The FLEXPART model to explore the moisture sources of rainy season precipitation interannual variations for the monsoon dominated humid South China and the westerly-dominated arid Central Asia.  The first rainy season precipitation variations in South China are largely influenced by the South China Sea summer monsoon (SCSSM). Before the onset of SCSSM, land sources (66.87%) play a more important role than ocean sources (33.13%), with the contributions mainly from Southeastern Asia (47.56%) and South China Sea (28.79%). After the onset of SCSSM, the contributions of land sources and ocean regions are comparable, and mainly from Southeastern Asia (33.53%) and the Bay of Bengal (32.26%). The moisture transports for the interannual variations in precipitation over South China before and after the onset of SCSSM are significantly correlated with the east-west contrast of sea surface temperature anomalies over northern part of North Pacific and the uniform warming over Indian Ocean, respectively. As to the summer precipitation in Central Asia, the Eurasian evaporation plays a dominant role in the interannual variations of Central Asian summer precipitation by contributing more than 90% of the total moisture. The moisture transports associated with Central Asian summer precipitation interannual variations are impacted by the anomalous cyclones over western and northeastern part of Central Asia during the wet years, which enhance the moisture convergence and hence increase the summer precipitation in Central Asia. The anomalous cyclone over western part of Central Asia is correlated with the changes in intensity of Eurasian Summer Subtropical Westerly Jet (ESSWJ), while the anomalous cyclone over northeastern part of Central Asia is correlated with both ESSWJ and the British–Baikal Corridor pattern teleconnection in association with the polar front jet.
 

水汽源；水汽输送；年际变化