A collaborative research project will be undertaken by investiga- tors at the University of Washington and the University of Alaska as part of the Ocean-Atmosphere-Ice Interactions (OAII) component of the Arctic System Science (ARCSS) global change research program. The research objective is to measure the transport of water through the Bering Straits and to determine the influence of this transport on the physical properties and variability of the Arctic Ocean, and particularly the surface layer. These physical properties, such as ice cover and thickness, vertical mixing, and thermo-haline structure affect the extent of the Arctic ice pack. If changing climate conditions caused the ice pack to shrink or change significantly, the effect would be felt throughout the world's atmosphere and ocean. The influx of water through the Bering Strait is one of the major inputs to the Arctic Ocean, therefore its volume and physical properties must be known if one is to understand the processes that control the Arctic Ocean's physical features. Three coordinated projects will each deal with one or more aspects of the system, and together provide insight into the broader workings of the Arctic's physical and geochemical processes. Moorings will be deployed for a three-year period at key locations. They will provide concurrent time series of water column properties including temperature, sal- inity, currents and an upward looking sonar (ULS) will make a full year of ice thickness observations. A hydrographic program will also examine water column variability in the northeastern Chukchi Sea, where the low-salinity portion of the Pacific inflow drains into the Arctic Ocean. The work builds on earlier efforts funded by ONR and NSF that were conducted in cooperation with the physical and chemical oceanographic programs of NOAA/PMEL.