ABSRTACT A combined program of field measurements and modeling of the Artic snow cover is proposed as an addition to the Land/ Atmosphere/ Ice/ Interactions (LAII) component of the Artic System Science Program. The objective of the proposed program is to understand the role of the Artic snow cover in governing the winter heat and mass exchange between the ground and atmosphere. The justification for studying the Artic snow cover is that it is one of the dominant features of the Artic system and needs to be accurately incorporated in an Artic system model. Studies have shown that long-term changes in the depth and thermal properties of the snow that could accompany a change in climate would affect plants under the snow and the temperature. Furthermore, thawing of carbon- rich permafrost may release CO2 to the atmosphere, providing a strong feedback mechanism for local and global warming. Predicting how the Artic will respond to changing climate will require understanding the role of the winter snow cover. The core of the proposed program is a series of over-snow traverses during which extensive measurements of the physical and thermal properties of the snow will be made. Traverse measurements, along with knowledge of the physical process that affect the Artic snow cover, will be used to develop an Artic snow distribution model. The validated snow distribution model can be incorporated in both climate and surface process models being developed under other LAII projects.
