|Model simulated sea surface temperature and surface velocity vectors for the the Amukta/Samalga pass region of the Aleutian Islands for a period from July 19th through August 5th 2009. For scale, surface velocity vectors are plotted every 6 km.|
High-resolution (2km) simulations reveal details of the complex circulation between the North Pacific ocean and the Bering Sea. Using an Eastern Bering Sea model that extends approximately 150 km south of the Aleutian Islands to just north of the Bering Straight, we explore the tidally modulated transport through Amukta and Samalga passes. Currents in excess of 2 m/s through the passes lead to intense mixing and promote the development of sharp fronts which are intermittently pulled in 10-20 km scale filaments into the passes. Anti-cyclonic circulation persists around the isles of the passes with an oscillation frequency generally associated with the M2 tidal cycle. However the influence of other tidal constituents is discernible as higher frequency motions are visible for several days towards the end of July. Over a spring/neap cycle the mixing fronts that develop both north and south of the passes press closer to each other, then spread farther apart.
Of particular interest is the influence that the intense mixing in this region has on the characteristics of the Aleutian North Slope current seen exiting the north east corner of the animation. This current continues on approximately 100 km toward the highly biologically productive Bering Sea Shelf, before turning north westward and becoming the Bering Slope Current.