Proposal Summary

We propose a comprehensive study of Aleutian Passes circulation, emphasizing physical processes controlling the ecosystem in the southern Bering Sea (BS). To reconstruct realistic oceanic conditions and to quantify the variability of the transports through the Aleutian passes we will synthesize the information from a variety of historical and contemporary data with the dynamical constraints of a primitive equation numerical model by the four-dimensional variational data assimilation technique. During the first step of the study we will investigate the influence of the local tides on the exchange of the properties through the Aleutian Passes and on the large-scale currents in the southern BS. Then we will proceed to reconstruction of the southern BS circulation during 2002-2008. We believe that combining historical and contemporary hydrographic data with drifter and current meter records and with satellite altimetry observations will allow us to derive a realistic circulation pattern and to analyze a wide spectrum of local variability. Finally, based on the obtained circulation, we will estimate silicate transports into the BS by assimilating silicate data into the passive tracer model. The developed data assimilation algorithms will provide the oceanographic community with efficient research tools, which can be used during the incoming Bering Ecosystem Study (BEST), International Polar Year (IPY), and other research programs.

1-2 years results:    Hydrophysical Atlas of the Bering Sea    New MDOT and SSH for the Bering Sea    Optimization of ARGO drifter observation    Optimization of velocity observations    Tides in the Aleutain Arc    Hydrochemical Atlas of the Bering Sea    ROMS    Aleutian Arc Transports    Seals T/S data