Eddy Cancellation of the Ekman Cell in Subtropical Gyres
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 circ...
| Published in: | Journal of Physical Oceanography |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
American Meteorological Society
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1885/152330 https://doi.org/10.1175/JPO-D-16-0097.1 https://openresearch-repository.anu.edu.au/bitstream/1885/152330/5/01_Doddridge_Eddy_Cancellation_of_the_Ekman_2016.pdf.jpg |
| Summary: | 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.” |
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