated with more electrons.
@--------------------------------------------------------------------
Title: Remote sensing of inner heliospheric plasmas
Authors: Jackson, Bernard V.
Bibliographic Code: 1991ucsd.rept.....J
Abstract
Solar disturbances produce major effects on the corona, the solar wind,
the interplanetary medium, and the Earth along with its magnetosphere.
We have developed new techniques for studying plasma disturbances in the
inner heliosphere by remotely sensing them. These techniques use data
from the HELIOS spacecraft zodiacal light photometers, the ISEE-3
spacecraft kilometer radio-wave experiment, and a variety of other
spacecraft and ground-based instruments. The zodiacal light photometers
on board the two HELIOS spacecraft (data coverage from 1974 to 1986)
provide the first good information about the heliospheric masses and
shapes of propagating disturbances. Metric and kilometric type II and
type III radiation caused by shock waves and fast moving electrons
respectively are another way to remotely sense the structures which
propagate outward from the Sun. The best kilometric radio wave sensing
of inner heliospheric plasma is available from the ISEE-3 spacecraft.
The investigations into the physics of the disturbances sensed by these
techniques and the ability to forecast their occurrences are well
underway.
@--------------------------------------------------------------------
Title: HELIOS spacecraft photometer observation of
elongated corotating structures in the
interplanetary medium
Authors: Jackson, B. V.
Bibliographic Code: 1991JGR....9611307J
Abstract
The Helios spacecraft zodiacal light photometers have observed coronal
mass ejections as they move outward in the inteplanetary medium. Images
formed from the Helios spacecraft photometer data show extended
structures moving from east to west over periods of many days. Sample
structures observed are shown to have positions relative to solar
elongation consistent with the curve of the Archimedian spiral. The
positions of over 40 of these structures ranged from low latitude to as
high as 50 deg, and their speeds have a mean value of 301 + or - 47
km/s. Modeling indicates that these structures can have densities many
times above the ambient and that the density in excess of an 1/r-squared
ambient can differ greatly along their curved extents at any given time.
Most of the structures measured in this sample either remain at about
the same density or decrease in density with height above the sun,
indicating that they are remnants of features formed near the solar
surface.
@--------------------------------------------------------------------
Title: Synoptic maps for the heliospheric Thomson
scattering brightness as observed by the HELIOS
photometers
Authors: Hick, P.; Jackson, B. V.; Schwenn, R.
Bibliographic Code: 1991A&A...244..242H
Abstract
A method for displaying the electron Thomson scattering intensity in the
inner heliosphere as observed by the zodiacal light photometers on board
the Helios spacecraft in the form of synoptic maps is presented. The
method is based on the assumption that the bulk of the scattering
electrons along the line of sight is located near the point closest to
the sun. Inner-heliospheric structures will generally be represented
properly in these synoptic maps only if they are sufficiently long-lived
(that is, a significant fraction of a solar rotation period). The
examples of Helios synoptic maps discussed (from data in April 1976 and
November 1978), indicate that it is possible to identify large-scale,
long-lived density enhancements in the inner heliosphere. It is expected
that the Helios synoptic maps will be particularly useful in the study
of corotating structures (e.g., streamers), and the maps will be most
reliable during periods when few transient featurs are present in the
corona, i.e., during solar minimum.
@--------------------------------------------------------------------
Title: The identification and characteristics of solar mass
ejections observed in the heliosphere by the HELIOS
2 photometers
Authors: Webb, D. F.; Jackson, B. V.
Bibliographic Code: 1990JGR....9520641W
Abstract
Observations were obtained using the three zodiacal light photometers of
the Helios 2 spacecraft in order to identify coronal mass ejections
(CMEs) in the interplanetary medium, to establish their heliospheric
characteristics, to compare them with those of CMEs observed near the
sun, and to determine the frequency of occurrence of CMEs from 1976
through 1979. Eighty percent of the white light transients are be
classified as CMEs moving outward from the sun. The average CME is found
to have a brightness increase of 2.3 S10 units in the 90-deg photometer,
an average duration of 37 h, and a speed of about 500 km/s, implying a
radial 'flow' dimension of about 0.4 AU, and a longitudinal width near
the sun of about 50 deg. The CMEs supply significant amounts of mass to
the inner heliosphere, especially around the maximum phase of solar
activity. During the rise of the last solar activity cycle, the CME
occurrence rate increased by an order of magnitude between cycle minimum
and maximum.
@--------------------------------------------------------------------
Title: On Representing the Large-scale Structure of the
Inner Heliosphere in Synoptic Maps
Authors: Hick, P.; Jackson, B. V.; Schwenn, R.
Bibliographic Code: 1990BAAS...22..810H
Abstract
@--------------------------------------------------------------------
Title: The HELIOS spacecraft zodiacal light photometers
used for comet observations and views of the Comet
West bow shock
Authors: Jackson, B. V.; Benensohn, R. M.
Bibliographic Code: 1990EM&P...48..139J
Abstract
Observations of Comet West (1976VI) and Comet Meier (1978XXI), obtained
during and after their perihelion passages with the UBV zodiacal-light
photometers on the Helios A and Helios B spacecraft, are reported and
analyzed. The motion of Comet West with respect to the earth and to
Helios A and B is characterized and illustrated with diagrams, and the
data are presented graphically. The extensive ion and dust tails of
Comet West are detected as blueing and reddening, respectively, in the
Helios observations, whereas Comet Meier is more compact and bluer, with
little evidence of a dust tail. A 'bump' of increased brightness in the
interplanetary medium ahead of Comet West is attributed to a bow shock
and shown to be consistent with previous direct observations indicating
neutral-gas production rates about 2.5 times greater than those seen in
Comet Halley.
@--------------------------------------------------------------------
Title: Type III Electron Beamwidth from Solar Flare
Longitudinal Distributions.
