Jet-Topography Interactions: What Sets the Vertical Structure of Eddy Effects Around Topography?

Alice Barthel, University of New South Wales, Climate Change Research Centre & ARC Centre of Excellence for Climate System Science, Sydney, NSW, Australia, Andrew M. Hogg, Research School of Earth Sciences & ARC Centre of Excellence for Climate System Science, Australian National University, Canberra, Australia and Stephanie Waterman, University of New South Wales, Climate Change Research Centre & ARC Centre of Excellence for Climate System Science, Sydney, Australia; University of British Columbia, Earth, Ocean and Atmospheric Sciences, Vancouver, BC, Canada
Abstract:
In the Southern Ocean, strong eastward flows interact with large topographic features, generating localized regions of high eddy activity. The resulting eddies play an important role in the circulation, contributing both to the mean Southern Ocean stratification, and to the meridional fluxes of tracers such as heat and nutrients.

We report on a study that investigates how the structure of the flow impinging on topography sets the vertical distribution of the eddy effects that result from jet-topography interactions. We use an ocean model with an imposed unstable jet encountering a topographic obstacle, in a configuration relevant to an Antarctic Circumpolar Current frontal jet. We investigate the spatial structure of eddy energy terms and eddy fluxes, and their sensitivity to changes in forcing.

This study focuses on improving our understanding of the processes which set the vertical distribution of eddy effects near topography. The results have implications for how eddy feedbacks on the mean flow might respond to future changes in Southern Ocean circulation.

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