This project will generate potential vorticity fields from the Agulhas South-Atlantic. The investigators will use the potential vorticity fields to model the dynamical behavior of mesoscale eddies and counter-rotating eddy fields to explore the leakage from the Agulhas Retroflection (transport and mixing of Indian Ocean water into the South Atlantic) and the coupling between the upper and deep ocean. Theoretical models of coupled upper-lower layer dipoles, including asymmetries from different layer depths and vortex sizes/ strengths will also be developed. From disturbed forms of these solutions and from numerical solutions, wave dispersion associated with mesoscale dipoles will be quantified. The significance of study is developing new understanding of the strength of the coupling between the upper and deep ocean due to lateral and vertical eddy-eddy interactions of cyclonic and anticyclonic eddies in the South Atlantic. These eddies can contribute significantly to the ventilation of the thermocline.
Broader Impacts This work will investigate mesoscale dipolar structures of cyclonic and anticyclonic eddies, using a combination of in situ and satellite data, together with numerical and analytical models. The investigators will contribute quantitative results to ocean-climate studies on Rossby waves versus mesoscale eddies and gain a better understanding of how mesoscale eddy processes in the South Atlantic Ocean aid in the thermocline ventilation process. In addition, this work will provide post doctoral training to a scientist from an under-represented ethnic group in oceanography who will gain new skills and additional training in geophysical fluid dynamics by modeling ocean vortices. Some of the training will include theoretical work on vortices, tracer transport simulations, and numerical data assimilation of in situ inverted echo sounder data and satellite altimeter data.
