- The earth's climate is mainly determined by the spatial structure of large-scale atmospheric circulation patterns and their associated temporal changes. Climate variations on seasonal and decadal time scales are influenced by externally and anthropogenically caused climate variability as well by the global dynamics of preferred oscillation modes of the coupled atmosphere-ocean-sea-ice system. Regional feedback mechanisms in the Arctic climate system, like sea-ice albedo and decoupling of the surface climate and the free troposphere in the stable planetary boundary layer have the potential to influence the global climate.
- The maximum temperature increase in IPCC coupled model projections at the end of this century is in the central Arctic, whereas the observations show the high latitude temperature increase over the continents. With these uncertainties the Arctic poses severe challenges to generate credible model-based projections of climate change. We need an understanding of the influence of large-scale dynamic variability connected with the natural circulation modes of the global climate system and the regional feedbacks involved in the complex Arctic atmosphere-sea-ice-ocean-land interactions.
- The GLIMPSE project will address and reduce the deficiences in our understanding of the Arctic by developing improved physical descriptions, understanding and parameterizations of regional Arctic climate feedbacks in atmospheric regional climate models and coupled atmosphere-ocean-sea-ice regional climate models with high horizontal and vertical resolution on the basis of data from the Surface Heat Budget of the Arctic Ocean - SHEBA project and of the network of meteorological stations over land.
- The improved parameterizations from regional models of the Arctic, obtained in the Arctic Regional Climate Model Intercomparison Project - ARCMIP will be implemented into state-of -the-art coupled Atmosphere-Ocean General Circulation Models, to determine and understand their global influences and consequences for Arctic climate feedbacks and decadal-scale climate variations. These results will be used to assess the probability of abrupt climate changes on decadal time scales in the past and in the future. Arctic climate changes should exert strong impacts on Northern ecosystems and communities.
