9320938 Curry This project is an integrated experimental and modeling effort to understand and interpret the evolution of sea ice characteristics, cloud properties, and radiation fluxes during the autumnal freezing of the coastal waters of the Beaufort Sea. It will carried out in the scientific context of the Beaufort and Arctic Seas Experiment (BASE), a Canadian program whose objective is an improved understanding of weather systems in the Canadian Arctic, and whose focus is the hydrologic balance of the Mackenzie River. This project will make use of the NCAR C-130 aircraft, and BASE will provide substantial synergistic observational facilities. The direct aircraft observations will be supplemented by satellite data to extend the time and space scales of the analyses, and will be used to interpret and validate satellite retrieval algorithms. A three-dimensional mesoscale model of the atmosphere will be used to interpret the temporal and spatial evolution of the sea ice cover and the atmospheric boundary layer characteristics. A coupled sea ice model will be used to interpret the physical processes of the sea ice that respond to atmospheric forcing. The result of the research will be an improved understanding of the atmospheric modulation of the surface radiation balance and the effect of the radiation balance on the freezing of coastal waters. ***