Overview of Research in Section Polar Meteorology
Research in the Section Polar Meteorology concentrates on physical processes in the polar troposphere including its interactions with ocean and sea ice. This is done
- to understand processes on the spatial scale of about 1 to 50 km,
- to simulate them with mathematical-physical models,
- to develop methods (so-called parameterization models) for the representation of the effects of small scale processes in models resolving only larger scale processes,
- to monitor the atmosphere and polar ice.
Crucial topics are the mass and energy exchange between atmosphere and ocean/sea ice,transports within the atmospheric boundary layer, cloud physics, radiation transfer, quality control of model data sets for polar regions, and remote sensing of sea and land ice. Investigations are carried out by a combination of modelling studies and data from short-term observations during expeditions, from long-term monitoring at Neumayer Station and from remote sensing.
Neumayer III Station
Photo: Bernd Loose, AWI
The aircraft Polar 5 and Polar 6 as well as the research vessel Polarstern are available for airborne measurements during campaigns. Standard atmospheric properties, but also turbulence parameters, radiation fluxes and methane (Polar 5, 6) can be obtained in high accuracy.
At the Meteorological Observatory Neumayer 3-hourly routine synoptic observations, daily upper air soundings (including stratospheric ozone soundings since 1992), and surface radiation measurements are obtained since 1981. The observatory delivers data to the network of Global Atmospheric Watch from the WMO and to the Baseline Surface Radiation Network (BSRN). Since 2011 AWI hosts the World Radiation Monitoring Center (WRMC) which is the central archive of BSRN. Observations from satellites allow monitoring of, e.g., the sea and land ice conditions over large areas and over long periods.
The central objective of the group Earth Observing Systems (EOS) is the development of methods for retrieving properties of the polar ice masses, ocean, and land surface from satellite informations.
Most observations are performed in close connection with the modelling studies.
Modelling of the polar atmosphere is based primarily on two meso-scale numerical models. The boundary layer model METRAS, which has been designed at the Institute of Meteorology at the University of Hamburg (UH), has been further developed at AWI and UH for polar applications. The model operates with various mesh sizes (few meters to several kilometers according to the considered processes), such that the evolution of the atmosphere over the (fractionally) sea ice covered ocean can be simulated for various flow regimes. The model can be coupled with a dynamic and thermodynamic sea ice model (developed at AWI) which enables the simulation of drift and melting/freezing of ice floes. The second model is the weather forecast model COSMO of the Deutscher Wetterdienst (DWD). Situations are simulated to study, among others, clouds and precipitation under polar conditions. This model can be run for a much larger domain than METRAS.
Parameterizations of the effect of small scale ('subgridscale') processes are developed based on a combination of basic theoretical studies, small scale modelling and observations. They can be applied in weather prediction and climate models operating with mesh sizes which are larger than the characteristic scale of the small scale processes.
These larger scale models can resolve only processes on a spatial scale larger than the mesh size. However, processes on smaller scales, such as e.g. turbulent transports, strongly influence the larger scale atmospheric flow. Therefore the effects of these smaller scale ('subgridscale') processes must somehow be catched. From a combination of basic theoretical studies, small scale modelling and observations we develop methods ('parameterizations') to catch the effects of the subgridscale processes in larger scale model simulations.