Examining the aerosol indirect effect over China using an SO2 emission inventory

The relationship between SO2 emissions and the effective particle radius of low-level water clouds (r(e)) over China was investigated to determine anthropogenic effects on clouds. Sulfur dioxide emission values were obtained from a statistical inventory, and r(e) origins were retrieved by satellite remote sensing on a 0.5degrees grid. Comparisons between annual mean SO2 emissions and r(e) showed generally decreasing r(e) values, explained by the Twomey effect. The existence of the Twomey effect is supported by comparisons with simulated aerosol optical depths. Results further suggest that clouds over land show sensitivity to the Twomey effect as well as clouds over the ocean. (C) 2004 Elsevier B.V. All rights reserved.