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The Impact of the Aerosol Direct Radiative Forcing on Deep Convection and Air Quality in the Pearl River Delta Region
Author(s) -
Liu Z.,
Yim Steve H. L.,
Wang C.,
Lau N. C.
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 - 10.1029/2018gl077517
Subject(s) - aerosol , troposphere , environmental science , atmospheric sciences , radiative forcing , convection , forcing (mathematics) , radiative transfer , air quality index , climatology , relative humidity , meteorology , geology , geography , physics , quantum mechanics
Literature has reported the remarkable aerosol impact on low‐level cloud by direct radiative forcing (DRF). Impacts on middle‐upper troposphere cloud are not yet fully understood, even though this knowledge is important for regions with a large spatial heterogeneity of emissions and aerosol concentration. We assess the aerosol DRF and its cloud response in June (with strong convection) in Pearl River Delta region for 2008–2012 at cloud‐resolving scale using an air quality‐climate coupled model. Aerosols suppress deep convection by increasing atmospheric stability leading to less evaporation from the ground. The relative humidity is reduced in middle‐upper troposphere due to induced reduction in both evaporation from the ground and upward motion. The cloud reduction offsets 20% of the aerosol DRF. The weaker vertical mixing further increases surface aerosol concentration by up to 2.90 μg/m 3 . These findings indicate the aerosol DRF impact on deep convection and in turn regional air quality.