Author name code: parenti ADS astronomy entries on 2022-09-14 author:"Parenti, Susanna" ------------------------------------------------------------------------ Title: What drives decayless kink oscillations in active region coronal loops on the Sun? Authors: Mandal, Sudip; Chitta, Lakshmi P.; Antolin, Patrick; Peter, Hardi; Solanki, Sami K.; Auchère, Frédéric; Berghmans, David; Zhukov, Andrei N.; Teriaca, Luca; Cuadrado, Regina A.; Schühle, Udo; Parenti, Susanna; Buchlin, Éric; Harra, Louise; Verbeeck, Cis; Kraaikamp, Emil; Long, David M.; Rodriguez, Luciano; Pelouze, Gabriel; Schwanitz, Conrad; Barczynski, Krzysztof; Smith, Phil J. Bibcode: 2022arXiv220904251M Altcode: We study here the phenomena of decayless kink oscillations in a system of active region (AR) coronal loops. Using high resolution observations from two different instruments, namely the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we follow these AR loops for an hour each on three consecutive days. Our results show significantly more resolved decayless waves in the higher-resolution EUI data compared with the AIA data. Furthermore, the same system of loops exhibits many of these decayless oscillations on Day-2, while on Day-3, we detect very few oscillations and on Day-1, we find none at all. Analysis of photospheric magnetic field data reveals that at most times, these loops were rooted in sunspots, where supergranular flows are generally absent. This suggests that supergranular flows, which are often invoked as drivers of decayless waves, are not necessarily driving such oscillations in our observations. Similarly, our findings also cast doubt on other possible drivers of these waves, such as a transient driver or mode conversion of longitudinal waves near the loop footpoints. In conclusion, through our analysis we find that none of the commonly suspected sources proposed to drive decayless oscillations in active region loops seems to be operating in this event and hence, the search for that elusive wave driver needs to continue. Title: The observed large scale equatorial UV corona: new perspectives with 'recent', 'future' and 'old' data Authors: Abbo, Lucia; Fineschi, Silvano; Parenti, Susanna; Romoli, Marco; Pancrazzi, Maurizio; Andretta, Vincenzo; Auchère, Frédéric; Susino, Roberto; Spadaro, Daniele; Nicolini, Gianalfredo; Giordano, Silvio; Zangrilli, Luca Bibcode: 2022cosp...44.1327A Altcode: In order to understand the sources and the physical mechanisms for the propagation of the Slow Solar Wind (SSW), it is essential to analyze solar data in the region which shapes the large scale structure in corona where the SSW is accelerated, such as streamers and boundaries coronal hole/streamer. The focus of this work is to trace the channels where the SSW escapes from the solar disk up to 5 solar radii in corona. We give an overview on how Solar Orbiter observations (remote sensing and in-situ) together with other space missions (i.e. SPP and PROBA-3) can give a major contribution to the study of the evolution of the streamer belt and global corona, of the role of the coronal magnetic field topology in controlling the solar wind dynamics and abundance, and of abundance anomalies in streamers and in boundaries CH/streamer. In particular, we study how to trace back some equatorial features from the extended corona to the disk. We analyse recent Metis observations in corona together with the Extreme Ultraviolet Imager (EUI) observations on disk and corona (by using the occulter). We also present results from SOHO observations in 1996-1997 (solar minimum), during which was observed a stable equatorial streamer belt with a typical dipole magnetic structure. We have analyzed data by UVCS, SUMER, CDS to trace large scale features and also sub-structures at very high spatial resolution from the disk up to 3 solar radii. This comparison and overlapping is still unique in solar physics and it can improve our knowledge about the origin, acceleration and propagation of the solar wind. Title: Linking the Sun to the Heliosphere Using Composition Data and Modelling: coronal jets as a test case Authors: Parenti, Susanna; Giunta, Alessandra Bibcode: 2022cosp...44.2584P Altcode: Understanding the formation and evolution of the solar wind is still a priority in the Solar and Heliospheric communities. A real progress is possible if we improve our understanding of the physical link between what measured in-situ and its source regions on the Sun. In this respect, the plasma chemical and charge-state compositions are considered good diagnostic tools. In this paper we present results from a work aiming at providing solid diagnostics for linking the in-situ and the remote sensing measurements. For our test cases, we selected a period when a single active region produced, close to its sunspot, jets which had a counterpart signature in the Heliosphere in the form of type-III radio bursts. This jet therefore marked magnetically open regions expanding in the heliosphere. We combine solar EUV and in-situ data together with magnetic field extrapolation, large scale MHD modeling and FIP (First Ionization Potential) bias modeling to provide a global picture from the source region of the jet to its possible signatures at 1AU. Our data analysis reveals the presence of outflow areas near the jet which are within open magnetic flux regions and which present FIP bias consistent with the FIP model results. In our picture, one of these open areas is the candidate jet source. Using a back-mapping technique we identified the arrival time of this solar plasma at the ACE spacecraft. The in-situ data show signatures of changes in the plasma and magnetic field parameters, with FIP bias consistent with the possible passage of the jet material. Our results highlight the importance of remote sensing and in-situ coordinated observations as a key to solve the connectivity problem. We discuss our results in view of the Solar Orbiter entering the nominal phase, which is currently providing such unique data in this regard. Title: Abundance diagnostics in active regions with Solar Orbiter/SPICE Authors: Giunta, Alessandra; Peter, Hardi; Parenti, Susanna; Buchlin, Eric; Thompson, William; Auchere, Frederic; Kucera, Therese; Carlsson, Mats; Janvier, Miho; Fludra, Andrzej; Hassler, Donald M.; Grundy, Timothy; Sidher, Sunil; Guest, Steve; Leeks, Sarah; Fredvik, Terje; Young, Peter Bibcode: 2022cosp...44.2583G Altcode: With the launch of Solar Orbiter in February 2020, we are now able to fully explore the link between the solar activity on the Sun and the inner heliosphere. Elemental abundance measurements provide a key tracer to probe the source regions of the solar wind and to track it from the solar surface and corona to the heliosphere. Abundances of elements with low first ionisation potential (FIP) are enhanced in the corona relative to high-FIP elements, with respect to the photosphere. This is known as the FIP effect, which is measured as abundance bias (FIP bias) of low and high FIP elements. This effect is vital for understanding the flow of mass and energy through the solar atmosphere. The comparison between in-situ and remote sensing composition data, coupled with modelling, will allow us to trace back the source of heliospheric plasma. Solar Orbiter has a unique combination of in-situ and remote sensing instruments that will help to make such a comparison. In particular, the SPICE (Spectral Imaging of the Coronal Environment) EUV spectrometer records spectra in two wavelength bands, 70.4-79.0 nm and 97.3-104.9 nm. SPICE is designed to provide spectroheliograms using a core set of emission lines arising from ions of both low-FIP and high-FIP elements such as C, N, O, Ne, Mg, S and Fe. These lines are formed over a wide range of temperatures from 20,000 K to over 1 million K, enabling the analysis of the different layers of the solar atmosphere. SPICE spectroheliograms can be processed to produce FIP bias maps, which can be compared to in-situ measurements of the solar wind composition of the same elements. During the Solar Orbiter Cruise Phase, SPICE observed several active regions. We will present some of these observations and discuss the SPICE diagnostic potential to derive relative abundances (e.g., Mg/Ne) and the FIP bias in those regions. Title: Automatic detection of small-scale EUV brightenings observed by the Solar Orbiter/EUI Authors: Alipour, N.; Safari, H.; Verbeeck, C.; Berghmans, D.; Auchère, F.; Chitta, L. P.; Antolin, P.; Barczynski, K.; Buchlin, É.; Aznar Cuadrado, R.; Dolla, L.; Georgoulis, M. K.; Gissot, S.; Harra, L.; Katsiyannis, A. C.; Long, D. M.; Mandal, S.; Parenti, S.; Podladchikova, O.; Petrova, E.; Soubrié, É.; Schühle, U.; Schwanitz, C.; Teriaca, L.; West, M. J.; Zhukov, A. N. Bibcode: 2022A&A...663A.128A Altcode: 2022arXiv220404027A Context. Accurate detections of frequent small-scale extreme ultraviolet (EUV) brightenings are essential to the investigation of the physical processes heating the corona.
Aims: We detected small-scale brightenings, termed campfires, using their morphological and intensity structures as observed in coronal EUV imaging observations for statistical analysis.
Methods: We applied a method based on Zernike moments and a support vector machine (SVM) classifier to automatically identify and track campfires observed by Solar Orbiter/Extreme Ultraviolet Imager (EUI) and Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA).
Results: This method detected 8678 campfires (with length scales between 400 km and 4000 km) from a sequence of 50 High Resolution EUV telescope (HRIEUV) 174 Å images. From 21 near co-temporal AIA images covering the same field of view as EUI, we found 1131 campfires, 58% of which were also detected in HRIEUV images. In contrast, about 16% of campfires recognized in HRIEUV were detected by AIA. We obtain a campfire birthrate of 2 × 10−16 m−2 s−1. About 40% of campfires show a duration longer than 5 s, having been observed in at least two HRIEUV images. We find that 27% of campfires were found in coronal bright points and the remaining 73% have occurred out of coronal bright points. We detected 23 EUI campfires with a duration greater than 245 s. We found that about 80% of campfires are formed at supergranular boundaries, and the features with the highest total intensities are generated at network junctions and intense H I Lyman-α emission regions observed by EUI/HRILya. The probability distribution functions for the total intensity, peak intensity, and projected area of campfires follow a power law behavior with absolute indices between 2 and 3. This self-similar behavior is a possible signature of self-organization, or even self-organized criticality, in the campfire formation process.

Supplementary material (S1-S3) is available at https://www.aanda.org Title: The SPICE spectrograph on Solar Orbiter: an introduction and results from the first Orbits Authors: Auchère, Frédéric; Peter, Hardi; Parenti, Susanna; Buchlin, Eric; Thompson, William; Auchere, Frederic; Teriaca, Luca; Kucera, Therese; Carlsson, Mats; Janvier, Miho; Fludra, Andrzej; Giunta, Alessandra; Schuehle, Udo; Hassler, Donald M.; Grundy, Timothy; Sidher, Sunil; Fredvik, Terje; Plowman, Joseph; Aznar Cuadrado, Regina Bibcode: 2022cosp...44.1338A Altcode: The Spectral Imaging of the Coronal Environment (SPICE) instrument is the EUV imaging spectrometer on board the Solar Orbiter mission. With its ability to derive physical properties of the coronal plasma, SPICE is a key component of the payload to establish the connection between the source regions and the in-situ measurements of the solar wind. The spacecraft was successfully launched in February 2020 and completed its cruise phase in December 2021. During this period, the remote sensing instruments were mostly operated during limited periods of time for 'checkout' engineering activities and synoptic observations. Nonetheless, several of these periods provided enough opportunities already to obtain new insights on coronal physics. During the march 2022 perihelion - close to 0.3 AU - SPICE will provide its highest spatial resolution data so far. Coordinated observations between the remote sensing and in-situ instruments will provide the first opportunity to use the full potential of the Solar Orbiter mission. We will review the instrument characteristics and present initial results from the cruise phase and first close encounter. Title: Prominence eruption observed in He II 304 Å up to >6 R⊙ by EUI/FSI aboard Solar Orbiter Authors: Mierla, M.; Zhukov, A. N.; Berghmans, D.; Parenti, S.; Auchère, F.; Heinzel, P.; Seaton, D. B.; Palmerio, E.; Jejčič, S.; Janssens, J.; Kraaikamp, E.; Nicula, B.; Long, D. M.; Hayes, L. A.; Jebaraj, I. C.; Talpeanu, D. -C.; D'Huys, E.; Dolla, L.; Gissot, S.; Magdalenić, J.; Rodriguez, L.; Shestov, S.; Stegen, K.; Verbeeck, C.; Sasso, C.; Romoli, M.; Andretta, V. Bibcode: 2022A&A...662L...5M Altcode: 2022arXiv220515214M
Aims: We report observations of a unique, large prominence eruption that was observed in the He II 304 Å passband of the Extreme Ultraviolet Imager/Full Sun Imager telescope aboard Solar Orbiter on 15-16 February 2022.
Methods: Observations from several vantage points - Solar Orbiter, the Solar-Terrestrial Relations Observatory, the Solar and Heliospheric Observatory, and Earth-orbiting satellites - were used to measure the kinematics of the erupting prominence and the associated coronal mass ejection. Three-dimensional reconstruction was used to calculate the deprojected positions and speeds of different parts of the prominence. Observations in several passbands allowed us to analyse the radiative properties of the erupting prominence.
Results: The leading parts of the erupting prominence and the leading edge of the corresponding coronal mass ejection propagate at speeds of around 1700 km s−1 and 2200 km s−1, respectively, while the trailing parts of the prominence are significantly slower (around 500 km s−1). Parts of the prominence are tracked up to heights of over 6 R⊙. The He II emission is probably produced via collisional excitation rather than scattering. Surprisingly, the brightness of a trailing feature increases with height.
Conclusions: The reported prominence is the first observed in He II 304 Å emission at such a great height (above 6 R⊙).

