Effect of sub-cloud evaporation on the δ^18O of precipitation in Qilian Mountains and Hexi Corridor, China

作     者：ZongXing Li Qi Feng YaMin Wang JianGuo Li XiaoYan Guo YongGe Li 

作者机构：Key Laboratory of Ecohydrology of Inland River Basins/Gansu Hydrology and Water Resources Engineering Research Center Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China Changsha Normal University Changsha Hunan 410100 China 

出 版 物：《Research in Cold and Arid Regions》 (寒旱区科学（英文版）)

年 卷 期：2016年第8卷第5期

页      面：378-387页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：supported by a West Light Program for Talent Cultivation of the Chinese Academy of Sciences Gansu Province Science Foundation for Distinguished Young Scholars (No. 1506RJDA282) the National Natural Science Foundation (No. 91547102) the CAS/SAFEA International Partnership Program for Creative Research Teams a postdoctoral fellowship of ZongXing Li in the International Exchange Plans from the China Postdoctoral Association (No. 20140043) the Youth Innovation Promotion Association, CAS (No. 2013274) 

主　　题：sub-cloud evaporation precipitation stable isotope Qilian Mountains 

摘      要：The sub-cloud evaporation effect refers to the evaporation process for raindrops that fall from the cloud base to the ground, which is usually accompanied by depleted light isotopes and enriched heavy isotopes in the precipitation. Based on 461 event-based precipitation samples collected from 12 weather stations in the Qilian Mountains and the Hexi Corridor from May to August of 2013, our results indicated that sub-cloud evaporation has a great influence on the δ^18O of precipitation, especially in small-amount precipitation events. In May, June, July, and August the δ18O composition was enriched by 35%, 26%, 39%, and 41%, respectively, from the cloud base to the ground. This influence clearly strengthened with temperature rise, from the Qilian Mountains to the Hexi Corridor. When falling raindrops are evaporated by 1.0% in the Qilian Mountains and the Hexi Corridor, the composition of δ18O would be enriched by 1.2% and 2.6%, respectively. Temperature dominated the sub-cloud evaporation in the Qilian Mountains, whereas relative humidity controlled it in the Hexi Corridor. These results provide new proofs of the evolutional process of stable isotopes in precipitation in arid regions.