9701831 Morison Stanton 9701391 Martinson 9701383 McPhee 9701558 This research project is a key component of a large, coordinated, multi-investigator program called SHEBA (Surface Heat Budget of the Arctic) Ocean. The SHEBA program will simultaneously measure, over an annual cycle, the various fluxes and properties of the atmosphere, ice pack, and upper ocean that determine the aggregate mass and energy budgets of Arctic sea ice. Its goal is improved understanding of how and to what extent, the ice covered Arctic Ocean affects climate variability in lower latitudes and in global climate models (GCMs). Towards that goal, two potentially important radiation/climate feedback processes have been singled out for study: Ice-Albedo Feedback and Cloud-Radiation Feedback. Work sponsored here is directed toward understanding the impact of the upper ocean on aggregate ice-albedo feedback via the ice mass and heat budgets. The ocean component of the program will provide (1) continuous time series of upper ocean state properties and turbulent fluxes at the main SHEBA station, supplemented by remote buoy measurements; and (2) measurements for determining the disposition of solar heating in summer leads. The research program will be conducted for 14 months from a ship frozen into the ice pack. The ocean measurements program makes an essential contribution to the SHEBA team of researchers who will measure atmospheric variables with a large array of instruments on the ice floe and aircraft flying above. The combined set of measurements in SHEBA will allow refinement of climate models for the Arctic region. Those improved models will lead to better predictions of the climate and the permanence of the Arctic ice cap under a proposed global warming that could occur if atmospheric carbon dioxide levels are increased above present levels.