Movies are available at https://www.aanda.org Title: Observation of Magnetic Switchback in the Solar Corona Authors: Telloni, Daniele; Zank, Gary P.; Stangalini, Marco; Downs, Cooper; Liang, Haoming; Nakanotani, Masaru; Andretta, Vincenzo; Antonucci, Ester; Sorriso-Valvo, Luca; Adhikari, Laxman; Zhao, Lingling; Marino, Raffaele; Susino, Roberto; Grimani, Catia; Fabi, Michele; D'Amicis, Raffaella; Perrone, Denise; Bruno, Roberto; Carbone, Francesco; Mancuso, Salvatore; Romoli, Marco; Da Deppo, Vania; Fineschi, Silvano; Heinzel, Petr; Moses, John D.; Naletto, Giampiero; Nicolini, Gianalfredo; Spadaro, Daniele; Teriaca, Luca; Frassati, Federica; Jerse, Giovanna; Landini, Federico; Pancrazzi, Maurizio; Russano, Giuliana; Sasso, Clementina; Berghmans, David; Auchère, Frédéric; Aznar Cuadrado, Regina; Chitta, Lakshmi P.; Harra, Louise; Kraaikamp, Emil; Long, David M.; Mandal, Sudip; Parenti, Susanna; Pelouze, Gabriel; Peter, Hardi; Rodriguez, Luciano; Schühle, Udo; Schwanitz, Conrad; Smith, Phil J.; Verbeeck, Cis; Zhukov, Andrei N. Bibcode: 2022arXiv220603090T Altcode: Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by the Parker Solar Probe. The switchbacks' formation mechanism and sources are still unresolved, although candidate mechanisms include Alfvénic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection, and geometrical effects related to the Parker spiral. This Letter presents observations from the Metis coronagraph onboard Solar Orbiter of a single large propagating S-shaped vortex, interpreted as first evidence of a switchback in the solar corona. It originated above an active region with the related loop system bounded by open-field regions to the East and West. Observations, modeling, and theory provide strong arguments in favor of the interchange reconnection origin of switchbacks. Metis measurements suggest that the initiation of the switchback may also be an indicator of the origin of slow solar wind. Title: Validation of a Wave Heated 3D MHD Coronal-wind Model using Polarized Brightness and EUV Observations Authors: Parenti, Susanna; Réville, Victor; Brun, Allan Sacha; Pinto, Rui F.; Auchère, Frédéric; Buchlin, Éric; Perri, Barbara; Strugarek, Antoine Bibcode: 2022ApJ...929...75P Altcode: 2022arXiv220310876P The physical properties responsible for the formation and evolution of the corona and heliosphere are still not completely understood. 3D MHD global modeling is a powerful tool to investigate all the possible candidate processes. To fully understand the role of each of them, we need a validation process where the output from the simulations is quantitatively compared to the observational data. In this work, we present the results from our validation process applied to the wave turbulence driven 3D MHD corona-wind model WindPredict-AW. At this stage of the model development, we focus the work to the coronal regime in quiescent condition. We analyze three simulation results, which differ by the boundary values. We use the 3D distributions of density and temperature, output from the simulations at the time of around the first Parker Solar Probe perihelion (during minimum of the solar activity), to synthesize both extreme ultraviolet (EUV) and white-light-polarized (WL pB) images to reproduce the observed solar corona. For these tests, we selected AIA 193 Å, 211 Å, and 171 Å EUV emissions, MLSO K-Cor, and LASCO C2 pB images obtained on 2018 November 6 and 7. We then make quantitative comparisons of the disk and off limb corona. We show that our model is able to produce synthetic images comparable to those of the observed corona. Title: Flux rope and dynamics of the heliospheric current sheet. Study of the Parker Solar Probe and Solar Orbiter conjunction of June 2020 Authors: Réville, V.; Fargette, N.; Rouillard, A. P.; Lavraud, B.; Velli, M.; Strugarek, A.; Parenti, S.; Brun, A. S.; Shi, C.; Kouloumvakos, A.; Poirier, N.; Pinto, R. F.; Louarn, P.; Fedorov, A.; Owen, C. J.; Génot, V.; Horbury, T. S.; Laker, R.; O'Brien, H.; Angelini, V.; Fauchon-Jones, E.; Kasper, J. C. Bibcode: 2022A&A...659A.110R Altcode: 2021arXiv211207445R Context. Solar Orbiter and Parker Solar Probe jointly observed the solar wind for the first time in June 2020, capturing data from very different solar wind streams: calm, Alfvénic wind and also highly dynamic large-scale structures. Context. Our aim is to understand the origin and characteristics of the highly dynamic solar wind observed by the two probes, particularly in the vicinity of the heliospheric current sheet (HCS).
Methods: We analyzed the plasma data obtained by Parker Solar Probe and Solar Orbiter in situ during the month of June 2020. We used the Alfvén-wave turbulence magnetohydrodynamic solar wind model WindPredict-AW and we performed two 3D simulations based on ADAPT solar magnetograms for this period.
Results: We show that the dynamic regions measured by both spacecraft are pervaded by flux ropes close to the HCS. These flux ropes are also present in the simulations, forming at the tip of helmet streamers, that is, at the base of the heliospheric current sheet. The formation mechanism involves a pressure-driven instability followed by a fast tearing reconnection process. We further characterize the 3D spatial structure of helmet streamer born flux ropes, which appears in the simulations to be related to the network of quasi-separatrices. Title: Stereoscopy of extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI Authors: Zhukov, A. N.; Mierla, M.; Auchère, F.; Gissot, S.; Rodriguez, L.; Soubrié, E.; Thompson, W. T.; Inhester, B.; Nicula, B.; Antolin, P.; Parenti, S.; Buchlin, É.; Barczynski, K.; Verbeeck, C.; Kraaikamp, E.; Smith, P. J.; Stegen, K.; Dolla, L.; Harra, L.; Long, D. M.; Schühle, U.; Podladchikova, O.; Aznar Cuadrado, R.; Teriaca, L.; Haberreiter, M.; Katsiyannis, A. C.; Rochus, P.; Halain, J. -P.; Jacques, L.; Berghmans, D. Bibcode: 2021A&A...656A..35Z Altcode: 2021arXiv210902169Z Context. The three-dimensional fine structure of the solar atmosphere is still not fully understood as most of the available observations are taken from a single vantage point.
Aims: The goal of the paper is to study the three-dimensional distribution of the small-scale brightening events ("campfires") discovered in the extreme-UV quiet Sun by the Extreme Ultraviolet Imager (EUI) aboard Solar Orbiter.
Methods: We used a first commissioning data set acquired by the EUI's High Resolution EUV telescope on 30 May 2020 in the 174 Å passband and we combined it with simultaneous data taken by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory in a similar 171 Å passband. The two-pixel spatial resolution of the two telescopes is 400 km and 880 km, respectively, which is sufficient to identify the campfires in both data sets. The two spacecraft had an angular separation of around 31.5° (essentially in heliographic longitude), which allowed for the three-dimensional reconstruction of the campfire position. These observations represent the first time that stereoscopy was achieved for brightenings at such a small scale. Manual and automatic triangulation methods were used to characterize the campfire data.
Results: The height of the campfires is located between 1000 km and 5000 km above the photosphere and we find a good agreement between the manual and automatic methods. The internal structure of campfires is mostly unresolved by AIA; however, for a particularly large campfire, we were able to triangulate a few pixels, which are all in a narrow range between 2500 and 4500 km.
Conclusions: We conclude that the low height of EUI campfires suggests that they belong to the previously unresolved fine structure of the transition region and low corona of the quiet Sun. They are probably apexes of small-scale dynamic loops heated internally to coronal temperatures. This work demonstrates that high-resolution stereoscopy of structures in the solar atmosphere has become feasible. Title: Adding a transition region in global MHD models of the solar corona Authors: Réville, V.; Parenti, S.; Brun, A. S.; Strugarek, A.; Rouillard, A. P.; Velli, M.; Perri, B.; Pinto, R. F. Bibcode: 2021sf2a.conf..230R Altcode: Global MHD simulations of the solar corona are an essential tool to investigate long standing problems, such as finding the source of coronal heating and the mechanisms responsible for the onset and propagation of coronal mass ejections. The very low atmospheric layers of the corona, are however, very difficult to model as they imply very steep gradients of density and temperature over only a few thousand kilometers. In this proceedings, we illustrate some of the benefits of including a very simple transition region in global MHD models and the differences in the plasma properties, comparing with in situ data of the Parker Solar Probe. Title: Full Vector Velocity Reconstruction Using Solar Orbiter Doppler Map Observations. Authors: Podladchikova, Olena; Harra, Louise; Barczynski, Krzysztof; Mandrini, Cristina; Auchere, F.; Berghmans, David; Buchlin, Eric; Dolla, Laurent; Mierla, Marilena; Parenti, Susanna; Rodriguez, Luciano Bibcode: 2021AGUFMNG35B0432P Altcode: The Solar Orbiter mission opens up opportunities forthe combined analysis of measurements obtained by solar imagers and spectrometers. For the first time, different space spectrometerswill be located at wide angles to each other, allowing three-dimensional (3D) spectroscopy of the solar atmosphere.The aim of this work is to prepare the methodology to facilitate the reconstruction of 3D vector velocities from two stereoscopicLOS Doppler velocity measurements using the Spectral Imaging of the Coronal Environment (SPICE) on board the Solar Orbiter andthe near-Earth spectrometers, while widely separated in space. We develop the methodology using the libraries designed earlier for the STEREO mission but applied to spectroscopicdata from the Hinode mission and the Solar Dynamics Observatory. We use well-known methods of static and dynamic solar rotationstereoscopy and the methods of EUV stereoscopic triangulation for optically-thin coronal EUV plasma emissions. We develop new algorithms using analytical geometry in space to determine the 3D velocity in coronal loops. We demonstrate our approach with the reconstruction of 3D velocity vectors in plasma flows along "open" and "closed"magnetic loops. This technique will be applied first to an actual situation of two spacecraft at different separations with spectrometers onboard (SPICE versus the Interface Region Imaging Spectrograph (IRIS) and Hinode imaging spectrometer) during the Solar Orbiternominal phase. We summarise how these observations can be coordinated. Title: Stereoscopy of extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI Authors: Zhukov, Andrei; Mierla, Marilena; Auchere, F.; Gissot, Samuel; Rodriguez, Luciano; Soubrie, Elie; Thompson, William; Inhester, Bernd; Nicula, Bogdan; Antolin, Patrick; Parenti, Susanna; Buchlin, Eric; Barczynski, Krzysztof; Verbeeck, Cis; Kraaikamp, Emil; Smith, Philip; Stegen, Koen; Dolla, Laurent; Harra, Louise; Long, David; Schuhle, Udo; Podladchikova, Olena; Aznar Cuadrado, Regina; Teriaca, Luca; Haberreiter, Margit; Katsiyannis, Athanassios; Rochus, Pierre; Halain, Jean-Philippe; Jacques, Lionel; Berghmans, David Bibcode: 2021AGUFMSH21A..03Z Altcode: We study the three-dimensional distribution of small-scale brightening events (campfires) discovered in the extreme-ultraviolet (EUV) quiet Sun by the EUI telescope onboard the Solar Orbiter mission. We use one of the first commissioning data sets acquired by the HRI_EUV telescope of EUI on 2020 May 30 in the 174 A passband, combined with the simultaneous SDO/AIA dataset taken in the very similar 171 A passband. The spatial resolution of the two telescopes is sufficient to identify the campfires in both datasets. The angular separation between the two spacecraft of around 31.5 degrees allowed for the three-dimensional reconstruction of the position of campfires. This is the first time that stereoscopy was achieved for structures at such a small scale. Manual and automatic triangulation methods were used. The height of campfires is between 1000 km and 5000 km above the photosphere, and there is a good agreement between the results of manual and automatic methods. The internal structure of campfires is mostly not resolved by AIA, but for a large campfire we could triangulate a few pixels, which are all in a narrow height range between 2500 and 4500 km. The low height of campfires suggests that they belong to the previously unresolved fine structure of the transition region and low corona of the quiet Sun. They are probably apexes of small-scale dynamic loops internally heated to coronal temperatures. This work demonstrates that high-resolution stereoscopy of structures in the solar atmosphere has become possible. Title: Extreme-UV quiet Sun brightenings observed by the Solar Orbiter/EUI Authors: Berghmans, D.; Auchère, F.; Long, D. M.; Soubrié, E.; Mierla, M.; Zhukov, A. N.; Schühle, U.; Antolin, P.; Harra, L.; Parenti, S.; Podladchikova, O.; Aznar Cuadrado, R.; Buchlin, É.; Dolla, L.; Verbeeck, C.; Gissot, S.; Teriaca, L.; Haberreiter, M.; Katsiyannis, A. C.; Rodriguez, L.; Kraaikamp, E.; Smith, P. J.; Stegen, K.; Rochus, P.; Halain, J. P.; Jacques, L.; Thompson, W. T.; Inhester, B. Bibcode: 2021A&A...656L...4B Altcode: 2021arXiv210403382B Context. The heating of the solar corona by small heating events requires an increasing number of such events at progressively smaller scales, with the bulk of the heating occurring at scales that are currently unresolved.
Aims: The goal of this work is to study the smallest brightening events observed in the extreme-UV quiet Sun.
Methods: We used commissioning data taken by the Extreme Ultraviolet Imager (EUI) on board the recently launched Solar Orbiter mission. On 30 May 2020, the EUI was situated at 0.556 AU from the Sun. Its High Resolution EUV telescope (HRIEUV, 17.4 nm passband) reached an exceptionally high two-pixel spatial resolution of 400 km. The size and duration of small-scale structures was determined by the HRIEUV data, while their height was estimated from triangulation with simultaneous images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory mission. This is the first stereoscopy of small-scale brightenings at high resolution.
Results: We observed small localised brightenings, also known as `campfires', in a quiet Sun region with length scales between 400 km and 4000 km and durations between 10 s and 200 s. The smallest and weakest of these HRIEUV brightenings have not been previously observed. Simultaneous observations from the EUI High-resolution Lyman-α telescope (HRILya) do not show localised brightening events, but the locations of the HRIEUV events clearly correspond to the chromospheric network. Comparisons with simultaneous AIA images shows that most events can also be identified in the 17.1 nm, 19.3 nm, 21.1 nm, and 30.4 nm pass-bands of AIA, although they appear weaker and blurred. Our differential emission measure analysis indicated coronal temperatures peaking at log T ≈ 6.1 − 6.15. We determined the height for a few of these campfires to be between 1000 and 5000 km above the photosphere.
Conclusions: We find that `campfires' are mostly coronal in nature and rooted in the magnetic flux concentrations of the chromospheric network. We interpret these events as a new extension to the flare-microflare-nanoflare family. Given their low height, the EUI `campfires' could stand as a new element of the fine structure of the transition region-low corona, that is, as apexes of small-scale loops that undergo internal heating all the way up to coronal temperatures. Title: First observations from the SPICE EUV spectrometer on Solar Orbiter Authors: Fludra, A.; Caldwell, M.; Giunta, A.; Grundy, T.; Guest, S.; Leeks, S.; Sidher, S.; Auchère, F.; Carlsson, M.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.; Buchlin, É.; Caminade, S.; DeForest, C.; Fredvik, T.; Haberreiter, M.; Harra, L.; Janvier, M.; Kucera, T.; Müller, D.; Parenti, S.; Schmutz, W.; Schühle, U.; Solanki, S. K.; Teriaca, L.; Thompson, W. T.; Tustain, S.; Williams, D.; Young, P. R.; Chitta, L. P. Bibcode: 2021A&A...656A..38F Altcode: 2021arXiv211011252F
Aims: We present first science observations taken during the commissioning activities of the Spectral Imaging of the Coronal Environment (SPICE) instrument on the ESA/NASA Solar Orbiter mission. SPICE is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths. In this paper we illustrate the possible types of observations to give prospective users a better understanding of the science capabilities of SPICE.
Methods: We have reviewed the data obtained by SPICE between April and June 2020 and selected representative results obtained with different slits and a range of exposure times between 5 s and 180 s. Standard instrumental corrections have been applied to the raw data.
Results: The paper discusses the first observations of the Sun on different targets and presents an example of the full spectra from the quiet Sun, identifying over 40 spectral lines from neutral hydrogen and ions of carbon, oxygen, nitrogen, neon, sulphur, magnesium, and iron. These lines cover the temperature range between 20 000 K and 1 million K (10 MK in flares), providing slices of the Sun's atmosphere in narrow temperature intervals. We provide a list of count rates for the 23 brightest spectral lines. We show examples of raster images of the quiet Sun in several strong transition region lines, where we have found unusually bright, compact structures in the quiet Sun network, with extreme intensities up to 25 times greater than the average intensity across the image. The lifetimes of these structures can exceed 2.5 hours. We identify them as a transition region signature of coronal bright points and compare their areas and intensity enhancements. We also show the first above-limb measurements with SPICE above the polar limb in C III, O VI, and Ne VIII lines, and far off limb measurements in the equatorial plane in Mg IX, Ne VIII, and O VI lines. We discuss the potential to use abundance diagnostics methods to study the variability of the elemental composition that can be compared with in situ measurements to help confirm the magnetic connection between the spacecraft location and the Sun's surface, and locate the sources of the solar wind.
Conclusions: The SPICE instrument successfully performs measurements of EUV spectra and raster images that will make vital contributions to the scientific success of the Solar Orbiter mission. Title: Linking the Sun to the Heliosphere Using Composition Data and Modelling Authors: Parenti, Susanna; Chifu, Iulia; Del Zanna, Giulio; Edmondson, Justin; Giunta, Alessandra; Hansteen, Viggo H.; Higginson, Aleida; Laming, J. Martin; Lepri, Susan T.; Lynch, Benjamin J.; Rivera, Yeimy J.; von Steiger, Rudolf; Wiegelmann, Thomas; Wimmer-Schweingruber, Robert F.; Zambrana Prado, Natalia; Pelouze, Gabriel Bibcode: 2021SSRv..217...78P Altcode: 2021arXiv211006111P Our understanding of the formation and evolution of the corona and the heliosphere is linked to our capability of properly interpret the data from remote sensing and in-situ observations. In this respect, being able to correctly connect in-situ observations with their source regions on the Sun is the key for solving this problem. In this work we aim at testing a diagnostics method for this connectivity. Title: Stereoscopic measurements of coronal Doppler velocities Authors: Podladchikova, O.; Harra, L.; Barczynski, K.; Mandrini, C. H.; Auchère, F.; Berghmans, D.; Buchlin, É.; Dolla, L.; Mierla, M.; Parenti, S.; Rodriguez, L. Bibcode: 2021A&A...655A..57P Altcode: 2021arXiv210802280P Context. The Solar Orbiter mission, with an orbit outside the Sun-Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time different space spectrometers will be located at wide angles to each other, allowing three-dimensional (3D) spectroscopy of the solar atmosphere.
Aims: The aim of this work is to prepare a methodology to facilitate the reconstruction of 3D vector velocities from two stereoscopic line of sight (LOS) Doppler velocity measurements using the Spectral Imaging of the Coronal Environment (SPICE) on board the Solar Orbiter and the near-Earth spectrometers, while widely separated in space.
Methods: We developed the methodology using the libraries designed earlier for the STEREO mission, but applied to spectroscopic data from the Hinode mission and the Solar Dynamics Observatory. We used well-known methods of static and dynamic solar rotation stereoscopy and the methods of extreme ultraviolet (EUV) stereoscopic triangulation for optically thin coronal EUV plasma emissions. We developed new algorithms using analytical geometry in space to determine the 3D velocity in coronal loops.
Results: We demonstrate our approach with the reconstruction of 3D velocity vectors in plasma flows along `open' and `closed' magnetic loops. This technique will be applied to an actual situation of two spacecraft at different separations with spectrometers on board during the Solar Orbiter nominal phase: SPICE versus the Interface Region Imaging Spectrograph (IRIS) and Hinode imaging spectrometer. We summarise how these observations can be coordinated.

Movies associated to Fig. 1 are available at https://www.aanda.org Title: Magnetic imaging of the outer solar atmosphere (MImOSA) Authors: Peter, H.; Ballester, E. Alsina; Andretta, V.; Auchère, F.; Belluzzi, L.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Calcines, A.; Chitta, L. P.; Dalmasse, K.; Alemán, T. del Pino; Feller, A.; Froment, C.; Harrison, R.; Janvier, M.; Matthews, S.; Parenti, S.; Przybylski, D.; Solanki, S. K.; Štěpán, J.; Teriaca, L.; Bueno, J. Trujillo Bibcode: 2021ExA...tmp...95P Altcode: The magnetic activity of the Sun directly impacts the Earth and human life. Likewise, other stars will have an impact on the habitability of planets orbiting these host stars. Although the magnetic field at the surface of the Sun is reasonably well characterised by observations, the information on the magnetic field in the higher atmospheric layers is mainly indirect. This lack of information hampers our progress in understanding solar magnetic activity. Overcoming this limitation would allow us to address four paramount long-standing questions: (1) How does the magnetic field couple the different layers of the atmosphere, and how does it transport energy? (2) How does the magnetic field structure, drive and interact with the plasma in the chromosphere and upper atmosphere? (3) How does the magnetic field destabilise the outer solar atmosphere and thus affect the interplanetary environment? (4) How do magnetic processes accelerate particles to high energies? New ground-breaking observations are needed to address these science questions. We suggest a suite of three instruments that far exceed current capabilities in terms of spatial resolution, light-gathering power, and polarimetric performance: (a) A large-aperture UV-to-IR telescope of the 1-3 m class aimed mainly to measure the magnetic field in the chromosphere by combining high spatial resolution and high sensitivity. (b) An extreme-UV-to-IR coronagraph that is designed to measure the large-scale magnetic field in the corona with an aperture of about 40 cm. (c) An extreme-UV imaging polarimeter based on a 30 cm telescope that combines high throughput in the extreme UV with polarimetry to connect the magnetic measurements of the other two instruments. Placed in a near-Earth orbit, the data downlink would be maximised, while a location at L4 or L5 would provide stereoscopic observations of the Sun in combination with Earth-based observatories. This mission to measure the magnetic field will finally unlock the driver of the dynamics in the outer solar atmosphere and thereby will greatly advance our understanding of the Sun and the heliosphere. Title: Vector Velocities Measurements with the Solar Orbiter SPICE Spectrometer Authors: Podladchikova, O.; Harra, L.; Barczynski, K.; Mandrini, C.; Auchère, F.; Berghmans, D.; Buchlin, E.; Dolla, L.; Mierla, M.; Parenti, S.; Rodriguez, L. Bibcode: 2021AAS...23831312P Altcode: The Solar Orbiter mission, with an orbit outside the Sun-Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time, different spectrometers will be located at wide angles to each other, allowing three-dimensional (3D) spectroscopy of the solar atmosphere. Here we develop a methodology to prepare for this kind of analysis, by using data from the Hinode mission and the Solar Dynamics Observatory, respectively. We employ solar rotation to simulate measurements of spectrometers with different views of the solar corona. The resulting data allow us to apply stereoscopic tie-pointing and triangulation techniques designed for the STEREO spacecraft pair, and to perform 3D analysis of the Doppler shifts of a quasi-stationary active region. Our approach allows the accurate reconstruction of 3D velocity vectors in plasma flows along "open" and "closed" magnetic loops. This technique will be applied to the actual situation of two spacecraft at different separations with spectrometers on board (the Solar Orbiter Spectral Imaging of the Coronal Environment versus the Interface Region Imaging Spectrograph (IRIS) and Hinode imaging spectrometer) and we summarise how these observations can be coordinated to assess vector velocity measurements. This 3D spectroscopy method will facilitate the understanding of the complex flows that take place throughout the solar atmosphere. Title: The Heating of the Solar Corona Authors: Viall, Nicholeen M.; De Moortel, Ineke; Downs, Cooper; Klimchuk, James A.; Parenti, Susanna; Reale, Fabio Bibcode: 2021GMS...258...35V Altcode: No abstract at ADS Title: Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST) Authors: Rast, Mark P.; Bello González, Nazaret; Bellot Rubio, Luis; Cao, Wenda; Cauzzi, Gianna; Deluca, Edward; de Pontieu, Bart; Fletcher, Lyndsay; Gibson, Sarah E.; Judge, Philip G.; Katsukawa, Yukio; Kazachenko, Maria D.; Khomenko, Elena; Landi, Enrico; Martínez Pillet, Valentín; Petrie, Gordon J. D.; Qiu, Jiong; Rachmeler, Laurel A.; Rempel, Matthias; Schmidt, Wolfgang; Scullion, Eamon; Sun, Xudong; Welsch, Brian T.; Andretta, Vincenzo; Antolin, Patrick; Ayres, Thomas R.; Balasubramaniam, K. S.; Ballai, Istvan; Berger, Thomas E.; Bradshaw, Stephen J.; Campbell, Ryan J.; Carlsson, Mats; Casini, Roberto; Centeno, Rebecca; Cranmer, Steven R.; Criscuoli, Serena; Deforest, Craig; Deng, Yuanyong; Erdélyi, Robertus; Fedun, Viktor; Fischer, Catherine E.; González Manrique, Sergio J.; Hahn, Michael; Harra, Louise; Henriques, Vasco M. J.; Hurlburt, Neal E.; Jaeggli, Sarah; Jafarzadeh, Shahin; Jain, Rekha; Jefferies, Stuart M.; Keys, Peter H.; Kowalski, Adam F.; Kuckein, Christoph; Kuhn, Jeffrey R.; Kuridze, David; Liu, Jiajia; Liu, Wei; Longcope, Dana; Mathioudakis, Mihalis; McAteer, R. T. James; McIntosh, Scott W.; McKenzie, David E.; Miralles, Mari Paz; Morton, Richard J.; Muglach, Karin; Nelson, Chris J.; Panesar, Navdeep K.; Parenti, Susanna; Parnell, Clare E.; Poduval, Bala; Reardon, Kevin P.; Reep, Jeffrey W.; Schad, Thomas A.; Schmit, Donald; Sharma, Rahul; Socas-Navarro, Hector; Srivastava, Abhishek K.; Sterling, Alphonse C.; Suematsu, Yoshinori; Tarr, Lucas A.; Tiwari, Sanjiv; Tritschler, Alexandra; Verth, Gary; Vourlidas, Angelos; Wang, Haimin; Wang, Yi-Ming; NSO and DKIST Project; DKIST Instrument Scientists; DKIST Science Working Group; DKIST Critical Science Plan Community Bibcode: 2021SoPh..296...70R Altcode: 2020arXiv200808203R The National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST) will revolutionize our ability to measure, understand, and model the basic physical processes that control the structure and dynamics of the Sun and its atmosphere. The first-light DKIST images, released publicly on 29 January 2020, only hint at the extraordinary capabilities that will accompany full commissioning of the five facility instruments. With this Critical Science Plan (CSP) we attempt to anticipate some of what those capabilities will enable, providing a snapshot of some of the scientific pursuits that the DKIST hopes to engage as start-of-operations nears. The work builds on the combined contributions of the DKIST Science Working Group (SWG) and CSP Community members, who generously shared their experiences, plans, knowledge, and dreams. Discussion is primarily focused on those issues to which DKIST will uniquely contribute. Title: Stereoscopic Measurements of Coronal Doppler Velocities aboard Solar Orbiter Authors: Podladchikova, Olena; Harra, Louise K.; Mandrini, Cristina H.; Rodriguez, Luciano; Parenti, Susanna; Dolla, Laurent; Buchlin, Eric; Auchere, Frederic; Mierla, Marilena; Barczynski, Krzysztof Bibcode: 2021cosp...43E.957P Altcode: The Solar Orbiter mission, whose orbit is outside the Sun-Earth line, opens up novel opportunities for the combined analysis of measurements by solar imagers and spectrometers. For the first time different spectrometers will be located at wide angles with each other allowing 3D spectroscopy in the solar atmosphere. In order to develop a methodology for these opportunities we make use of the Hinode EUV Imaging Spectrometer (EIS) and Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) and by employing solar rotation we simulate the measurements of spectrometers that have different views of solar corona. The resulting data allows us to apply stereoscopic tie-pointing and triangulation techniques designed for SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) imaging suite on the STEREO (Solar Terrestrial Relations Observatory) spacecraft pair and perform three-dimensional analysis of Doppler shifts of quasi-stationary active region.We present a technique that allows the accurate reconstruction of the 3D velocity vector in plasma flows along open and closed magnetic loops. This technique will be applied to the real situation of two spacecraft at different separations with spectrometers onboard. This will include the Solar Orbiter Spectral Imaging of the Coronal Environment (SPICE), the Solar Orbiter Extreme Ultraviolet Imager (EUI), the Interface Region Imaging Spectrograph (IRIS) and Hinode EIS spectrometers and we summarise how these can be coordinated. This 3D spectroscopy is a new research domain that will aid the understanding of the complex flows that take place throughout the solar atmosphere. Title: Expected science from the Solar Orbiter Remote Sensing instruments Authors: Parenti, Susanna Bibcode: 2021cosp...43E.948P Altcode: Solar Orbiter payload consists of a ten instruments, six of which for remote sensing observations. The mission has a unique profile with the main properties of being deep, with orbits varying uniquely in latitudes and solar distance. These aspects produce limits in the telemetry rate, which vary greatly along each orbit, posing great challenge for the remote sensing instruments. In this context, the instrument teams and ESA-NASA have been working together incessantly to prepare the operations for optimizing the instruments performances and thus maximize the science return from this complementarity and comprehensive remote sensing payload. In this talk I will summarize the mission profile and the remote sensing instruments observational characteristics. These will serve to discuss the science opportunities to provide a new view of our star, from its interior to the corona and solar wind. Observations during recurrent unique configurations of Solar Orbiter with other Earth and space observatories will be used to obtain both contextual and multi-point of view data, providing the first ever data of such a kind. I will also present some of the first data obtained during Commissioning in 2020 which already anticipate significant novelties. Title: Magnetic Imaging of the Outer Solar Atmosphere (MImOSA): Unlocking the driver of the dynamics in the upper solar atmosphere Authors: Peter, H.; Alsina Ballester, E.; Andretta, V.; Auchere, F.; Belluzzi, L.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Calcines, A.; Chitta, L. P.; Dalmasse, K.; del Pino Aleman, T.; Feller, A.; Froment, C.; Harrison, R.; Janvier, M.; Matthews, S.; Parenti, S.; Przybylski, D.; Solanki, S. K.; Stepan, J.; Teriaca, L.; Trujillo Bueno, J. Bibcode: 2021arXiv210101566P Altcode: The magnetic activity of the Sun directly impacts the Earth and human life. Likewise, other stars will have an impact on the habitability of planets orbiting these host stars. The lack of information on the magnetic field in the higher atmospheric layers hampers our progress in understanding solar magnetic activity. Overcoming this limitation would allow us to address four paramount long-standing questions: (1) How does the magnetic field couple the different layers of the atmosphere, and how does it transport energy? (2) How does the magnetic field structure, drive and interact with the plasma in the chromosphere and upper atmosphere? (3) How does the magnetic field destabilise the outer solar atmosphere and thus affect the interplanetary environment? (4) How do magnetic processes accelerate particles to high energies? New ground-breaking observations are needed to address these science questions. We suggest a suite of three instruments that far exceed current capabilities in terms of spatial resolution, light-gathering power, and polarimetric performance: (a) A large-aperture UV-to-IR telescope of the 1-3 m class aimed mainly to measure the magnetic field in the chromosphere by combining high spatial resolution and high sensitivity. (b) An extreme-UV-to-IR coronagraph that is designed to measure the large-scale magnetic field in the corona with an aperture of about 40 cm. (c) An extreme-UV imaging polarimeter based on a 30 cm telescope that combines high throughput in the extreme UV with polarimetry to connect the magnetic measurements of the other two instruments. This mission to measure the magnetic field will unlock the driver of the dynamics in the outer solar atmosphere and thereby greatly advance our understanding of the Sun and the heliosphere. Title: Relative coronal abundance diagnostics with Solar Orbiter/SPICE Authors: Zambrana Prado, N.; Buchlin, E.; Peter, H.; Young, P. R.; Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Aznar Cuadrado, R.; Caminade, S.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.; Parenti, S.; Schmutz, W. K.; Schühle, U.; Sidher, S.; Teriaca, L.; Thompson, W. T.; Williams, D. Bibcode: 2020AGUFMSH038..09Z Altcode: Linking solar activity on the surface and in the corona to the inner heliosphere is one of Solar Orbiter's main goals. Its UV spectrometer SPICE (SPectral Imaging of the Coronal Environment) will provide relative abundance measurements which will be key in this quest as different structures on the Sun have different abundances as a consequence of the FIP (First Ionization Potential) effect. Solar Orbiter's unique combination of remote sensing and in-situ instruments coupled with observation from other missions such as Parker Solar Probe will allow us to compare in-situ and remote sensing composition data. With the addition of modeling, these new results will allow us to trace back the source of heliospheric plasma. As high telemetry will not always be available with SPICE, we have developed a method for measuring relative abundances that is both telemetry efficient and reliable. Unlike methods based on Differential Emission Measure (DEM) inversion, the Linear Combination Ratio (LCR) method does not require a large number of spectral lines. This new method is based on linear combinations of UV spectral lines. The coefficients of the combinations are optimized such that the ratio of two linear combinations of radiances would yield the relative abundance of two elements. We present some abundance diagnostics tested on different combinations of spectral lines observable by SPICE. Title: Dynamics and thermal structure in the quiet Sun seen by SPICE Authors: Peter, H.; Aznar Cuadrado, R.; Schühle, U.; Teriaca, L.; Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Buchlin, E.; Caminade, S.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.; Parenti, S.; Schmutz, W. K.; Sidher, S.; Thompson, W. T.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH038..03P Altcode: We will present some of the early data of the Spectral Imaging of the Coronal Environment (SPICE) instrument on Solar Orbiter. One of the unique features of SPICE is its capability to record a wide range of wavelengths in the extreme UV with the possibility to record spectral lines giving access to a continuous plasma temperature range from 10.000 K to well above 1 MK. The data taken so far were for commissioning purposes and they can be used for a preliminary evaluation of the science performance of the instrument. Here we will concentrate on sample spectra covering the whole wavelength region and on the early raster maps acquired in bright lines in the quiet Sun close to disk center. Looking at different quiet Sun features we investigate the thermal structure of the atmosphere and flow structures. For this we apply fits to the spectral profiles and check the performance in terms of Doppler shifts and line widths to retrieve the structure of the network in terms of dynamics. While the amount of data available so far is limited, we will have a first look on how quiet Sun plasma responds to heating events. For this, we will compare spectral lines forming at different temperatures recorded at strictly the same time. Title: Observation of Smallest Ever Detected Brightening Events with the Solar Orbiter EUI HRI-EUV Imager Authors: Parenti, S.; Berghmans, D.; Buchlin, E.; Teriaca, L.; Auchere, F.; Harra, L.; Long, D.; Rochus, P. L.; Schühle, U.; Aznar Cuadrado, R.; Gissot, S.; Kraaikamp, E.; Smith, P.; Stegen, K.; Verbeeck, C. Bibcode: 2020AGUFMSH038..01P Altcode: The Extreme Ultraviolet Imager (EUI) suite on board Solar Orbiter acquired its first images in May 2020. The passband of the 17.4 nm High Resolution Imager (HRI-EUV) is dominated by emission lines of Fe IX and Fe X, that is the 1 million degree solar corona. The solar atmosphere at this temperature is dynamic at all scales, down to the highest spatial resolution available from instruments priori to Solar Orbiter. During the Commissioning phase, HRI-EUV acquired several high temporal resolution (a few seconds) sequences at quiet Sun regions at disk center. The instrument revealed a multitude of brightenings at the smallest-ever detectable spatial scales which, at that time, was about 400 km (two pixels). These events appear to be present everywhere all the time. We present the first results of the analysis of these sequences with the aim of understanding the role of these small scale events in the heating of the solar corona. Title: First Results From SPICE EUV Spectrometer on Solar Orbiter Authors: Fludra, A.; Caldwell, M.; Giunta, A. S.; Grundy, T.; Guest, S.; Sidher, S.; Auchere, F.; Carlsson, M.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.; Buchlin, E.; Caminade, S.; DeForest, C.; Fredvik, T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Leeks, S.; Mueller, D.; Parenti, S.; Schmutz, W. K.; Schühle, U.; Teriaca, L.; Thompson, W. T.; Tustain, S.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH038..02F Altcode: SPICE (Spectral Imaging of Coronal Environment) is one of the remote sensing instruments onboard Solar Orbiter. It is an EUV imaging spectrometer observing the Sun in two wavelength bands: 69.6-79.4 nm and 96.6-105.1 nm. SPICE is capable of recording full spectra in these bands with exposures as short as 1s. SPICE is the only Solar Orbiter instrument that can measure EUV spectra from the disk and low corona of the Sun and record all spectral lines simultaneously. SPICE uses one of three narrow slits, 2"x11', 4''x11', 6''x11', or a wide slit 30''x14'. The primary mirror can be scanned in a direction perpendicular to the slit, allowing raster images of up to 16' in size.

