The work on Arctic climate processes at the institute involves all scales and is based on expertise in dynamic and chemical meteorology, with strong focus on the interactions between marine biology and chemistry – gases- aerosol – cloud formation and boundary-layer dynamics – radiation – cloud physics and chemistry. A very strong component of this research evolves around the organization of field experiments to the central Arctic basin on the Swedish icebreaker Oden, where the department has an internationally leading role. There are also larger-scale dynamics and cloud studies using global models, for example EC-Earth and other climate model data (e.g. CMIP5), reanalysis data (ERA-Interim) and different satellite products.

 

 
Oden
photo by M. Tjernström
 

The Arctic is a primary heat sinks in the global climate system and the central Arctic Ocean sea ice exerts a strong control of low-level atmospheric conditions, regulating fluxes of energy and organic and inorganic matter across the ocean/atmosphere interface. The climate in the Arctic is changing faster than anywhere else on Earth. The near-surface temperature is increasing more than twice as fast as the global averaged temperature and the sea ice is melting rapidly, especially in summer. The sea ice extent at the annual summer minimum for all years after the dramatic sea-ice loss in the summer of 2007 has been smaller than any of the years before 2007. That the climate in the Arctic is changing faster than globally is often referred to as the "Arctic amplification".

 

In spite of a considerable effort, there is not yet a clear understanding of several feedback mechanisms likely responsible for the Arctic amplification, involving for example changes in surface reflectivity, turbulent fluxes, aerosol particles, clouds, radiation and marine biology, as the sea-ice cover shrinks. Consequently, climate models perform poorly in the Arctic and the uncertainty in scenarios of future climate is larger here than elsewhere on the globe. The amount of empirical data on Arctic climate processes is inadequate for a proper understanding and long-term monitoring of Arctic climate from space-borne instruments suffers from a lack of ground-truth measurements for validation and development of new improved inversion algorithms. The work at the institute aims at improving many of these deficiencies.