Seasonal patterns of surface wind stress and heat flux over the Southern California Bight

Abstract

Patterns of wind stress and heat flux between the atmosphere and the ocean over the Southern California Bight are described based on observations from buoys and ships. During the winter, the wind stress is spatially homogeneous and temporally variable, with strong events corresponding to low‐pressure systems sweeping through the area. During the summer, spatial patterns are more persistent, with large gradients. Inshore of a line running approximately between Point Conception and Ensenada, Mexico, winds are weak. Offshore wind speeds are comparable in magnitude to those found over the continental shelf north of Point Conception. The boundary is the location of maximum wind stress curl, and the spatial resolution afforded by California Cooperative Fisheries Investigation (CalCOFI) observations suggests maximum wind stress curls over 3 times larger than the values proposed by Nelson [1977]. Net heat flux estimates derived from the CalCOFI measurements are somewhat larger than the values proposed by Nelson and Husby [1983], due to differences in latent heat flux estimates. Possible mechanisms responsible for the spring‐summer spatial structure in the wind and the relationship between these gradients and the properties of the underlying ocean are discussed.