Collaborative Research: Boundary Current Control of Upwelling in Southern Drake Passage: Whither Weddies?

California Institute Of Technology, Pasadena CA

Investigators

Abstract

Mesoscale processes (~ length scales of up to 100km) are an essential ingredient of the coupling between the waters of the Antarctic margins and the greater Southern Ocean, yet there is a paucity of observations at these space and time scales. The tip of the Antarctic Peninsula is a unique and dynamic environment, and it is of interest to understand how the interaction of large currents with local topographic features and the coupling between physical and biogeochemical processes lead to the transformation of low productivity Antarctic Surface Water (ASW) to high productivity ASW in this region, following admixture with Weddell Sea eddies. By combining high resolution in situ ocean glider observations with remotely-sensed properties of the surface flow, as well as long-term historical data sets, these investigators will infer long-term changes in the frontal structure and mixed layer dynamics of the ACC. The project involves monitoring the fronts in southern Drake Passage over a period of 15 weeks by deploying and piloting a pair of ocean gliders that will collect approximately 1000 profiles of temperature, salinity, dissolved oxygen, fluorescence and optical backscatter. Mesoscale variability in southern Drake Passage influences at least three aspects of Earth?s climate system: the Southern Ocean?s meridional overturning circulation (MOC), air-sea exchange of CO2 and the productivity of the Southern Ocean ecosystems. These processes are of importance to simulating Earth?s climate, and thus to society in general