Baroclinic Control of Southern Ocean Eddy Upwelling Near Topography
In the Southern Ocean, mesoscale eddies contribute to the upwelling of deep waters along sloping isopycnals, helping to close the upper branch of the meridional overturning circulation. Eddy energy (EE) is not uniformly distributed along the Antarctic Circumpolar Current (ACC). Instead, “hotspots” of EE that are associated with enhanced eddy-induced upwelling exist downstream of topographic features. This study shows that, in idealized eddy-resolved simulations, a topographic feature in the ACC path can enhance and localize eddy-induced upwelling. However, the upwelling systematically occurs in regions where eddies grow through baroclinic instability, rather than in regions where EE is large. Across a range of parameters, along-stream eddy growth rate is a more reliable indicator of eddy upwelling than traditional parameterizations such as eddy kinetic energy, eddy potential energy, or isopycnal slope. Ocean eddy parameterizations should consider metrics specific to the growth of baroclinic instability to accurately model eddy upwelling near topography.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE; Australian Research Council; National Science and Engineering Research Council of Canada; UNSW Silverstar Research; Australian Commonwealth Government.
- Grant/Contract Number:
- 89233218CNA000001; DE120102927; 22R23085
- OSTI ID:
- 1866942
- Report Number(s):
- LA-UR-18-30922
- Journal Information:
- Geophysical Research Letters, Vol. 49, Issue 7; ISSN 0094-8276
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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