Authors: Jackson, B. V.
Bibliographic Code: 1990ppsa.conf..209J
Abstract
@--------------------------------------------------------------------
Title: Broad-band images of AKR from ISEE-3
Authors: Jackson, Bernard V.; Steinberg, Jean-Louis
Bibliographic Code: 1990LNP...362..102J
Abstract
The ISEE-3 observations (Steinberg et al., 1989) showed that radio waves
from naturally-occurring auroral kilometric radiation (AKR) in the range
of 45 to 150 kHz can, in some instances, be refracted or ducted away
from the location of the radio source. Linear contour images of AKR
source intensity at different frequencies, observed on three different
days when the solar wind density had different values are presented as
an evidence of this, showing that, as seen from ISEE-3, the apparent
location of the radiation from the spacecraft can be many degrees
tailward of the earth.
@--------------------------------------------------------------------
Title: Type III bursts traced from the solar surface to 1
AU
Authors: Leblanc, Yolande; Jackson, Bernard V.
Bibliographic Code: 1990IAUS..142..509L
Abstract
Type III radio bursts were traced from the sun until they can be
observed as in situ electrons at the ISEE-3 spacecraft. The study
extends over the period of operation of the electron experiment on
ISEE-3 from August 1978 to November 1979. The observations include data
from solar flares, kilometric-type III burst spectra from ISEE-3, and in
situ measurements of low-energy electrons from ISEE-3. By carefully
restricting the data sets involved, a peak is found of 20-deg width in
the number of flares associated with in situ electrons near 60-deg west
solar longitude. This peak shows that the electron beams of type III
bursts are not spread over a great range of longitudes as earlier
studies indicate, but are fairly limited in spatial extent. However,
even in that longitude range, only 40 percent of type-III-flare events
are associated with in situ electrons.
@--------------------------------------------------------------------
Title: Giant solar arches and coronal mass ejections in
November 1980
Authors: Svestka, Zdenek F.; Jackson, Bernard V.;
Howard, Russell A.; Sheeley, Neil R., Jr.
Bibliographic Code: 1989SoPh..122..131S
Abstract
Data from the Solwind coronagraph and photometers aboard Helios-A are
used to examine coronal mass ejections from an active region which
produced a series of giant postflare coronal arches. HXIS X-ray
observations reveal that in several cases underlying flares did not
disrupt these arch structures, but simply revived them, enhancing their
temperature, density and brightness. Reliable evidence is found that two
dynamic flares which clearly revived the preexisting giant arch were not
associated with any mass ejection. After two other flares, which were
associated with mass ejections, the arch might have been newly formed
when the ejection was over. In one of these cases, however, the arch had
typical characteristics of a revived structure, so that it is likely
that it survived a powerful mass ejection nearby.
@--------------------------------------------------------------------
Title: Remote Observation of Co-rotating Interplanetary
Structures Using the HELIOS Zodiacal Light
Photometers
Authors: Jackson, B. V.
Bibliographic Code: 1989BAAS...21..858J
Abstract
@--------------------------------------------------------------------
Title: Interplanetary Solar Wind Brightness Synoptic Maps
from the HELIOS Zodiacal Light Photometers
Authors: Hick, P. L.; Jackson, B. V.; Schwenn, R.
Bibliographic Code: 1989BAAS...21..858H
Abstract
@--------------------------------------------------------------------
Title: Design considerations for a "Solar Mass Ejection
Imager" on a rotating spacecraft.
Authors: Jackson, B. V.; Hudson, H. S.; Nichols, J. D.;
Gold, R. E.
Bibliographic Code: 1989GMS....54..291J
Abstract
The authors describe an instrument capable of imaging the time-varying
features of the entire outer corona (from near the Sun to beyond 90°
elongation) via the Thomson-scattered diffuse solar light. This "all
sky" imager works on a spin-stabilized spacecraft, preferably in deep
space.
@--------------------------------------------------------------------
Title: Heliospheric remote sensing using the zodiacal light
photometers of the Helios spacecraft.
Authors: Jackson, B. V.
Bibliographic Code: 1989GMS....54..287J
Abstract
The Helios spacecraft zodiacal light photometers have been used to image
solar mass ejections, corotating heliospheric density enhancements and
density enhancements behind shock waves to distances of 1 AU from the
Sun. To first order, sunlight scattered from heliospheric electrons
provides the measured brightness ascribed to these features. Remote
sensing observations of these features indicate extensive structures
which propagate throughout the inner heliosphere.
@--------------------------------------------------------------------
Title: Coronal mass ejections and coronal structures.
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.; Kahler, S. W.; Kopp, K.; Low, B. C.;
Lantos, P.; Phillips, K. J. H.; Poletto, G.;
Sheeley, N. R., Jr.; Stewart, R. T.; Svestka, Z.;
Waggett, P. W.; Wu, S. T.
Bibliographic Code: 1989epos.conf..493H
Abstract
The work of this team was concerned with modelling of post-flare arches,
the reconnection theory of flares, the slow variation of coronal
structure, and the coronal and interplanetary detection, evolution, and
consequences of mass ejections.
@--------------------------------------------------------------------
Title: Three-dimensional reconstruction of coronal mass
ejections
Authors: Jackson, B. V.
Bibliographic Code: 1989AdSpR...9...69J
Abstract
Computer assisted tomography techniques are used to reconstruct the
three-dimensional shapes of coronal mass ejections in the interplanetary
medium. It is assumed that Thomson scattering of sunlight from electrons
is the source of variations in the observed brightness in the data
provided by the HELIOS spacecraft zodiacal light photometers and by the
SOLWIND coronagraph. The density of a mass ejection which arose from the
sun on May 7, 1979 is determined.
