| Summary: | The Bering Strait throughflow is critical for the Chukchi Sea and the upper Arctic Ocean. It is important in the global freshwater cycle and influences the Atlantic overturning circulation and possibly world climate. The throughflow variability (seasonal and interannual) impacts the role of Pacific waters in the Arctic, especially the ventilation depth. The water properties provide valuable boundary information for Arctic and global studies, including realistic modeling of the Chukchi Sea and Arctic Ocean. The Bering Strait is divided into two channels, both with differing water properties. Although year-round moorings have been deployed in the Bering Strait region since 1990, very few simultaneous measurements of both channels exist, since the western channel (which carries the colder, saltier, higher nutrient water) lies within the Russian Exclusive Economic Zone (EEZ). At the start of this grant, there were only three years of records from the western channel. To counter this lack of data, a mooring site had been established north of the strait, where the sea-floor topography diverts the western channel flow into the U.S.-EEZ for a short distance. The hypothesis is that this mooring captures a useful average of the flow through both channels of the strait. However, prior to this grant, only one year of insitu data was available for comparison. In early 2005, it became clear that in summer 2005, a continuation of a joint National Oceanic and Atmospheric Administration (NOAA) -Russian program would deploy three moorings in the western (Russian) channel, giving the best-ever coverage of the western channel. Unfortunately, at that time U.S. measurements in the Bering Strait were set to conclude in 2005 and there was no funded plan for continued measurements in the eastern (U.S.) channel. This motivated the request for a Small Grants for Exploratory Research (SGER) grant in order to seize this rare opportunity to compare the water properties of the two channels of the strait and to quantify the usefulness of the northern site as an integrator of Bering Strait properties. This work will improve past estimates of the Bering Strait fluxes and allow a continued measurement of the Bering Strait throughflow properties. These are important contributions to national and international programs, including Study of Environmental Arctic Change (SEARCH), Arctic and Subarctic Ocean Fluxes (ASOF) and Freshwater Initiative (FWI), and to many projects in the Bering and Chukchi seas, Arctic Ocean studies and global modeling efforts. Furthermore, the work will also foster U.S.-Russian and National Science Foundation (NSF) - National Oceanic and Atmospheric Administration (NOAA) collaborations.
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