Barotropic response to cooling
Citable URI
https://hdl.handle.net/1912/10242DOI
10.1575/1912/10242Keyword
Cooling; Ocean circulationAbstract
Imposed horizontal density differences in a nonrotating fluid generate vertical circulation which has
vanishing vertically integrated transports. When the system is rotating, geostrophic velocities can balance
the density differences and the vertically integrated transports need not vanish locally. In a two-layer
fluid, fin ite amplitude disturbances lead to barotropic flows that have the same direction as the velocity in
the layer that thickens as a result of the disturbance. Specific calculations are carried out for the geostrophic
adjustment model in situations that approximate those in which 18° water is formed south of the
Gulf Stream. The upper layer transport that results from sudden cooling (as simulated by density differences
that are initially unbalanced geostrophically) is in the same direction as the Gulf Stream transport
and comparable to it in magnitude. A lower level transport of the same magnitude flows in the opposite
direction with a maximum value about an internal radius of deformation to the right of that of the upper
layer. The barotropic transport is about 1/ 5 as large and flows downstream in the Gulf Stream and upstream
to the right of the Gulf Stream.
Description
Also published as: Journal of Geophysical Research 85 (1980): 6661-6666