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

Abstract

Xinjiang is located in inner Eurasia and is characterized by a typical mountain-basin system composed of "Three Mountains and Two Basins" (Figure 1). Its unique geographic location and topographic features result in a typical arid and semiarid climate that is highly sensitive to global climate change (Wu et al., 2010;Zhao et al., 2010). From the mid-1980s to 2000, the average annual air temperature increased by 0.7°C compared to that measured from 1961 to the mid-1980s in northwest China (Shi et al., 2006;Yao, Chen, Yu, et al., 2020); this increase is much higher than the global average increase of approximately 0.2°C (Shi et al., 2006;L. Wang et al., 2020). In an interesting phenomenon observed in northwest China, the regional climate changed from warm-dry to warm-wet conditions in the mid-1980s under the background of global warming (B.

The Precipitation‐Recycling Process Enhanced Extreme Precipitation in Xinjiang, China

“…For TS, both external moisture and internal evapotranspiration contribute positively to the increased precipitation. However, the deepening of the Central Asian trough facilitates the intensification of upward motion and guides more water vapor transport into TS (Ma et al., 2021; Zhang et al., 2022). Furthermore, the increase in evapotranspiration over TS is relatively limited compared to KL.…”

“…The Modern‐Era Retrospective Analysis for Research and Applications, version 2 (MERRA2) is generated by NASA Global Modeling and Assimilation Office based on the Goddard Earth Observation System Model version 5, and offers products that cover a long‐term period from 1980 to the present (Gelaro et al., 2017). Previous studies have indicated that MERRA2 outperforms other reanalysis datasets in terms of accurately representing climate characteristics and long‐term patterns of water cycles in CA and northwestern China (Jiang et al., 2019; Ren et al., 2022; Zhang et al., 2022). We utilized the observed daily precipitation data from the China Meteorological Agency (CMA) to assess the accuracy of MERRA2 in Xinjiang, which exhibited overall consistency (Figure S2 in Supporting Information ).…”

“…To calculate the precipitation recycling ratio, the hourly precipitation, evapotranspiration, precipitable water, and wind field data in MERRA2 at a horizontal resolution of 0.5 × 0.625 and 37 vertical levels were used to drive the Dynamic Recycle Model (DRM). Notably, the data in 1981 were excluded from our study because of the abnormal error possibly attributed from spin‐up effects (Reichle et al., 2017; Ren et al., 2022; Zhang et al., 2022).…”

“…(2022) and Wang et al. (2016) indicated that the contribution of recycled moisture to precipitation was 37% and 16% in the wet season over Xinjiang and the large oases of Urumqi, respectively, which have exhibited significantly increasing trends over the last few decades (Yao et al., 2020; Zhang et al., 2022). Regarding extreme precipitation, Yao et al.…”

“…Yao et al (2020) and Wu et al (2019) revealed that the annual average precipitation-recycling ratio varied by approximately 10%. Moreover, Zhang et al (2022) and Wang et al (2016) indicated that the contribution of recycled moisture to precipitation was 37% and 16% in the wet season over Xinjiang and the large oases of Urumqi, respectively, which have exhibited significantly increasing trends over the last few decades (Yao et al, 2020;Zhang et al, 2022). Regarding extreme precipitation, Yao et al (2021) and Zhou et al (2019) explored the sources of moisture related to heavy rainfall in Xinjiang, showing that the moisture from Xinjiang and Central Asia (CA) transported by westerlies are key contributors.…”