We present an overview of the first SPICE data taken on several days during the instrument commissioning carried out by the RAL Space team between 2020 April 21 and 2020 June 14. We also include results from SPICE observations at the first Solar Orbiter perihelion at 0.52AU, taken between June 16-21st. We give examples of full spectra from the quiet Sun near disk centre and provide a list of key spectral lines emitted in a range of temperatures between 10,000 K and over 1 million K, from neutral hydrogen and ions of carbon, oxygen, nitrogen, neon, sulphur and magnesium. We show examples of first raster images in several strong lines, obtained with different slits and a range of exposure times between 5s and 180s. We describe the temperature coverage and density diagnostics, determination of plasma flows, and discuss possible applications to studies of the elemental abundances in the corona. We also show the first off-limb measurements with SPICE, as obtained when the spacecraft pointed at the limb. Title: Calibrating optical distortions in the Solar Orbiter SPICE spectrograph Authors: Thompson, W. T.; Schühle, U.; Young, P. R.; Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.; Buchlin, E.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.; Parenti, S.; Caminade, S.; Schmutz, W. K.; Teriaca, L.; Williams, D.; Sidher, S. Bibcode: 2020AGUFMSH0360029T Altcode: The Spectral Imaging of the Coronal Environment (SPICE) instrument on Solar Orbiter is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths from 70.4-79.0 nm and 97.3-104.9 nm. A single-mirror off-axis paraboloid focuses the solar image onto the entrance slit of the spectrometer section. A Toroidal Variable Line Space (TVLS) grating images the entrance slit onto a pair of MCP-intensified APS detectors. Ray-tracing analysis prior to launch showed that the instrument was subject to a number of small image distortions which need to be corrected in the final data product. We compare the ray tracing results with measurements made in flight. Co-alignment with other telescopes on Solar Orbiter will also be examined. Title: First results from the EUI and SPICE observations of Alpha Leo near Solar Orbiter first perihelion Authors: Buchlin, E.; Teriaca, L.; Giunta, A. S.; Grundy, T.; Andretta, V.; Auchere, F.; Peter, H.; Berghmans, D.; Carlsson, M.; Fludra, A.; Harra, L.; Hassler, D.; Long, D.; Rochus, P. L.; Schühle, U.; Aznar Cuadrado, R.; Caldwell, M.; Caminade, S.; DeForest, C.; Fredvik, T.; Gissot, S.; Heerlein, K.; Janvier, M.; Kraaikamp, E.; Kucera, T. A.; Müller, D.; Parenti, S.; Schmutz, W. K.; Sidher, S.; Smith, P.; Stegen, K.; Thompson, W. T.; Verbeeck, C.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH0360024B Altcode: On June 16th 2020 Solar Orbiter made a dedicated observing campaign where the spacecraft pointed to the solar limb to allow some of the high resolution instruments to observe the ingress (at the east limb) and later the egress (west limb) of the occultation of the star Alpha Leonis by the solar disk. The star was chosen because its luminosity and early spectral type ensure high and stable flux at wavelengths between 100 and 122 nanometers, a range observed by the High Resolution EUI Lyman alpha telescope (HRI-LYA) and by the long wavelength channel of the SPICE spectrograph. Star observations, when feasible, allow to gather a great deal of information on the instrument performances, such as the radiometric performance and the instrument optical point spread function (PSF).

We report here the first results from the above campaign for the two instruments. Title: First results from combined EUI and SPICE observations of Lyman lines of Hydrogen and He II Authors: Teriaca, L.; Aznar Cuadrado, R.; Giunta, A. S.; Grundy, T.; Parenti, S.; Auchere, F.; Vial, J. C.; Fludra, A.; Berghmans, D.; Carlsson, M.; Harra, L.; Hassler, D.; Long, D.; Peter, H.; Rochus, P. L.; Schühle, U.; Buchlin, E.; Caldwell, M.; Caminade, S.; DeForest, C.; Fredvik, T.; Gissot, S.; Heerlein, K.; Janvier, M.; Kraaikamp, E.; Kucera, T. A.; Mueller, D.; Schmutz, W. K.; Sidher, S.; Smith, P.; Stegen, K.; Thompson, W. T.; Verbeeck, C.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH0360003T Altcode: The Solar Orbiter spacecraft carries a powerful set of remote sensing instruments that allow studying the solar atmosphere with unprecedented diagnostic capabilities. Many such diagnostics require the simultaneous usage of more than one instrument. One example of that is the capability, for the first time, to obtain (near) simultaneous spatially resolved observations of the emission from the first three lines of the Lyman series of hydrogen and of He II Lyman alpha. In fact, the SPectral Imaging of the Coronal Environment (SPICE) spectrometer can observe the Lyman beta and gamma lines in its long wavelength (SPICE-LW) channel, the High Resolution Lyman Alpha (HRI-LYA) telescope of the Extreme Ultraviolet Imager (EUI) acquires narrow band images in the Lyman alpha line while the Full Disk Imager (FSI) of EUI can take images dominated by the Lyman alpha line of ionized Helium at 30.4 nm (FSI-304). Being hydrogen and helium the main components of our star, these very bright transitions play an important role in the energy budget of the outer atmosphere via radiative losses and the measurement of their profiles and radiance ratios is a fundamental constraint to any comprehensive modelization effort of the upper solar chromosphere and transition region. Additionally, monitoring their average ratios can serve as a check out for the relative radiometric performance of the two instruments throughout the mission. Although the engineering data acquired so far are far from ideal in terms of time simultaneity (often only within about 1 h) and line coverage (often only Lyman beta was acquired by SPICE and not always near simultaneous images from all three telescopes are available) the analysis we present here still offers a great opportunity to have a first look at the potential of this diagnostic from the two instruments. In fact, we have identified a series of datasets obtained at disk center and at various positions at the solar limb that allow studying the Lyman alpha to beta radiance ratio and their relation to He II 30.4 as a function of the position on the Sun (disk center versus limb and quiet Sun versus coronal holes). Title: A joint study of Solar Orbiter first data and PSP E5 through 3D MHD modeling Authors: Réville, V.; Strugarek, A.; Brun, S.; Rouillard, A. P.; Velli, M. C. M.; Poirier, N.; Parenti, S.; Hazra, S.; Perri, B.; Pinto, R.; Lavraud, B.; Louarn, P.; Fedorov, A.; Owen, C. J.; Bruno, R.; Livi, R.; Horbury, T. S.; O'Brien, H.; Evans, V.; Angelini, V.; Bale, S. D.; Kasper, J. C. Bibcode: 2020AGUFMSH039..09R Altcode: The first remote sensing window of Solar Orbiter started mid-June 2020. After a successful commissioning, Solar Orbiter in situ instruments were then continuously monitoring. This window is coincidentally close to the fifth perihelion of Parker Solar Probe. This offers an opportunity for a joint study between the two probes' data. We use a 3D MHD model of a turbulence driven solar wind, and compare the structure of the inner heliosphere obtained by the model and the available in situ and remote sensing data of the spacecraft. We discuss the key features of the model and tricky points that require care, such as the choice of the input magnetogram. In particular, we notice the strong influence of two active regions on the magnetic sectors and solar wind properties. These regions will be increasingly important features in future encounters and joint studies as we go towards solar maximum. Title: Coordination within the remote sensing payload on the Solar Orbiter mission Authors: Auchère, F.; Andretta, V.; Antonucci, E.; Bach, N.; Battaglia, M.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Caminade, S.; Carlsson, M.; Carlyle, J.; Cerullo, J. J.; Chamberlin, P. C.; Colaninno, R. C.; Davila, J. M.; De Groof, A.; Etesi, L.; Fahmy, S.; Fineschi, S.; Fludra, A.; Gilbert, H. R.; Giunta, A.; Grundy, T.; Haberreiter, M.; Harra, L. K.; Hassler, D. M.; Hirzberger, J.; Howard, R. A.; Hurford, G.; Kleint, L.; Kolleck, M.; Krucker, S.; Lagg, A.; Landini, F.; Long, D. M.; Lefort, J.; Lodiot, S.; Mampaey, B.; Maloney, S.; Marliani, F.; Martinez-Pillet, V.; McMullin, D. R.; Müller, D.; Nicolini, G.; Orozco Suarez, D.; Pacros, A.; Pancrazzi, M.; Parenti, S.; Peter, H.; Philippon, A.; Plunkett, S.; Rich, N.; Rochus, P.; Rouillard, A.; Romoli, M.; Sanchez, L.; Schühle, U.; Sidher, S.; Solanki, S. K.; Spadaro, D.; St Cyr, O. C.; Straus, T.; Tanco, I.; Teriaca, L.; Thompson, W. T.; del Toro Iniesta, J. C.; Verbeeck, C.; Vourlidas, A.; Watson, C.; Wiegelmann, T.; Williams, D.; Woch, J.; Zhukov, A. N.; Zouganelis, I. Bibcode: 2020A&A...642A...6A Altcode: Context. To meet the scientific objectives of the mission, the Solar Orbiter spacecraft carries a suite of in-situ (IS) and remote sensing (RS) instruments designed for joint operations with inter-instrument communication capabilities. Indeed, previous missions have shown that the Sun (imaged by the RS instruments) and the heliosphere (mainly sampled by the IS instruments) should be considered as an integrated system rather than separate entities. Many of the advances expected from Solar Orbiter rely on this synergistic approach between IS and RS measurements.
Aims: Many aspects of hardware development, integration, testing, and operations are common to two or more RS instruments. In this paper, we describe the coordination effort initiated from the early mission phases by the Remote Sensing Working Group. We review the scientific goals and challenges, and give an overview of the technical solutions devised to successfully operate these instruments together.
Methods: A major constraint for the RS instruments is the limited telemetry (TM) bandwidth of the Solar Orbiter deep-space mission compared to missions in Earth orbit. Hence, many of the strategies developed to maximise the scientific return from these instruments revolve around the optimisation of TM usage, relying for example on onboard autonomy for data processing, compression, and selection for downlink. The planning process itself has been optimised to alleviate the dynamic nature of the targets, and an inter-instrument communication scheme has been implemented which can be used to autonomously alter the observing modes. We also outline the plans for in-flight cross-calibration, which will be essential to the joint data reduction and analysis.
Results: The RS instrument package on Solar Orbiter will carry out comprehensive measurements from the solar interior to the inner heliosphere. Thanks to the close coordination between the instrument teams and the European Space Agency, several challenges specific to the RS suite were identified and addressed in a timely manner. Title: Models and data analysis tools for the Solar Orbiter mission Authors: Rouillard, A. P.; Pinto, R. F.; Vourlidas, A.; De Groof, A.; Thompson, W. T.; Bemporad, A.; Dolei, S.; Indurain, M.; Buchlin, E.; Sasso, C.; Spadaro, D.; Dalmasse, K.; Hirzberger, J.; Zouganelis, I.; Strugarek, A.; Brun, A. S.; Alexandre, M.; Berghmans, D.; Raouafi, N. E.; Wiegelmann, T.; Pagano, P.; Arge, C. N.; Nieves-Chinchilla, T.; Lavarra, M.; Poirier, N.; Amari, T.; Aran, A.; Andretta, V.; Antonucci, E.; Anastasiadis, A.; Auchère, F.; Bellot Rubio, L.; Nicula, B.; Bonnin, X.; Bouchemit, M.; Budnik, E.; Caminade, S.; Cecconi, B.; Carlyle, J.; Cernuda, I.; Davila, J. M.; Etesi, L.; Espinosa Lara, F.; Fedorov, A.; Fineschi, S.; Fludra, A.; Génot, V.; Georgoulis, M. K.; Gilbert, H. R.; Giunta, A.; Gomez-Herrero, R.; Guest, S.; Haberreiter, M.; Hassler, D.; Henney, C. J.; Howard, R. A.; Horbury, T. S.; Janvier, M.; Jones, S. I.; Kozarev, K.; Kraaikamp, E.; Kouloumvakos, A.; Krucker, S.; Lagg, A.; Linker, J.; Lavraud, B.; Louarn, P.; Maksimovic, M.; Maloney, S.; Mann, G.; Masson, A.; Müller, D.; Önel, H.; Osuna, P.; Orozco Suarez, D.; Owen, C. J.; Papaioannou, A.; Pérez-Suárez, D.; Rodriguez-Pacheco, J.; Parenti, S.; Pariat, E.; Peter, H.; Plunkett, S.; Pomoell, J.; Raines, J. M.; Riethmüller, T. L.; Rich, N.; Rodriguez, L.; Romoli, M.; Sanchez, L.; Solanki, S. K.; St Cyr, O. C.; Straus, T.; Susino, R.; Teriaca, L.; del Toro Iniesta, J. C.; Ventura, R.; Verbeeck, C.; Vilmer, N.; Warmuth, A.; Walsh, A. P.; Watson, C.; Williams, D.; Wu, Y.; Zhukov, A. N. Bibcode: 2020A&A...642A...2R Altcode: Context. The Solar Orbiter spacecraft will be equipped with a wide range of remote-sensing (RS) and in situ (IS) instruments to record novel and unprecedented measurements of the solar atmosphere and the inner heliosphere. To take full advantage of these new datasets, tools and techniques must be developed to ease multi-instrument and multi-spacecraft studies. In particular the currently inaccessible low solar corona below two solar radii can only be observed remotely. Furthermore techniques must be used to retrieve coronal plasma properties in time and in three dimensional (3D) space. Solar Orbiter will run complex observation campaigns that provide interesting opportunities to maximise the likelihood of linking IS data to their source region near the Sun. Several RS instruments can be directed to specific targets situated on the solar disk just days before data acquisition. To compare IS and RS, data we must improve our understanding of how heliospheric probes magnetically connect to the solar disk.
Aims: The aim of the present paper is to briefly review how the current modelling of the Sun and its atmosphere can support Solar Orbiter science. We describe the results of a community-led effort by European Space Agency's Modelling and Data Analysis Working Group (MADAWG) to develop different models, tools, and techniques deemed necessary to test different theories for the physical processes that may occur in the solar plasma. The focus here is on the large scales and little is described with regards to kinetic processes. To exploit future IS and RS data fully, many techniques have been adapted to model the evolving 3D solar magneto-plasma from the solar interior to the solar wind. A particular focus in the paper is placed on techniques that can estimate how Solar Orbiter will connect magnetically through the complex coronal magnetic fields to various photospheric and coronal features in support of spacecraft operations and future scientific studies.
Methods: Recent missions such as STEREO, provided great opportunities for RS, IS, and multi-spacecraft studies. We summarise the achievements and highlight the challenges faced during these investigations, many of which motivated the Solar Orbiter mission. We present the new tools and techniques developed by the MADAWG to support the science operations and the analysis of the data from the many instruments on Solar Orbiter.
Results: This article reviews current modelling and tool developments that ease the comparison of model results with RS and IS data made available by current and upcoming missions. It also describes the modelling strategy to support the science operations and subsequent exploitation of Solar Orbiter data in order to maximise the scientific output of the mission.
Conclusions: The on-going community effort presented in this paper has provided new models and tools necessary to support mission operations as well as the science exploitation of the Solar Orbiter data. The tools and techniques will no doubt evolve significantly as we refine our procedure and methodology during the first year of operations of this highly promising mission. Title: The Solar Orbiter Science Activity Plan. Translating solar and heliospheric physics questions into action Authors: Zouganelis, I.; De Groof, A.; Walsh, A. P.; Williams, D. R.; Müller, D.; St Cyr, O. C.; Auchère, F.; Berghmans, D.; Fludra, A.; Horbury, T. S.; Howard, R. A.; Krucker, S.; Maksimovic, M.; Owen, C. J.; Rodríguez-Pacheco, J.; Romoli, M.; Solanki, S. K.; Watson, C.; Sanchez, L.; Lefort, J.; Osuna, P.; Gilbert, H. R.; Nieves-Chinchilla, T.; Abbo, L.; Alexandrova, O.; Anastasiadis, A.; Andretta, V.; Antonucci, E.; Appourchaux, T.; Aran, A.; Arge, C. N.; Aulanier, G.; Baker, D.; Bale, S. D.; Battaglia, M.; Bellot Rubio, L.; Bemporad, A.; Berthomier, M.; Bocchialini, K.; Bonnin, X.; Brun, A. S.; Bruno, R.; Buchlin, E.; Büchner, J.; Bucik, R.; Carcaboso, F.; Carr, R.; Carrasco-Blázquez, I.; Cecconi, B.; Cernuda Cangas, I.; Chen, C. H. K.; Chitta, L. P.; Chust, T.; Dalmasse, K.; D'Amicis, R.; Da Deppo, V.; De Marco, R.; Dolei, S.; Dolla, L.; Dudok de Wit, T.; van Driel-Gesztelyi, L.; Eastwood, J. P.; Espinosa Lara, F.; Etesi, L.; Fedorov, A.; Félix-Redondo, F.; Fineschi, S.; Fleck, B.; Fontaine, D.; Fox, N. J.; Gandorfer, A.; Génot, V.; Georgoulis, M. K.; Gissot, S.; Giunta, A.; Gizon, L.; Gómez-Herrero, R.; Gontikakis, C.; Graham, G.; Green, L.; Grundy, T.; Haberreiter, M.; Harra, L. K.; Hassler, D. M.; Hirzberger, J.; Ho, G. C.; Hurford, G.; Innes, D.; Issautier, K.; James, A. W.; Janitzek, N.; Janvier, M.; Jeffrey, N.; Jenkins, J.; Khotyaintsev, Y.; Klein, K. -L.; Kontar, E. P.; Kontogiannis, I.; Krafft, C.; Krasnoselskikh, V.; Kretzschmar, M.; Labrosse, N.; Lagg, A.; Landini, F.; Lavraud, B.; Leon, I.; Lepri, S. T.; Lewis, G. R.; Liewer, P.; Linker, J.; Livi, S.; Long, D. M.; Louarn, P.; Malandraki, O.; Maloney, S.; Martinez-Pillet, V.; Martinovic, M.; Masson, A.; Matthews, S.; Matteini, L.; Meyer-Vernet, N.; Moraitis, K.; Morton, R. J.; Musset, S.; Nicolaou, G.; Nindos, A.; O'Brien, H.; Orozco Suarez, D.; Owens, M.; Pancrazzi, M.; Papaioannou, A.; Parenti, S.; Pariat, E.; Patsourakos, S.; Perrone, D.; Peter, H.; Pinto, R. F.; Plainaki, C.; Plettemeier, D.; Plunkett, S. P.; Raines, J. M.; Raouafi, N.; Reid, H.; Retino, A.; Rezeau, L.; Rochus, P.; Rodriguez, L.; Rodriguez-Garcia, L.; Roth, M.; Rouillard, A. P.; Sahraoui, F.; Sasso, C.; Schou, J.; Schühle, U.; Sorriso-Valvo, L.; Soucek, J.; Spadaro, D.; Stangalini, M.; Stansby, D.; Steller, M.; Strugarek, A.; Štverák, Š.; Susino, R.; Telloni, D.; Terasa, C.; Teriaca, L.; Toledo-Redondo, S.; del Toro Iniesta, J. C.; Tsiropoula, G.; Tsounis, A.; Tziotziou, K.; Valentini, F.; Vaivads, A.; Vecchio, A.; Velli, M.; Verbeeck, C.; Verdini, A.; Verscharen, D.; Vilmer, N.; Vourlidas, A.; Wicks, R.; Wimmer-Schweingruber, R. F.; Wiegelmann, T.; Young, P. R.; Zhukov, A. N. Bibcode: 2020A&A...642A...3Z Altcode: 2020arXiv200910772Z Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operations are essential to address the following four top-level science questions: (1) What drives the solar wind and where does the coronal magnetic field originate?; (2) How do solar transients drive heliospheric variability?; (3) How do solar eruptions produce energetic particle radiation that fills the heliosphere?; (4) How does the solar dynamo work and drive connections between the Sun and the heliosphere? Maximising the mission's science return requires considering the characteristics of each orbit, including the relative position of the spacecraft to Earth (affecting downlink rates), trajectory events (such as gravitational assist manoeuvres), and the phase of the solar activity cycle. Furthermore, since each orbit's science telemetry will be downloaded over the course of the following orbit, science operations must be planned at mission level, rather than at the level of individual orbits. It is important to explore the way in which those science questions are translated into an actual plan of observations that fits into the mission, thus ensuring that no opportunities are missed. First, the overarching goals are broken down into specific, answerable questions along with the required observations and the so-called Science Activity Plan (SAP) is developed to achieve this. The SAP groups objectives that require similar observations into Solar Orbiter Observing Plans, resulting in a strategic, top-level view of the optimal opportunities for science observations during the mission lifetime. This allows for all four mission goals to be addressed. In this paper, we introduce Solar Orbiter's SAP through a series of examples and the strategy being followed. Title: The Solar Orbiter SPICE instrument. An extreme UV imaging spectrometer Authors: SPICE Consortium; Anderson, M.; Appourchaux, T.; Auchère, F.; Aznar Cuadrado, R.; Barbay, J.; Baudin, F.; Beardsley, S.; Bocchialini, K.; Borgo, B.; Bruzzi, D.; Buchlin, E.; Burton, G.; Büchel, V.; Caldwell, M.; Caminade, S.; Carlsson, M.; Curdt, W.; Davenne, J.; Davila, J.; Deforest, C. E.; Del Zanna, G.; Drummond, D.; Dubau, J.; Dumesnil, C.; Dunn, G.; Eccleston, P.; Fludra, A.; Fredvik, T.; Gabriel, A.; Giunta, A.; Gottwald, A.; Griffin, D.; Grundy, T.; Guest, S.; Gyo, M.; Haberreiter, M.; Hansteen, V.; Harrison, R.; Hassler, D. M.; Haugan, S. V. H.; Howe, C.; Janvier, M.; Klein, R.; Koller, S.; Kucera, T. A.; Kouliche, D.; Marsch, E.; Marshall, A.; Marshall, G.; Matthews, S. A.; McQuirk, C.; Meining, S.; Mercier, C.; Morris, N.; Morse, T.; Munro, G.; Parenti, S.; Pastor-Santos, C.; Peter, H.; Pfiffner, D.; Phelan, P.; Philippon, A.; Richards, A.; Rogers, K.; Sawyer, C.; Schlatter, P.; Schmutz, W.; Schühle, U.; Shaughnessy, B.; Sidher, S.; Solanki, S. K.; Speight, R.; Spescha, M.; Szwec, N.; Tamiatto, C.; Teriaca, L.; Thompson, W.; Tosh, I.; Tustain, S.; Vial, J. -C.; Walls, B.; Waltham, N.; Wimmer-Schweingruber, R.; Woodward, S.; Young, P.; de Groof, A.; Pacros, A.; Williams, D.; Müller, D. Bibcode: 2020A&A...642A..14S Altcode: 2019arXiv190901183A; 2019arXiv190901183S
Aims: The Spectral Imaging of the Coronal Environment (SPICE) instrument is a high-resolution imaging spectrometer operating at extreme ultraviolet wavelengths. In this paper, we present the concept, design, and pre-launch performance of this facility instrument on the ESA/NASA Solar Orbiter mission.
Methods: The goal of this paper is to give prospective users a better understanding of the possible types of observations, the data acquisition, and the sources that contribute to the instrument's signal.
Results: The paper discusses the science objectives, with a focus on the SPICE-specific aspects, before presenting the instrument's design, including optical, mechanical, thermal, and electronics aspects. This is followed by a characterisation and calibration of the instrument's performance. The paper concludes with descriptions of the operations concept and data processing.
Conclusions: The performance measurements of the various instrument parameters meet the requirements derived from the mission's science objectives. The SPICE instrument is ready to perform measurements that will provide vital contributions to the scientific success of the Solar Orbiter mission. Title: The Solar Orbiter EUI instrument: The Extreme Ultraviolet Imager Authors: Rochus, P.; Auchère, F.; Berghmans, D.; Harra, L.; Schmutz, W.; Schühle, U.; Addison, P.; Appourchaux, T.; Aznar Cuadrado, R.; Baker, D.; Barbay, J.; Bates, D.; BenMoussa, A.; Bergmann, M.; Beurthe, C.; Borgo, B.; Bonte, K.; Bouzit, M.; Bradley, L.; Büchel, V.; Buchlin, E.; Büchner, J.; Cabé, F.; Cadiergues, L.; Chaigneau, M.; Chares, B.; Choque Cortez, C.; Coker, P.; Condamin, M.; Coumar, S.; Curdt, W.; Cutler, J.; Davies, D.; Davison, G.; Defise, J. -M.; Del Zanna, G.; Delmotte, F.; Delouille, V.; Dolla, L.; Dumesnil, C.; Dürig, F.; Enge, R.; François, S.; Fourmond, J. -J.; Gillis, J. -M.; Giordanengo, B.; Gissot, S.; Green, L. M.; Guerreiro, N.; Guilbaud, A.; Gyo, M.; Haberreiter, M.; Hafiz, A.; Hailey, M.; Halain, J. -P.; Hansotte, J.; Hecquet, C.; Heerlein, K.; Hellin, M. -L.; Hemsley, S.; Hermans, A.; Hervier, V.; Hochedez, J. -F.; Houbrechts, Y.; Ihsan, K.; Jacques, L.; Jérôme, A.; Jones, J.; Kahle, M.; Kennedy, T.; Klaproth, M.; Kolleck, M.; Koller, S.; Kotsialos, E.; Kraaikamp, E.; Langer, P.; Lawrenson, A.; Le Clech', J. -C.; Lenaerts, C.; Liebecq, S.; Linder, D.; Long, D. M.; Mampaey, B.; Markiewicz-Innes, D.; Marquet, B.; Marsch, E.; Matthews, S.; Mazy, E.; Mazzoli, A.; Meining, S.; Meltchakov, E.; Mercier, R.; Meyer, S.; Monecke, M.; Monfort, F.; Morinaud, G.; Moron, F.; Mountney, L.; Müller, R.; Nicula, B.; Parenti, S.; Peter, H.; Pfiffner, D.; Philippon, A.; Phillips, I.; Plesseria, J. -Y.; Pylyser, E.; Rabecki, F.; Ravet-Krill, M. -F.; Rebellato, J.; Renotte, E.; Rodriguez, L.; Roose, S.; Rosin, J.; Rossi, L.; Roth, P.; Rouesnel, F.; Roulliay, M.; Rousseau, A.; Ruane, K.; Scanlan, J.; Schlatter, P.; Seaton, D. B.; Silliman, K.; Smit, S.; Smith, P. J.; Solanki, S. K.; Spescha, M.; Spencer, A.; Stegen, K.; Stockman, Y.; Szwec, N.; Tamiatto, C.; Tandy, J.; Teriaca, L.; Theobald, C.; Tychon, I.; van Driel-Gesztelyi, L.; Verbeeck, C.; Vial, J. -C.; Werner, S.; West, M. J.; Westwood, D.; Wiegelmann, T.; Willis, G.; Winter, B.; Zerr, A.; Zhang, X.; Zhukov, A. N. Bibcode: 2020A&A...642A...8R Altcode: Context. The Extreme Ultraviolet Imager (EUI) is part of the remote sensing instrument package of the ESA/NASA Solar Orbiter mission that will explore the inner heliosphere and observe the Sun from vantage points close to the Sun and out of the ecliptic. Solar Orbiter will advance the "connection science" between solar activity and the heliosphere.
Aims: With EUI we aim to improve our understanding of the structure and dynamics of the solar atmosphere, globally as well as at high resolution, and from high solar latitude perspectives.
Methods: The EUI consists of three telescopes, the Full Sun Imager and two High Resolution Imagers, which are optimised to image in Lyman-α and EUV (17.4 nm, 30.4 nm) to provide a coverage from chromosphere up to corona. The EUI is designed to cope with the strong constraints imposed by the Solar Orbiter mission characteristics. Limited telemetry availability is compensated by state-of-the-art image compression, onboard image processing, and event selection. The imposed power limitations and potentially harsh radiation environment necessitate the use of novel CMOS sensors. As the unobstructed field of view of the telescopes needs to protrude through the spacecraft's heat shield, the apertures have been kept as small as possible, without compromising optical performance. This led to a systematic effort to optimise the throughput of every optical element and the reduction of noise levels in the sensor.
Results: In this paper we review the design of the two elements of the EUI instrument: the Optical Bench System and the Common Electronic Box. Particular attention is also given to the onboard software, the intended operations, the ground software, and the foreseen data products.
Conclusions: The EUI will bring unique science opportunities thanks to its specific design, its viewpoint, and to the planned synergies with the other Solar Orbiter instruments. In particular, we highlight science opportunities brought by the out-of-ecliptic vantage point of the solar poles, the high-resolution imaging of the high chromosphere and corona, and the connection to the outer corona as observed by coronagraphs. Title: Solar physics in the 2020s: DKIST, parker solar probe, and solar orbiter as a multi-messenger constellation Authors: Martinez Pillet, V.; Tritschler, A.; Harra, L.; Andretta, V.; Vourlidas, A.; Raouafi, N.; Alterman, B. L.; Bellot Rubio, L.; Cauzzi, G.; Cranmer, S. R.; Gibson, S.; Habbal, S.; Ko, Y. K.; Lepri, S. T.; Linker, J.; Malaspina, D. M.; Matthews, S.; Parenti, S.; Petrie, G.; Spadaro, D.; Ugarte-Urra, I.; Warren, H.; Winslow, R. Bibcode: 2020arXiv200408632M Altcode: The National Science Foundation (NSF) Daniel K. Inouye Solar Telescope (DKIST) is about to start operations at the summit of Haleakala (Hawaii). DKIST will join the early science phases of the NASA and ESA Parker Solar Probe and Solar Orbiter encounter missions. By combining in-situ measurements of the near-sun plasma environment and detail remote observations of multiple layers of the Sun, the three observatories form an unprecedented multi-messenger constellation to study the magnetic connectivity inside the solar system. This white paper outlines the synergistic science that this multi-messenger suite enables. Title: Spectroscopic detection of coronal plasma flows in loops undergoing thermal non-equilibrium cycles Authors: Pelouze, Gabriel; Auchère, Frédéric; Bocchialini, Karine; Froment, Clara; Parenti, Susanna; Soubrié, Elie Bibcode: 2020A&A...634A..54P Altcode: 2019arXiv191202538P Context. Long-period intensity pulsations were recently detected in the EUV emission of coronal loops and attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations that reproduce this phenomenon also predict the formation of periodic flows of plasma at coronal temperatures along some of the pulsating loops.
Aims: We aim to detect these predicted flows of coronal-temperature plasma in pulsating loops.
Methods: We used time series of spatially resolved spectra from the EUV imaging spectrometer (EIS) onboard Hinode and tracked the evolution of the Doppler velocity in loops in which intensity pulsations have previously been detected in images of SDO/AIA.
Results: We measured signatures of flows that are compatible with the simulations but only for a fraction of the observed events. We demonstrate that this low detection rate can be explained by line of sight ambiguities combined with instrumental limitations, such as low signal-to-noise ratio or insufficient cadence.