@--------------------------------------------------------------------
Title: Solar and interplanetary observations of the mass
ejection on 7 May, 1979
Authors: Jackson, Bernard V.; Rompolt, Bogdan;
Svestka, Zdenek
Bibliographic Code: 1988SoPh..115..327J
Abstract
Observations of mass ejection obtained on May 7, 1979 by five different
instruments from the solar surface out to more than 100 solar radii are
used to produce a three-dimensional density reconstruction of the mass
ejection and to fit the best velocity curve for its propagation. The
results show higher speeds at greater distances from the sun. The plasma
acceleration was found to continue beyond the outer limit of the
coronagraph view at about 8 solar radii.
@--------------------------------------------------------------------
Title: Scientific background and design specifications for
a near-earth heliospheric imager
Authors: Jackson, B. V.
Bibliographic Code: 1988ucsd.rept.....J
Abstract
This report is intended to define the instrument specifications for a
heliospheric imager capable of observing transient, diffuse features in
the heliosphere from a spacecraft near 1 AU. These features include
coronal mass ejections, co-rotating density enhancements, shock waves
and any other disturbances that can affect the intensity of the
electron-scattering coronal brightness. Our technique of imaging a large
portion of the heliosphere using the HELIOS spacecraft zodiacal-light
photometers has shown that it is possible to measure the structures
around a spacecraft and to make good measurements of material in and out
of the ecliptic plane. The HELIOS data show that it is possible to
determine the velocities and spatial distributions of the large-scale
features which propagate into the heliosphere. The instrumentation may
be regarded as a successor to the zodiacal light photometers of the
HELIOS spacecraft. Such a second-generation instrument based on these
principals could make effective use of in situ solar wind data from
spacecraft in the vicinity of the imager, and would allow study of the
effects of heliospheric structure interaction with the magnetosphere as
never before possible. In addition, the imager would allow up to three
days warning of the arrival of a mass ejection at Earth from the Sun.
@--------------------------------------------------------------------
Title: Comet West: A view from the HELIOS zodiacal light
photometers
Authors: Benensohn, R. M.; Jackson, B. V.
Bibliographic Code: 1987sici.symp...46B
Abstract
Comet West passed through perihelion on February 25, 1976. The comet
crossed the HELIOS A and B spacecraft zodiacal light photometer fields
of view as the spacecraft orbited the Sun, allowing them to record the
brightness, polarization, and color of the comet and its surrounding
interplanetary medium. Data from the U, B, and V photometers across the
tail shows a distinct bluing followed by a slight reddening
corresponding to the ion and dust tails, respectively, entering the
field of view. The non-Earth perspective of the HELIOS photometers
allows a comparison of the tail with Earth observations at the same
time. Precise location of the nucleus and tail allow the photometer data
to be searched for evidence of the comet bow shock and orbital dust. A
brightness bump present in the data before the comet reaches some
photometer positions, can be shown to approximately form a parabolic
shape Sunward and ahead of the orbital motion of the Comet West nucleus.
If this is the comet bow shock or bow compression, then it corresponds
to a density enhancement of the ambient medium by 1.5 to 2 times in the
vicinity of the comet. The distance of the brightness increase from the
nucleus by comparison with Comet Halley implies a neutral gas production
rate of approximately 3 times that of Halley.
@--------------------------------------------------------------------
Title: Three-Dimensional Reconstruction of Coronal Mass
Eiections
Authors: Froehling, B. R.; Jackson, B. V.
Bibliographic Code: 1987BAAS...19R.931F
Abstract
@--------------------------------------------------------------------
Title: A Current System Asymmetry Relative to the Poles of
an Expanding Bipolar Active Region
Authors: Jackson, B. V.
Bibliographic Code: 1987BAAS...19..941J
Abstract
@--------------------------------------------------------------------
Title: Solar and Interplanetary Observations of the Mass
Ejection on 7 May 1979
Authors: Jackson, B. V.; Rompolt, B.; Svestka, Z.
Bibliographic Code: 1987sowi.conf..272J
Abstract
@--------------------------------------------------------------------
Title: Detection of CMEs in the Interplanetary Medium from
1976-1979 Using Helios-2 Photometer data
Authors: Webb, D. F.; Jackson, B. V.
Bibliographic Code: 1987sowi.conf..267W
Abstract
@--------------------------------------------------------------------
Title: Coronal mass ejections and coronal structures
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.
Bibliographic Code: 1986epos.conf..6.1H
Abstract
Research on coronal mass ejections (CMF) took a variety of forms, both
observational and theoretical. On the observational side there were:
case studies of individual events, in which it was attempted to provide
the most complete descriptions possible, using correlative observations
in diverse wavelengths; statistical studies of the properties CMEs and
their associated activity; observations which may tell us about the
initiation of mass ejections; interplanetary observations of associated
shocks and energetic particles even observations of CMEs traversing
interplanetary space; and the beautiful synoptic charts which show to
what degree mass ejections affect the background corona and how rapidly
(if at all) the corona recovers its pre-disturbance form. These efforts
are described in capsule form with an emphasis on presenting pictures,
graphs, and tables so that the reader can form a personal appreciation
of the work and its results.
@--------------------------------------------------------------------
Title: A metric type III burst asymmetry relative to simple
bipolar active regions
Authors: Jackson, B. V.
Bibliographic Code: 1986SoPh..105..123J
Abstract
Metric type III solar radio burst positions are compared spatially and
temporally to underlying active region geometry. The positions of these
radio bursts have an asymmetric location distribution relative to simple
bipolar regions. The type III bursts show a tendency to occur nearer the
leading active region - an association shown before from type III burst
and magnetic field polarity measurements. The type III bursts also
generally occur to the left of the outward to inward directed magnetic
field. The asymmetry relative to the outward directed magnetic field has
a sense that is consistent with a mechanism of type III burst production
that involves a pre-existing coronal current system situated between
expanding closed and open magnetic field lines.
