Premium
Sensitivity of the Southern Ocean overturning circulation to surface buoyancy forcing
Author(s) -
Morrison Adele K.,
Hogg Andrew M.,
Ward Marshall L.
Publication year - 2011
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 - 10.1029/2011gl048031
Subject(s) - forcing (mathematics) , buoyancy , geology , climatology , circulation (fluid dynamics) , sensitivity (control systems) , thermohaline circulation , shutdown of thermohaline circulation , ocean current , oceanography , environmental science , north atlantic deep water , mechanics , physics , electronic engineering , engineering
The sensitivity of the Southern Ocean overturning to altered surface buoyancy forcing is investigated in a series of eddy‐permitting, idealised simulations. The modelled response indicates that heat and freshwater fluxes in the Southern Hemisphere mid‐latitudes may play a significant role in setting the strength of the overturning circulation. Enhanced buoyancy fluxes act to increase the meridional overturning up to a limit approaching the wind‐driven Ekman transport. The sensitivity of the overturning to surface buoyancy forcing is strongly dependent on the relative locations of the wind stress profile, buoyancy forcing and upwelling region. The numerical simulations provide support for the hypothesis that changes in upwelling during deglaciations may have been driven by changes in heat and freshwater fluxes, instead of, or in addition to, changes in wind stress.