Shelf Currents, Ice and Wind: A Numerical Modeling Study

Sarah Russell, Ph.D., 2003
W. Brechner Owens, Paola Rizzoli, Advisors

The effects of sea ice, downwelling favorable winds and barotropic background currents on shelf fronts are examined using numerical models.

The first part of the thesis uses a three dimensional, primitive equation model to examine the behavior of a shelf front under steady, along shelf winds and barotropic currents. The wind stress generates shoreward surface Ekman transport and the barotropic current generates an offshore bottom Ekman transport. In both cases, the Ekman transport causes the creation of mixed layers and a relationship describing the mixed layer thickness is derived relating the cross shelf flux of density to the along shelf flux of density.

The second part of the thesis focuses on the ice-ocean interaction using a simple, two layer, one dimensional toy model. In the presence of a current and the absence of wind, the ice is transported downstream with the current. In the presence of wind and the absence of a current, the net ice-ocean transport is perpendicular to the wind, as is expected for Ekman layer theory. The two layer system acts like a poorly resolved Ekman spiral: the ice has down wind and shoreward transport while the ocean has up wind and shoreward transport.