Surface water subduction during a downwelling event in a semienclosed bay

摘要: The Ria de Vigo is a bay strongly influenced by upwelling-downwelling cycles along the adjacent coast of NW Iberia. Moored and ship-board observations during September 2006 showed that subduction, initially associated with an estuarine circulation, strengthened when strong downwelling resulting from northward wind over coastal ocean, was generated in outer ria causing ambient waters to be advected outward lower layer. Incoming surface confined circulation shallow interior displaced isopleths downward through water column at ∼10 m d−1. As retreated inward, flow convergence developed between middle inner layer above 15 m, while divergence beneath. increased period downwelling-favorable rate consistent observed isopleth displacement velocities. coefficient turbulent diffusion Kt, microstructure profiler, indicated mixing subsequently zone, where localized instabilities temperature-salinity inversions were observed. During downwelling, concentrations phytoplankton, including potentially harmful species, increased, especially ria, as result inward advection, subduction ability dinoflagellates maintain their position swimming. In course 5 day event, mass all but innermost flushed completely replaced originating coastally-trapped poleward Atlantic coastline. This article protected copyright. All rights reserved.