上海降水中氢氧同位素特征及与ENSO的关系  

Characteristics of Stable Isotope in Precipitation and Its Relationship with ENSO in Shanghai

作　　者：董小芳[1] 邓黄月 张峦[1] 朱志鹏[1] 王琳[1] 郑祥民[1] 周立旻[1] 

机构地区：[1]华东师范大学地理科学学院,地理信息科学教育部重点实验室,上海200241

出　　处：《环境科学》2017年第5期1817-1827,共11页Environmental Science

基　　金：国家自然科学基金项目(41271054,41371032,41571040)

摘　　要：基于收集2014年8月至2015年8月上海70个降水样品,分析上海降水同位素特征与温度、降水量的相关关系,分析不同时间尺度下降水中δ^(18)O、氘盈余与ENSO事件的联系.结果表明上海地区大气降水中δD与δ^(18)O冬春较高,夏秋较低.上海大气降水线方程截距和斜率比全球降水线方程偏小,可能是因为降水过程中受到不平衡的二次蒸发.在不同的时间尺度下,上海地区降水中δ^(18)O与气温和降水量具有不同的相关关系,冬季存在着较弱的温度效应,而全年呈现出较显著的降水量效应,受大气环流过程影响明显.取样期间,降水中δ^(18)O与d值(过量氘)清晰记录了La Ni1a向El Ni1o之间的过渡,拉尼娜期间,降水中δ^(18)O与d值偏负;El Ni1o期间,δ^(18)O与d值偏正.A total of 70 precipitation samples were collected from August 2014 to August 2015 in Shanghai and the oxygen and hydrogen isotope of precipitation were analyzed. The relationship between the δ^18O and deuterium excess of precipitation and ENSO events was addressed. The results showed that δD and δ^18O of precipitation in Shanghai were higher in winter and spring than in summer and fall. The slope of meteoric water line with these data was a little smaller than the global meteoric water line. The main reason could be the unbalanced secondary evaporation in the process of precipitation. The correlation between the δ^18O in precipitation and temperature and precipitation varied in different time scales. On a seasonal scale,this work revealed that there was no significant temperature effect in winter,but significant precipitation effect was found in the annual scales,which was obviously affected by the atmospheric circulation. δ^18O values and deuterium excess in precipitation recorded the La Ni1 a and El Ni1 o conversion process.During the La Ni1 a event,the δ^18O and d values were more negative than those in the El Ni1 o event.

关 键 词：上海 稳定同位素 ENSO 大气环流 Δ^18O δD 

分 类 号：X142[环境科学与工程—环境科学]