Polar Meteorology
Research in the section Polar Meteorology focusses on the physics of processes in the polar troposphere and of the interaction between atmosphere and ocean/ice. This is done by simulation studies with numerical forecast models, studies on theoretical aspects and measurements during expeditions. Thereby we will improve our understanding of the complex physical processes in the coupled atmosphere - ocean - ice system and model the development of the system. Crucial points in our investigations are transports within the atmospheric boundary layer, exchange of heat, mass, and momentum between atmosphere and ocean/ice, cloud physical processes, and radiation transfer.
Modelling of the polar atmosphere is based primarily on two meso-scale numerical models. The boundary layer model METRAS, which had been designed at the Institute of Meteorology at the University of Hamburg, was further developed for polar application in collaboration of scientists from the AWI and from University of Hamburg. This model is operated, depending on the processes under study, with different mesh sizes (few meters to several kilometers); thus the air flow e.g. over a lead with some hundred meters width as well as a cold air outbreak extending over hundreds of kilometers can be simulated. Furthermore, the model can be coupled with a so called dynamic and thermodynamic sea ice model (developed at AWI) which enables the simulation of drift and melting/freezing of ice floes.
The second central model is the COSMO (previously named Lokal-Modell (LM) and developed at of the Deutscher Wetterdienst DWD). The COSMO-Model is an operational nonhydrostatic numerical weather forecast model, which can be run with grid spacing between ca 2 and 50 km. Situations in the polar regions are simulated with the COSMO-Model to study, among others, special aspects of the hydrological cycle. Since the model equations are formulated, in contrast to METRAS, in spherical coordinates, we can simulate with the COSMO-Model the atmospheric evolution for a much larger region than with METRAS; at AWI it is applied for arctic as well as antarctic conditions, the COSMO-Model is run at present for a region of about 2000 km x 2000 km.
In parallel to the modelling research, basic theoretical studies are performed.
In close connection to the research mentioned above, we carry out measurements during expeditions to the arctic region. For that we make use of the research vessel Polarstern as well as polar aircraft. The aircraft can be equipped with instruments for measuring radiation, turbulence, and cloud particles. Recent campaigns are SVALEX (2005) and ICESAR (2007). RV Polarstern can be equipped at the bow with a mast which carries instruments for measuring atmospheric turbulence. This system has been used several times in the central arctic during campaigns to study the air flow around ice ridges and leads for summer conditions.
The research is part of the PACES-program in workpackages 1.1 and 1.3 and contributions to the operations of the Neumayer-Station are part of Topic 6.