Research supported by this grant is under the auspices of the Arctic Systems Science (ARCSS) Global Change Research Program and is jointly sponsored by the Division of Ocean Sciences and the Office of Polar Programs. Work to be performed represents preliminary steps towards a major 5-year research project named SHEBA, which is envisioned to study the heat budget of the Arctic Ocean and its impact on global change. The primary goals of SHEBA are: (1) to develop, test and implement models of arctic ocean-atmosphere-ice processes that demonstrably improve simulations of the present day arctic climate, including its variability, using General Circulation Models (GCMs), and (2) to improve the interpretation of satellite remote sensing data in the Arctic for analysis of the arctic climate system and provide reliable data for model input, model validation and climate monitoring. The investigator will use a model to simulate the effects of open leads in the pack ice and melt ponds on top of the ice to examine the factors that have the greatest effect on the heat transfer from the warm ocean to the cold atmosphere. This heat transfer from ocean to atmosphere is an important aspect of the overall Arctic heat budget and must be determined so that the response of sea ice to global climate change may be examined. Some global climate models predict an elimination of the arctic pack ice if global warming occurs and improvement of the proposed model simulations is necessary to increase the predictability of such an occurrence.