摘要
降水氢氧稳定同位素组分是一种良好的示踪剂,对水汽循环的研究有重要意义.本研究基于2016年在南京、溧阳、宜兴和东山这4个站点按降水事件采集的降水样品,测定了降水HDO和H_2^(18)O组分,分析了降水HDO、H_2^(18)O组分以及过量氘的时间变化特征;探讨了水汽源地和局地蒸发对降水稳定同位素组分的影响.结果表明:(1)冬夏季风期间水汽源地的差异使4个站点降水HDO、H_2^(18)O组分及过量氘有明显的季节变化,主要表现为HDO和H_2^(18)O组分夏季风期间贫化,冬季风期间富集;过量氘夏季风期间小于冬季风期间;(2)夏季风期间,太湖蒸发补给使下游地区的降水过量氘变大,局地大气降水线方程的截距变高;冬季风期间,局地蒸发对降水同位素影响很小,降水HDO、H_2^(18)O组分以及过量氘的空间变化不明显;(3) 4个站点局地大气降水线方程的斜率和截距均较高,原因可能是冬夏季风期间的降水水汽来源的差异和冬季风期间水汽再循环过程的影响.
Stable hydrogen and oxygen isotopic compositions in precipitation are good tracers and can provide unique information about the water cycle. Precipitation samples were collected at the Nanjing,Liyang,Yixing,and Dongshan sites in 2016,and the HDO and H218O compositions of precipitation were measured. The temporal variability of HDO and H218O compositions and deuterium-excess of precipitation were analyzed,and the influence of the water vapor source and local evaporation on stable isotopic composition of precipitation were discussed. The results indicated that:(1) Seasonal variations in the HDO composition,H218O composition,and deuterium-excess of precipitation occurred due to different water vapor sources during the summer and winter monsoon seasons. The HDO and H218O compositions were depleted during the summer monsoon season and enriched during the winter monsoon season. The deuterium-excess during the summer monsoon season was lower compared to the winter monsoon season.(2) During the summer monsoon,the evaporation of Lake Taihu made the deuterium-excess of downwind precipitation and the downwind intercept of the local meteoric water line higher. During the winter monsoon season,local evaporation had little influence on HDO and H218O components in precipitation.(3) Both of the intercepts and slopes of the local meteoric water line were higher than those of the global meteoric water line,due to moisture recycling during the winter monsoon season and different water vapor sources between the summer and winter monsoon seasons.
作者
胡勇博
肖薇
钱雨妃
刘强
谢成玉
张秀芳
张文庆
温学发
刘寿东
李旭辉
HU Yong-bo;XIAO Wei;QIAN Yu-fei;LIU Qiang;XIE Cheng-yu;ZHANG Xiu-fang;ZHANG Wen-qing;WEN Xue-fa;LIU Shou-dong;LEE Xu-hui(Yale-NUIST Center on Atmospheric Environment,Nanjing University of Information Science and Technology,Nanjing 210044,China;Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET),Nanjing University of Information Science and Technology,Nanjing 210044,China;Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2019年第2期573-581,共9页
Environmental Science
基金
国家自然科学基金项目(41475141
41505005
41575147)
江苏省高校优势学科建设工程项目(PAPD)
教育部长江学者和创新团队发展计划项目(PCSIRT)
关键词
降水
氢氧同位素
过量氘
大气降水线
水汽源地
局地蒸发
precipitation
hydrogen and oxygen stable isotopic compositions
deuterium-excess
local meteoric water line
water vapor source
local evaporation