@--------------------------------------------------------------------
Title: Coronal mass ejection associated with the stationary
post-flare arch of 21-22 May 1980
Authors: McCabe, M. K.; Svestka, Z. F.; Howard, R. A.;
Sheeley, N. R., Jr.; Jackson, B. V.
Bibliographic Code: 1986SoPh..103..399M
Abstract
By using a combination of X-ray (HXIS), Halpha (Haleakala),
white-light corona (Soiwind), and zodiacal light (Helios) images on
21-22 May, 1980 we demonstrate, and try to explain, the co-existence of
a coronal mass ejection with a stationary post-flare coronal arch. The
mass ejection was seen, both by Solwind and Helios, in prolongation of
the path of a powerful spray, whereas the active region filament did not
erupt. A tentative comparison is made with other occurrences of
stationary, or quasi-stationary post-flare coronal arches.
@--------------------------------------------------------------------
Title: Helios Images of Coronal Mass Ejections
Authors: Jackson, B. V.
Bibliographic Code: 1986shtd.symp..113J
Abstract
The zodiacal light photometers on board the HELIOS spacecraft can be
used to form images of coronal mass ejections in the interplanetary
medium. Several aspects of these data are unique: they trace coronal
mass ejections using Thomson scattering techniques to distances from the
Sun greater than 0.5 AU; their perspective from the HELIOS orbits allow
information to be gained about the three-dimensional shapes of specific
mass ejections viewed both by coronagraphs and HELIOS; the global view
afforded by the spacecraft photometers can image the mass ejection from
within and thus relate in situ measurements to the shape of the whole
structure.
@--------------------------------------------------------------------
Title: Coronal mass ejections and coronal structures.
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.; Kahler, S. W.; Kopp, K.; Low, B. C.;
Lantos, P.; Phillips, K. J. H.; Poletto, G.;
Sheeley, N. R., Jr.; Stewart, R. T.; Svestka, Z.;
Waggett, P. W.; Wu, S. T.
Bibliographic Code: 1986NASCP2439....6H
Abstract
Contents: 1. Introduction. 2. Observations. 3. Initiation of coronal
mass ejections - observations. 4. Modelling of coronal mass ejections
and post-flare arches. 5. Interplanetary effects of coronal mass
ejections. 6. The slowly varying corona near solar activity maximum. 7.
Summary.
@--------------------------------------------------------------------
Title: Modelling of Coronal Mass Ejections and POST Flare
Arches
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.; Kahler, S. W.; Kopp, K.; Low, B. C.;
Lantos, P.; Phillips, K. J. H.; Poletto, G.;
Sheeley, N. R., Jr.; Steward, R. T.; Svestka, Z.;
Waggett, P. W.; Wu, S. T.
Bibliographic Code: 1986epos.conf6.366H
Abstract
@--------------------------------------------------------------------
Title: The Slowly Varying Corona Near Solar Activity
Maximum
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.; Kahler, S. W.; Kopp, K.; Low, B. C.;
Lantos, P.; Phillips, K. J. H.; Poletto, G.;
Sheeley, N. R., Jr.; Steward, R. T.; Svestka, Z.;
Waggett, P. W.; Wu, S. T.
Bibliographic Code: 1986epos.conf.6.57H
Abstract
@--------------------------------------------------------------------
Title: Interplanetary Effects of Coronal Mass Ejections
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.; Kahler, S. W.; Kopp, K.; Low, B. C.;
Lantos, P.; Phillips, K. J. H.; Poletto, G.;
Sheeley, N. R., Jr.; Steward, R. T.; Svestka, Z.;
Waggett, P. W.; Wu, S. T.
Bibliographic Code: 1986epos.conf.6.52H
Abstract
@--------------------------------------------------------------------
Title: Initiations of Coronal Mass Ejections
Authors: Hildner, E.; Bassi, J.; Bougeret, J. L.;
Duncan, R. A.; Gary, D. E.; Gergely, T. E.;
Harrison, R. A.; Howard, R. A.; Illing, R. M. E.;
Jackson, B. V.; Kahler, S. W.; Kopp, K.; Low, B. C.;
Lantos, P.; Phillips, K. J. H.; Poletto, G.;
Sheeley, N. R., Jr.; Steward, R. T.; Svestka, Z.;
Waggett, P. W.; Wu, S. T.
Bibliographic Code: 1986epos.conf.6.27H
Abstract
@--------------------------------------------------------------------
Title: HELIOS photometer measurement of in-situ density
enhancements
Authors: Jackson, B. V.
Bibliographic Code: 1986AdSpR...6..307J
Abstract
The Helios spacecraft zodiacal light photometers have been used to image
coronal mass ejections and coronal streamers in the interplanetary
medium. The Helios photometers have the ability to image such features
beyond 90 deg angular distance from the sun. This provides a unique
opportunity to measure brightness enhancements which are also observed
as density increases in situ by the Helios spacecraft plasma probes.
Here, comparisons are made of the brightness enhancements and in situ
density increases following shocks defined by the plasma and magnetic
field data. Five well-observed shocks from 1986 and 1979 illustrate
these comparisons. Each event can be followed in photometer data as it
sweeps past the Helios spacecraft. To first order, the enhancements of
brightness following shocks indicate structures which extent over many
tenths of an astronomical unit and colors which are consistent with
Thomson scattering of sunlight by electrons.
@--------------------------------------------------------------------
Title: HELIOS images of solar mass ejections
Authors: Jackson, B. V.; Leinert, C.