Movies associated to Figs. 1, 4, 7, 10 are available at https://www.aanda.org Title: The SPICE (Spectral Imaging of the Coronal Environment) Ultraviolet Imaging Spectrograph Investigation Authors: Hassler, D.; Auchere, F.; Carlsson, M.; Fludra, A.; Giunta, A. S.; Mueller, D.; Peter, H.; Parenti, S.; Teriaca, L.; Fredvik, T. Bibcode: 2019AGUFMSH24A..02H Altcode: One of the primary objectives of the Solar Orbiter mission is to link remote sensing observations of the solar surface structures with in-situ observations of solar wind streams. The SPICE (Spectral Imaging of the Coronal Environment) instrument will characterize the plasma properties of regions near the Sun to directly compare with in-situ measurements from both Solar Orbiter & Parker Solar Probe. Specifically, SPICE will map outflow velocities of surface features to solar wind structures with similar composition (FIP, M/q) measured in-situ by the SWA/HIS instrument on Solar Orbiter. These observations will help discriminate models of solar wind origin by matching composition signatures in solar wind streams to surface feature composition, and discriminate physical processes that inject material from closed structures into solar wind streams.

This presentation will provide an overview of the SPICE investigation, including science & measurement objective, instrument design, capabilities and performance as measured during calibration prior to delivery to the Solar Orbiter spacecraft. The presentation will also provide a description of the operations concept and data processing during the mission. Title: Linking the Sun to the heliosphere using composition data and modelling: coronal jets as a test case Authors: Wimmer-Schweingruber, Robert F.; Parenti, Susanna; Del Zanna, G.; Edmondson, J.; Giunta, A.; Hansteen, V. H.; Higginson, A.; Lepri, S.; Laming, M.; Lynch, B. J.; von Steiger, R. E.; Wiegelmann, T.; Zambrana Prado, N. Bibcode: 2019shin.confE.231W Altcode: Understanding the formation and evolution of the solar wind is still a priority in the Solar and Heliospheric communities. We expect a significant progress in terms of observations with the upcoming Solar Orbiter mission (launch in 2020), which will provide detailed in-situ measurements of the solar wind and several remote-sensing observations. However, real progress will only be possible if we improve our understanding of the physical link between what measured in-situ and its source regions on the Sun. In this respect, the plasma chemical and charge-state compositions are considered good diagnostic tools. In this paper we present results obtained from an extensive team work aiming at providing solid diagnostics for linking the in-situ and the remote sensing measurements. For our test cases, we selected two periods when a single active region produced, close to its sunspot, jets which had a counterpart signature in the Heliosphere in the form of type-III radio bursts. These jets therefore marked magnetically open regions expanding in the heliosphere. Firstly, we looked for signatures of the open field associated with the active regions in in-situ data from ACE and WIND, finding potential tracers. Secondly, we studied the magnetic topology of the full Sun and Heliosphere with extrapolations of photospheric data and MHD modeling. We found that the open field area is consistent with the source and evolution of the jets, as observed with EUV imagers (SDO/AIA, STEREO/EUVI). Thirdly, we analysed remote sensing EUV spectroscopic observations to measure the plasma conditions (densities, temperatures and chemical composition) whenever available. We then modeled the solar wind and charge state evolution with the solar distance along the open fields to establish a link between the in-situ signatures and the remote sensing observations. We discuss the various difficulties associated with such studies, and highlight how Solar Orbiter measurements can improve them. Title: Modeling the Solar-Heliospheric Connection of Active Region-Adjacent Open Fields Authors: Lynch, Benjamin J.; Higginson, A. K.; Edmondson, J. K.; Parenti, S. Bibcode: 2019shin.confE.234L Altcode: We present MHD simulation results of the 2010 August 02 coronal jet rooted in the negative polarity spot of AR 11092. We examine the 'steady state' MHD solar wind outflow and compare the helmet streamer and coronal hole configurations to the PFSS extrapolations obtained using NSO GONG and SDO HMI synoptic maps. We compare the structure of the open fields in the periphery of the AR to EUV imaging in the low corona. We model the macroscopic twist propagation of the jet as a simple rotational flow imposed at the lower boundary and examine its interaction with and the evolution of the open-closed flux system boundary. We show how the disturbance maps to the ecliptic plane and compare the simulation dynamics to STEREO EUV and white light observations. Title: Elemental composition in quiescent prominences Authors: Parenti, S.; Del Zanna, G.; Vial, J. -C. Bibcode: 2019A&A...625A..52P Altcode: 2019arXiv190500871P Context. The first ionization potential (FIP) bias is currently used to trace the propagation of solar features ejected by the wind and solar eruptions (coronal mass ejections). The FIP bias also helps us to understand the formation of prominences, as it is a tracer for the solar origin of prominence plasma.
Aims: This work aims to provide elemental composition and FIP bias in quiescent solar prominences. This is key information to link these features to remnants of solar eruptions measured in-situ within the heliosphere and to constrain the coronal or photospheric origin of prominence plasma.
Methods: We used the differential emission measure technique to derive the FIP bias of two prominences. Quiet Sun chromospheric and transition region data were used to test the atomic data and lines formation processes. We used lines from low stage of ionization of Si, S, Fe, C, N, O, Ni, Mg, and Ne, constraining the FIP bias in the range 4.2 ≤ log T ≤ 5.8. We adopted a density-dependent ionization equilibrium.
Results: We showed that the two prominences have photospheric composition. We confirmed a photospheric composition in the quiet Sun. We also identified opacity and/or radiative excitation contributions to the line formation of a few lines regularly observed in prominences.
Conclusions: With our results we thus provide important elements for correctly interpreting the upcoming Solar Orbiter/SPICE spectroscopic data and to constrain prominence formation. Title: Elemental composition in quiescent prominences Authors: Parenti, Susanna; Del Zanna, Giulio; Vial, Jean-Claude Bibcode: 2019shin.confE.182P Altcode: The first ionization potential (FIP) bias is currently used to trace the propagation of solar features ejected by the wind and solar eruptions (coronal mass ejections). The FIP bias also helps us to understand the formation of prominences, as it is a tracer for the solar origin of prominence plasma. This work aims to provide elemental composition and FIP bias in quiescent solar prominences. This is key information to link these features to remnants of solar eruptions measured in-situ within the heliosphere and to constrain the coronal or photospheric origin of prominence plasma. We used the differential emission measure technique to derive the FIP bias of two prominences observed with SOHO/SUMER. Quiet Sun chromospheric and transition region data were used to test the atomic data and lines formation processes. We used lines from low stage of ionization of Si, S, Fe, C, N, O, Ni, Mg, and Ne, constraining the FIP bias in the range 4.2 < log T< 5.8. We adopted a density-dependent ionization equilibrium. We showed that the two prominences have photospheric composition. We also identified opacity and/or radiative excitation contributions to the line formation of a few lines regularly observed in prominences. With our results we thus provide important elements for correctly interpreting the upcoming Solar Orbiter/SPICE spectroscopic data and to constrain prominence formation. Title: Solar data, dataproducts, and tools at MEDOC Authors: Buchlin, Eric; Caminade, Stéphane; Dufourg, Nicolas; Auchère, Frédéric; Baudin, Frédéric; Bocchialini, Karine; Boumier, Patrick; Janvier, Miho; Parenti, Susanna; Alingery, Pablo; Ballans, Hervé; Chane-Yook, Martine; Dexet, Marc; Mercier, Claude; Poulleau, Gilles Bibcode: 2019EGUGA..2117362B Altcode: MEDOC (Multi-Experiment Data and Operation Centre), initially created as a European data and operation centre for the SOHO mission, has grown with data from other solar physics space missions, from STEREO to SDO. Derived data products such as DEM maps from SDO/AIA, synoptic EUV intensity maps from SOHO/EIT, and catalogues of solar structures are also automatically produced and redistributed. Both the data and the derived data products are publicly available from web interfaces and from programmatic interfaces (with clients for IDL and Python), allowing classical data analysis as well as automatic queries, data download, and processing to be made on large datasets. Title: The SDO AIA and HMI archive at MEDOC Authors: Alingery, Pablo; Buchlin, Éric; Caminade, Stéphane; Ballans, Hervé; Baudin, Frédéric; Parenti, Susanna; Bocchialini, Karine Bibcode: 2018csc..confE.113A Altcode: MEDOC, created as the European data and operations center for SoHO, hosts also data from STEREO, SDO, and various other solar physics missions. The SDO archive at MEDOC represents more than 415TB of data, and covers the full length of the mission. It includes aia.lev1 data at a minimum cadence of 60s in the EUV channels (12s at specific periods of interest), and most of the 720s-cadence HMI series. It is complemented by a database of DEM maps derived from AIA. MEDOC provides a reliable, convenient, and fast (especially for European users) access to these SDO data, by a web interface and webservices. We also provide IDL and Python clients to these webservices, allowing complex queries and automated analyses on large datasets to be made. Title: Chemical fractionation in solar prominences Authors: Parenti, Susanna; Vial, Jean-Claude; Del Zanna, Giulio Bibcode: 2018cosp...42E2585P Altcode: The First Ionization Potential (FIP) fractionation of elemental abundances in the solar atmosphere and solar wind is a known process which appears to vary depending on the magnetic field property and the dynamic nature of the environment. It is generally identified by an increase of the low FIP elements (with FIP energy below 10 eV) compared to the high FIP elements (with respect to the photospheric values). For instance, the low FIP element abundance is enhanced within active regions by about a factor of 3-4, with respect to photospheric values. A similar property is measured in the slow solar wind. This is one of the reasons why the FIP fractionation is used as a proxy for identifying the solar wind source regions on the Sun, a topic of particular relevance for the upcoming Solar Orbiter mission.Cool, low-state ionized plasma and its composition have been measured in-situ within interplanetary Coronal Mass Ejections (ICMEs) in only a few cases. This cool plasma has been associated to remnants of erupting prominences. However, this association is not confirmed, because the measurement of the composition within prominence plasma is very difficult and poorly known. The scope of this paper is to provide a reliable measurement of elements composition and FIP fractionation in a prominence using the available SOHO/SUMER dataset of the prominence atlas presented in Parenti et. al 2005. Our investigation will consider ions formed in the prominence-corona transition region, taking into account possible density and opacity effects in the formation of the spectral lines. Title: Search for predicted periodic flows in loops undergoing thermal non-equilibrium Authors: Pelouze, Gabriel; Parenti, Susanna; Bocchialini, Karine; Soubrie, Elie; Auchere, Frederic; Froment, Clara Bibcode: 2018cosp...42E2623P Altcode: Long-period intensity pulsations have been recently detected in coronal loopswith EUV images of both SoHO/EIT (Auchère et al., 2014) and SDO/AIA (Froment etal., 2015). These pulsations have been interpreted as resulting from thermalnon-equilibrium (TNE), thus providing a signature of a highly-stratified andquasi-constant heating at the loops footpoints (Froment et al., 2017; Auchèreet al., 2016). Depending on the adequacy between the geometry of the loop andthe characteristics of the heating, this can result in either complete (atchromospheric temperatures) or incomplete (> 1 MK) condensation and evaporationcycles, that are responsible for the observed intensity pulsations. Using 1Dhydrodynamic simulations, Froment et al. (2017) were able to reproduce theobserved pulsations, with incomplete condensation for the active region studiedin their previous paper. The simulations also predict periodic plasma flowsalong the loops footpoints, with velocities up to 40 km/s. We try to detect these flows by using time series of spatially resolved spectrafrom the EUV spectrometer Hinode/EIS. We systematically search for EIS datasetsthat correspond to the observation of pulsation events among the 3000+ thatwere detected in AIA data, between 2010 and 2016. For the 9 datasets that arefound, we derive series of Doppler velocity maps, which allows us to track theevolution of the plasma velocity in the loop over several pulsation periods. Wethen compare these data to the results of previous simulations andobservations. However the expected pulsations in velocity cannot be identifiedin any of the datasets that we analysed. We demonstrate that line of sightambiguities, combined with low signal to noise ratio or lack of time cadence,can explain this non-detection. Title: Spectroscopy of Very Hot Plasma in Non-flaring Parts of a Solar Limb Active Region: Spatial and Temporal Properties Authors: Parenti, Susanna; del Zanna, Giulio; Petralia, Antonino; Reale, Fabio; Teriaca, Luca; Testa, Paola; Mason, Helen E. Bibcode: 2017ApJ...846...25P Altcode: 2017arXiv170708445P In this work we investigate the thermal structure of an off-limb active region (AR) in various non-flaring areas, as it provides key information on the way these structures are heated. In particular, we concentrate on the very hot component (> 3 {MK}) as it is a crucial element to distinguish between different heating mechanisms. We present an analysis using Fe and Ca emission lines from both the Solar Ultraviolet Measurement of Emitted Radiation (SUMER) on board the Solar and Heliospheric Observatory (SOHO) and the EUV Imaging Spectrometer (EIS) on board Hinode. A data set covering all ionization stages from Fe x to Fe xix has been used for the thermal analysis (both differential emission measure and emission measure, EM). Ca xiv is used for the SUMER-EIS radiometric cross calibration. We show that the very hot plasma is present and persistent almost everywhere in the core of the limb AR. The off-limb AR is clearly structured in Fe xviii. Almost everywhere, the EM analysis reveals plasma at 10 MK (visible in Fe xix emission), which is down to 0.1% of EM of the main 3 {MK} plasma. We estimate the power-law index of the hot tail of the EM to be between -8.5 and -4.4. However, the question about the possible existence of a small minor peak at around 10 {MK} remains open. The absence in some part of the AR of the Fe xix and Fe xxiii lines (which fall into our spectral range) enables us to determine an upper limit on the EM at these temperatures. Our results include a new Ca xiv 943.59 Å atomic model. Title: The SDO AIA and HMI archive at MEDOC Authors: Alingery, P.; Wang, G.; Buchlin, E.; Caminade, S.; Ballans, H.; Baudin, F.; Parenti, S. Bibcode: 2016usc..confE..97A Altcode: MEDOC, created as the European data and operations center for SoHO, hosts also data from STEREO, SDO, and various other solar physics missions. The SDO archive at MEDOC represents more than 250TB of data, and covers the full length of the mission. It includes aia.lev1 data at a minimum cadence of 60s in the EUV channels (12s at specific periods of interest), and most of the 720s-cadence HMI series. It is complemented by a database of DEM maps derived from AIA, that will be presented at the mini-workshop on thermal diagnostics. MEDOC provides a reliable, convenient, and fast (especially for European users) access to these SDO data, by a web interface and webservices. We also provide IDL and Python clients to these webservices, allowing complex queries and automated analyses on large datasets to be made. Title: GAIA-DEM: a database providing AIA/SDO DEM maps Authors: Guennou, C.; Auchère, F.; Bocchialini, F.; Soubrié, E.; Mercier, C.; Parenti, S.; Alingery, P. Bibcode: 2016usc..confE.108G Altcode: The Gaussian AIA DEm Maps (GAIA-DEM) database at MEDOC (IAS) provides through a simple and intuitive web interface DEM inversions of the SDO/AIA data, computed every 30min. The Gaussian approximation is used to describe the main features of the true DEM(log T) by its first moments. For each date, maps of the three Gaussian fit parameters (central temperature, total emission measure and Gaussian width) and of the chi^2 are available in FITS format. Users can preview the maps before downloading them. In addition, users can display the initial SDO/AIA images using Helioviewer, and query the database through webservices accessible from IDL and Python clients. This presentation is for the "Thermal Diagnostics with SDO/AIA" mini-workshop. Title: The SPICE Spectral Imager on Solar Orbiter: Linking the Sun to the Heliosphere Authors: Fludra, Andrzej; Haberreiter, Margit; Peter, Hardi; Vial, Jean-Claude; Harrison, Richard; Parenti, Susanna; Innes, Davina; Schmutz, Werner; Buchlin, Eric; Chamberlin, Phillip; Thompson, William; Gabriel, Alan; Morris, Nigel; Caldwell, Martin; Auchere, Frederic; Curdt, Werner; Teriaca, Luca; Hassler, Donald M.; DeForest, Craig; Hansteen, Viggo; Carlsson, Mats; Philippon, Anne; Janvier, Miho; Wimmer-Schweingruber, Robert; Griffin, Douglas; Davila, Joseph; Giunta, Alessandra; Waltham, Nick; Eccleston, Paul; Gottwald, Alexander; Klein, Roman; Hanley, John; Walls, Buddy; Howe, Chris; Schuehle, Udo Bibcode: 2016cosp...41E.607F Altcode: The SPICE (Spectral Imaging of the Coronal Environment) instrument is one of the key remote sensing instruments onboard the upcoming Solar Orbiter Mission. SPICE has been designed to contribute to the science goals of the mission by investigating the source regions of outflows and ejection processes which link the solar surface and corona to the heliosphere. In particular, SPICE will provide quantitative information on the physical state and composition of the solar atmosphere plasma. For example, SPICE will access relative abundances of ions to study the origin and the spatial/temporal variations of the 'First Ionization Potential effect', which are key signatures to trace the solar wind and plasma ejections paths within the heliosphere. Here we will present the instrument and its performance capability to attain the scientific requirements. We will also discuss how different observation modes can be chosen to obtain the best science results during the different orbits of the mission. To maximize the scientific return of the instrument, the SPICE team is working to optimize the instrument operations, and to facilitate the data access and their exploitation. Title: Solar abundances with the SPICE spectral imager on Solar Orbiter Authors: Giunta, Alessandra; Haberreiter, Margit; Peter, Hardi; Vial, Jean-Claude; Harrison, Richard; Parenti, Susanna; Innes, Davina; Schmutz, Werner; Buchlin, Eric; Chamberlin, Phillip; Thompson, William; Bocchialini, Karine; Gabriel, Alan; Morris, Nigel; Caldwell, Martin; Auchere, Frederic; Curdt, Werner; Teriaca, Luca; Hassler, Donald M.; DeForest, Craig; Hansteen, Viggo; Carlsson, Mats; Philippon, Anne; Janvier, Miho; Wimmer-Schweingruber, Robert; Griffin, Douglas; Baudin, Frederic; Davila, Joseph; Fludra, Andrzej; Waltham, Nick; Eccleston, Paul; Gottwald, Alexander; Klein, Roman; Hanley, John; Walls, Buddy; Howe, Chris; Schuehle, Udo; Gyo, Manfred; Pfiffner, Dany Bibcode: 2016cosp...41E.681G Altcode: Elemental composition of the solar atmosphere and in particular abundance bias of low and high First Ionization Potential (FIP) elements are a key tracer of the source regions of the solar wind. These abundances and their spatio-temporal variations, as well as the other plasma parameters , will be derived by the SPICE (Spectral Imaging of the Coronal Environment) EUV spectral imager on the upcoming Solar Orbiter mission. SPICE is designed to provide spectroheliograms (spectral images) using a core set of emission lines arising from ions of both low-FIP and high-FIP elements. These lines are formed over a wide range of temperatures, enabling the analysis of the different layers of the solar atmosphere. SPICE will use these spectroheliograms to produce dynamic composition maps of the solar atmosphere to be compared to in-situ measurements of the solar wind composition of the same elements (i.e. O, Ne, Mg, Fe). This will provide a tool to study the connectivity between the spacecraft (the Heliosphere) and the Sun. We will discuss the SPICE capabilities for such composition measurements. Title: Spectral Diagnostics of Cool Prominence and PCTR Optically Thin Plasmas Authors: Parenti, Susanna Bibcode: 2015ASSL..415...61P Altcode: This chapter is dedicated to introduce information we can derive from optically thin emission of prominences plasma. This emission comes mostly from the interface region with the corona, the prominence-corona transition region, and it is observable in the UV-EUV wavebands. After a general introduction to the formation of the optically thin emission, we present the diagnostics methods which are used to infer the thermal properties of the emitting plasma under isothermal and multi-thermal hypothesis. We then describe a diagnostics technique to infer the electron density. For each method presented we give advantages and limitations, together with the main results. We then discuss the diagnostics at small, unresolved scales introducing the filling factor and conclude with some final remarks. Title: Time Evolution of the Altitude of an Observed Coronal Wave Authors: Delannée, C.; Artzner, G.; Schmieder, B.; Parenti, S. Bibcode: 2014SoPh..289.2565D Altcode: 2014SoPh..tmp...49D; 2013arXiv1310.5623D The nature of coronal wave fronts is intensely debated. They are observed in several wavelength bands and are frequently interpreted as magnetosonic waves propagating in the lower solar atmosphere. However, they can also be attributed to the line-of-sight projection of the edges of coronal mass ejections. Therefore, estimating the altitude of these features is crucial for deciding in favor of one of these two interpretations. We took advantage of a set of observations obtained from two different view directions by the EUVI instrument onboard the STEREO mission on 7 December 2007 to derive the time evolution of the altitude of a coronal wave front. We developed a new technique to compute the altitude of the coronal wave and found that the altitude increased during the initial 5 min and then slightly decreased back to the low corona. We interpret the evolution of the altitude as follows: the increase in the altitude of the wave front is linked to the rise of a bubble-like structure depending on whether it is a magnetosonic wave front or a CME in the initial phase. During the second phase, the observed brightness of the wave front was mixed with the brightening of the underlying magnetic structures as the emission from the wave front faded because the plasma became diluted with altitude. Title: Solar Prominences: Observations Authors: Parenti, Susanna Bibcode: 2014LRSP...11....1P Altcode: Solar prominences are one of the most common features of the solar atmosphere. They are found in the corona but they are one hundred times cooler and denser than the coronal material, indicating that they are thermally and pressure isolated from the surrounding environment. Because of these properties they appear at the limb as bright features when observed in the optical or the EUV cool lines. On the disk they appear darker than their background, indicating the presence of a plasma absorption process (in this case they are called filaments). Prominence plasma is embedded in a magnetic environment that lies above magnetic inversion lines, denoted a filament channel. Title: MASC: Magnetic Activity of the Solar Corona Authors: Auchere, Frederic; Fineschi, Silvano; Gan, Weiqun; Peter, Hardi; Vial, Jean-Claude; Zhukov, Andrei; Parenti, Susanna; Li, Hui; Romoli, Marco Bibcode: 2014cosp...40E.149A Altcode: We present MASC, an innovative payload designed to explore the magnetic activity of the solar corona. It is composed of three complementary instruments: a Hard-X-ray spectrometer, a UV / EUV imager, and a Visible Light / UV polarimetric coronagraph able to measure the coronal magnetic field. The solar corona is structured in magnetically closed and open structures from which slow and fast solar winds are respectively released. In spite of much progress brought by two decades of almost uninterrupted observations from several space missions, the sources and acceleration mechanisms of both types are still not understood. This continuous expansion of the solar atmosphere is disturbed by sporadic but frequent and violent events. Coronal mass ejections (CMEs) are large-scale massive eruptions of magnetic structures out of the corona, while solar flares trace the sudden heating of coronal plasma and the acceleration of electrons and ions to high, sometimes relativistic, energies. Both phenomena are most probably driven by instabilities of the magnetic field in the corona. The relations between flares and CMEs are still not understood in terms of initiation and energy partition between large-scale motions, small-scale heating and particle acceleration. The initiation is probably related to magnetic reconnection which itself results magnetic topological changes due to e.g. flux emergence, footpoints motions, etc. Acceleration and heating are also strongly coupled since the atmospheric heating is thought to result from the impact of accelerated particles. The measurement of both physical processes and their outputs is consequently of major importance. However, despite its fundamental importance as a driver for the physics of the Sun and of the heliosphere, the magnetic field of our star’s outer atmosphere remains poorly understood. This is due in large part to the fact that the magnetic field is a very difficult quantity to measure. Our knowledge of its strength and orientation is primarily based on extrapolations from photospheric observations, not from direct measurements. These extrapolations require strong assumptions on critical but unobserved quantities and thus fail to accurately reproduce the complex topologies inferred from remote-sensing observations of coronal structures in white light, EUV, and X-rays. Direct measurements of the coronal magnetic field are also clearly identified by the international heliophysics community as a key element susceptible to lead to major breakthroughs in the understanding of our star. MASC is thus designed to answer the following top-level scientific questions: 1. What is the global magnetic field configuration in the corona? 