The presence of large-scale Ekman pumping associated with the climatological wind stress curl is the textbook explanation for low biological activity in the subtropical gyres. Using an idealized, eddy-resolving model, it is shown that Eulerian-mean Ekman pumping may be opposed by an eddy-driven circulation, analogous to the way in which the atmospheric Ferrel cell and the Southern Ocean Deacon cell are opposed by eddy-driven circulations. Lagrangian particle tracking, potential vorticity fluxes, and depth–density streamfunctions are used to show that, in the model, the rectified effect of eddies acts to largely cancel the Eulerian-mean Ekman downwelling. To distinguish this effect from eddy compensation, it is proposed that the suppression of Eulerian-mean downwelling by eddies be called “eddy cancellation.”
History
Publication title
Journal of Physical Oceanography
Volume
46
Issue
10
Pagination
2995-3010
ISSN
0022-3670
Department/School
Institute for Marine and Antarctic Studies
Publisher
Amer Meteorological Soc
Place of publication
45 Beacon St, Boston, USA, Ma, 02108-3693
Rights statement
2016 American Meteorological Society. This article is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license, (https://creativecommons.org/licenses/by/4.0/)
Repository Status
Open
Socio-economic Objectives
Oceanic processes (excl. in the Antarctic and Southern Ocean)