|Author(s)||Sévellec Florian1, Naveira Garabato A. C.2, Huck Thierry|
|Affiliation(s)||1 : Laboratoire d'Océanographie Physique et Spatiale, Univ-Brest CNRS IRD Ifremer, Brest, France
2 : Ocean and Earth Science, University of Southampton, Southampton, UK
|Source||Journal Of Physical Oceanography (0022-3670) (American Meteorological Society), 2021-01 , Vol. 51 , N. 2 , P. 491-503|
|Note||This article is included in the The Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) Special Collection.|
|Keyword(s)||Ocean, Southern Ocean, Eddies, Large-scale motions, Nonlinear dynamics, In situ oceanic observations|
The impact of mesoscale eddy turbulence on long-term, climatic variability in the ocean's buoyancy structure is investigated using observations from a mooring deployed in the Drake Passage, Southern Ocean. By applying the Temporal-Residual-Mean framework and characterizing the variance contributors and the buoyancy variance budget, we identify the main source and sink of long-term buoyancy variance. Long-term buoyancy variance amplitude is set by long-term vertical velocity fluctuations acting on the steady stratification. This baro-clinic buoyancy flux is also the main source of the variance, indicative of the effect of large-scale baroclinic instability. This source is balanced by a sink of long-term buoyancy variance associated with the vertical advection of the steady stratification by the eddy-induced circulation. We conclude that mesoscale eddy turbulence acts as a damping mechanism for long-term, climatic variability in the region of the observations, consistent with an ‘eddy saturated’ behaviour of the Antarctic Circumpolar Current.
Sévellec Florian, Naveira Garabato A. C., Huck Thierry (2021). Damping of climate-scale oceanic variability by mesoscale eddy turbulence. Journal Of Physical Oceanography, 51(2), 491-503. Publisher's official version : https://doi.org/10.1175/JPO-D-20-0141.1 , Open Access version : https://archimer.ifremer.fr/doc/00658/77057/