2. What is the role of the magnetic field in the triggering of flares and CMEs? 3. What is the role of the magnetic field in the acceleration mechanisms of the solar winds? 4. What is the energy spectrum and in particular what are the highest energies to which charged particles can be accelerated in the solar corona? MASC will address these fundamental questions with a suite of instruments composed of an X-ray spectrometer, a UV / EUV imager, and a coronagraph working in the visible and at Lyman alpha. The spectrometer will provide information on the energetics of solar flares, in particular at very high energies of accelerated particles. The UV / EUV imager will provide constraints on the temperature of the flaring and non-flaring corona. The coronagraph will provide the number density of free electrons in the corona, maps of the outflow velocity of neutral hydrogen, and measurements of the coronal magnetic field, via the Hanle effect. These measurements will be performed at all steps of the flare-CME processes, thus providing a detailed picture of the solar coronal dynamics in the quiet and eruptive periods. Title: On the nature of the prominence - corona transition region Authors: Parenti, Susanna; Vial, Jean-Claude Bibcode: 2014IAUS..300...69P Altcode: Due to the complexity of their environment, prominences properties are still a matter of controversy. Prominences cool and dense plasma is suspended in the hot corona by a magnetic structure poorly known. Their thermal insulation from the corona results in a thin geometrical interface called prominence-corona-transition-region (PCTR). Here we will review the main properties of such a region as derived primarily from observations. We will introduce the thermal structure properties, describe the fine structure together with the Doppler-shift and width properties of lines of the emitting plasma. We will introduce the proposed interpretations of such observations and the limits of our knowledge imposed by the present instrumentation. We will conclude with a perspective for the future observations of the PCTR. Title: Can the Differential Emission Measure Constrain the Timescale of Energy Deposition in the Corona? Authors: Guennou, C.; Auchère, F.; Klimchuk, J. A.; Bocchialini, K.; Parenti, S. Bibcode: 2013ApJ...774...31G Altcode: 2013arXiv1306.3114G In this paper, the ability of the Hinode/EIS instrument to detect radiative signatures of coronal heating is investigated. Recent observational studies of active region cores suggest that both the low and high frequency heating mechanisms are consistent with observations. Distinguishing between these possibilities is important for identifying the physical mechanism(s) of the heating. The differential emission measure (DEM) tool is one diagnostic that allows us to make this distinction, through the amplitude of the DEM slope coolward of the coronal peak. It is therefore crucial to understand the uncertainties associated with these measurements. Using proper estimations of the uncertainties involved in the problem of DEM inversion, we derive confidence levels on the observed DEM slope. Results show that the uncertainty in the slope reconstruction strongly depends on the number of lines constraining the slope. Typical uncertainty is estimated to be about ±1.0 in the more favorable cases. Title: Solar activity and its evolution across the corona: recent advances Authors: Zuccarello, Francesca; Balmaceda, Laura; Cessateur, Gael; Cremades, Hebe; Guglielmino, Salvatore L.; Lilensten, Jean; Dudok de Wit, Thierry; Kretzschmar, Matthieu; Lopez, Fernando M.; Mierla, Marilena; Parenti, Susanna; Pomoell, Jens; Romano, Paolo; Rodriguez, Luciano; Srivastava, Nandita; Vainio, Rami; West, Matt; Zuccarello, Francesco P. Bibcode: 2013JSWSC...3A..18Z Altcode: Solar magnetism is responsible for the several active phenomena that occur in the solar atmosphere. The consequences of these phenomena on the solar-terrestrial environment and on Space Weather are nowadays clearly recognized, even if not yet fully understood. In order to shed light on the mechanisms that are at the basis of the Space Weather, it is necessary to investigate the sequence of phenomena starting in the solar atmosphere and developing across the outer layers of the Sun and along the path from the Sun to the Earth. This goal can be reached by a combined multi-disciplinary, multi-instrument, multi-wavelength study of these phenomena, starting with the very first manifestation of solar active region formation and evolution, followed by explosive phenomena (i.e., flares, erupting prominences, coronal mass ejections), and ending with the interaction of plasma magnetized clouds expelled from the Sun with the interplanetary magnetic field and medium. This wide field of research constitutes one of the main aims of COST Action ES0803: Developing Space Weather products and services in Europe. In particular, one of the tasks of this COST Action was to investigate the Progress in Scientific Understanding of Space Weather. In this paper we review the state of the art of our comprehension of some phenomena that, in the scenario outlined above, might have a role on Space Weather, focusing on the researches, thematic reviews, and main results obtained during the COST Action ES0803. Title: SDO/AIA Prominence physical conditions Authors: Schmieder, B.; Parenti, S.; Dudik, J.; Aulanier, G.; Heinzel, P.; Zapior, M.; Golub, L. Bibcode: 2013enss.confE..27S Altcode: SDO/AIA has carried out continuous observations of prominences in multiple wavelengths, with high spatial and temporal resolution. These data provide us an opportunity to understand the physical conditions and dynamics of prominences. The surprising brightness of prominences in some coronal lines has been well explained by the presence of transition region lines in the bandpass of the filters (171 A, 131 A), a result that leads us to revise our model of the transition region of prominences and to consider a relatively dense transition region in some prominence evolutionary phases or in some viewing orientation. An additional aspect of prominence dynamics will be presented with a new quasi-static MHD model proposed for bubbles and plumes. We propose an alternative to the interpretation that thermal instabilities are responsible for the formation of bubbles. The bubbles are found to correspond to magnetic separatrices formed by emerging magnetic field close to prominence footpoints. Title: Can the Differential Emission Measure diagnostic be used to constrain the timescale of energy deposition in the corona? Authors: Guennou, C.; Auchère, F.; Klimchuk, J. A.; Bocchialini, K.; Parenti, S. Bibcode: 2013enss.confE..34G Altcode: Differential emission measure (DEM) analysis is a widespread tool used to diagnose the thermal properties of coronal plasmas. The slope of the DEM distribution coolward of the coronal peak (near 3-4MK in active regions) can be used to diagnose the timescale for the energy deposition repeating on a given magnetic strand. Recent AR studies suggest that some active region cores are consistent with low frequency heating mechanisms, where the plasma cools completely before being reheated, while other show consistency with high frequency energy deposition, where rapid reheating causes the temperature to fluctuate about a particular value. Distinguishing between these possibilities is important for identifying the physical mechanism of the heating. It is therefore crucial to understand the uncertainties in measurements of observed DEM slopes. In this work, based on a probabilistic approach and Monte Carlo simulations, we carefully assess the errors in the slopes determined from EIS data. We consider both the random errors due to photon counting statistics, and the systematic errors associated with uncertainties in atomic physics and instrument calibration. The technique developed provides all the solutions consistent with the data and their associated probabilities. We demonstrate how the quality and the accuracy of the inversion are affected by the presence of noises and systematic errors, and we characterise the quality of the DEM inversion and its statistical properties. From these results, estimation of the uncertainties in the reconstructed slopes can be derived, thereby allowing a proper interpretation of the degree of agreement between observations and heating model predictions. Title: MEDIA : MEDoc Interface for AIA Authors: Alingery, P.; Soubrié, E.; Auchère, F.; Bocchialini, K.; Boignard, J. P.; Buchlin, E.; Malappert, J. C.; Parenti, S. Bibcode: 2013enss.confE..88A Altcode: MEDOC, the space solar data center at Orsay (http://www.ias.u-psud.fr/medoc) is now providing a new web access to the AIA/SDO level 1 images. This interface has the advantage of being simple, intuitive, very stable and fast. The full resolution 4k x 4k AIA level 1 images archived at MEDOC are downloaded from upstream DRMS nodes with a 1 minute cadence at all wavelengths. The dataset will be kept online on a redundant archive for the whole SDO mission duration. The FITS files are accessible via an user friendly web interface (http://medoc-sdo.ias.u-psud.fr) that allows users to request data by selecting a date range, the desired wavelengths and a sampling rate (choosing a cadence from 1 minute to 1 day). For each file, users can preview the image (using the Helioviewer tool) or display the header information before downloading the FITS files (with or without Rice-compression). This web interface was built using Sitools2, a tool developed by CNES, the French space agency, and supports most browsers. For more advanced users, a Search/Get Python module is also available at http://sdo.ias.u-psud.fr/python. The users can use it to build more complex yet more powerful queries. We encourage everyone in Europe and beyond to use these new services! Title: On the Accuracy of the Differential Emission Measure Diagnostics of Solar Plasmas. Application to SDO/AIA. II. Multithermal Plasmas Authors: Guennou, C.; Auchère, F.; Soubrié, E.; Bocchialini, K.; Parenti, S.; Barbey, N. Bibcode: 2012ApJS..203...26G Altcode: 2012arXiv1210.2302G Differential emission measure (DEM) analysis is one of the most used diagnostic tools for solar and stellar coronae. Being an inverse problem, it has limitations due to the presence of random and systematic errors. We present in this series of papers an analysis of the robustness of the inversion in the case of SDO/AIA observations. We completely characterize the DEM inversion and its statistical properties, providing all the solutions consistent with the data along with their associated probabilities, and a test of the suitability of the assumed DEM model. While Paper I focused on isothermal conditions, we now consider multithermal plasmas and investigate both isothermal and multithermal solutions. We demonstrate how the ambiguity between noises and multithermality fundamentally limits the temperature resolution of the inversion. We show that if the observed plasma is multithermal, isothermal solutions tend to cluster on a constant temperature whatever the number of passbands or spectral lines. The multithermal solutions are also found to be biased toward near-isothermal solutions around 1 MK. This is true even if the residuals support the chosen DEM model, possibly leading to erroneous conclusions on the observed plasma. We propose tools for identifying and quantifying the possible degeneracy of solutions, thus helping the interpretation of DEM inversion. Title: On the Accuracy of the Differential Emission Measure Diagnostics of Solar Plasmas. Application to SDO/AIA. I. Isothermal Plasmas Authors: Guennou, C.; Auchère, F.; Soubrié, E.; Bocchialini, K.; Parenti, S.; Barbey, N. Bibcode: 2012ApJS..203...25G Altcode: 2012arXiv1210.2304G Differential emission measure (DEM) analysis is a major diagnostic tool for stellar atmospheres. However, both its derivation and its interpretation are notably difficult because of random and systematic errors, and the inverse nature of the problem. We use simulations with simple thermal distributions to investigate the inversion properties of SDO/AIA observations of the solar corona. This allows a systematic exploration of the parameter space, and using a statistical approach the respective probabilities of all the DEMs compatible with the uncertainties can be computed. Following this methodology, several important properties of the DEM inversion, including new limitations, can be derived and presented in a very synthetic fashion. In this first paper, we describe the formalism and we focus on isothermal plasmas as building blocks to understand the more complex DEMs studied in the second paper. The behavior of the inversion of AIA data being thus quantified, and we provide new tools to properly interpret the DEM. We quantify the improvement of the isothermal inversion with six AIA bands compared to previous EUV imagers. The maximum temperature resolution of AIA is found to be 0.03 log Te , and we derive a rigorous test to quantify the compatibility of observations with the isothermal hypothesis. However, we demonstrate limitations in the ability of AIA alone to distinguish different physical conditions. Title: LEMUR: Large European module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission Authors: Teriaca, Luca; Andretta, Vincenzo; Auchère, Frédéric; Brown, Charles M.; Buchlin, Eric; Cauzzi, Gianna; Culhane, J. Len; Curdt, Werner; Davila, Joseph M.; Del Zanna, Giulio; Doschek, George A.; Fineschi, Silvano; Fludra, Andrzej; Gallagher, Peter T.; Green, Lucie; Harra, Louise K.; Imada, Shinsuke; Innes, Davina; Kliem, Bernhard; Korendyke, Clarence; Mariska, John T.; Martínez-Pillet, Valentin; Parenti, Susanna; Patsourakos, Spiros; Peter, Hardi; Poletto, Luca; Rutten, Robert J.; Schühle, Udo; Siemer, Martin; Shimizu, Toshifumi; Socas-Navarro, Hector; Solanki, Sami K.; Spadaro, Daniele; Trujillo-Bueno, Javier; Tsuneta, Saku; Dominguez, Santiago Vargas; Vial, Jean-Claude; Walsh, Robert; Warren, Harry P.; Wiegelmann, Thomas; Winter, Berend; Young, Peter Bibcode: 2012ExA....34..273T Altcode: 2011ExA...tmp..135T; 2011arXiv1109.4301T The solar outer atmosphere is an extremely dynamic environment characterized by the continuous interplay between the plasma and the magnetic field that generates and permeates it. Such interactions play a fundamental role in hugely diverse astrophysical systems, but occur at scales that cannot be studied outside the solar system. Understanding this complex system requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1'' and 0.3''), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 170 Å and 1270 Å. The LEMUR slit covers 280'' on the Sun with 0.14'' per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km s - 1 or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission. Title: Plasma Diagnostics and Magnetic Complexity of a Post-Flare Active Region with Hinode/XRT: Spatial and Temporal Evolution Authors: Parenti, S.; Reale, F.; Reeves, K. K. Bibcode: 2012ASPC..454..291P Altcode: Flares are localized phenomena in active regions, but the magnetic and plasma responses may propagate to a larger area. In this work we investigate the temporal evolution of a flare in an active region with particular attention to the morphological details, and to the temperature and emission measure diagnostics allowed by Hinode/XRT. Title: On the Thermal diagnostics of Coronal Loops with SDO/AIA Authors: Guennou, Chloe; Parenti, Susanna; Bocchialini, Karine; Soubrie, Elie; Auchere, Frederic; Barbey, Nicolas Bibcode: 2012cosp...39..675G Altcode: 2012cosp.meet..675G With simultaneous observations in 6 coronal bands, AIA has the capability to provide spectral diagnostics over an extended field of view at high resolution and high cadence. Therefore, DEM diagnostics of coronal loops can in principle be performed routinely for statistical studies. We investigate here the pertinence of the DEM analysis with AIA. The inevitable presence of noises and uncertainties, incompleteness of the atomic physics databases lead to notable difficulties in the inversion process. The complications involved in the derivation of the DEM are one of the reasons of the controversial results regarding the thermal structure and thus the heating scenario of the coronal loops. The purpose of this work, based on a probabilistic approach, is precisely to investigate the properties of the solutions, providing a quantification of the DEM inversion problem robustness. The technique relies on Monte Carlo simulations of observed intensities in the six AIA coronal bands. The comparison between the known inputs and the inversion results allows us to determine the degree of robustness. This approach provides all the solutions consistent with the data along with their associated probabilities, as well as a test of the validity of the assumptions made on the DEM shape. Applications to SDO/AIA coronal loops data are presented. Title: Prominences observations with SDO/AIA Authors: Parenti, Susanna; Schmieder, Brigitte; Golub, Leon; Heinzel, Petr Bibcode: 2012cosp...39.1447P Altcode: 2012cosp.meet.1447P The Prominence-Corona-Transition-Region (PCTR) plays a key role in the thermal and pressure equilibrium of prominences. However, several open issues limit our knowledge of this important interface. Among them we find the thermal structure and the maximum temperature of its emitting plasma. This work is a new step toward resolving these issues. By noting that prominences may be observed in emission in the 171 and 131 SDO/AIA images, while they are seen in absorption in others (e.g. 193) we investigate the temperature content of these channels. Using the CHIANTI atomic database and previously derived prominence DEMs, we built synthetic spectra in these AIA channels to establish the main contributors. We find that the Fe IX line always dominates the 171 band, even in absence of a coronal plasma, while the 131 channel is dominated by Fe VIII. Our conclusion is that the PCTR reaches, at least, 4x 10^5 K. Title: On the Nature of Prominence Emission Observed by SDO/AIA Authors: Parenti, S.; Schmieder, B.; Heinzel, P.; Golub, L. Bibcode: 2012ApJ...754...66P Altcode: 2012arXiv1205.5460P The prominence-corona transition region (PCTR) plays a key role in the thermal and pressure equilibrium of solar prominences. Our knowledge of this interface is limited and several major issues remain open, including the thermal structure and, in particular, the maximum temperature of the detectable plasma. The high signal-to-noise ratio of images obtained by the Atmospheric Imaging Assembly (AIA) on NASA's Solar Dynamics Observatory clearly shows that prominences are often seen in emission in the 171 and 131 bands. We investigate the temperature sensitivity of these AIA bands for prominence observations, in order to infer the temperature content in an effort to explain the emission. Using the CHIANTI atomic database and previously determined prominence differential emission measure distributions, we build synthetic spectra to establish the main emission-line contributors in the AIA bands. We find that the Fe IX line always dominates the 171 band, even in the absence of plasma at >106 K temperatures, while the 131 band is dominated by Fe VIII. We conclude that the PCTR has sufficient plasma emitting at >4 × 105 K to be detected by AIA. Title: Radio observations of weak energy releases in the solar corona Authors: Ramesh, Rengaswamy; Parenti, Susanna Bibcode: 2012cosp...39.1568R Altcode: 2012cosp.meet.1568R .. Title: Comparing Radiative signatures of conductive heating in coronal loops Authors: West, Matthew; Parenti, Susanna Bibcode: 2012cosp...39.2149W Altcode: 2012cosp.meet.2149W No abstract at ADS Title: On the Visibility of Solar Prominences in SDO/AIA Channels Authors: Heinzel, P.; Schmieder, B.; Parenti, S.; Golub, L. Bibcode: 2012ASPC..456...75H Altcode: Prominences in EUV lines are observed as dark structures over the limb due absorption and emission blocking mechanisms. However, at 171 Å is observed emission in prominences with TRACE and SDO/AIA, and it is believed to be due to the prominence-corona transition region (PCTR) emitting in cool lines. To check this, we use the Differential Emission Measure (DEM) recently obtained for quiescent prominences using SOHO/SUMER spectra (Parenti and Vial 2007) and compute the synthetic spectra in selected AIA channels. We then compare 171 Å and 195 Å channels and derive conclusions concerning the PCTR emissivity, as well well as the absorption and blocking. The emission seen in the 171 Å channel can be used to better constrain prominence DEM curves. Title: Stability of thermal modes in cool prominence plasmas Authors: Soler, R.; Ballester, J. L.; Parenti, S. Bibcode: 2012A&A...540A...7S Altcode: 2012arXiv1201.4668S Magnetohydrodynamic thermal modes may play an important role in the formation, plasma condensation, and evolution of solar prominences. Unstable thermal modes due to unbalance between radiative losses and heating can lead to rapid plasma cooling and condensation. An accurate description of the radiative loss function is therefore crucial for this process. We study the stability of thermal modes in unbounded and uniform plasmas with properties akin to those in solar prominences. Effects of partial ionization are taken into account. Three different parametrizations of the radiative loss function are used. By means of a normal mode analysis, we investigate linear nonadiabatic perturbations superimposed on the equilibrium state. We find an approximate instability criterion for thermal modes, while the exact linear growth rate is obtained by numerically solving the general dispersion relation. The stability of thermal disturbances is compared for the three different loss functions that we consider. Using up-to-date computations of radiative losses derived from the CHIANTI atomic database, we find that thermal modes may be unstable in prominences for lower temperatures than those predicted with previously existing loss functions. Thermal instability can take place for temperatures as low as about 15 000 K. The obtained linear growth rates indicate that this instability might have a strong impact on the dynamics and evolution of cool prominence condensations. Title: Solar magnetism eXplorer (SolmeX). Exploring the magnetic field in the upper atmosphere of our closest star Authors: Peter, Hardi; Abbo, L.; Andretta, V.; Auchère, F.; Bemporad, A.; Berrilli, F.; Bommier, V.; Braukhane, A.; Casini, R.; Curdt, W.; Davila, J.; Dittus, H.; Fineschi, S.; Fludra, A.; Gandorfer, A.; Griffin, D.; Inhester, B.; Lagg, A.; Landi Degl'Innocenti, E.; Maiwald, V.; Sainz, R. Manso; Martínez Pillet, V; Matthews, S.; Moses, D.; Parenti, S.; Pietarila, A.; Quantius, D.; Raouafi, N. -E.; Raymond, J.; Rochus, P.; Romberg, O.; Schlotterer, M.; Schühle, U.; Solanki, S.; Spadaro, D.; Teriaca, L.; Tomczyk, S.; Trujillo Bueno, J.; Vial, J. -C. Bibcode: 2012ExA....33..271P Altcode: 2011arXiv1108.5304P; 2011ExA...tmp..134P The magnetic field plays a pivotal role in many fields of Astrophysics. This is especially true for the physics of the solar atmosphere. Measuring the magnetic field in the upper solar atmosphere is crucial to understand the nature of the underlying physical processes that drive the violent dynamics of the solar corona—that can also affect life on Earth. SolmeX, a fully equipped solar space observatory for remote-sensing observations, will provide the first comprehensive measurements of the strength and direction of the magnetic field in the upper solar atmosphere. The mission consists of two spacecraft, one carrying the instruments, and another one in formation flight at a distance of about 200 m carrying the occulter to provide an artificial total solar eclipse. This will ensure high-quality coronagraphic observations above the solar limb. SolmeX integrates two spectro-polarimetric coronagraphs for off-limb observations, one in the EUV and one in the IR, and three instruments for observations on the disk. The latter comprises one imaging polarimeter in the EUV for coronal studies, a spectro-polarimeter in the EUV to investigate the low corona, and an imaging spectro-polarimeter in the UV for chromospheric studies. SOHO and other existing missions have investigated the emission of the upper atmosphere in detail (not considering polarization), and as this will be the case also for missions planned for the near future. Therefore it is timely that SolmeX provides the final piece of the observational quest by measuring the magnetic field in the upper atmosphere through polarimetric observations. Title: Synthetic differential emission measure curves of prominence fine structures. II. The SoHO/SUMER prominence of 8 June 2004 Authors: Gunár, S.; Parenti, S.; Anzer, U.; Heinzel, P.; Vial, J. -C. Bibcode: 2011A&A...535A.122G Altcode:
