The California Current system in the Southern California Bight and the Santa Barbara channel

Recent observations in the Santa Barbara Channel and over the California Co operative Oceanic Fisheries Investigations (CalCOFI) southern California gr id are used to examine seasonal circulation patterns in and near the Southe rn California Eight, defined as the region east of the Santa Rosa Ridge and including the Santa Barbara Channel. Poleward flow relative to 500 m is fo und throughout the bight, in all seasons except for spring and all subregio ns except the western part of the Santa Barbara Channel. In spring there is equatorward flow throughout the bight at all depths to 500 m, though it te nds to be surface or midcolumn intensified. Equatorward flow offshore of th e bight, present in all seasons, narrows and accelerates into a jet-like fe ature and simultaneously moves close to the Santa Rosa Ridge in summer. Cur rent meter data from the eastern entrance to the Santa Barbara Channel are consistent with the seasonal results from the CalCOFI data and further show an upward propagation of phase at annual period, with a phase speed of 1 t o 2 m d(-1). Comparison with the CalCOFI ship winds suggests that poleward flow in the bight may be the result of positive wind stress curl, through a Sverdrup balance, though the observed transport is only about 75% of that expected from the curl amplitude. Equatorward flow in the bight may be the result of coastal upwelling, though the transport is larger than expected f rom the relatively weak winds in the bight, and the offshore extent of the equatorward flow is about 10 Rossby radii, farther than might be expected f or linearized coastal upwelling. Equatorward flow outside the bight cannot be explained as a Sverdrup flow because the wind stress curl is positive th roughout mast of the region. Upward propagation of phase and downward propa gation of energy may be indicative of forcing by remote wind equatorward of the bight. Given the complexity of possible forcing mechanisms for circula tion in and near the bight, a model that includes effects of remote wind fo rcing, Ekman pumping, and topography is needed to explain the observations in a satisfactory way.