Response of precipitation isotopes and water vapor sources to regional climate change on the Gannan Plateau,China  

作　　者：CHEN Fenli KANG Nan WANG Shengjie GAO Minyan ZHANG Qiuyan LI Huizhen YAO Yiwen 

机构地区：[1]College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China [2]Key Laboratory of Resource Environment and Sustainable Development of Oasis of Gansu Province,Northwest Normal University,Lanzhou 730070,China

出　　处：《Journal of Arid Land》2025年第4期440-456,共17页干旱区科学(英文版)

基　　金：supported by the National Natural Science Foundation of China(42161007);the Innovation Foundation of Higher Education Institutions of Gansu Province(2021B-081);the Foundation for Distinguished Young Scholars of Gansu Province(20JR10RA112).

摘　　要：Precipitation isotopes(δ^(18)O and δ^(2)H)are closely related to meteorological conditions for precipitation generation and the initial state of water vapor source areas,and are essential to the study of the regional hydrological cycle.The deuterium excess(d-excess)indicates deviation in isotope fractionation during evaporation and can trace water vapor sources.This study analyzed 443 precipitation samples collected from the Gannan Plateau,China in 2022 to assess precipitation isotope variations and their driving factors.Water vapor sources were evaluated using the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT),Concentration Weighted Trajectory(CWT),and Potential Source Contribution Factor(PSCF)models.Results showed that precipitation isotope values showed significant spatial and temporal variations on the Gannan Plateau.Temporally,precipitation isotope values peaked in June(when evaporation dominated)and minimized in March(depletion effect of air masses in the westerly wind belt).Spatially,the isotope values showed a distribution pattern of"high in the east and low in the west",which was mainly regulated by the differences in altitude and local meteorological conditions.Compared with the global meteoric water line(GMWL)with equation of δ^(2)H=8.00δ^(18)O+10.00,the slope and intercept of local meteoric water line(LMWL)for precipitation on the Gannan Plateau were smaller(7.49 and 7.63,respectively),reflecting the existence of a stronger secondary evaporation effect under the clouds in the region.The sources of water vapor on the Gannan Plateau showed significant seasonality and spatial heterogeneity.Specifically,the westerly belt and monsoon were the main water vapor transport paths at each sampling point,with Central Asian continental water vapor dominating in spring(53.49%),Indian Ocean water vapor dominating in summer(52.53%),Atlantic Ocean water vapor dominating in autumn(46.74%),and Atlantic Ocean and Mediterranean Sea water vapor dominating in winter(42.30%and 33.68%,respectively).Chang

关 键 词：precipitation isotopes deuterium excess(d-excess) water vapor sources Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT) Concentration Weighted Trajectory(CWT) Potential Source Contribution Factor(PSCF) Gannan Plateau 

分 类 号：P426.6[天文地球—大气科学及气象学]