Eddy Cancellation of the Ekman Cell in Subtropical Gyres

Date

2016

Authors

Doddridge, Edward W.
Marshall, David P.
Hogg, Andrew

Journal Title

Journal ISSN

Volume Title

Publisher

American Meteorological Society

Abstract

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.”

Description

Keywords

Citation

Source

Journal of Physical Oceanography

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

DOI

10.1175/JPO-D-16-0097.1

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