Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

The Large-Scale Vorticity Balance of the Antarctic Continental Margin in a Fine-Resolution Global Simulation

TitleThe Large-Scale Vorticity Balance of the Antarctic Continental Margin in a Fine-Resolution Global Simulation
Publication TypeJournal Article
Year of Publication2020
JournalJournal of Physical Oceanography
Volume50
Number8
Pages2173-2188
Abstract / Summary

The depth-integrated vorticity budget of a global, eddy-permitting ocean/sea-ice simulation over the Antarctic Continental Margin (ACM) is diagnosed to understand the physical mehanisms implicated in meridional transport. The leading-order balance is between the torques due to lateral friction, nonlinear effects, and bottom vortex stretching, although details vary regionally. Maps of the time-averaged depth-integrated vorticity budget terms and time series of the spatially-averaged, depth-integrated vorticity budget terms reveal that the flow in the Amundsen, Bellingshausen and Weddell Seas and, to a lesser extent, in the western portion of East Antarctica, is closer to an approximate Topographic Sverdrup Balance (TSB) compared to other segments of the ACM. Correlation and coherence analyses further support these findings, and also show that inclusion of the vorticity tendency term in the response (the planetary vorticity advection and the bottom vortex stretching term) increases the correlation with the forcing (the vertical net stress curl), and also increases the coherence between forcing and response at high frequencies across the ACM, except for the West Antarctic Peninsula. These findings suggest that the surface-stress curl, imparted by the wind and the sea ice, has the potential to contribute to the meridional, approximately cross-slope, transport to a greater extent in the Amundsen, Bellingshausen, Weddell and part of the East Antarctic continental margin than elsewhere in the ACM.

URLhttp://dx.doi.org/10.1175/jpo-d-19-0307.1
DOI10.1175/jpo-d-19-0307.1
Journal: Journal of Physical Oceanography
Year of Publication: 2020
Volume: 50
Number: 8
Pages: 2173-2188
Publication Date: 08/2020

The depth-integrated vorticity budget of a global, eddy-permitting ocean/sea-ice simulation over the Antarctic Continental Margin (ACM) is diagnosed to understand the physical mehanisms implicated in meridional transport. The leading-order balance is between the torques due to lateral friction, nonlinear effects, and bottom vortex stretching, although details vary regionally. Maps of the time-averaged depth-integrated vorticity budget terms and time series of the spatially-averaged, depth-integrated vorticity budget terms reveal that the flow in the Amundsen, Bellingshausen and Weddell Seas and, to a lesser extent, in the western portion of East Antarctica, is closer to an approximate Topographic Sverdrup Balance (TSB) compared to other segments of the ACM. Correlation and coherence analyses further support these findings, and also show that inclusion of the vorticity tendency term in the response (the planetary vorticity advection and the bottom vortex stretching term) increases the correlation with the forcing (the vertical net stress curl), and also increases the coherence between forcing and response at high frequencies across the ACM, except for the West Antarctic Peninsula. These findings suggest that the surface-stress curl, imparted by the wind and the sea ice, has the potential to contribute to the meridional, approximately cross-slope, transport to a greater extent in the Amundsen, Bellingshausen, Weddell and part of the East Antarctic continental margin than elsewhere in the ACM.

DOI: 10.1175/jpo-d-19-0307.1
Citation:
Paloczy, A, J McClean, S Gille, and H Wang.  2020.  "The Large-Scale Vorticity Balance of the Antarctic Continental Margin in a Fine-Resolution Global Simulation."  Journal of Physical Oceanography 50(8): 2173-2188.  https://doi.org/10.1175/jpo-d-19-0307.1.