The global warming is enhanced in the Arctic where surface air temperature has increased twice as much as the global average in recent decades, also called Arctic amplification. Arctic warming implies melting of sea ice, but its dynamic-thermodynamic response is neither straightforward

or necessarily linear, nor is the response of the atmosphere to sea ice

reductions. Satellite observations (1979 to present) show that the Arctic

sea ice cover has declined over the past three decades, with a record-low

summer ice extent in 2007. Furthermore, the projections from the IPCC

AR4 models show that the summer Arctic sea ice could disappear by the

end of 21st century. Recent studies suggest that the summer Arctic Ocean

can be ice-free faster than the projections of the coupled climate models.

This will have severe consequences for climate, environment and human

activities in high latitudes. Although previous studies show that the variability

of atmospheric circulation plays a dominant role in sea ice variability,

some observation-based studies also suggest that Arctic sea ice change

will have impact on the atmosphere circulation. Numerous simulations

(atmosphere-only models, not coupled climate models) have been performed

to investigate the potential impact of sea ice on the atmosphere where sea

ice is used as a fixed boundary. The objective of this project is to explore the

impact of a summer ice-free Arctic Ocean on the high-latitude climate. The

project will consist of comprehensive data analysis and use of the Bergen

Coupled Climate Model and the atmosphere-only model. For the coupled

model simulation, a special technique, the so-called partial coupling will be

used. The project will compare a Blue Arctic Ocean high latitude climate

scenario with the present climate situation in order to quantify and assess the

future changes. Improved knowledge about climate change at high latitudes

is essential for planning and policy making.