Bibliographic Code: 1985JGR....9010759J
Abstract
The zodiacal light photometers on board the Helios B spacecraft are used
to form images of solar mass ejection transients in the interplanetary
medium. Several aspects of these data are unique: (1) They trace shapes
of solar mass ejections observed near the solar surface in coronagraph
images to distances at least as great as 0.5 AU using electron Thomson
scattering. (2) When compared with earth-based observations, the Helios
data allow determination of the three-dimensional shapes of the
ejections. (3) The global viewpoint of the Helios spacecraft photometers
allows imaging of mass ejections heading toward the spacecraft and then
observations from within the ejection. Excess masses (above the ambient
level) are determined for several ejections, and the authors find that
they are generally comparable to or somewhat larger than masses obtained
by coronagraph observations of ejections when they are closer to the
sun.
@--------------------------------------------------------------------
Title: Imaging of coronal mass ejections by the HELIOS
spacecraft
Authors: Jackson, B. V.
Bibliographic Code: 1985SoPh..100..563J
Abstract
An account is given of the use of the zodiacal light photometers on
board the Helios spacecraft to form images of coronal mass ejections in
the interplanetary medium. Several aspects of these data are unique:
they trace coronal mass ejections using Thomson scattering techniques to
distances from the sun greater than 0.5 AU; their perspective from the
Helios orbits allows information to be gained about the
three-dimensional shapes of specific mass ejections viewed both by
coronagraphs and Helios; the global view afforded by the spacecraft
photometers can image the mass ejection from within and thus relate in
situ measurements to the shape of the whole structure. To date, the
Helios photometers have been used to study coronagraph-observed mass
ejections including those originating at the sun on May 7, May 24, and
November 27, 1979 and May 21, June 18, and November 6, 1980. Masses of
ejections determined from these data are generally a few times larger
than masses determined from Solwind coronagraph images.
@--------------------------------------------------------------------
Title: HELIOS spacecraft and earth perspective observations
of three looplike solar mass ejection transients
Authors: Jackson, B. V.; Howard, R. A.; Sheeley, N. R., Jr.;
Michels, D. J.; Koomen, M. J.; Illing, R. M. E.
Bibliographic Code: 1985JGR....90.5075J
Abstract
Three looplike mass ejection transients observed from earth with the
SOLWIND coronagraph and the solar maximum mission coronagraph are imaged
by Helios spacecraft zodiacal light photometers. Because the Helios
spacecraft are not earth orbiting, views of these ejections from the two
perspectives allow conclusions to be drawn about their three-dimensional
shapes. The mass ejection of May 24, 1979, in Helios data is
concentrated in an outer structure followed by bright features separated
by a region of depleted material. The ejections of June 18 and 29, 1980,
appear restricted in position angle in Helios observations too less and
the same, respectively, as in coronagraph observations. The observations
imply that the ejections essentially retain their basic structure and
speed out to heights (0.2 - 0.4 AU) observed by the Helios spacecraft.
@--------------------------------------------------------------------
Title: Use of interplanetary scintillation for Earth space
environment and geomagnetic forecasting
Authors: Jackson, B. V.; Rickett, B. J.
Bibliographic Code: 1985ucsd.reptQ....J
Abstract
A comparison is presented between solar wind velocities determined from
IPS (Interplanetary Scintillation) observations made from 1973 to 1981
with those measured in situ by spacecraft instruments. The IPS method is
indirect but it provides reasonably accurate estimates of the large
scale and slowly varying velocity structures in the solar wind. Thus the
corotating solar wind streams typical of 1973 to 1975 (declining and low
solar activity) are well estimated; the slower average speed typical of
1979 to 1981 was also well estimated. However, the transient increases
during this period of high solar activity were often not detected. The
difficulties of interpretation are offset by the capacity to monitor the
solar wind speed out of the ecliptic and over long periods of the time
without the expense of a spacecraft.
@--------------------------------------------------------------------
Title: The Brightness of the Interplanetary Medium in
Thomson Scattering from 0.3 to 1.0 AU: Comparison
with a View from Helios B
Authors: Venkataraman, A.; Hudson, H. S.; Jackson, B. V.
Bibliographic Code: 1985BAAS...17..638V
Abstract
@--------------------------------------------------------------------
Title: The Mass Distribution of Coronal Mass Ejections
Authors: Jackson, B. V.; Howard, R. A.; Koomen, M. J.;
Michels, D. J.; Sheeley, N. R., Jr.
Bibliographic Code: 1985BAAS...17..636J
Abstract
@--------------------------------------------------------------------
Title: HELIOS observations of the earthward-directed mass
ejection of 27 November, 1979
Authors: Jackson, B. V.
Bibliographic Code: 1985SoPh...95..363J
Abstract
The Helios-spacecraft zodiacal light photometers are used to observe the
earthward-directed solar-mass ejection transient of November 27, 1979
described by Howard et al. (1982) that completely circles the sun in
coronagraph observations. At this time, Helios B was situated 30 deg
east of the sun-earth line at 0.5 AU. The brightness increase moved
outward directly along the sun-earth line over a period of approximately
24 hr, indicating a strong collimation of the ejection. The outward
motion and mass estimates of the ejected material from the photometers
compared with near-earth observations from IMP spacecraft show that at
least a portion of the density increase observed at earth on November 29
and 30 was associated with this ejection.
@--------------------------------------------------------------------
Title: Helios Observations of the Earthward-Directed Mass
Ejection of 27 November 1979
Authors: Jackson, B. V.
Bibliographic Code: 1984BAAS...16..930J
Abstract
@--------------------------------------------------------------------
Title: A New UHF Antenna for IPS and Pulsar Observations
Authors: Kojima, M.; Coles, W. A.; Jackson, B. V.;
Frehlich, R. B.
Bibliographic Code: 1984BAAS...16..517K
Abstract
@--------------------------------------------------------------------
Title: Helios Spacecraft and Earth Perspective Observations
of the Loop-Like Solar Mass Ejection of 24 May 1979
Authors: Jackson, B. V.
