Effect of sea surface temperature-wind stress coupling on baroclinic instability in the ocean
Spall, Michael A.
MetadataShow full item record
The impact of the observed relationship between sea surface temperature and surface wind stress on baroclinic instability in the ocean is explored using linear theory and a nonlinear model. A simple parameterization of the influence of sea surface temperature on wind stress is used to derive a surface boundary condition for the vertical velocity at the base of the oceanic Ekman layer. This boundary condition is applied to the classic linear, quasigeostrophic stability problem for a uniformly sheared flow originally studied by Eady in the 1940s. The results demonstrate that for a wind directed from warm water toward cold water, the coupling acts to enhance the growth rate, and increase the wavelength, of the most unstable wave. Winds in the opposite sense reduce the growth rate and decrease the wavelength of the most unstable wave. For representative coupling strengths, the change in growth rate can be as large as ±O(50%). This effect is largest for shallow, strongly stratified, low-latitude flows.
Author Posting. © American Meteorological Society, 2007. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 37 (2007): 1092–1097, doi:10.1175/JPO3045.1.
Showing items related by title, author, creator and subject.
Spall, Michael A. (American Meteorological Society, 2007-08-01)The influences of strong gradients in sea surface temperature on near-surface cross-front winds are explored in a series of idealized numerical modeling experiments. The atmospheric model is the Naval Research Laboratory ...
Arbic, Brian K. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-08)The plausibility of local baroclinic instability as a generation mechanism for midocean mesoscale eddies is examined with a two-layer, quasi-geostrophic (QG) model forced by an imposed, horizontally homogeneous, vertically ...
Stern, Melvin E.; Mellor, Florence K. (Woods Hole Oceanographic Institution, 1983-11)"Baroclinic instability as the largest scale of motion participating in the cross frontal oceanic transport process" was the theme of the 25th summer program at G.F.D. Killworth (Cambridge University) reviewed ...