资源环境科技发展态势分析平台

The regional features of long-term changes in total and extreme precipitations over eight China domains and their seasonality and relationships with large-scale and local atmospheric and oceanic factors are investigated. A newly compiled data set of 917 China stations from the China National Meteorological Information Center with strict quality control is analysed. Wintertime extreme precipitation has increased persistently in all China domains, together with an obvious wetting tendency except in North China. In spring, an increase in extreme precipitation is also seen except in South China, but total precipitation increases only in half of China. A 'northern drying and southern wetting' (NDSW) pattern is found over eastern China for both extreme and total precipitations in summer when precipitation increases significantly in Northwest China (NWCH). Different features are found in autumn when negative trends are found in most of the China domains for total precipitation (except in NWCH and the Tibetan Plateau) and half of the domains for extreme precipitation. Overall, the frequency of extreme precipitation plays a dominant role in determining the extreme precipitation trend compared to the intensity of precipitation. The long-term changes in total precipitation and extreme ratio (extreme precipitation to total precipitation) are both strongly linked to the sea surface temperatures (SSTs) from the Indian Ocean to the Maritime Continent, the Kuroshio, the central-eastern Pacific, and part of the Atlantic Ocean. In summer, the NDSW pattern is closely associated with the weakening of East Asian monsoon circulation and the increase in land surface temperature of 40 degrees-60 degrees N. Local warming trends also contribute to the trends of extreme ratio in several domains in particular seasons.