The Magellan Plume

ELBIO D. PALMA; RICARDO P. MATANO

Salt Lake City

Congreso; Ocean Sciences Meeting 2012; 2012

American Geophysical Union

This presentation investigate, through numerical experiments, the dynamical mechanismscontrolling the development of the Magellan Plume, a low salinity tongue that covers large partof the Patagonian Shelf. The model results indicate that the spatial extent and vertical structureof the plume is largely shaped by the tides, both through tidal mixing and residual currents. Theinteraction of tides and winds reinforce the downstream and upstream buoyancy transports,the former is driven by tidally induced homogenization and wind-driven enhancement of thenorthward transport while the latter is associated with the strengthening of a southward coastalcurrent. Sensitivity experiments show that the downstream buoyancy transport decreases withincreasing wind intensity due to enhanced mixing, while the upstream transport is reinforcedby a stronger southward coastal current. Variations in the magnitude of the discharge modifiedthe downstream penetration and cross-shelf salinity gradients, both increasing with largerdischarges. Comparison with previous numerical studies over the shelf indicates that thedischarge generates a northeastward current in the middle shelf, a recirculation gyre south ofthe inlet and a region of weak currents father north