Analysis and Interpretation of Current Measurements from the Beaufort Sea.

The present view of ocean circulation in the Beaufort Sea is based principally upon dynamic heights and computed baroclinic, geostrophic currents. These computations show a vertical shear westward toward the surface. If a reference level of no motion is assumed at the bottom (or in fact any depth be...

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Bibliographic Details
Main Authors: Greisman,P, Blaskovich,A
Other Authors: DOBROCKY SEATECH LTD SIDNEY (BRITISH COLUMBIA)
Format: Text
Language:English
Published: 1984
Subjects:
Online Access:http://www.dtic.mil/docs/citations/ADA145197
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA145197
Description
Summary:The present view of ocean circulation in the Beaufort Sea is based principally upon dynamic heights and computed baroclinic, geostrophic currents. These computations show a vertical shear westward toward the surface. If a reference level of no motion is assumed at the bottom (or in fact any depth below 100 m), the results of these computations are in qualitative agreement with the observed westward ice drift in the southern Beaufort Sea. Recent measurements by Aagaard (in press) showed, however, that the flow on the continental shelf is eastward. The cross-slope array deployed by the USCG in 1981 was designed to locate the region where the eastward continental shelf flow vanishes and is replaced by the westward flow of the Beaufort gyre. The cross-slope array of instruments in fact demonstrated that there is no mean westward flow below 40 m depth and the Beaufort gyre is confined to the surface layers in this region. The deeper layers move eastward in the southern Beaufort, and the possibility exists that all deeper waters of the Beaufort gyre circulate in an anti-clockwise sense. Coherence spectra among various current meter records and meteorological forcings were computed. The coherence computations between a current meter record from the shelf break and a) the direct wind stress, b) the longshore gradient of the wind stress, and c) the curl of the wind stress, all show a high degree of coherence (above the 95% significant level), but none of these atmospheric driving forces appears to dominate. Large events in the current records in July appear uncorrelated with atmospheric processes.