阿拉善地区降水同位素特征与水汽来源  

Hydrogen and oxygen isotopic characteristic and moisture source of precipitation of Alxa Desert Plateau

作　　者：王帅[1] 饶文波[1] 金可[1] 张文兵[1] 陈堂清 郑芳文 王雅宁 WANG Shuai;RAO Wenbo;JIN Ke;ZHANG Wenbing;CHEN Tangqing;ZHENG Fangwen;WANG Yaning(College of Earth Sciences and Engineering,Hohai University,Nanjing 210100,China)

机构地区：[1]河海大学地球科学与工程学院

出　　处：《河海大学学报（自然科学版）》2019年第5期411-419,共9页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金(41273015)

摘　　要：基于2013—2015年阿拉善高原阿右旗的降水氢氧稳定同位素组成数据,分析阿拉善高原降水δD和δ18 O的特征与变化规律,揭示当地的水汽来源与迁移路径。结果表明:(a)阿拉善高原降水δD和δ18 O的变化呈现明显的季节特征,即夏季偏高,冬季偏低。(b)主要气象参数(降水量、气温、大气湿度和风速)中,气温是控制阿拉善高原降水δD和δ18 O的主导因素;通过与周边区域的比较,阿拉善高原当地大气降水线的斜率和截距较低,这是由阿拉善高原降水受到非平衡蒸发作用强烈所致;(c)HYSPLIT气团轨迹模型模拟和降水同位素分析揭示了阿拉善高原阿右旗降水主要来自西风和极低气团。Local precipitation is a precious water resource on the Alxa Desert Plateau of West Inner-Mongolia,Northwest China.The Hydrogen and oxygen isotope compositions in the precipitation of this region were investigated during 2013 and 2015 to explore the influences on precipitation isotopes and to reveal the moisture source of precipitation.The results show that:(a)δD andδ18 O values in the precipitation show a distinct seasonal variation,with higher values in summer and lower values in winter,on the Alxa Desert Plateau.(b)Among main meteorological parameters(precipitation amount,air temperature,atmospheric humidity and wind speed),air temperature is the most predominant factor controlling isotopic compositions of precipitation on both daily and monthly scales.The local meteoric water line is defined by the relationship betweenδD andδ18 O on the Alxa Desert Plateau and has lower slope and intercept than those of surrounding areas,implying stronger non-equilibrium evaporation of raindrops in this region.(c)In combination with the HYSPLT air mass trajectory model,the evidence of precipitation isotopes suggests there was a dominant control of westerly and polar air masses on the Alxa Desert Plateau,and the moisture of local precipitation mainly originated from the north and west throughout all the year.

关 键 词：氢氧同位素 降水 气象参数 HYSPLIT气团轨迹模型 水汽来源 阿拉善高原 阿右旗 

分 类 号：P426[天文地球—大气科学及气象学]