Destabilization of the thermohaline circulation by atmospheric eddy transports
- Massachusetts Institute of Technology, Cambridge, MA (United States)
Simple process models have been developed to investigate the role of atmosphere-ocean feedbacks in the stability of the current mode of the thermohaline circulation in the North Atlantic. A positive feedback between the meridional atmospheric transport of moisture and the high-latitude sinking thermohaline circulation (EMT feedback) has been found to help destabilize the latter. The minimum perturbation required to shut off the high latitude sinking is considerably smaller when this feedback is included. Also, the high-latitude sinking is shut off much faster with this feedback than without it, given a perturbation of the same magnitude. There is also a strong positive feedback between atmospheric heat transport and the thermohaline circulation, but this can be modeled accurately on the global scale by using a properly tuned Newtonian cooling law for the surface heat flux. Idealized flux adjustment experiments suggest that the sensitivity of the real climate is not represented well in coupled atmosphere-ocean general circulation models that require O(1) adjustments in the surface fluxes of heat and freshwater to simulate the current climate.
- DOE Contract Number:
- FC03-90ER61010
- OSTI ID:
- 79399
- Journal Information:
- Journal of Climate, Journal Name: Journal of Climate Journal Issue: 12 Vol. 7; ISSN 0894-8755; ISSN JLCLEL
- Country of Publication:
- United States
- Language:
- English
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