Contribution of the Precipitation‐Recycling Process to the Wetting Trend in Xinjiang, China

Abstract

AbstractXinjiang, China has experienced a significant wetting trend since the mid‐1980s in the context of climate warming. However, the features and mechanism associated with the water cycles in this region remain unclear. In this study, the contributions of the precipitation‐recycling process to the wet‐season (May‐August) wetting trend are investigated using a dynamic recycling model and the Modern Era Retrospective analysis for Research and Application version 2 reanalysis product from 1982 to 2020. The results show that the mean precipitation recycling ratio is 37.91%, implying that Xinjiang precipitation is mainly contributed by external moisture. Moreover, the recycling ratio exhibits a significantly increasing trend of 2.29% per decade, and this increased recycled precipitation contributes 55.55% to the wet‐season wetting trend in Xinjiang. The amount of externally advected moisture transported to Xinjiang has also increased in recent decades, accounting for 44.45% of the wetting trend. Further analysis reveals that a deepening anomalous trough over Central Asia accompanied by strengthening moisture inflow through the southwest and south boundaries induce the increased inflow of moisture to Xinjiang, thereby increasing external‐cycle precipitation in Xinjiang. Along with the strengthened ascending movement in the lower troposphere, the increasing atmospheric moisture content induced by enhanced evapotranspiration is beneficial for recycling precipitation in Xinjiang. These results imply that both the internal and external water cycles deserve further attention when exploring the wetting phenomenon in Xinjiang.