Bibliographic Code: 1984BAAS...16..453J
Abstract
@--------------------------------------------------------------------
Title: Energetics and Interplanetary Effects of the August
14 and 18, 1979 Solar Flares: Summary of
Observations Made during the Smy/stip Event no.
Authors: Kane, S. R.; Bird, M. K.; Domingo, V.; Gapper, G. R.;
Green, G.; Hewish, A.; Howard, R. A.; Iwers, B.;
Jackson, B. V.; Koren, U.; Kunow, H.; McGuire, R. E.;
Muller-Mellin, R.; Rompolt, B.; Sanahuja, B.;
Sawant, H. S.; Stewart, R. T.; von Rosenvinge, T.;
Wibberenz, G.; Zlobec, P.
Bibliographic Code: 1984sii..conf..175K
Abstract
@--------------------------------------------------------------------
Title: IPS and Spacecraft Observations of the 14 August
1979 Mass Ejection Transient
Authors: Jackson, B. V.
Bibliographic Code: 1984sii..conf..169J
Abstract
@--------------------------------------------------------------------
Title: Helios Images of a Coronal Mass Ejection Transient
Authors: Jackson, B. V.; Howard, R. A.; Koomen, M. J.;
Michels, D. J.; Sheeley, N. R.
Bibliographic Code: 1983BAAS...15..705J
Abstract
@--------------------------------------------------------------------
Title: Energetics and interplanetary effects of the August
14 and 18, 1979 solar flares
Authors: Kane, S. R.; Bird, M. K.; Domingo, V.; Green, G.;
Gapper, G. R.; Hewish, A.; Howard, R. A.; Iwers, B.;
Jackson, B. V.; Koren, U.
Bibliographic Code: 1983STIN...8329164K
Abstract
The STIP Event No. 1, which covered the time interval August 14 - 18,
1979, was characterized by two energetic flares: one on August 14
(approximately 1243 UT) and the other on August 18 (approximately 1400
UT). The hard X-ray, soft X-ray, optical, radio and energetic particle
emissions from these flares and their interplanetary effects were
observed with many instruments in space and on the ground. A summary of
some of these observations is presented. The results of a preliminary
analysis relevant to the acceleration of particles, coronal transients
and evolution of shocks are as follows: (1) During the August 14 flare
energetic particles were probably accelerated but could not escape the
Sun in large numbers. On the other hand, during the August 18 flare the
acceleration of high energy particles occurred relatively high in the
corona, from whence they could easily escape into interplanetary space
but could not penetrate down to the lower altitudes in the solar
atmosphere in large numbers. (2) The kinetic energy of the coronal
transient associated with the August 14 flare was much larger than the
total energy of energetic electrons, indicating an additional energy
source for the transient. (3) The shock associated with the August 18
flare extended to greater than 2 (3.14) steradians. The shock maintained
its speed from the flare site to a distance of approximately 35 R and
then decelerated to a distance of approximately 1 AU as approximately R
to the minus 0.8 power.
@--------------------------------------------------------------------
Title: Kinematical analysis of flare spray ejecta observed
in the corona
Authors: Webb, D. F.; Jackson, B. V.
Bibliographic Code: 1981SoPh...73..341W
Abstract
Observations in H-alpha, soft X-ray, white light and radio wavelengths
are used to track cool and hot material from limb de-occultation to the
extent of six solar radii. The kinematics and thermodynamics of the
internal material are determined, along with the overall mass and energy
budget of the event. It is found that the majority of the mass and
energy is linked with the coronal material, but at least 20% of the
ejected mass originated as near-surface prominence material, leading to
the conclusions that the upper part of the prominence was being heated
to coronal temperatures as it rose through the corona. Evidence was
found that a moving type IV burst, indicative of strong magnetic fields,
was associated with the upper part of the prominence, and the
observations are judged to be most consistent with magnetic propulsion
models of coronal transients.
@--------------------------------------------------------------------
Title: A comparison of Type III metric radio bursts and
global solar potential field models
Authors: Jackson, B. V.; Levine, R. H.
Bibliographic Code: 1981SoPh...73..183J
Abstract
Evidence of coronal magnetic fields from polarized metric type III radio
bursts is compared with (1) global potential field models, (2) direct
averages of the observed photospheric magnetic field, and (3) H-alpha
synoptic charts. The comparison clearly indicates both that the
principal aspects of type III burst radiation are understood and that
global potential field models are a significantly more accurate
representation of coronal magnetic field structure than either the
large-scale photospheric field or H-alpha synoptic charts.
@--------------------------------------------------------------------
Title: Forerunners - Early coronal manifestations of solar
mass ejection events
Authors: Jackson, B. V.
Bibliographic Code: 1981SoPh...73..133J
Abstract
Coronal ejection transients viewed with the white light coronagraph on
Skylab are studied from the times of their very earliest manifestations
for clues to their origin. Excess coronal mass with a configuration like
that of the eventual transient is seen in twelve events prior to the
transient's associated near-surface H-alpha eruption or flare. In seven
of the events, data are adequate to observe the rates of outward mass
motion of coronal material prior to their surface manifestations. The
observations place severe constraints on different solar mass ejection
mechanisms because they spread the process responsible for the ejection
over a larger region of the corona and over a longer period of time than
normally considered. The observations suggest the corona is an active
participant in the ejection that begins with the acceleration of the
outer portion of a preexisting structure and ends with the obvious
surface manifestation.
@--------------------------------------------------------------------
Title: The three-dimensional structure of the solar wind
from radio scintillations
Authors: Jackson, B. V.; Nagendran, A.
Bibliographic Code: 1981ucsd.rept.....J
Abstract
Since 1972 the UCSD 74 MHz radio observatory has continuously monitored
the solar wind using the method of interplanetary scintillation (IPS).
