Climate and Water Cycle

Climate & the Hydrological Cycle 2014 (MO408M)

A course on the role of water in our climate

This is an optional course (7.5 ects) within the fourth year of the Masters program in "Meteorology, Physical Oceanography and Climate" at the Utrecht University (UU).

Given by Geert-Jan Roelofs and Aarnout van Delden.

First lecture second part of the course: Wednesday 23 April 2014, 13:15-15:00, Room BBG 077.

Schedule for the presentations: PresentationsCandHC2014.pdf

Introduction and Content

The course consists of the three parts.

1.Cloud microphysics, rain and ice formation in clouds.Physical and chemical processes of aerosol particles, natural and anthropogenic sources, atmospheric lifetime of aerosol and connection with the hydrological cycle. Interactions of aerosol with atmospheric radiative transfer (scattering, absorption) and their influence on cloud properties. Radiative forcing by aerosol and climate impacts.

2.Role of water cycle in the energy budget of the climate system. Influence of water cycle on climate sensitivity. General circulation of the atmosphere: jets, tropical Hadley circulation, mid-latitude Ferrel circulation, stratospheric Brewer Dobson circulation. Role of the water cycle, radiation and waves and vortices in forcing these zonal mean circulations. Transport of momentum, heat and mass by these circulations and by eddies. Interaction between adiabatic dynamics and diabatic processes (radiation and heat sources and sinks due to phase changes of water). Dynamics of the tropopause.

The background values (shown in black) of the energy fluxes are based on observations for 2000–05 (Trenberth et al. 2009). Superposed, with the key in lower left corner), are values from the various reanalyses for the 2002–08 period except for ERA-40, which is for the 1990's (color coded; W m−2). Above the graphic, values are given for albedo (%), Absorbed Solar Radiation (ASR), net Top of the Atmosphere (TOA) radiation, and Outgoing Long-wave Radiation (OLR); the box labeled SFC near the bottom gives the net flux absorbed at the surface. For the 1990's the latter value is 0.6 W m−2. Note the important role of water in the energy balance (Figure due to Trenberth et al., 2011).

Goal of the Course

1. ability to describe and basically understand the seasonal and interannual variability of the large scale circulation of the atmosphere and the associated transport of water vapour.
2. ability to describe and basically understand on how atmospheric radiative processes, the energetics of the water cycle and large scale planetary waves determine the seasonal cycle of temperature and wind-jets.
3. understand the physical (radiative and thermodynamic) aspects of aerosol, clouds and land surface processes
4. acquire knowledge on microphysical and chemical properties of aerosol and clouds, and understand their role in aerosol direct and indirect climate effects
5. demonstrate a broad insight in how the different aspects of the hydrological cycle are related and interact with other diabatic and adiabatic processes
6. understand how the hydrological cycle affects and is affected by climate (change)
7. explore and understand scientific literature on a subject associated with aerosol, clouds, water cycle, radiation and atmospheric circulation and climate
8. process and analyse records of observations and model output

Lecture Notes

The first part of the course focusses on aerosols, clouds and climate

The second part of the course focusses on the role of water in the general circulation of the atmosphere

Lecture notes for the second part of the course are boxes 2.1-2.4 in chapter 2 and chapters 10, 11 and 12 of the lecture notes on "Atmospheric Dynamics": see AtmosphericDynamics.htm

Books

Schedule

Schedule of the second part of the course (Spring 2014): ScheduleCandHC2014.pdf

Evaluation/assessment

1 exam (April)

Several exercises using reanalysis data

1 essay and 1 oral presentation

Grade

Essays

Exam

1 exam in April (week 16)

Internetsites on Climate