A Numerical Study of the Effect of Different Aerosol Types on East Asian Summer Clouds and Precipitation

TitleA Numerical Study of the Effect of Different Aerosol Types on East Asian Summer Clouds and Precipitation
Publication TypeJournal Article
Year of Publication2013
JournalAtmospheric Environment
Pages51-63
Date Published05/2013
Abstract / Summary

In this study, the anthropogenic aerosol impact on the summer monsoon clouds and precipitation in East Asia is investigated using the NCAR Community Atmospheric Model version 5 (CAM5), a state-of-the-art climate model considering aerosol direct, semi-direct and indirect effects. The effects of all anthropogenic aerosols, and anthropogenic black carbon (BC), sulfate, and primary organic matter (POM) are decomposed from different sensitivity simulations. Anthropogenic sulfate and POM reduce the solar flux reaching the surface directly by scattering the solar radiation, and indirectly by increasing the cloud droplet number concentration and cloud liquid water path over East China. The surface air temperature over land is reduced, and the precipitation in North China is suppressed. Unlike anthropogenic sulfate and POM, anthropogenic BC does not have a significant effect on the air temperature at the surface, because of the reduction of the cloud liquid water path and the weakening of shortwave cloud forcing by its semi-direct effect. The anthropogenic BC strengthens the southwesterly wind over South China and leads to stronger deep convection at the 25°N–30°N latitudinal band. The effect of all anthropogenic aerosols on air temperature, clouds, and precipitation is not a linear summation of effects from individual anthropogenic sulfate, BC and POM. Overall all anthropogenic aerosols suppress the precipitation in North China and enhance the precipitation in South China and adjacent ocean regions.

URLhttp://www.sciencedirect.com/science/article/pii/S135223101300006X
DOI10.1016/j.atmosenv.2012.12.039
Journal: Atmospheric Environment
Year of Publication: 2013
Pages: 51-63
Date Published: 05/2013

In this study, the anthropogenic aerosol impact on the summer monsoon clouds and precipitation in East Asia is investigated using the NCAR Community Atmospheric Model version 5 (CAM5), a state-of-the-art climate model considering aerosol direct, semi-direct and indirect effects. The effects of all anthropogenic aerosols, and anthropogenic black carbon (BC), sulfate, and primary organic matter (POM) are decomposed from different sensitivity simulations. Anthropogenic sulfate and POM reduce the solar flux reaching the surface directly by scattering the solar radiation, and indirectly by increasing the cloud droplet number concentration and cloud liquid water path over East China. The surface air temperature over land is reduced, and the precipitation in North China is suppressed. Unlike anthropogenic sulfate and POM, anthropogenic BC does not have a significant effect on the air temperature at the surface, because of the reduction of the cloud liquid water path and the weakening of shortwave cloud forcing by its semi-direct effect. The anthropogenic BC strengthens the southwesterly wind over South China and leads to stronger deep convection at the 25°N–30°N latitudinal band. The effect of all anthropogenic aerosols on air temperature, clouds, and precipitation is not a linear summation of effects from individual anthropogenic sulfate, BC and POM. Overall all anthropogenic aerosols suppress the precipitation in North China and enhance the precipitation in South China and adjacent ocean regions.

DOI: 10.1016/j.atmosenv.2012.12.039
Citation:
Jiang, Y, X Liu, X Yang, and M Wang.  2013.  "A Numerical Study of the Effect of Different Aerosol Types on East Asian Summer Clouds and Precipitation."  Atmospheric Environment 51-63.  https://doi.org/10.1016/j.atmosenv.2012.12.039.