The two reports presented here bear on the problems involved in tracing
the fast changing three dimensional structure of the solar wind from the
solar surface out to the vicinity of the Earth. The interplanetary
scintillation technique is a radio propagation method for studying the
velocity and small scale (approximately 100 to 1000 km) turbulence in
the solar wind. The signals are cross-correlated from three spaced
antennas to yield time offsets from which the speed of the scintillation
pattern can be deduced. Comparisons of IPS observations with spacecraft
measurements have shown excellent agreement when the IPS source lies in
the ecliptic plane. Furthermore, observations can be made in the
direction of many radio sources (almost) simultaneously so as to
generate a three-dimensional map of the solar wind. The eight-year data
base is important for correlative studies throughout the solar cycle. In
our analysis we emphasize three time scales are emphasized: (1) the
solar cycle evolution of six month average velocity structures; (2)
studies of one solar rotation duration; and (3) variations in the solar
wind structure on time scales of a few days.
@--------------------------------------------------------------------
Title: An Active Region-Type III Burst Association
Authors: Jackson, B. V.
Bibliographic Code: 1981BAAS...13..861J
Abstract
@--------------------------------------------------------------------
Title: Solar Cycle Variation of IPS Transients Observed
Near Earth
Authors: Jackson, B. V.
Bibliographic Code: 1980BAAS...12..920J
Abstract
@--------------------------------------------------------------------
Title: Kinematical Analysis of a Spray Observed in the
Corona
Authors: Webb, D. F.; Jackson, B. V.
Bibliographic Code: 1980BAAS...12..527W
Abstract
@--------------------------------------------------------------------
Title: A Comparison of Type III Metric Radio Bursts and
Global Solar Potential Field Models
Authors: Jackson, B. V.; Levine, R. H.
Bibliographic Code: 1980BAAS...12..515J
Abstract
@--------------------------------------------------------------------
Title: The preflare state
Authors: van Hoven, G.; Barbosa, D. D.; Birn, J.;
Cheng, C.-C.; Hansen, R. T.; Jackson, B. V.;
Martin, S. F.; McIntosh, P. S.; Nakagawa, Y.;
Anzer, U.
Bibliographic Code: 1980sfsl.work...17V
Abstract
The accumulation, storage and irreversible release of the free energy
necessary for a solar flare are discussed on the basis of data obtained
from the Apollo Telescope Mount on Skylab and other pertinent sources.
Skylab and OSO 7 observations of possible flare precursors and flare
evolution are presented, and the evolution of the flare of Sept. 5,
1973, the most completely observed flare of the Skylab program, is
described in detail, with account given to magnetic structures and H
alpha radiation. Theories of the preflare state are then reviewed, with
attention given to the force-free fields and coronal arcades, thermal
and magnetic structures and the MHD stability of coronal loops.
@--------------------------------------------------------------------
Title: The association of type III bursts and coronal
transient activity
Authors: Jackson, B. V.; Dulk, G. A.; Sheridan, K. V.
Bibliographic Code: 1980IAUS...91..379J
Abstract
A broad peak in the number of isolated type III bursts occurring about
five hours prior to large H-alpha solar flares is reported. It is
suggested that the increase and subsequent decrease in type III activity
indicates a new phase in the coronal adjustment to the long-term
addition of energy, with some of the energy going into lifting the
plasma and some possibly into the kinetic energy of moving plasma. The
peak in the type III activity may signal the beginning of outward
coronal plasma motion. The peak may thus be studied for clues to the
energy input mechanism or mechanisms responsible for mass ejection
transients.
@--------------------------------------------------------------------
Title: Comparison of radioheliograph, coronagraph and
K-coronameter observations of a coronal streamer
Authors: Jackson, B. V.; Dulk, G. A.; Sheridan, K. V.
Bibliographic Code: 1979PASAu...3..387J
Abstract
A comparison is made of observations of a bright coronal streamer made
with an 80 MHz radioheliograph, a K-coronameter, and the Skylab white
light coronagraph. The values of polarization radiance were used to
derive a coronal density model, and an alternative model was calculated
for a streamer density distribution such as given by Newkirk (1961);
neither model fits the radioheliograph observations well. In particular,
radio brightnesses are lower than expected on the basis of white light
or EUV data, at least at low heights near the plasma level. With regard
to this discrepancy, fundamental questions about the nature of the
corona and wave propagation through a streamer structure are considered.
@--------------------------------------------------------------------
Title: Evidence for a peak in the number of isolated Type
III bursts prior to large solar flares
Authors: Jackson, B. V.; Sheridan, K. V.
Bibliographic Code: 1979PASAu...3..383J
Abstract
Evidence for a broad maximum in the number of isolated metric-wave Type
III bursts prior to the large H alpha solar flares observed between May
1973 and February 1974 is reported. The time distribution of isolated
Type III bursts within 12.6 h of each of the 111 solar flares of
importance 1 or greater recorded during the period is shown to peak
approximately 5 h before the time of flare maximum, most markedly in the
case of bursts with projected positions near the solar flare position.
The examination of H alpha, X-ray and magnetogram data in the vicinity
of the flare implies a purely coronal storage and release mechanism for
the flare energy. The peak of Type III burst activity is thus suggested
as a good indicator of coronal energy input and storage near the time of
a large solar flare, although not a reliable flare predictor.
@--------------------------------------------------------------------
Title: Forerunners - Outer rims of solar coronal transients
Authors: Jackson, B. V.; Hildner, E.
