Shelf/Deep-Ocean Frontal Interaction in the Southwestern Atlantic

Oregon State University, Corvallis OR

Investigators

Abstract

The South Atlantic basin hosts the largest chlorophyll-a blooms of the Southern Ocean, dominance likely associated with off-shelf flows of highly fertilized waters drawn from the southwestern continental shelf region. This project will investigate the extent to which these continental shelf outflows are controlled by the interactions of two distinct western boundary currents, the Brazil and Malvinas currents, with the shelf circulation. The numerical simulations with sub-mesoscale permitting resolution will generate the most detailed description of the circulation to date. This project will also advance the characterization of the southwestern Atlantic shelf circulation through the novel use of in situ and remote observations. The goal of this project is to characterize the shelf and deep-ocean exchanges in the southwestern Atlantic region. The project will test the hypothesize that the boundary currents regulate these exchanges by injecting deep ocean waters onto the northern and southern portions of the shelf and detraining shelf waters at the frontal system. The dynamical mechanisms connecting the shelf to the deep-ocean circulation will be identified. The dominant modes of variability of the coupled system will be characterized and the influence of these modes on the mass exchanges between the shelf and the deep ocean will be investigated. The analyses will include data produced by a suite of numerical experiments along with in-situ observations and satellite data to establish confidence in the model results. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.