Monthly climatology of the continental shelf waters of the South Atlantic Bight

Abstract

Monthly circulation of the South Atlantic Bight is diagnosed using a 3‐D, shallow water, finite element model forced with monthly wind stress and hydrographic climatology. Temperature and salinity observations from the period 1950–1999 are objectively interpolated onto the model domain, and Comprehensive Ocean‐Atmosphere Data Set (COADS) wind velocities from 1975–1999 are used to prescribe the model surface wind stress. The resulting monthly temperature and salinity fields compare favorably to existing shelf climatology. River discharge maxima are evident in the spring temperature and salinity fields, and the rapid heating and cooling of the shelf are captured. The diagnostic circulation is largely wind‐driven in the inner and mid‐shelf, and the Gulf Stream is apparent in the solutions on the outer shelf. We present the monthly fields, including the temporal and spatial distribution of available hydrographic data, the regional COADS data that provide surface wind stress forcing, the objective analysis, and the model response to these forcings. The hydrographic and velocity fields provide best‐prior‐estimates of the circulation for data assimilation studies in the region, as well as initial conditions for process‐oriented prognostic model studies in the Georgia coastal region.