Premium
Two competing pathways of aerosol effects on cloud and precipitation formation
Author(s) -
Takemura Toshihiko,
Kaufman Yoram J.,
Remer Lorraine A.,
Nakajima Teruyuki
Publication year - 2007
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 - 10.1029/2006gl028349
Subject(s) - aerosol , precipitation , environmental science , atmospheric sciences , cloud computing , cloud physics , meteorology , general circulation model , liquid water content , climate model , climatology , climate change , physics , geology , computer science , operating system , oceanography
Aerosols may influence cloud formation through two pathways: One is the effect on cloud microphysics by forming smaller and more numerous cloud droplets reducing precipitation and consequently enhancing cloud lifetime. The second is referred to as the aerosol dynamic‐hydrological effect in which the aerosol direct, semi‐direct, and indirect effects can modulate atmospheric radiation, which perturbs atmospheric circulation, leading to redistributions of clouds and precipitation. Here this study examines climate sensitivities using a general circulation model coupled with an aerosol transport‐radiation model. The model is run first with prescribed meteorology in order to isolate the cloud microphysical effect. It is run in a separate experiment with internally generated meteorology that includes dynamic‐hydrological effect as the aerosols modify clouds and interact with the radiation. We find in some regions that the dynamic‐hydrological effect in the free model runs counteracts the microphysical effects seen in the prescribed runs.