WU Xixi, CHEN Fenli, ZHU Guofeng, ZHOU Xin, LIU Xueyuan, QIAN Rui, WANG Shenghui, CHEN Jufan
(College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730000, China)
Abstract: The isotopic data of 9 stations in southwest China was interpolated with the LMDZ model, and the contribution of different sources of water vapor to precipitation was estimated using the isotope mixing model. The results showed that the contribution of advection moisture to precipitation in southwest China, with exception at some sites, was more than 90%, then followed by plant transpiration water vapor and surface evaporation water vapor, which accounted for 0.3%-21.3% and 0.1% -8.1% of total precipitation, respectively.. At the same time, the contribution of advection moisture to precipitation in summer was greater than that in winter, while the contribution of surface evaporation water vapor and plant transpiration water vapor to precipitation was slightly greater in winter than summer. The water vapor recirculation rate presented a spatial difference. The surface evaporated water vapor and plant water vapor in the Sichuan Basin and surrounding mountains were slightly higher than that in the Qinghai-Tibet Plateau and the Yunnan-Guizhou Plateau. MeteoInfo software combined with the meteorological data provided by the National Center for Atmospheric Research was run to track the backward trajectories of stations in southwest China for nearly ten years (1998-2007) and the cluster analysis was performed. It indicated that, in summer, higher contributions of near-source local evaporation was observed at some stations, e.g., two stations in Sichuan Province and Chongqing with contribution over 50% and station in Guiyang with contribution of 28.95%. The rest station’s summer water vapor mostly comes from the Arabian Sea, Bay of Bengal and Indian Ocean. There was also a part of the water vapor coming from the westerly zone and the western Pacific brought by the southeast monsoon. However, the source of water vapor in winter dominantly came from the westerly zone.
Key word: LMDZ model; Southwest China; Source of water vapor; moisture recycling
EARTH AND ENVIRONMENT Vol.49, No.4, Tot No.342, 2021, Page 400-408