Aims: This study is the first attempt to combine the prominence observations in Lyman, UV, and EUV lines with the determination of the prominence differential emission measure derived using two different techniques, one based on the inversion of the observed UV and EUV lines and the other employing 2D non-LTE prominence fine-structure modeling of the Lyman spectra.
Methods: We use a trial-and-error method to derive the 2D multi-thread prominence fine-structure model producing synthetic Lyman spectra in good agreement with the observations. We then employ a numerical method to perform the forward determination of the DEM from 2D multi-thread models and compare the synthetic DEM curves with those derived from observations using inversion techniques.
Results: A set of available observations of the June 8, 2004 prominence allows us to determine the range of input parameters, which contains models producing synthetic Lyman spectra in good agreement with the observations. We select three models, which represent this parametric-space area well and compute the synthetic DEM curves for multi-thread realizations of these models. The synthetic DEM curves of selected models are in good agreement with the DEM curves derived from the observations.
Conclusions: We show that the evaluation of the prominence fine-structure DEM complements the analysis of the prominence hydrogen Lyman spectra and that its combination with the detailed radiative-transfer modeling of prominence fine structures provides a useful tool for investigating the prominence temperature structure from the cool core to the prominence-corona transition region. Title: Automated detection of filaments in SDO data Authors: Buchlin, É.; Mercier, C.; Engin, S.; Parenti, S.; Vial, J. -C. Bibcode: 2010sf2a.conf..297B Altcode: Solar eruption can eject billions of tons of plasma to the interplanetary space, with geophysical effects and impacts on human activities. The time constraints for space weather application as well as the huge volume of data that needs to be analyzed, especially since the launch of SDO, imply that the detection of solar filaments and their eruptions must be automated. Most current detection codes use Hα data, which are not available frequently enough for these applications. We present a new detection code that we have developed at IAS and that uses the high spatial and temporal-resolution SDO/AIA He II 30.4 nm data. Title: An iterative method in a probabilistic approach to the spectral inverse problem. Differential emission measure from line spectra and broadband data Authors: Goryaev, F. F.; Parenti, S.; Urnov, A. M.; Oparin, S. N.; Hochedez, J. -F.; Reale, F. Bibcode: 2010A&A...523A..44G Altcode: 2010arXiv1010.5170G Context. Inverse problems are of great importance in astrophysics, e.g., for deriving information about the physical characteristics of hot optically thin plasma sources from their extreme ultraviolet and X-ray spectra.
Aims: We describe and test an iterative method developed within the framework of a probabilistic approach to the spectral inverse problem for determining the thermal structures of the emitting plasma. We also demonstrate applications of this method to both high resolution line spectra and broadband imaging data.
Methods: Our so-called Bayesian iterative method (BIM) is an iterative procedure based on Bayes' theorem and is used to reconstruct differential emission measure (DEM) distributions.
Results: To demonstrate the abilities of the BIM, we performed various numerical tests and model simulations establishing its robustness and usefulness. We then applied the BIM to observable data for several active regions (AR) previously analyzed with other DEM diagnostic techniques: both SUMER/SOHO (Landi & Feldman 2008, ApJ, 672, 674) and SPIRIT/CORONAS-F (Shestov et al. 2010, Astron. Lett., 36, 44) line spectra data, and XRT/Hinode (Reale et al. 2009, ApJ, 698, 756) broadband imaging data. The BIM calculations confirmed the main results for SUMER/SOHO data showing very good quantitative agreement between both DEMs at log T ≈ 6.5 (T is the temperature in units of Kelvin) and a slight shift for two maxima at lower temperatures with ≈30-50% difference in the DEM values for the coolest peak. For the SPIRIT data, we revised and validated AR DEM results including the inference of hot plasma in ARs with an emission measure (EM) at temperatures ≈9-15 MK comparable to the EM at ≈2-4 MK. In the case of XRT broadband data, the BIM solutions provided evidence of hot plasma at temperatures ≈4-6 MK with EM up to ~30% as compared to that at ≈2-4 MK in a non-flaring AR on 2006 November 12.
Conclusions: The BIM results show that this method is an effective tool for determining the thermal structure of emitting plasma and can be successfully used for the DEM analysis of both line spectra and broadband imaging data. The BIM calculations correlate with recent studies confirming the existence of hot plasma in solar ARs. The BIM results also indicate that the coronal plasma may have the continuous distributions predicted by the nanoflare paradigm. Title: Post-flare evolution of AR 10923 with Hinode/XRT Authors: Parenti, S.; Reale, F.; Reeves, K. K. Bibcode: 2010A&A...517A..41P Altcode: 2010arXiv1010.3124P Context. Flares are dynamic events which involve rapid changes in coronal magnetic topology end energy release. Even if they may be localized phenomena, the magnetic disturbance at their origin may propagate and be effective in a larger part of the active region.
Aims: We investigate the temporal evolution of a flaring active region with respect to the loops morphology, the temperature, and emission measure distributions.
Methods: We consider Hinode/XRT data of a the 2006 November 12th C1.1 flare. We inspect the evolution of the morphology of the flaring region also with the aid of TRACE data. XRT filter ratios are used to derive temperature and emission measure maps and evolution.
Results: The analyzed flare includes several brightenings. We identify a coherent sequence of tangled and relaxed loop structures before, during, and after the brightenings. Although the thermal information is incomplete because of pixel saturation at the flare peak, thermal maps show fine, evolving spatial structuring. Temperature and emission measure variations show up in great detail, and we are able to detect a secondary heating of larger loops close to the proper flaring region. Finally we estimate the amount of energy released in these flaring loops during the flare decay. Title: Physics of Solar Prominences: I—Spectral Diagnostics and Non-LTE Modelling Authors: Labrosse, N.; Heinzel, P.; Vial, J. -C.; Kucera, T.; Parenti, S.; Gunár, S.; Schmieder, B.; Kilper, G. Bibcode: 2010SSRv..151..243L Altcode: 2010SSRv..tmp...34L; 2010arXiv1001.1620L This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE ( i.e. when there is a departure from Local Thermodynamic Equilibrium) radiative transfer models. We first describe the spectral inversion techniques that have been used to infer the plasma parameters important for the general properties of the prominence plasma in both its cool core and the hotter prominence-corona transition region. We also review studies devoted to the observation of bulk motions of the prominence plasma and to the determination of prominence mass. However, a simple inversion of spectroscopic data usually fails when the lines become optically thick at certain wavelengths. Therefore, complex non-LTE models become necessary. We thus present the basics of non-LTE radiative transfer theory and the associated multi-level radiative transfer problems. The main results of one- and two-dimensional models of the prominences and their fine-structures are presented. We then discuss the energy balance in various prominence models. Finally, we outline the outstanding observational and theoretical questions, and the directions for future progress in our understanding of solar prominences. Title: The SDO data centre at IDOC/MEDOC in France Authors: Parenti, Susanna; Bocchialini, Karine; Soubrie, Elie; Auchere, Frederic; Ballans, Herv; Buchlin, Eric; Gabriel, Alan; Mercier, Claude; Poulleau, Gilles; Vial, Jean-Claude Bibcode: 2010cosp...38.2888P Altcode: 2010cosp.meet.2888P The IDOC/MEDOC centre at the Institut d'Astrophysique Spatiale (IAS, Université Paris 11/CNRS) has a long experience in solar data archiving and distribution, including almost 15 years of data from SOHO, STEREO and TRACE. The center is now expanding its activity and becoming a Pˆle Thématique Solaire of the CNES and INSU/CNRS. Part of the new activities of the centre will be linked to the arrival of the enormous volume of the new SDO data. The center will be one of the three European centers to receive and redistribute the data to the community. It will also be the only European site to permanently store about 10% of the data (mainly from AIA). In continuity with its previous activities, SDO data will be included in the data visualization tool FESTIVAL and it will provide new services, like tools for the solar feature identification (filaments, EUV intensity fluctuations). We will present an overview of the facilities and activities of the centre in relation to the SDO data. Title: Distributing and mining SDO data in Europe Authors: Parenti, Susanna; Delouille, Véronique; Dalla, Silvia; Bocchialini, Karine; Ballans, Herv; Boyes, David; Chapman, Steve; Hochedez, Jean-François; Mampaey, Benjamin; March, Mike S.; Soubrie, Elie; Walsh, Robert Bibcode: 2010cosp...38.2883P Altcode: 2010cosp.meet.2883P The properties of the highly dynamic Sun will soon be revealed by the newly launched SDO, with data provided by its three instruments: AIA, HMI and EVE. This suite will produce, for the first time in solar physics, a large volume of data, equivalent to about 1.5 Tb/day, by observing the full disk Sun continuously at high cadence. A backbone network of data centres has been established to handle these data and redistribute them to Europe. The Royal Observatory of Belgium (Belgium) will receive the entire flow directly from the Harvard-Smithsonian Center for Astrophysics. This will next be further redistributed to University of Central Lancashire (United Kingdom), and to Institut d'Astrophysique Spatiale (France). These institutes will also permanently store part of the data. With such huge data rate, it is necessary to develop automated algorithms that scan the data and extract information related to important events or features. The European partners have gathered within an ISSI team on 'Mining and exploiting the NASA Solar Dynamics Observatory data in Europe', a.k.a the Soldyneuro project. One of the outputs from the ISSI team will be to use the feature recognition algorithms to populate the Heliophysics Events Knowledgebase (HEK) hosted by LMSAL, and provide a service as added value to the local database centers. Title: DEM analysis for AIA/SDO EUV channels using a probabilistic approach to the spectral inverse problem Authors: Goryaev, Farid; Parenti, Susanna; Hochedez, Jean-François; Urnov, Alexander Bibcode: 2010cosp...38.2867G Altcode: 2010cosp.meet.2867G The Atmospheric Imaging Assembly (AIA) for the Solar Dynamics Observatory (SDO) mis-sion is designed to observe the Sun from the photosphere to the flaring corona. These data have to improve our understanding of processes in the solar atmosphere. The differential emis-sion measure (DEM) analysis is one of the main methods to derive information about coronal optically thin plasma characteristics from EUV and SXR emission. In this work we analyze AIA/SDO EUV channels to estimate their ability to reconstruct DEM(T) distributions. We use an iterative method (called Bayesian iterative method, BIM) within the framework of a probabilistic approach to the spectral inverse problem for determining the thermal structures of the emitting plasma sources (Goryaev et al., submitted to AA). The BIM is an iterative procedure based on Bayes' theorem and used for the reconstruction of DEM profiles. Using the BIM algorithm we performed various numerical tests and model simulations demonstrating abilities of our inversion approach for DEM analysis with AIA/SDO EUV channels. Title: Differential emission measure for line spectra and broadband data from the Bayesian iterative method Authors: Goryaev, Farid; Parenti, Susanna; Urnov, Alexander; Oparin, S. N.; Hochedez, Jean-François; Reale, Fabio Bibcode: 2010cosp...38.2901G Altcode: 2010cosp.meet.2901G Inverse problems techniques allow deriving physical characteristics of hot optically thin so-lar and stellar plasma from their extreme ultraviolet and X-ray spectra. One of them, called Bayesian iterative method (BIM), relies on a probabilistic Bayesian framework for the spec-tral inverse problem, and reconstructs differential emission measure (DEM) distributions. We present here the application of BIM to both high resolution solar line spectra as well as to broadband imaging data. To demonstrate its abilities, we present various numerical tests and model simulations establishing robustness and usefulness. We then apply BIM to several so-lar non flaring active regions data previously analyzed with other techniques and instruments (SOHO-SUMER, CORONAS/F-SPIRIT, and HINODE-XRT). Title: XRT Detection of Hot Plasma in Active Regions and Nanoflare Heating Authors: Reale, F.; Klimchuk, J. A.; Parenti, S.; Testa, P. Bibcode: 2009ASPC..415..256R Altcode: Nanoflares occurring in sub-resolution strands have been long invoked as strong candidates for the heating of active region (AR) coronal loops. However, the frequent occurrence of nanoflares requires the steady presence of flare-hot plasma in the active region, which has been difficult to detect so far. We report on the analysis of multi-filter Hinode/XRT observations of an active region, which may show the widespread presence of 10 MK plasma. Title: Evidence of Widespread Hot Plasma in a Nonflaring Coronal Active Region from Hinode/X-Ray Telescope Authors: Reale, Fabio; Testa, Paola; Klimchuk, James A.; Parenti, Susanna Bibcode: 2009ApJ...698..756R Altcode: 2009arXiv0904.0878R Nanoflares, short and intense heat pulses within spatially unresolved magnetic strands, are now considered a leading candidate to solve the coronal heating problem. However, the frequent occurrence of nanoflares requires that flare-hot plasma be present in the corona at all times. Its detection has proved elusive until now, in part because the intensities are predicted to be very faint. Here, we report on the analysis of an active region observed with five filters by Hinode/X-Ray Telescope (XRT) in 2006 November. We have used the filter ratio method to derive maps of temperature and emission measure (EM) both in soft and hard ratios. These maps are approximate in that the plasma is assumed to be isothermal along each line of sight. Nonetheless, the hardest available ratio reveals the clear presence of plasma around 10 MK. To obtain more detailed information about the plasma properties, we have performed Monte Carlo simulations assuming a variety of nonisothermal EM distributions along the lines of sight. We find that the observed filter ratios imply bi-modal distributions consisting of a strong cool (log T ~ 6.3 - 6.5) component and a weaker (few percent) and hotter (6.6 < log T < 7.2) component. The data are consistent with bi-modal distributions along all lines of sight, i.e., throughout the active region. We also find that the isothermal temperature inferred from a filter ratio depends sensitively on the precise temperature of the cool component. A slight shift of this component can cause the hot component to be obscured in a hard ratio measurement. Consequently, temperature maps made in hard and soft ratios tend to be anti-correlated. We conclude that this observation supports the presence of widespread nanoflaring activity in the active region. Title: Observations of Nanoflare Produced Hot ( 10 Mk) Plasma Authors: Klimchuk, James A.; Reale, F.; Testa, P.; Parenti, S. Bibcode: 2009SPD....40.1214K Altcode: Indirect observational evidence suggests that some or most of the corona is heated impulsively on sub-resolution scales by nanoflares. Theoretical studies of possible heating mechanisms also support this picture. However, the most direct evidence of nanoflares---plasma hotter than 5 MK---has been difficult to obtain because the emission is expected to be very faint. The reason is two-fold: first, hot plasma cools very rapidly by thermal conduction; and second, densities are small because chromospheric evaporation has not had time to fill the corona. Recent observations from several instruments have now provided strong evidence of hot plasma. We report here on the detection of 10 MK plasma by the X-Ray Telescope (XRT) on Hinode. We show that the intensity of the emission is consistent with nanoflare models, but is extremely difficult to explain with steady heating. Title: On the ultraviolet signatures of small scale heating in coronal loops Authors: Parenti, S.; Young, P. R. Bibcode: 2008A&A...492..857P Altcode: 2010arXiv1009.4112P Aims: Studying the statistical properties of solar ultraviolet emission lines could provide information about the nature of small scale coronal heating. We expand on previous work to investigate these properties. We study whether the predicted statistical distribution of ion emission line intensities produced by a specified heating function is affected by the isoelectronic sequence to which the ion belongs, as well as the characteristic temperature at which it was formed (as found previously). Particular emphasis is placed on the strong resonance lines belonging to the lithium isoelectronic sequence. Predictions for emission lines observed by existing space-based UV spectrometers are given. The effects on the statistics of a line when observed with a wide-band imaging instrument rather than a spectrometer are also investigated.
Methods: We use a hydrodynamic model to simulate the UV emission of a loop system heated by nanoflares on small, spatially unresolved scales. We select lines emitted at similar temperatures but belonging to different isoelectronic groups: Fe IX and Ne VIII, Fe XII and Mg X, Fe XVIII, Fe XIX and Fe XXIV.
Results: Our simulations confirm previous results that almost all lines have an intensity distribution that follows a power-law, in a similar way to the heating function. However, only the high temperature lines best preserve the heating function's power law index (Fe XIX being the best ion in the case presented here). The Li isoelectronic lines have different statistical properties with respect to the lines from other sequences, due to the extended high temperature tail of their contribution functions. However, this is not the case for Fe XXIV which may be used as a diagnostic of the coronal heating function. We also show that the power-law index of the heating function is effectively preserved when a line is observed by a wide-band imaging instrument rather than a spectromenter. Title: The redshifted footpoints of coronal loops Authors: Dammasch, I. E.; Curdt, W.; Dwivedi, B. N.; Parenti, S. Bibcode: 2008AnGeo..26.2955D Altcode: The physics of coronal loops holds the key to understanding coronal heating and the flow of mass and energy in the region. However, the energy source, structure maintenance and mass balance in coronal loops are not yet fully understood. Observations of blue- and redshifted emissions have repeatedly been used in the construction of loop models. But observations and interpretations of line shifts have been widely debated. Here we present detailed SUMER observations, which clearly show a steady downflow in both footpoints of coronal loops observed at transition region (TR) and lower corona temperatures. We also show and quantify a correlation existing between this Doppler shift and the spectral radiance. Our results indicate a strong correlation which holds from the chromosphere to the lower corona. We suggest that the downflow in the footpoints may be a common phenomenon on all scales, which could explain, why on a statistical basis bright pixels tend to be more redshifted. We conclude by presenting interpretation of such results and their implications in the light of a viable coronal loop model. The observation of steady downflow in redshifted footpoints seems to be in conflict with impulsive heating. Title: Fine Thermal Structure of a Flare Observed with Hinode/XRT Authors: Parenti, S.; Reale, F.; Reeves, K. K. Bibcode: 2008ASPC..397..182P Altcode: In this work we investigate the fine thermal structure of a flare observed in November 2006 by Hinode/XRT. For this analysis we adopted a new technique which optimizes the use of five different filters, resulting in a good diagnostic of temperature. Title: Heating and Dynamics of Loops and Flares Authors: Parenti, S. Bibcode: 2008ESPM...12.2.78P Altcode: Loops may be considered the building blocks of the solar corona. Understanding their heating and dynamics becomes extremely important to solve the heating problem in the full corona.

