First results of the POLEX project will be presented. The objectives of our project comprise: 1) An improvement of the representation of atmosphere-sea ice-ocean interaction in climate models by developing and implementing a suite of advanced turbulence parametrizations for polar conditions 2) Performance of present day and future climate change simulations for the 21st century using the new suite of parametrizations 3) Understanding the dynamical linkages between Arctic climate change, mid-latitude atmospheric circulation changes and subsequent changes in extreme events 4) Determination of recent and future changes in extreme events over the Arctic, Middle Europe and Russia and assessment of their impact on Northern Sea route, wildfire and vegetation over the key regions Arctic and Russia Our project will strongly enhance the climate models capability to represent Arctic processes that are known to be critical for simulating linkages between the Arctic and mid-latitudes.