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The effect of global climate change on the regions of tropical convection in CSM1
Author(s) -
Dutton Jan F.,
Poulsen Chris J.,
Evans Jenni L.
Publication year - 2000
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 - 10.1029/2000gl011542
Subject(s) - environmental science , climatology , convection , deep convection , climate model , carbon dioxide , atmospheric sciences , outgoing longwave radiation , climate change , longwave , tropical cyclone , meteorology , radiation , geology , chemistry , geography , oceanography , physics , organic chemistry , quantum mechanics
The impact of enhanced carbon dioxide concentrations on deep tropical convection (DTC) is explored using the National Center for Atmospheric Research (NCAR) Climate System Model (CSM1) model. A 134‐year simulation in which CO 2 concentrations increase 1 % year −1 is analyzed. With approximately present‐day CO 2 concentrations (367 ppmv) the CSM1 simulation captures the observed relationship between outgoing longwave radiation (OLR) and sea‐surface temperature (SST) in the tropics. The temperature threshold for deep convection in the model is approximately 24.75°C. As CO 2 concentrations increase, the simulated threshold temperature for tropical convection progressively increases to ∼25.55° C and 26.55°C at 2×CO 2 (year 80) and 3.4×CO 2 (year 133). The fully coupled climate model response to increased CO 2 concentrations implies that the expansion of the 26°C isotherm, the present‐day observed threshold, will not yield an expansion of the regions of DTC.