The Spatial and Temporal Characteristics of Aerosol-Cloud-Precipitation Interactions during Summer in East Asia

Aerosol-cloud-precipitation has an effect on the East Asian summer monsoon, and it is of great importance to analyze the relation amongst them. In this study, we use aerosol optical depth and cloud data from MODIS on board the Terra satellite and precipitation data from TRMM to study spatial and temporal characteristics of aerosol-cloud-precipitation interactions (ACPI). We also analyze ACPI with statistical methods. The aerosol optical depth ranges from 0.4 to 0.68 with an obvious decreasing trend in Pearl River Delta. The highest annual cloud optical depth is 23.6 and lowest 18.7. The cloud drop effective radius is ranges from 20.2 to 25.6 μm for ice clouds and 12.9 to 15.3 μm for liquid clouds. Cloud water paths range from 222.2 to 243.3 g m^-2. The precipitation rate was 3.6 to 8.6 mm d^-1. Aerosol optical depth was positively correlated with cloud optical depth (the highest, 0.77, was observed in Yangtze River Delta) and changes the cloud drop effective radius. Aerosol optical depth also has a positive correlation with cloud water path (the highest 0.92 in YRD). Heavy rains occur much more frequently under heavily-polluted conditions than lightly-polluted conditions and light rains show the opposite trend. The composition and vertical distribution of aerosols have an important effect on ACPI and need more research.