The isotopic composition of precipitation has been measured in samples simultaneously collected during individual precipitation events at a high-altitude station (Hulugou at 3260 m a.s.l.) in the middle Qilian Mountains, northwestern China. The observed changes of delta O-18 (delta D) and deuterium excess with surface air temperature, precipitation and season have been evaluated to derive information on water vapor sources and the effects from monsoon moisture. The results indicated monsoonal moisture can arrive in the Qilian Mountains in summer, as indicated by: (1) under temperatures between 8 degrees C and 15 degrees C, the precipitation events are characterized by the decrease of delta O-18 and d excess owing to the influence from monsoonal moisture; (2) delta O-18 and dD showed statistically negative correlation with precipitation, which reflected the amount effect in at precipitation events scale; (3) not only the water vapor transporting vector but also composite circulation maps verified the arrival of monsoonal moisture in summer along the eastern margin of the Tibetan Plateau, which made a great contribution to regional precipitation under climate warming. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.
; Wang Yamin
; Li Jianguo
; Chen Aifang
; Wang Tingting
; Han Chuntan
; Song Yaoxuan] Chinese Acad Sci, Cold & Arid Reg Environm & Engn Res Inst, State Key Lab Cryospher Sci, Gansu Hydrol & Water Resources Engn Res Ctr, Lanzhou 730000, Peoples R China
; [Gao Yan] Shaanxi Normal Univ, Coll Tourism & Environm, Xian 710062, Peoples R China
; [Pan Yanhui] Lanzhou Univ, Minist Educ, Key Lab Western Chinas Environm Syst, Lanzhou 730000, Peoples R China
; [Theakstone, W. H.] Univ Manchester, Sch Environm & Dev, Manchester M13 9PL, Lancs, England
Li, ZX (reprint author), Chinese Acad Sci, Cold & Arid Reg Environm & Engn Res Inst, State Key Lab Cryospher Sci, Gansu Hydrol & Water Resources Engn Res Ctr, Lanzhou 730000, Peoples R China.