The CRYO-FImBack workshop - Atmospheric forcing and surface energy balance - impacts and feedbacks on the Arctic terrestrial cryosphere

Glaciers and permafrost are the two major components of the terrestrial cryosphere, which will be strongly affected by the changing climate system. A warming climate will change ground temperatures or the glacier mass balance, with important consequences, e.g. release of methane from thawing permafrost or increased global see level . Atmosphere processes pose a forcing on the energy balance of the terrestrial cryosphere. Within this framework the Cryo-FImBack workshop addresses three major topics which a re of ultimate importance to understand the interaction between atmosphere and ground processes of the cryosphere in the Arctic: - The forcing from the atmosphere to the ground or glacier surface, which governs the surface energy balance. - The impact of this forcing to ground thermal regime (permafrost) and glacier mass balance/dynamics - The feedback of these processes to the atmosphere Within these three areas we can identify major knowledge gaps, especially related to the lack of co-operative eff orts of the different scientific communities. One example is the scaling problem. Earth System Models (ESMs), upon which all predictions on the future climate are based, operate on coarse spatial grids with grid spacings of 50 to 300 km. An adequate repr esentation of topography and land surface properties is impossible on such scales, and in such models often not appropriate parameterised. Hence there is a scale issue between the atmospheric models and the models describing the land-based cryosphere. A major feedback process can be exemplified by thawing of organic-rich permafrost, which could lead to the release of large quantities of the greenhouse gases carbon dioxide and methane, which would contribute an additional global warming potential.