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Impact of Dust Shortwave Absorbability on the East Asian Summer Monsoon
Author(s) -
Wang Zheng,
Bi Lei,
Jia Xiaojing,
Yi Bingqi,
Lin Xiubin,
Zhang Feng
Publication year - 2020
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 - 10.1029/2020gl089585
Subject(s) - rainband , shortwave , atmospheric sciences , precipitation , environmental science , convection , climatology , radiative transfer , albedo (alchemy) , aerosol , monsoon , geology , meteorology , geography , physics , art , quantum mechanics , performance art , art history
Dust shortwave absorbability suffers from significant uncertainties. We investigated the radiative effects of dust aerosols from the circum‐Tibet region using four shortwave absorbability schemes and examined their impacts on the East Asian summer monsoon by using the Community Earth System Model (CESM). We adopted superspheroidal models to compute dust aerosol optical properties and found that more absorptive particles have larger asymmetry factor and lower single‐scattering albedo. Meiyu precipitation, as a part of the East Asian summer monsoon, is weakened by dust aerosols, particularly for the convective precipitation. The mechanism is that dust aerosols transported mainly from the Gobi desert radiatively heat the lower atmosphere to the north of the Meiyu rainband and decrease the meridional temperature gradient, leading to the weakening of the midtropospheric westerly jet over the Meiyu rainband, which is important for convection. More absorptive dust aerosols with a stronger radiative heating effect inhibit more convective Meiyu precipitation.