A beta-control of buoyancy-driven geostrophic flows

Abstract

Gill (1982) has recently reviewed the history of theoretical studies of small-amplitude stationary baroclinic planetary waves in the atmosphere induced by topography, surface friction and buoyancy forcing. Inasmuch as we are considering buoyancy forcing, Smagorinsky’s early (1953) study particularly comes to mind. In the subpolar gyres of the ocean, there is considerable buoyancy loss (Luyten et al., 1985) with accompanying deep convection and unlike the atmospheric counterpart the scale of the appropriate waves appears to be in the non-dispersive range. Moreover, the process may be driven toward finite amplitude control, thus restricting the possible structures of the zonal flow itself. It seems plausible that the horizontal spreading of the North Atlantic Drift and some features of front formation in it may be dynamically associated with the planetary flow pattern caused by the buoyancy loss.