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Ocean gyres driven by surface buoyancy forcing
  • Andrew McC. Hogg,
  • Bishakhdatta Gayen
Andrew McC. Hogg
Australian National University

Corresponding Author:andy.hogg@anu.edu.au

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Bishakhdatta Gayen
Australian National University
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Abstract

Midlatitude gyres in the ocean are large scale horizontal circulations that are intensified on the western boundary of the ocean, giving rise to currents such as the Gulf Stream. The physical mechanism underlying gyres is widely recognised to involve the curl of the wind stress, which injects potential vorticity into the upper ocean. However, model results have highlighted the role of surface buoyancy fluxes (principally heating and cooling of the ocean surface) in driving circulation and enhancing gyre variability. Here we present results from numerical simulations in the fully turbulent regime which show that gyre-like circulation can be driven by surface buoyancy fluxes alone. We explore this phenomenon through a combination of modelling and linear theory to highlight that the transport of ocean gyres depends upon surface buoyancy fluxes as well as wind stress. Thus, the strength of gyres may be influenced by surface warming in response to climate change.
28 Aug 2020Published in Geophysical Research Letters volume 47 issue 16. 10.1029/2020GL088539