A modeling group has been established at AWI to improve our understanding of the polar  climate system. Following questions are of our interest: What are the key physical processes and feedbacks ? What complexity of physical process parameterizations is needed? What is the level of uncertainty in regional climate models? What is their representation of natural variability and how is their estimate of future regional change?

The aim is to simulate the coupled atmosphere-sea ice-ocean-land system in the Arctic. The coupled model system includes:

Atmosphere, represented by ECHAM [Roeckner et al., 1996, 2003]
Ocean, represented by MOM-2
Sea ice, represented by a dynamic-thermodynamic sea ice model [Lemke at al, 2000] with elastic-viscous plastic rheology according to Hunke & Dunkowicz [1997].
Land surface, represented by ECHAM [Roeckner et al., 1996, 2003] or NCAR-LSM [Bonan et al., 1996].

Two model domains are in our use the whole Arctic north of about 60°N, and the whole Antarctic south of about 60°S

Activities:

• EU: Global implications of Arctic climate processes and feedbacks - GLIMPSE
• DFG Schwerpunkt Antarktisforschung: Water cycle in a regional atmospheric model of Antarctica
• EU: Quantifying the carbon budget in Northern Russia: past, present and future - CARBO-North

The following pages provide the concept of using regional climate models in general, information about the HIRHAM model in particular, an overview of the ongoing work.