Blanton, J.O. 1996. Reinforcement of gravitational circulation by
wind. In: D. G. Aubrey and C.T. Friedrichs (eds.),
Buoyancy Effects On Coastal and Estuarine Dynamics, Coastal and
Estuarine Studies, Volume 53, pp. 47-58. American Geophysical
Union. Washington, D.C.
Buoyancy inputs from riverine discharges form an estuarine-like frontal zone along coasts. The gravitational component of across-shelf circulation drives a near-surface flow seaward and a near-bottom flow shoreward. Using data from the southeastern U.S. continental shelf, the buoyancy field is examined under upwelling and downwelling favorable wind stress. Numerical simulations and field data show that prolonged upwelling-favorable winds reinforce the gravitational circulation by enhancing its offshore component. Larger-than-normal riverine discharges in 1993 showed that this reinforcement caused a lens of warm, low-salinity coastal water to become detached from the coastal front and be advected seaward. Reinforcement of this process enhances the loss of estuarine discharges from coastal areas. Climatological data show that this loss increases as the mean upwelling favorable wind stress for the year increases.