Marine Science Faculty Publications

Document Type

Article

Publication Date

1-1991

Digital Object Identifier (DOI)

https://doi.org/10.1175/1520-0485(1991)021<0068:OTACOE>2.0.CO;2

Abstract

The annual cycle of the upper ocean's vertical velocity component (w) on the equator at 28°W is examined by integrating the continuity equation using current meter data from the Seasonal Response of the Equatorial Atlantic Experiment. The annual cycle consists in part of an intense, but brief (∼1 month), upwelling season beginning with the onset of strong easterly wind stress in boreal spring. This upwelling is followed by weaker downwelling during the summer despite the persistence of strong easterly wind stress. The record-length averaged w profile shows that maximum upwelling (0.6 x 10-3cm s-1) is located slightly above the core of the Equatorial Undercurrent and downwelling is located below the base of the thermocline. The standard deviations are about tenfold the magnitude of the means. Independent evidence supporting these results are that 1) sea surface temperature (SST) is related to w during the springtime changes in easterly wind stress with the observed and computed isotherm displacements in agreement, 2) temperature and w are coherent and in quadrature within the thermocline over a broad range of frequencies exclusive of the instability wave band, 3) during the instability wave season, upwelling is associated with increasing SST and the vertical Reynolds' heat flux is maximum and divergent in the thermocline, and 4) after the instability waves abate, w and easterly wind stress are coherent and out-of-phase. The observed evolution of w differs from that implied by climatology, and these differences are attributed to the ocean's response to rapidly varying winds that are observed in-situ versus slowly varying winds characteristic of climatology.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Journal of Physical Oceanography, v. 21, issue 1, p. 68-82

© Copyright 1991 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. All AMS journals and monograph publications are registered with the Copyright Clearance Center (http://www.copyright.com). Questions about permission to use materials for which AMS holds the copyright can also be directed to permissions@ametsoc.org. Additional details are provided in the AMS Copyright Policy statement, available on the AMS website (http://www.ametsoc.org/CopyrightInformation).

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