OP: PhD-student position; “Validation and improvement of the ECHAM5 cloud-radiation parameterization scheme by comparison with satellite observations” ; Institute of Atmospheric Physics
17. Juni 2008
The Institute for Atmospheric Physics at DLR (Deutsches Zentrum fuer Luft- und Raumfahrt) Oberpfaffenhofen,  Germany, invites applications for a three years

PhD-student position (payment according to a civil service position 50% TVoeD 13)

in the field of remote sensing and model evaluation, to start as soon as possible.

“Validation and improvement of the ECHAM5 cloud-radiation parameterization scheme by comparison with satellite observations”

According to the Intergovernmental Panel of Climate Change (IPCC, 2007), clouds represent the major uncertainty in climate model predictions. Clouds are complex three-dimensional structures and consist of droplets and particles of different sizes and shapes. Simulating this complexity accurately is extremly time consuming. For this reason parameterizations have been developed which allow to calculate the interaction of clouds with radiation efficiently. There are parameterizations for the optical properties of clouds and for the overlapping of clouds in different atmospheric layers.

In a DLR project CATS (Climate-compatible air transport system) we try to improve our knowledge of the environmental impact of air traffic on the one hand, while developing strategies to minimize this impact on the other hand. One of the well-known consequences of air-traffic with large impact on climate is the formation of contrails which eventually turn into cirrus clouds. To quantify the global climate impact of contrails requires correct representation of contrails and cirrus clouds in a global climate model which is validated by observations.

The aim of this PhD thesis is in a first step to validate the cloud overlap scheme implemented in the climate model ECHAM5 by comparison with satellite observations. CloudSat/CALIPSO, two satellites of the AQUA train, provide cloud profiles with high vertical resolution and are    therefore ideally suited for this task. The second step is to develop an improved cloud overlap scheme based on the results of the validation and to implement this scheme into ECHAM5, with special emphasis on contrails and cirrus clouds.

We are looking for a motivated PhD student for this exciting task. In our group we develop and use remote sensing algorithms to study clouds, with special emphasis on ice clouds and aircraft contrails, see http://www.dlr.de/pa/. For this purpose we develop one-and three-dimensional radiative transfer models, see http://www.libradtran.org and http://www.bmayer.de/mystic.html.

Requirements are a diploma/master in physics, meteorology, mathematics or related disciplines and good programming skills (e.g. in C or FORTRAN). Knowledge in satellite remote sensing as well as physics of the atmosphere would of course be helpful.

Please send your application, preferably in electronic form, to the following address.

For more information please contact

Kontakt
Dr.rer.nat. Claudia Emde 
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Physik der Atmosphäre, Fernerkundung der Atmosphäre
Oberpfaffenhofen-Wessling
Tel.: +49 8153 28-3031
Fax: +49 8153 28-1841 

Email:	Claudia.Emde(AT)dlr.de
Internet:	http://www.dlr.de/ipa