The debate on weather steady or impulsive heating (such as envisioned by the nanoflares scenario) should be considered as the dominant heating process in loops, is still lively in the solar community.

From the observational point of view, key elements to progress on the understanding of the corona are the correct interpretation of the observational data together with precise measurements. Limitations are often present because of the finite resolution of the instruments, their limited temperature coverage and the fact that we are dealing with optically thin plasma when observing the corona. In spite of such limitations, considerable progress has been made in the past years. Results obtained in the past decades are now strengthened by the new observations from the Hinode and STEREO missions.

This talk will show and discuss new observational results that address selected aspects as key elements to understand the physics of loops. These include:

The monolithic vs. multi-thread configurations. Can we resolve the elemental coronal loop?;

Flows and dynamics. New exciting results from SOHO and Hinode.

Loops and active region thermal structures. Do we have a complete map of them?

I will conclude by briefing introducing the last efforts in the 3D loops reconstruction: a further essential element to help solving the complex phenomenon of the loops heating and dynamics. Title: Hinode/XRT Diagnostics of Loop Thermal Structure Authors: Reale, F.; Parenti, S.; Reeves, K. K.; Weber, M.; Bobra, M. G.; Barbera, M.; Kano, R.; Narukage, N.; Shimojo, M.; Sakao, T.; Peres, G.; Golub, L. Bibcode: 2008ASPC..397...50R Altcode: We investigate possible diagnostics of the thermal structure of coronal loops from Hinode/XRT observations made with several filters. We consider the observation of an active region with five filters. We study various possible combinations of filter data to optimize for sensitivity to thermal structure and for signal enhancement. Title: Solar prominence properties derived from the UV-EUV SUMER spectral atlas Authors: Parenti, S.; Vial, J. -C.; Lemaire, P. Bibcode: 2008AdSpR..41..144P Altcode: In this paper, we summarize the work done to build a UV-EUV spectral atlas of a prominence and we introduce some recent scientific results obtained from these data. For this work we used SOHO/SUMER data covering the full wavelength range accessible by the instrument (from about 800 to 1600 Å), when a prominence and the quiet Sun (used as spectral reference) were observed in October 1998. We present here only a fraction of the data, which results in the analysis of more than 600 spectral lines, including some new identifications. Here we also present the differential emission measure obtained from the data, both for the quiet Sun and the prominence. The main differences in characteristics are discussed. Title: Post flare evolution of AR 10923 from Hinode/XRT Authors: Parenti, Susanna; Reale, Fabio; Reeves, Kathy Bibcode: 2008cosp...37.2353P Altcode: 2008cosp.meet.2353P The Hinode/XRT high resolution, multi band instrument is a suitable instrument for the detailed study of the fine structure of the hot corona. We present the analysis of the morphological and thermal evolution of AR 10923 loops structures during a post-flare period. The analysis is performed using the powerful Reale et al. 2007 diagnostic tool. Title: Methods of Analyzing Temperatures in Post-Flare Loops using the XRT on Hinode Authors: Reeves, K. K.; Parenti, S.; Reale, F.; Weber, M. A. Bibcode: 2007AGUFMSH51C..08R Altcode: The X-Ray Telescope on Hinode has unrivaled temperature coverage, with 9 X-Ray filters in the focal plane. Using 7 different filter combinations, XRT observed a C8.2 flare on July 10, 2007. We use two different methods to glean temperature information about the post-flare loop system in this event. First, we examine the flare loops using the combined filter ratio method, which is a ratio method that utilizes observations in multiple filters in order to optimize the signal quality. Secondly, we calculate temperatures based on a differential emission measure method, which is a forward fitting method of determining temperatures. The results of these two methods will be compared. Title: Fine Thermal Structure of a Coronal Active Region Authors: Reale, Fabio; Parenti, Susanna; Reeves, Kathy K.; Weber, Mark; Bobra, Monica G.; Barbera, Marco; Kano, Ryouhei; Narukage, Noriyuki; Shimojo, Masumi; Sakao, Taro; Peres, Giovanni; Golub, Leon Bibcode: 2007Sci...318.1582R Altcode: The determination of the fine thermal structure of the solar corona is fundamental to constraining the coronal heating mechanisms. The Hinode X-ray Telescope collected images of the solar corona in different passbands, thus providing temperature diagnostics through energy ratios. By combining different filters to optimize the signal-to-noise ratio, we observed a coronal active region in five filters, revealing a highly thermally structured corona: very fine structures in the core of the region and on a larger scale further away. We observed continuous thermal distribution along the coronal loops, as well as entangled structures, and variations of thermal structuring along the line of sight. Title: Prominence and quiet-Sun plasma parameters derived from FUV spectral emission Authors: Parenti, S.; Vial, J. -C. Bibcode: 2007A&A...469.1109P Altcode: Context: A solar prominence and the quiet-Sun (QS) were observed with SOHO/SUMER in October 1999. With this dataset we built the first comprehensive UV spectral atlas in the range 800-1250 Å for a prominence, thus complementing the existing reference atlases for the QS.
Aims: This is a detailed study based on the information in this atlas, with the aim of deriving the plasma parameters in two distinct regions. The large amount of information available allows us to establish these parameters with lower uncertainty than in previous studies, leading to reference values for theoretical investigations.
Methods: The measured lines' FWHM were used to derive the distribution of the non-thermal velocities at various temperatures. The lines intensities were used to derive the electron densities at temperatures of 7 × 104 K and the differential emission measure.
Results: The comparison with the QS shows lower velocities in the prominence for temperature T with log~T < 5.4. The velocities derived in the highest part of the prominence show a lower gradient with the temperature. The value obtained for the electron density indicates a low pressure prominence. We conclude with a discussion of the energy budget in the prominence.

