The Influence of Stratification on the Wind-Driven Cross-Shelf Circulation over the North Carolina Shelf

TLDR: In this paper, the presence or absence of stratification had a profound influence on the wind-driven, cross-shelf circulation over this shallow shelf, which was consistent with a two-dimensional upwelling/downwelling response.

Abstract: Wind-driven, cross-shelf circulation is studied using current observations spanning the 90 km wide North Carolina shelf. Most of the shelf is less than 40 m deep. Current measurements were made at five sites within 16 km of the coast from August through October or early December 1994 and at mid- and outer-shelf sites from February 1992 through February 1994. In both studies the water column was stratified in summer and often unstratified during fall and winter. The presence or absence of stratification had a profound influence on the wind-driven, cross-shelf circulation over this shallow shelf. When the water column was stratified, the wind-driven cross-shelf circulation was consistent with a two-dimensional upwelling/downwelling response. Over the mid and outer shelf, near-surface and near-bottom cross-shelf transports had similar magnitudes but opposite directions and were approximately equal to the Ekman transports associated with the alongshelf wind stress and bottom stress, respectively. Win...