HR: 0800h
AN: OS51A-06    [Abstracts]
TI: Inner Shelf Circulation Patterns Under Downwelling and Stratified Conditions off a Curved Coastline
AU: * Sanay, R
EM: rsanay@geol.sc.edu
AF: Marine Science Program Department of Geological Sciences University of South Carolina , 706 Sumter ST., Columbia, SC 29208, United States
AU: Yankovsky, A
EM: ayankovsky @geol.sc.edu
AF: Marine Science Program Department of Geological Sciences University of South Carolina , 706 Sumter ST., Columbia, SC 29208, United States
AU: Voulgaris, G
EM: gvoulgaris@geol.sc.edu
AF: Marine Science Program Department of Geological Sciences University of South Carolina , 706 Sumter ST., Columbia, SC 29208, United States
AB: Recent observations in Long Bay, SC (USA), a typical shelf environment with a curved coastline bounded by capes, showed the existence of a countercurrent near the shore during downwelling favorable wind. Motivated by this, a 3D numerical study (using ROMS) was carried out to investigate downwelling circulation patterns that develop on a stratified shelf with a curved coastline. Numerous numerical experiments were carried out using an ideal domain for stationary or variable wind stress and various bottom friction settings. The results show that for all experiments the curved coastline leads to the generation of both a velocity and pycnocline disturbance at the upstream cape, which propagates in the downwind direction. This transient disturbance is more pronounced under non-stationary forcing and is best developed after the wind stress peaks. The propagation path differs depending on the relative strength of inertia and bottom friction in the vicinity of the capes. When inertia dominates, the disturbance detaches from the cape and travels downwind along the isobaths. In this case, a strong countercurrent develops near the shore. When friction is more important than inertia, the disturbance propagates at a lower speed and is located close to the shore (i.e., coastline-arrested disturbance). This results to a significant alongshore temperature gradient and the formation of an almost shore- perpendicular thermal front that moves with the disturbance. The numerical results appear to agree with the observations in Long Bay and with satellite imagery and emphasize the role that the coastline morphology can play a role in enhancing cross-shelf transport and exchange.
DE: 4217 Coastal processes
DE: 4255 Numerical modeling (0545, 0560)
DE: 4528 Fronts and jets
DE: 4534 Hydrodynamic modeling
DE: 4562 Topographic/bathymetric interactions
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly