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An inquiry into the cirrus‐cloud thermostat effect for tropical sea surface temperature
Author(s) -
Lau K.M.,
Sui C.H.,
Chou M. D.,
Tao W.K.
Publication year - 1994
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 - 10.1029/94gl00222
Subject(s) - cirrus , cloud forcing , environmental science , cloud feedback , climatology , cloud cover , sea surface temperature , shortwave , atmospheric sciences , shortwave radiation , latent heat , thermostat , radiative transfer , meteorology , forcing (mathematics) , climate model , cloud computing , climate change , climate sensitivity , geology , radiation , physics , oceanography , quantum mechanics , computer science , operating system , thermodynamics
In this paper, we investigate the relative importance of local vs remote control on cloud radiative forcing using a cumulus ensemble model. It is found that cloud and surface radiation forcings are much more sensitive to the mean vertical motion associated with large scale tropical circulation than to the local SST. When the local SST is increased with the mean vertical motion held constant, increased surface latent and sensible heat flux associated with enhanced moisture recycling is found to be the primary mechanism for cooling the ocean surface. Large changes in surface shortwave fluxes are related to changes in cloudiness induced by changes in the large scale circulation. These results are consistent with a number of earlier empirical studies, which raised concerns regarding the validity of the cirrus‐thermostat hypothesis (Ramanathan and Collins, 1991). It is argued that for a better understanding of cloud feedback, both local and remote controls need to be considered and that a cumulus ensemble model is a powerful tool that should be explored for such purpose.