Moisture sources of summer precipitation over easternChina during 1979–2009: A Lagrangian transient simulation

Abstract

Using the Lagrangian model FLEXPART and the quantitative method WaterSip, moisture sources of summer (June–July–August) precipitation overeastern China are investigated for the period 1979–2009 in this study. It is found that the Indochinese Peninsula plus southern China, the South ChinaSea, the northwestern Pacific Ocean, the Asian continent, and the Bay of Bengal are the major moisture sources in our results, and the moisture from eastern China, the Arabian Sea, and the Indian subcontinent also has minor contributions. Note that the contribution of the oceanic sources substantially surpasses that of the continental sources, and the contributions of sources exhibit interannual variations during 1979–2009, especially in the Indochinese Peninsula plus southern China, the South China Sea, the northwestern Pacific Ocean, the Asian continent, and the Bay of Bengal. Moreover, moisture sources have evident monthly variations and seasonal cycle features, which are responsible for supplying moisture to precipitating over eastern China in the different monsoonal periods. In addition, the major moisture sources for different intensities of precipitation over eastern China vary considerably; for light and moderate precipitation, a great amount of moisture originates from the local and northwestern continental regions and eastern oceanic regions adjacent to eastern China, while more moisture comes from southwestern oceanic sources and the surrounding continental regions of them for heavy precipitation.