Diapycnal Fluxes due to Mixed Layer Processes in the Southern Ocean

University Of Massachusetts, Dartmouth, North Dartmouth MA

Investigators

Abstract

0136546/Tandon This project will compute the diapycnal fluxes due to surface mixed-layer processes in the Southern Ocean. The resulting fluxes are important inputs needed for such applications as the estimation of the three-dimensional circulation of the Southern ocean using inverse box models and hydrographic data. The approach that will be used is to force a mixed-layer model with surface flux fields with high temporal resolution, obtained from meteorological analysis products. This model will be used to determine mixed-layer buoyancy, depth and entrainment rates. These properties, when combined with buoyancy gradients determined from hydrographic data, can be used to determine the diapycnal flux across the base of the mixed layer associated with deepening and small-scale mixing. The diapycnal flux associated with stirring by mesoscale eddies will also be estimated and a net diapycnal flux determined. At present, there is significant uncertainty about the size of upper-ocean diapycnal fluxes in the Southern Ocean. It is anticipated that more robust estimates of these fluxes and their variability will enable investigators to gain a much clearer picture of the lateral and overturning circulation in the Southern Ocean from data collected during the World Ocean Circulation Experiment.