Wind-Driven Circulation on a Shallow, Stratified Shelf
Abstract
Data from the Coastal Ocean Processes Inner Shelf Study are analyzed to determine atmospheric forcing characteristics and the heat balance of the inner shelf, and are used as motivation for a numerical study of inner shelf circulation during upwelling and downwelling. Variation in meteorological forcing on the North Carolina Inner shelf is dominated by synoptic weather systems. The structure of cold fronts and the local meteorological conditions they produce, result in a correlation between the surface heat flux and wind orientation. During weakly-stratified conditions the surface heat flux dominated variation in heat content. During stratified conditions, cross-shelf heat fluxes due to Ekman dynamics dominate variation in heat content of the inner shelf. The dominance of wind-driven cross-shelf transport motivated numerical studies of upwelling and downwelling. The feedback between mixing and stratification played a role in determining the strength of the circulation on the inner shelf. During upwelling, denser water is brought onto the lower half of the inner shelf, producing vertical stratification and enhancing the inner shelf circulation. During downwelling, circulation was weakened by the presence of stratification. These circulation patterns are discussed in the context of coastal observations, and the implications for cross-shelf transport and exchange processes are considered.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1998
- Accession Number
- ADA363569
Entities
People
- Jay A. Austin
Organizations
- Massachusetts Institute of Technology