Atmosphere Ocean Science Colloquium
A Three-Dimensional Analysis of the Southern Ocean Residual Circulation
Speaker: Madeleine Youngs, NYU
Date: Wednesday, September 30, 2020, 3:30 p.m.
The Southern Ocean has a major role in the global air-sea carbon fluxes, with some estimates suggesting it takes up 40% of anthropogenic carbon dioxide. Understanding the Southern Ocean residual overturning is particularly important because it fluxes tracers between the depth and the surface. The Southern Ocean is faced with a changing climate and changing winds, but there is little theory to describe how the residual overturning in a Southern Ocean-like channel will respond to changes in wind when there is a blocking ridge, or how the existence of the ridge changes the circulation. This study uses a re-entrant MITgcm channel to examine how residual overturning, generated by appropriate relaxation boundary conditions, varies with the wind. An analysis of the three-dimensional residual circulation highlights the localized nature of this transport and the non-linear response of the circulation to changes in wind. The localization of the vertical flow shows the necessity of highly focused observations in the Southern Ocean to understand the transport.