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Dynamical and Thermodynamic Elements of Modeled Climate Change at the East African Margin of Convection
Author(s) -
Giannini Alessandra,
Lyon Bradfield,
Seager Richard,
Vigaud Nicolas
Publication year - 2018
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 - 10.1002/2017gl075486
Subject(s) - climatology , climate model , convection , advection , structural basin , climate change , sea surface temperature , moisture , environmental science , east asia , geology , atmospheric sciences , oceanography , geography , meteorology , physics , paleontology , archaeology , china , thermodynamics
We propose a dynamical interpretation of model projections for an end‐of‐century wetting in equatorial East Africa. In the current generation of global climate models, increased atmospheric moisture content associated with warming is not the dominant process explaining the increase in rainfall, as the regional circulation is only weakly convergent even during the rainy seasons. Instead, projected wetter future conditions are generally consistent with the El Niño‐like trend in tropical Pacific sea surface temperatures in climate models. In addition, a weakening in moisture convergence over the adjacent Congo Basin and Maritime Continent cores of convection results in the weakening of near‐surface winds, which increases moisture advection from the Congo Basin core toward the East African margin. Overall confidence in the projections is limited by the significant biases in simulation of the regional climatology and disagreement between observed and modeled tropical Pacific sea surface temperature trends to date.