Flow-topography interactions in the northern California Current System observed from geostationary satellite data

Data from Geostationary Operational Environmental Satellites are used to study the seasonal evolution of temperature fronts in the northern California Current System (CCS), focusing on the interactions with topographic features. Fronts first appear close to the coast in response to upwelling winds, moving offshore with the continuous input of energy to the system. Late in the upwelling season (after July), the upwelling front is persistently found over deeper waters south of Heceta Bank, Oregon, than north of it, suggesting that the equatorward jet separates from the shelf at Heceta Bank. Inshore of the upwelling front, weak gradients are found on the Bank. The interaction of the equatorward flow with Heceta Bank and Cape Blanco, Oregon, farther south, substantially increases the mesoscale activity and oceanic frontal habitat downstream to the south in the CCS, where fronts are persistently found greater than 100 km from the coast.