The upper-oceanic response to overflows: A mechanism for the Azores current

Shinichiro Kida, James F. Price, Jiayan Yang

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

The oceanic response to overflows is explored using a two-layer isopycnal model. Overflows enter the open ocean as dense gravity currents that flow along and down the continental slope. While descending the slope, overflows typically double their volume transport by entraining upper oceanic water. The upper oceanic layer must balance this loss of mass, and the resulting convergent flow produces significant vortex stretching. Overflows thus represent an intense and localized mass and vorticity forcing for the upper ocean. In this study, simulations show that the upper ocean responds to the overflow-induced forcing by establishing topographic β plumes that are aligned more or less along isobaths and that have a transport that is typically a few times larger than that of the overflows. For the topographic β plume driven by the Mediterranean overflow, the occurrence of eddies near Cape St. Vincent, Portugal, allows the topographic β plume to flow across isobaths. The modeled topographic β-plume circulation forms two transatlantic zonal jets that are analogous to the Azores Current and the Azores Countercurrent. In other cases (e.g., the Denmark Strait overflow), the same kind of circulation remains trapped along the western boundary and hence would not be readily detected.

Original languageEnglish
Pages (from-to)880-895
Number of pages16
JournalJournal of Physical Oceanography
Volume38
Issue number4
DOIs
Publication statusPublished - Apr 1 2008

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plume
upper ocean
isopycnal layer
volume transport
countercurrent
open ocean
continental slope
vorticity
vortex
strait
eddy
gravity
simulation
water

All Science Journal Classification (ASJC) codes

  • Oceanography

Cite this

The upper-oceanic response to overflows : A mechanism for the Azores current. / Kida, Shinichiro; Price, James F.; Yang, Jiayan.

In: Journal of Physical Oceanography, Vol. 38, No. 4, 01.04.2008, p. 880-895.

Research output: Contribution to journalArticle

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