Extended Measurements in Bering Strait and the Variable Outflow from the Chukchi Shelf to the Arctic Ocean and an Extended Analysis of Time Series and Hydrographic Data with Reference to Shelf-Basin Interactions.

摘要

LONG-TERM GOALS. Our long-term research goals are to understand the circulation and physical properties of the high latitude ocean, both quantitatively and mechanistically. We also seek to understand the effects of physical processes in the ocean on the ice cover, biology, and chemistry of the marine environment. The variability of that environment is a special focus and concern. OBJECTIVES. Our three major objectives are closely related, reflecting the three grants on which we are reporting. Our first objective is to extend direct measurements of velocity, temperature, and salinity in Bering Strait, supplemented by time series measurements of ice-thickness and of in situ nutrients and related optical properties using upward-looking sonars, nutrient analyzers, and other sensors. This upstream information is vital to the Shelf-Basin Interaction (SBI) initiative, since the influx of Pacific waters provides a key forcing for the western Arctic shelf-slope-basin system, including its biogeochemistry. A particularly important dynamical aspect of the Pacific water presence in the Arctic Ocean is its contribution to stabilizing the upper ocean, thereby influencing heat flux and ice thickness. Our second objective is to make moored measurements of velocity, temperature, salinity, and ice drift in the northern Chukchi Sea during 2002-2004 in support of SBI Phase 2. These time series are being supplemented by hydrographic sections. Our focus is on the transformation and outflow from the shelf of Pacific waters that have entered through Bering Strait, and also on providing a context in which both the SBI process studies and the downstream Beaufort moored measurements can be embedded.