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CMIP5 models' shortwave cloud radiative response and climate sensitivity linked to the climatological Hadley cell extent
Author(s) -
Lipat Bernard R.,
Tselioudis George,
Grise Kevin M.,
Polvani Lorenzo M.
Publication year - 2017
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 - 10.1002/2017gl073151
Subject(s) - hadley cell , shortwave , climatology , climate sensitivity , climate model , environmental science , atmospheric sciences , middle latitudes , radiative transfer , subsidence , shortwave radiation , cloud feedback , coupled model intercomparison project , cloud cover , northern hemisphere , climate change , geology , general circulation model , cloud computing , radiation , structural basin , physics , oceanography , quantum mechanics , computer science , operating system , paleontology
This study analyzes Coupled Model Intercomparison Project phase 5 (CMIP5) model output to examine the covariability of interannual Southern Hemisphere Hadley cell (HC) edge latitude shifts and shortwave cloud radiative effect (SWCRE). In control climate runs, during years when the HC edge is anomalously poleward, most models substantially reduce the shortwave radiation reflected by clouds in the lower midlatitude region (LML; ∼28°S–∼48°S), although no such reduction is seen in observations. These biases in HC‐SWCRE covariability are linked to biases in the climatological HC extent. Notably, models with excessively equatorward climatological HC extents have weaker climatological LML subsidence and exhibit larger increases in LML subsidence with poleward HC edge expansion. This behavior, based on control climate interannual variability, has important implications for the CO 2 ‐forced model response. In 4×CO 2 ‐forced runs, models with excessively equatorward climatological HC extents produce stronger SW cloud radiative warming in the LML region and tend to have larger climate sensitivity values than models with more realistic climatological HC extents.