编号 zgly0001585936
文献类型 期刊论文
文献题名 西北干旱地区大气降水δ18O的特征及水汽来源(英文)
作者单位 KeyLaboratoryofWaterCycleandRelatedLandSurfaceProcesses InstituteofGeographicSciencesandNaturalResourcesResearch CAS Beijing100101 China GraduateUniversityofChineseAcademyofSciences Beijing100039 China CERNSub-centerofWater Be
母体文献 Journal of Geographical Sciences
年卷期 2009年02期
年份 2009
分类号 P426.61
关键词 AridNorthwesternChina(ANC) δ18O precipitation watervapororigin
文摘内容 In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Precipitation(CHNIP).During the year 2005 and 2006, monthly precipitation samples have been collected and analyzed for the composition of δD and δ18O.The established local meteoric water line δD=7.42δ18O+1.38, based on the 95 obtained monthly composite samples, could be treated as isotopic input function across the region.The deviations of slope and intercept from the Global Meteoric Water Line indicated the specific regional meteorological conditions.The monthly δ18O values were characterized by a positive correlation with surface air temperature(δ18O(‰) =0.33 T(℃)-13.12).The amount effect visualized during summer period(δ18O(‰) =-0.04P(mm)-3.44) though not appeared at a whole yearly-scale.Spatial distributions of δ18O have properly portrayed the atmospheric circulation background in each month over Arid Northwestern China.The quan-titative simulation of δ18O, which involved a Rayleigh fractionation and a kinetic fractionation, demonstrated that the latter one was the dominating function of condensation of raindrops.Furthermore, the raindrop suffered a re-evaporation during falling processes, and the precipitation vapor might have been mixed with a quantity of local recycled water vapor.Multiple linear regression equations and a δ18O-T relation have been gained by using meteorological parameters and δ18O data to evaluate physical controls on the long-term data.The established δ18O-T relation, which has been based on the present-day precipitation, could be considered as a first step of quantitatively reconstructing the historical environmental climate.