资源环境科技发展态势分析平台

Daily sunshine duration data from 384 stations in Eastern China was used to separate light rain in the warm season during the period 1979-2009 into light rain occurred in overcast and partly cloudy weather. Light rain reduction over past 30years mainly happened in partly cloudy weather, which accounted for 84% of the decrease of total light rain days and amount in the warm seasons over Eastern China during the period 1979-2009. The primary cause of the significant reduction of light rain in partly cloudy weather was the relative humidity decrease in the low troposphere, which was induced by both the air temperature increase and water vapour content (WVC) decrease, while warming played a much more important role compared with the WVC in the change of light rain in most regions of Eastern China.