Subinertial Currents on the Southern Califoinia Shelf

Abstract

Abstract Subinertial currents on the southern California shelf are investigated using observations from a current meter array deployed near San Diego during the summer, fall and winter of 1978/79. This region is characterized by weak winds (order 1–2 m s−1) and thus other driving mechanisms for the subinertial currents may be important. A simplified depth-averaged longshore momentum equation consisting of a balance between current accelerations, the adjusted sea level (ASL) gradient and the wind and bottom stress is examined. The ASL gradient is estimated using sea level and atmospheric pressure observations separated by 350 km. A linear parameterization of the bottom stress is used with a drag coefficient of 5 × 10−4 m s−1. During fall and winter, the first-order balance of terms in the longshore momentum equation over the inner-shelf (15 m depth) is between the wind and bottom stress. Over the outer-shelf (60 m) the primary balance is between the ASL gradient and the bottom stress. At midshelf (30 m) bo...