Bibliographic Code: 1978SoPh...60..155J
Abstract
The large loop or blob-like transient events viewed in the white-light
corona are rimmed by broad regions where the density is slightly
enhanced above the pretransient corona. Every one of the Skylab events
studied for which sufficiently good Skylab coronagraph coverage is
available shows this effect. The upper boundaries of these 'forerunners'
blend gradually into the background corona 1-2 solar radii above the
transient's leading edges. In any single event, the coronal mass
enhancement represented by the forerunner comprises up to 25% of the
total excess mass present in the coronagraph's field of view and
includes a much larger volume of the corona than previously attributed
to the underlying transient. A forerunner without an accompanying
transient has not yet been seen. Clearly, forerunners must be reckoned
with in any proposed models of discrete outward coronal mass motions,
because they indicate the presence of disturbed corona far ahead of the
denser portions of the event.
@--------------------------------------------------------------------
Title: Radio observations of a massive, slow moving
ejection of coronal material
Authors: Sheridan, K. V.; Jackson, B. V.; McLear, D. J.;
Dulk, G. A.
Bibliographic Code: 1978PASAu...3..249S
Abstract
@--------------------------------------------------------------------
Title: A possible association of solar type III bursts and
white light transients
Authors: Jackson, B. V.; Sheridan, K. V.; Dulk, G. A.;
McLean, D. J.
Bibliographic Code: 1978PASAu...3..241J
Abstract
The possibility is considered whether type III bursts are in any way
related to mass ejections indicated by white-light coronal transients.
Forty coronal transients observed from Skylab are used to investigate
the possible association with meter-wave type III bursts. It is shown
that the time interval 5 to 10 hr prior to the time of a transient
observation has at least 2.5 times the number of type III bursts
expected and that the peak in the number of type III bursts also occurs
in this time interval when the data are divided into various groupings.
Positions of type III bursts are found usually to be located within 20
deg of the solar position angle of the corresponding transients.
@--------------------------------------------------------------------
Title: Coronal Mass Increases Prior to Surface Halpha Eruptions
from the Sun.
Authors: Jackson, B. V.
Bibliographic Code: 1977BAAS....9..569J
Abstract
@--------------------------------------------------------------------
Title: Atmospheric water vapor at South Pole
Authors: Smythe, William D.; Jackson, Bernard V.
Bibliographic Code: 1977ApOpt..16.2041S
Abstract
@--------------------------------------------------------------------
Title: Open magnetic structures on the sun
Authors: Levine, R. H.; Altschuler, M. D.; Harvey, J. W.;
Jackson, B. V.
Bibliographic Code: 1977ApJ...215..636L
Abstract
High-resolution harmonic analysis of the solar magnetic field has been
used succesfully to calculate the geometry of open magnetic field lines
in the solar corona. Comparison of the loci of open-field-line
footpoints with solar X-ray photographs shows that all the coronal holes
during two solar rotations are successfully represented, including
details of their evolution. Some open magnetic configurations derived in
the calculations precede by up to one solar rotation the manifestation
of coincident dark areas on the X-ray photographs. The only other areas
that contribute open field lines to the corona are separations between
active-region loop systems. By varying the radius at which field lines
are forced to be open in the calculation, it is possible to reproduce
more closely the surface configuration of particular coronal holes.
Comparison of the size of X-ray holes with the fraction of the solar
surface covered by open field lines leads to the conclusion that a
significant part of the area of coronal holes must contain closed
magnetic fields. Comparison of open field lines which lie in the
equatorial plane of the sun with solar-wind data indicates that eventual
high-speed solar-wind streams are associated with those parts of open
magnetic structures that diverge the least.
@--------------------------------------------------------------------
Title: Physical properties of a polar coronal hole from 2
to 5 solar radii
Authors: Munro, R. H.; Jackson, B. V.
Bibliographic Code: 1977ApJ...213..874M
Abstract
Observations with a white-light coronagraph aboard Skylab are used to
determine the boundaries of a coronal hole in the northern polar region
and the three-dimensional density structure within the hole between
heights of 2 and 5 solar radii. The boundary of the hole is found to be
essentially axisymmetric about the polar axis, nearly radial from 3 to 6
solar radii, and located near 25 deg latitude at these heights. The
radiances arising from the hole are interpreted as resulting from an
axisymmetric density distribution whose logarithmic radial gradient is
independent of position within the hole and whose magnitude increases
with angular distance away from the hole's axis. The velocity
distribution within the hole is obtained from the continuity equation by
assuming that the particle flux flowing outward in the hole is similar
to that measured for high-speed solar-wind streams at 1 AU, and it is
shown that the transition from subsonic to supersonic flow occurs
between 2.2 and 3 solar radii.
@--------------------------------------------------------------------
Title: Forerunners Rim Solar Transients.
Authors: Jackson, B. V.
Bibliographic Code: 1977BAAS....9..368J
Abstract
@--------------------------------------------------------------------
Title: A Polar Coronal Hole: I. The Three Dimensional
Boundary
Authors: Jackson, B. V.
Bibliographic Code: 1976BAAS....8..325J
Abstract
@--------------------------------------------------------------------
Title: The Residual Daily Earth Tides at the South Pole
Authors: Jackson, B. V.; Slichter, L. B.
Bibliographic Code: 1974JGR....79.1711J
Abstract
@--------------------------------------------------------------------
Title: Cool-Star Spectrum Synthesis
Authors: Jackson, Bernard V.
Bibliographic Code: 1970BAAS....2..322J
Abstract
@--------------------------------------------------------------------
Title: The rotational temperature of a TiO band in the
spectrum of R Hydrae.
Authors: Keller, C. F.; Jackson, B. V.; Poland, A. I.;
Peery, B. F., Jr.
Bibliographic Code: 1970A&A.....4..415K
Abstract
Abstract image available at:
http://esoads.eso.org/abs/1970A&A.....4..415K
@--------------------------------------------------------------------
Title: A Procedure for Determining Molecular Rotational
Temperature.
Authors: Jackson, Bernard V.; Peery, Benjamin F., Jr.
Bibliographic Code: 1968AJS....73Q..20J
Abstract