Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
The Impact of Wind Stress Feedback on the Stability of the Atlantic Meridional Overturning Circulation
 

Summary: The Impact of Wind Stress Feedback on the Stability of the Atlantic Meridional
Overturning Circulation
OLIVIER ARZEL AND MATTHEW H. ENGLAND
Climate Change Research Centre, University of New South Wales, New South Wales, Sydney, Australia
OLEG A. SAENKO
Canadian Centre for Climate Modelling and Analysis, Environment Canada, Victoria, British Columbia, Canada
(Manuscript received 13 March 2009, in final form 30 April 2010)
ABSTRACT
Recent results based on models using prescribed surface wind stress forcing have suggested that the net
freshwater transport S by the Atlantic meridional overturning circulation (MOC) into the Atlantic basin is
a good indicator of the multiple-equilibria regime. By means of a coupled climate model of intermediate
complexity, this study shows that this scalar S cannot capture the connection between the properties of the
steady state and the impact of the wind stress feedback on the evolution of perturbations. This implies that,
when interpreting the observed value of S, the position of the present-day climate is systematically biased
toward the multiple-equilibria regime. The results show, however, that the stabilizing influence of the wind
stress feedback on the MOC is restricted to a narrow window of freshwater fluxes, located in the vicinity of the
state characterized by a zero freshwater flux divergence over the Atlantic basin. If the position of the present-
day climate is farther away from this state, then wind stress feedbacks are unable to exert a persistent effect on
the modern MOC. This is because the stabilizing influence of the shallow reverse cell situated south of the
equator during the off state rapidly dominates over the destabilizing influence of the wind stress feedback

  

Source: Arzel, Olivier - Climate Change Research Centre, University of New South Wales
England, Matthew - Climate Change Research Centre & School of Mathematics and Statistics, University of New South Wales

 

Collections: Environmental Sciences and Ecology; Geosciences