Premium
Ocean Gyres Driven by Surface Buoyancy Forcing
Author(s) -
Hogg Andrew McC.,
Gayen Bishakhdatta
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl088539
Subject(s) - ocean gyre , buoyancy , wind stress , ocean current , geology , forcing (mathematics) , boundary current , climatology , oceanography , potential vorticity , environmental science , vorticity , atmospheric sciences , meteorology , vortex , mechanics , geography , physics , subtropics , fishery , biology
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 recognized 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 two numerical simulations—one in the fully turbulent regime and the second an eddy‐permitting ocean model—which show that gyre‐like circulation can be driven by surface buoyancy fluxes alone. We explore this phenomenon through a combination of modeling and linear theory to highlight that the transport of ocean gyres depends upon surface buoyancy fluxes as well as wind stress.