Pressure Response in the Santa Barbara Channel and Santa Maria Basin

An eight-year time series of physical observations in the Santa Barbara Channel (SBC) and Santa Maria Basin (SMB) is used to explore the role of pressure gradients in the coastal circulation. Previous work has characterized the regional wind stress field and demonstrated that both wind stress and pressure gradients are important to regional circulation patterns. The relationship between the wind stress and pressure gradients and their roles in driving the coastal ciruculation in the SBC is investigated by quantifying correlations and lags between the two forcing mechanisms. Along the north coast of the SBC wind forcing is weak, and alongshore pressure gradients have been significantly correlated to alongshore flow in accordance with a model of simplified pressure-gradient driven flow. In contrast, the southern shelf of the SBC is exposed to stronger, more consistent winds which correlate with a model of simplified wind-driven flow. This work demonstrates the need for an operational Coastal Ocean Observing System to include observations from which pressure gradients can be estimated.