Table 1 is only available in electronic form at http://www.aanda.org Title: EUI, The Ultraviolet Imaging Telescopes Of Solar Orbiter Authors: Hochedez, J. -F.; Appourchaux, T.; Defise, J. -M.; Harra, L. K.; Schühle, U.; Auchère, F.; Curdt, W.; Hancock, B.; Kretzschmar, M.; Lawrence, G.; Leclec'h, J. -C.; Marsch, E.; Mercier, R.; Parenti, S.; Podladchikova, E.; Ravet, M. -F.; Rochus, P.; Rodriguez, L.; Rouesnel, F.; Solanki, S.; Teriaca, L.; Van Driel, L.; Vial, J. -C.; Winter, B.; Zhukov, A. Bibcode: 2007ESASP.641E..33H Altcode: The scientific objectives of Solar Orbiter rely ubiquitously on EUI, its suite of solar atmosphere imaging telescopes. In the configuration discussed here, EUI includes three co-aligned High Resolution Imagers (HRI) and one Full Sun Imager (FSI). FSI and two HRIs observe in extreme ultraviolet passbands, dominated by coronal emission. Another HRI is designed for the hydrogen Lyman α radiation in the far UV, imaging the Chromosphere and the lower Transition Region. The current EUI design and some of its development challenges are highlighted. EUI profits from co-rotation phases, solar proximity and departure from the ecliptic. In synergy with the other S.O. payload, EUI probes the dynamics of the solar atmosphere, provides context data for all investigations and helps to link in-situ and remote-sensing observations. In short, it serves all four top-level goals of the mission. For these reasons, the EUI suite is keenly anticipated in the European scientific community and beyond. Title: Magnetic activity and the solar corona: first results from the Hinode satellite . Authors: Reale, Fabio; Parenti, Susanna; Reeves, Kathy K.; Weber, Mark; Bobra, Monica G.; Barbera, Marco; Kano, Ryohei; Narukage, Noriyuki; Shimojo, Masumi; Sakao, Taro; Peres, Giovanni; Golub, Leon Bibcode: 2007MmSAI..78..591R Altcode: The structure, dynamics and evolution of the solar corona are governed by the magnetic field. In spite of significant progresses in our insight of the physics of the solar corona, several problems are still under debate, e.g. the role of impulsive events and waves in coronal heating, and the origin of eruptions, flares and CMEs. The Hinode mission has started on 22 september 2006 and aims at giving new answers to these questions. The satellite contains three main instruments, two high resolution telescopes, one in the optical and one in the X-ray band, and an EUV imaging spectrometer. On the Italian side, INAF/Osservatorio Astronomico di Palermo has contributed with the ground-calibration of the filters of the X-ray telescope. We present some preliminary mission results, with particular attention to the X-ray telescope data. Title: Modeling the Radiative Signatures of Turbulent Heating in Coronal Loops Authors: Parenti, S.; Buchlin, E.; Cargill, P. J.; Galtier, S.; Vial, J. -C. Bibcode: 2006ApJ...651.1219P Altcode: The statistical properties of the radiative signature of a coronal loop subject to turbulent heating obtained from a three-dimensional (3D) magnetohydrodynamics (MHD) model are studied. The heating and cooling of a multistrand loop is modeled and synthetic spectra for Fe XII 195.12, Fe XV 284.163, and Fe XIX 1118.06 Å are calculated, covering a wide temperature range. The results show that the statistical properties of the thermal and radiative energies partially reflect those of the heating function in that power-law distributions are transmitted, but with very significant changes in the power-law indices. There is a strong dependence on the subloop geometry. Only high-temperature radiation (~107 K) preserves reasonably precise information on the heating function. Title: Looking for Signature of Coronal Heating in the Radiative Emission of a Coronal Loop Authors: Parenti, S.; Buchlin, E.; Cargill, P. J.; Caltier, S.; Vial, J. -C. Bibcode: 2006ESASP.617E.104P Altcode: 2006soho...17E.104P No abstract at ADS Title: Solar Hydrogen Lyman Contimuum Observations with Soho/sumer Authors: Parenti, S.; Vial, J. -C.; Lemaire, P. Bibcode: 2005ESASP.600E..93P Altcode: 2005ESPM...11...93P; 2005dysu.confE..93P No abstract at ADS Title: Prominence atlas in the SUMER range 800-1250 Å. II. Line profile properties and ions identifications Authors: Parenti, S.; Vial, J. -C.; Lemaire, P. Bibcode: 2005A&A...443..679P Altcode: We present a SOHO/SUMER spectral atlas in the 800-1250 Å range of a prominence and a Quiet Sun (QS) region observed in 1999. The atlas is produced for two separate areas of the prominence. The QS spectrum is used as a reference. This is the first prominence atlas obtained with high spectral resolution (≈0.044 Å). It provides information concerning more than 550 line profiles, in terms of position, total radiance, and FWHM, along with the ion identification. Forty new lines have been identified with respect to previously published spectra. Title: Solar hydrogen-Lyman continuum observations with SOHO/SUMER Authors: Parenti, S.; Lemaire, P.; Vial, J. -C. Bibcode: 2005A&A...443..685P Altcode: In this work we analyze the emission of the H Lyman continuum (HI LyC) in the Quiet Sun (QS) and a solar prominence, in order to derive information on the temperature of the emitting plasma. We used the spectral atlas obtained with SOHO/SUMER detector A in 1999 (Parenti et al. 2005, A&A, 443, 679). The high spectral resolution of this instrument allows a good selection of the continuum, free from emission lines. However, in the HI LyC wavelength domain, the data suffer from large radiometric uncertainties, which lead us to use detector B as a reference. We obtained electron temperatures of 8281 K ± 280 K and 7564 K ± 230 K in two separate parts of the prominence. Title: Radiative Signatures of Coronal Loops Submitted to Turbulent Heating Authors: Parenti, S.; Buchlin, E.; Galtier, S.; Vial, J. -C. Bibcode: 2005ESASP.592..523P Altcode: 2005soho...16E..97P; 2005ESASP.592E..97P No abstract at ADS Title: Electron Density and Temperature in Streamer Derived from the H-LY Emission Authors: Parenti, S.; Noci, G. Bibcode: 2005ESASP.592..519P Altcode: 2005ESASP.592E..96P; 2005soho...16E..96P No abstract at ADS Title: Modelling the Radiative Signatures of Turbulent Heating in Coronal Loops Authors: Parenti, S.; Buchlin, E.; Galtier, S.; Vial, J. -C. Bibcode: 2004ESASP.575..497P Altcode: 2004soho...15..497P No abstract at ADS Title: SOHO CDS and SUMER observations of quiescent filaments and their interpretation Authors: Del Zanna, G.; Chiuderi Drago, F.; Parenti, S. Bibcode: 2004A&A...420..307D Altcode: Three quiescent filaments located at different positions on the solar disk were selected from the SOHO CDS data archive: one of them was also observed by SUMER in the raster mode. We investigate the filament-corona transition region (PCTR) emission, to determine whether it is indeed negligible, as found in one previously-analysed case. The observations are interpreted on the basis of two different models: an isothermal (cool) prominence located above the quiet sun transition region (TR) with a portion of the corona below it, and a model composed of several cool threads embedded in the hot coronal plasma without any quiet sun TR below it. The first model indicates that, for all filaments, the PCTR emission at the top of the filament is indeed negligible, and that the chromosphere-corona TR emission under the filament is lower than the average. All filaments have similar column densities, ranging from ∼2 to 7× 1017 cm-2 according to model A, and from 5 to 17×1017 cm-2 according to Model B. It is not possible to determine which model better accounts for the observations, on the basis of the two prominences observed above and below the Lyman continuum limit. Model B predicts absorptions that are generally less consistent with the observations, and produces higher column densities. The comparison between the line intensities observed above and below the He I ionization limit provides an estimate of the relative neutral helium abundance N(He I)/N(H I) in the prominences. Title: Prominence atlas in the SUMER range 800 1250 Å: I. Observations, data reduction and preliminary results Authors: Parenti, S.; Vial, J. -C.; Lemaire, P. Bibcode: 2004SoPh..220...61P Altcode: The aim of this work is to build an EUV-UV spectral catalogue of a prominence. Here we focus on the preparatory work for the final result and we give an example of the results obtained. As a first step, we present the information needed for a full understanding of the results that will form the final entire catalogue. The data are composed of a full SUMER spectrum in the range 800-1250 Å of a prominence observed on 8 October 1999. A quiet-Sun area was also observed in the same spectral range in order to have a reference spectrum. Beside the standard corrections, we give details of the estimated stray light and the wavelength calibration of both datasets. We also present a short list of lines as an example of the results from the line-fitting procedure we applied to the data. For each line we give the measured position, the total intensity and the FWHM in the quiet Sun and at two different spatial positions in the prominence. With a final atlas of the prominence it will be possible to investigate several properties of the feature such as mass motion, differential emission measure, density, and elemental composition. Title: Solar prominence properties derived from the UV-EUV SUMER spectral atlas Authors: Parenti, S. Bibcode: 2004cosp...35.2958P Altcode: 2004cosp.meet.2958P We present the first results for the properties of solar prominence obtained using spectral lines from an UV-EUV atlas of prominence. We built this catalogue using data from the high resolution SUMER spectrometer on board SOHO. The data are composed by a full spectrum in the range 800 - 1250 Å of a prominence observed on October 8, 1999. A catalogue of prominence spectra at such spectral and spatial resolutions is a new item in prominence literature, and much information on prominences properties ca be derived. The Differential Emission Measure and other plasma properties are here investigated. Title: Temporal Evolution of a Streamer Complex: Coronal and in Situ Plasma Parameters Authors: Bemporad, A.; Poletto, G.; Suess, S. T.; Ko, Y. K.; Parenti, S.; Riley, P.; Romoli, M.; Zurbuchen, T. Z. Bibcode: 2003ApJ...593.1146B Altcode: We report on observations acquired by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO), from 2000 June 10 to June 17 at the time of a SOHO-Sun-Ulysses quadrature. UVCS took data at 1.6 and 1.9 Rsolar with a slit normal to the solar radius and centered along the radial to Ulysses. A streamer complex was sampled by UVCS throughout the quadrature campaign, giving us the opportunity to derive plasma parameters in different streamers and to compare them with plasma properties measured in situ. Large Angle Spectroscopic Coronagraph images above 2 Rsolar helped us understand the temporal evolution of the streamer complex. We derive densities, temperatures, and elemental abundances in two streamers, which have different temperatures and element abundances. In spite of these differences, both structures have the same first ionization potential (FIP) bias. The Fe/O ratio, which may be considered a proxy for the FIP effect, was measured in situ by the Solar Wind Ion Composition Spectrometer aboard the Ulysses spacecraft. Values of Fe/O measured in the corona at the sites where in situ plasma originated agree with in situ Fe/O values. Title: SOHO-Ulysses Spring 2000 Quadrature: Coronal Diagnostic Spectrometer and SUMER Results Authors: Parenti, S.; Landi, E.; Bromage, B. J. I. Bibcode: 2003ApJ...590..519P Altcode: We present results from SOHO/CDS and SOHO/SUMER coordinated observations of coronal streamers made during the spring 2000 quadrature of SOHO, the Sun, and Ulysses. These observations form part of the JOP 112, which is primarily aimed at investigating the composition of the regions of the corona and the solar wind observed by both SOHO and Ulysses. SUMER and CDS observed the low corona from the limb up to about 1.3 Rsolar from the Sun center. The physical parameters of the plasma, such as electron density, temperature, emission measure, and composition, are measured along the radial direction, toward Ulysses. The variation in these parameters over the 6 day series of observations was examined, and no significant change was seen. The dependence of these parameters on the solar latitude was also investigated. The results indicate that the observed streamers are homogeneous, of coronal composition, and nearly in hydrostatic equilibrium. The structures remained almost stable during the whole period of the observations. Title: Properties of the base of streamers from UV and EUV observations Authors: Parenti, S.; Landi, E.; Bromage, B. J. I. Bibcode: 2003MmSAI..74..717P Altcode: In this paper we investigate the physical parameters of a streamer observed during the Spring 2000 quadrature of SOHO, the Sun and Ulysses. The analysis was carried out using SOHO/CDS and SOHO/SUMER coordinated observations of the low corona. We analysed six days of observations of the same region, deriving electron temperature, density, emission measure and composition. We found full agreement in the results from the two instruments. We conclude that we were observing an omogeneus streamer, with coronal composition and not completely isothermal. Title: The "careers in solar physics" session of the SPM10 meeting Authors: Aulanier, G.; Parenti, S.; Krijger, J. M. Bibcode: 2002ESASP.506..981A Altcode: 2002ESPM...10..981A; 2002svco.conf..981A During the SPM10 meeting held in Prague (Czech Republic) on September 9-14, 2002, a half-day 'young session' was organized on the topic of careers in solar physics. Several young researchers and senior scientists were invited to give oral contributions on the current advantages and difficulties attached to the current system for post-doctoral contracts. A scientist from USA also presented the American system for contractors, and an ESA representative presented the official position of ESA regarding funding researchers. From the talks as well as from the long open discussion which followed, it was widely agreed that several typical rules for EU post-doc contracts (their short duration, their mandatory mobility, their age limit and their administrative and financial difficulties) not only lead to serious problems in the private life of postdocs, but essentially can have serious drawbacks on the follow-up of long-term scientific developments, and could quickly result in a dramatic loss of expertise, from the scale of individual institutes to the European scientific community at large. Many participants and most of the young researchers naturally agreed that new longer-term, renewable and stable contracts are necessary. In order to create such types of contracts, several fund raising initiative achieveable by the scientific community were discussed. The development of better public outreach initiatives on the European scale was a possibility which federated most of the participants. The resulting conclusion on this session were transmitted to the new board of the Solar Physics Section of the EAS/SPS. Title: The European solar physics community: outcome from a questionnaire Authors: Parenti, Susanna Bibcode: 2002ESASP.506..985P Altcode: 2002svco.conf..985P; 2002ESPM...10..985P At the SPM10 meeting held in Prague, for the first time was organized a "young section" which was dedicated to "the career in Solar Physics" (Aulanier, this issue). Prior to the meeting a questionnaire was distributed to the community with the aim to build statistic on the career. The informations collected in this way relate to personal and professional aspects of the career, how much the countries' policy and the working environment can affect it. Moreover, particular attention was given to the PhD and post-doctorate (post-doc) conditions. From the statistics it comes clear that the European Solar Physics is having a difficult period. Besides the main problems, we found the lack of an integrated European community, the lack of permanent positions, the low salary and the lost of popularity among students. Several ideas were proposed to improve the situation. Title: A SUMER spectral atlas for prominences Authors: Parenti, Susanna; Vial, J. -C.; Lemaire, P. Bibcode: 2002ESASP.508..327P Altcode: 2002soho...11..327P We present preliminary results of a study aimed at building a SUMER atlas for prominences. Using the atlas as reference, further studies can be addressed at deriving prominence properties, such as DEM distribution and anomalies in element abundances. Moreover, a comparison with previous atlas (e.g. Curdt et al., 2001) of other solar regions can be made. An extended prominence was observed with SUMER in the South-West solar limb in October 1999. A full spectrum was obtained in the waveband 790 - 1600 Å. After dealing with off-limb scattered light, the data are processed using multi-Gaussian fitting in order to derive the spectral properties of the observed structure. These properties are then also compared with those of the Quiet Sun area observed in the same wavelength range. Title: SOHO/CDS and SUMER coordinated observations of coronal streamer Authors: Parenti, Susanna; Landi, Enrico; Bromage, B. J. I. Bibcode: 2002ESASP.508..399P Altcode: 2002soho...11..399P In June 2000 the SOHO and Ulysses satellites reached the quadrature configuration with respect to the Sun. On this occasion the JOP 112 was run, with the aim of studying the coronal and solar wind physical parameters, with particular attention to the element composition. In this paper we present preliminary results from SOHO/SUMER and CDS/NIS data. The two instruments were pointed off-limb and observed the lower solar corona in the Ulysses direction (-58.2 deg in the S-E quadrant). During the period of observations (12-17 June) the observed corona was filled with streamers. From each instrument the electron density, temperature and element composition of the studied areas have been derived. A comparison of the results from the two instruments is then presented. Title: An erupting macrospicule. Characteristics derived from SOHO-CDS spectroscopic observations Authors: Parenti, S.; Bromage, B. J. I.; Bromage, G. E. Bibcode: 2002A&A...384..303P Altcode: We report results from the analysis of a sequence of SOHO/CDS observations obtained off-limb in the south polar coronal hole on 6 March 1998. Three successive data sets were obtained with the Normal Incidence Spectrometer (NIS), the first of which showed a jet-like feature visible in the chromospheric and low transition region lines. The morphological characteristics of this feature suggested it was a macrospicule. The two remaining observations of the same region indicated a quiet coronal hole with a density of 108 cm-3 and a temperature rising from 0.95 x 106 K near the limb to 1.2 x 106 K at about 4.7 x 104 km above the limb. These data were averaged and used as ``background'' for the macrospicule observation. The resulting subtracted spectra showed more details of the feature. In particular, a cloud of plasma was detected at about 3 x 104 km above the limb. The macrospicule was found to have a density of the order of 1010 cm-3 and a temperature of about 2-3 x 105 K. The initial outflow velocity near the limb was over 80 km s-1. This decreased to a terminal value of 26 km s-1 above about 6 x 104 km. Title: Preliminary results from coordinated SOHO-Ulysses observations Authors: Parenti, S.; Poletto, G.; Bromage, B. J. I.; Suess, S. T.; Raymond, J. C.; Noci, G.; Bromage, G. E. Bibcode: 2001AIPC..598...83P Altcode: 2001sgc..conf...83P SOHO-Ulysses quadratures occur at times when the SOHO-Sun-Ulysses angle is 90° and offer a unique possibility to compare properties of plasma parcels observed in the low corona with properties of the same parcels measured, in due time, in situ. The June 2000 quadrature occurred at a time Ulysses was at 3.35 AU and at a latitude of 58.2 degrees in the south-east quadrant. Here we focus on the UVCS observations made on June 11, 12, 13, 16. UVCS data were acquired at heliocentric altitudes ranging from 1.6 to 2.2 solar radii, using different grating positions, in order to get a wide wavelength range. The radial direction to Ulysses, throughout the 4 days of observation, traversed a region where high latitude streamers were present. Analysis of the spectra taken by UVCS along this direction shows a variation of the element abundances in the streamers over our observing interval: however, because the radial to Ulysses crosses through different parts of streamers in different days, the variation could be ascribed either to a temporal or to a spatial effect. The oxygen abundance, however, seems to increase at the edge of streamers, as indicated by previous analyses. This suggests the variation may be a function of position within the streamer, rather than a temporal effect. Physical conditions in streamers, as derived from UVCS observations, are also discussed. . Title: Coronal and solar wind elemental abundances Authors: Raymond, J. C.; Mazur, J. E.; Allegrini, F.; Antonucci, E.; Del Zanna, G.; Giordano, S.; Ho, G.; Ko, Y. -K.; Landi, E.; Lazarus, A.; Parenti, S.; Poletto, G.; Reinard, A.; Rodriguez-Pacheco, J.; Teriaca, L.; Wurz, P.; Zangrilli, L. Bibcode: 2001AIPC..598...49R Altcode: 2001sgc..conf...49R Coronal elemental abundances, as compared with abundances in the solar wind and solar energetic particles, provide the means for connecting solar wind gas with its coronal source. Comparison of coronal abundances with photospheric values shows fractionation with the ionization potential of the atom, providing important, though not yet fully understood, information about the exchange of material between corona and chromosphere. Fractionation due to gravitational settling provides clues about flows within the corona. In this paper, we discuss the uncertainties of abundance determinations with spectroscopic techniques and in situ measurements, we survey the ranges of abundance variations in both the corona and solar wind, and we discuss the progress in correlating solar wind features with their coronal sources. . Title: Properties of Different Coronal Stremers Authors: Parenti, S.; Bromage, B. J. I.; Poletto, G.; Noci, G.; Reymond, J. C.; Bromage, G. E. Bibcode: 2001IAUS..203..413P Altcode: Element abundance in equatorial and mid-latitude streamers have been derived from data taken by SOHO/CDS and UVCS experiments. Observations were made at 1.1, 1.5,1.6 Rodot, to allow us to check a possible variation of elemental composition with altitude. Part of the CDS data were taken at the border of the south Corona Hole, so that the variation of coronal composition at the streamer edge is investigated. UVCS spectra have been acquired using three different grating positions to cover lines from low and high First Ionization Potential. Absolute abundance of Oxygen and Iron have been determined via the evaluation of the radiat ive and collisional components of the H-Lyman β and O VI (1032 Å) lines and of th e intensities of lines from Fe X-XIII-XV-XVIII. Abundance of Fe, Si, Al, Mg were estimated using the Differential Emission Measure technique. This method gives us information also on the plasma electron temperature (Te), which is compared with temperatures estimates from line ratio technique. The variability of (Te) and of abundances in the observed streamers are discussed and compared with estimates from the literature. Title: Element abundances in streamers from SOHO/UVCS CDS observations Authors: Parenti, S.; Poletto, G.; Bromage, B. J. I.; Raymond, J. C.; Noci, G. Bibcode: 2001MmSAI..72..604P Altcode: The variation of the element abundances in coronal streamers with solar distance and latitude has been studied. The data were acquired in an equatorial and mid-latitude streamer by SOHO/UVCS and CDS, during a coordinated observing campaign held on March, 8 1998. CDS data refer to 1.1 solar radii, UVCS data to 1.6 solar radii. A further mid-latitude streamer was observed by UVCS at 1.6 solar radii, on May 24 of the same year. Element abundances, relative to photospheric iron, were derived from CDS data using the Differential Emission Measure (DEM) technique. Absolute element abundances were derived from UVCS data using a) the O VI doublet lines for oxygen, b) the line ratio between Fe lines and Lyman-beta for iron and, c) the DEM technique for the other elements. Our results show a depletion of the abundances from their photospheric values in the high corona, while almost photospheric values of the abundances relative to iron have been found in the low corona. Spectra do not show any clear indication for a latitude dependence of elemental abundances. Title: EUV Macrospicule in an Off-Limb Observation of the Solar South Coronal Hole (CD-ROM Directory: contribs/parenti) Authors: Parenti, S.; Bromage, G. E.; Del Zanna, G.; Bromage, B. J. I. Bibcode: 2001ASPC..223..715P Altcode: 2001csss...11..715P No abstract at ADS Title: Characteristics of solar coronal streamers. Element abundance, temperature and density from coordinated CDS and UVCS SOHO observations Authors: Parenti, S.; Bromage, B. J. I.; Poletto, G.; Noci, G.; Raymond, J. C.; Bromage, G. E. Bibcode: 2000A&A...363..800P Altcode: This paper presents the results from coordinated observations of streamers acquired by the SOHO Coronal Diagnostic Spectrometer (CDS) and UltraViolet Coronograph Spectrometer (UVCS) experiments. Data from different altitudes within the solar corona were taken, with the purpose of determining their physical parameters - densities, electron temperatures and element abundances - and their changes over the altitude range between 1.02 and 1.6 R_sun. Further UVCS streamer data, taken about two months later are used for comparison with the behaviour seen in two different streamers. Whenever possible, alternative methods have been adopted to determine the same physical parameter, as a cross check. In particular, the DEM technique has been applied to UVCS data, in order to compare abundance values derived in this way, with those obtained using the method of Raymond et al. (\cite{ray97}). We conclude that abundances in the low corona covered by CDS data do not show evidence for abundance variation, with respect to photospheric values, while, at UVCS altitudes, a depletion of all element abundances is clearly evident. No clear evidence of a FIP effect in streamers was found; we get contrasting results from the only two high FIP elements present in our spectra. Title: A SOHO/CDS Observation of a Macrospicule in the South Coronal Hole Authors: Parenti, S.; Del Zanna, G.; Bromage, B. J. I. Bibcode: 1999ESASP.448..623P Altcode: 1999mfsp.conf..623P; 1999ESPM....9..623P No abstract at ADS Title: Physical Parameters in Streamer From CDS and UVCS Observations Authors: Parenti, S.; Poletto, G.; Raymond, J.; Bromage, B. J. I. Bibcode: 1999ESASP.446..531P Altcode: 1999soho....8..531P UVCS and CDS observations of a streamer in the southern hemisphere, at a latitude of 40 Degrees, have been acquired on March 8, 1998. UVCS data have been taken at an heliocentric altitude of 1.6 solar radii and cover the spectral range from 950 to 1250 Angstrom; CDS data have been taken at an altitude of 1.1 solar radii and cover the range from 308 to 381, and 513 to 633, Angstrom. These data have been used to determine the physical conditions of a streamer structure: in particular, we give an estimate of the electron temperature, electron density and element abundance in the structure. The electron temperature has been evaluated from lines of different ions from the same elements, crude values of densities have been derived from an analysis of the OVI doublet lines at 1032 and 1037 Angstrom and element abundances have been estimated both from a DEM (Differential Emission Measure) analysis and from other techniques. Because UVCS spectra have been taken at different times, during the day, we have been looking also at temporal variations in the physical parameters of the streamer. Changes across the streamer have been analyzed as well. Coordinated CDS and UVCS observations allow us also to compare results from the two experiments and look for variations, with solar distance, of the streamer physical parameters. Title: Magnetic Flux Tubes at 3 Au? Authors: Parenti, S.; Velli, M.; Poletto, G.; Suess, S. T.; McComas, D. J. Bibcode: 1997SoPh..174..329P Altcode: We present an analysis of plasma and magnetic field data acquired by the Ulysses spacecraft on May 1994. Our study is motivated by the result of Poletto et al. (1996) who found some evidence for a peak in the power spectrum of magnetic pressure at a frequency ν ≈ 2 × 10−5 Hz, during that period. A re-evaluation of the plasma pressure power spectrum, on the basis of better data than used in the previous work, gives only marginal evidence for a peak at that frequency. If both spectra had excess power in the same spectral range, one might hypothesize that the Pressure Balanced Structures (PBS) detected in the data trace periodically distributed coronal structures which maintain their identity up to large distances. A careful data analysis, however, shows that this interpretation is hardly tenable. Hence, we consider the alternative hypotheses that the observed PBS are either a bundle of magnetic flux tubes, with no characteristic periodicity, in pressure equilibrium with the ambient, or the manifestation, at large distances, of waves generated close to the Sun. To prove the latter case, we made a test simulation of the evolution with heliocentric distance of an ensemble of Alfvén and slow mode waves, generated close to the Sun, and show that structures similar to those we analyzed may form in the interplanetary medium. Our simulations also seem to show that together with PBS, magnetic holes, frequently observed in the Ulysses data, could also originate from the nonlinear evolution of large amplitude slow waves in quasi-perpendicular propagation. We conclude that the observed PBS most likely arise via an in situ generation mechanism, rather than being remnants of solar structures. Title: Searching for coronal plumes in ULYSSES observations of the far solar wind. Authors: Poletto, G.; Parenti, S.; Noci, G.; Livi, S.; Suess, S. T.; Balogh, A.; McComas, D. J. Bibcode: 1996A&A...316..374P Altcode: In the past, from the analysis of data acquired by the Helios spacecrafts within distances <=1AU, some evidence has been found of the presence of coronal plumes in the solar wind. Ulysses observations offer a unique opportunity to search for plume remnants in the polar wind at larger distances. Pressure balanced structures (PBS), which might possibly be a signature of those features, have in fact been recently identified in its data. On the basis of previous work, which detected significant peaks (possibly related to plumes) in power spectra of solar wind parameters, we present here the results from a similar research. However, our analysis does not confirm previous findings, because power spectra bear no evidence of significant periodicities. This result allows for different interpretations, but does not rule out the presence of a typical periodicity in the data. By developing a simple 2-D model for structures traversed by Ulysses, we show how easily, even if they were regularly distributed, the original periodicity may become hardly identifiable in power spectra analyses. We conclude that this is not a viable technique for tracing plumes in the solar wind and we suggest alternative means for an unambiguous identification of these features. Title: Search for fine scale structures in high latitude solar wind Authors: Livi, S.; Parenti, S.; Poletto, G. Bibcode: 1995sowi.conf...93L Altcode: About 25 years ago, E. Parker suggested that, as a consequence of the inhomogeneous structure of the corona, the solar wind might consist of adjacent structures with different physical conditions. Since that suggestion was made, the solar wind plasma characteristics have been measured in situ through many experiments, but little has been done to check whether the solar wind shows any evidence for fine scale structures, and, in the affirmative, how far from the Sun these structures persist. A previous work on this subject, by Thieme, Marsch and Schwenn (1990), based on Helios data, lead these authors to claim that the solar wind, between 0.3 and 1 AU, is inhomogeneous on a scale consistent with the hypothesis that the plume-interplume plasmas, at those distances, still retain their identity. In this work we present preliminary results from an investigation of the solar wind fine structure from Ulysses high latitude observations. To this end, we have analyzed data over several months, during 1994, at times well after Ulysses's last encounter with the Heliospheric Current Sheet, when the spacecraft was at latitudes above 50 degrees. These data refer to high speed wind coming from southern polar coronal holes and are best suited for plume-interplume identification. We have performed a power spectra analysis of typical plasma parameters, to test whether the wind plasma consist of two distinct plasma populations. We also examined data to check whether there is any evidence for an horizontal pressure balance over the hypothesized distinct structures. Our results are discussed and compared with previous findings.