Direct and indirect effects of anthropogenic aerosols on regional precipitation over east Asia

摘要: [1] A regional coupled climate-chemistry-aerosol model is developed. It used to assess the direct and indirect effects of anthropogenic sulfate carbonaceous aerosols on climate over east Asia with a focus precipitation. The simulated first for most part reduce solar radiation hence decrease surface temperature, while second effect generates both negative forcing substantial positive long-wave forcing. decreases precipitation, but because cancelling effect, temperature does not change very much. With interactively model-calculated current aerosol loading combined direct/semidirect/first precipitation reduced by about 10% in fall winter 5% spring summer. has largest impact, itself decreasing from 3% 20%, depending autoconversion scheme assumed. semidirect relatively small. An empirical orthogonal function analysis climatological since last century shows trend leading modes China winter, which generally geographically consistent distribution model-simulated reduction aerosols.