A numerical study of barotropicly forced intrusion in DeSoto Canyon

Abstract

The intrusion of open ocean water across the head of DeSoto Canyon offshore of Pensacola, Florida, is investigated using a version of the Bryan‐Cox model of the entire Gulf of Mexico. The Loop Current‐forced model circulation in DeSoto Canyon features an eastward, nearly along‐isobath, current with a weak cross‐isobath velocity component. In contrast, the southward wind‐driven currents over the west Florida shelf in response to northerly winds induce strong cross‐isobath flow at the head of DeSoto Canyon. The flow is diagnosed to be the bottom Ekman flow associated with the strong along‐isobath currents. In addition, transient responses of sea levels to the northerly wind bursts give rise to pressure gradient‐forced currents up the canyon during the collapse phase of the winds. A case study in November 1997 is conducted, and the above arguments are substantiated with the simulated and the observed currents.