Regional circulation of the Monterey Bay region-
the effects of Monterey Canyon

Yu-Heng Tseng

Johns Hopkins University

Abstract:

Ocean circulation off the west coast of the United States is driven by a variety of mechanisms, the most important of which are the seasonally varying local wind stress and coastal irregularities. Remote forcing is also important and expressed through the open boundary conditions; they include the effects of the Kuroshio Current. We use a non-hydrostatic, z-level DieCAST ocean model to simulate the regional circulation in the vicinity of Monterey Bay, California. Satellite images often show a cyclonic eddy in the bay and an anti-cyclonic eddy outside the bay during spring and summer. We compare the simulation results with observed mooring data and compare the simulated upwelling with the satellite images. The mean currents follow the annual cycle of the seasonal circulation. The coastal geometry plays an important role in the generation and movement of coastal eddies. We also study the effects of Monterey Submarine Canyon on the large scale coastal circulation. Quantitative comparisons between hydrostatic and non-hydrostatic models are made to investigate the importance of the non-hydrostatic effects in coastal ocean simulation. We also find that the deep Canyon contributes significantly to non-hydrostatic effects that cannot be ignored in coastal ocean modeling with complex topography.