孔兴功1,2,3,,,
赵侃1,2,3,
梁怡佳1,2,3,
王权4,
汪永进1,2,3
1. 南京师范大学地理科学学院, 江苏 南京 210023
2. 虚拟地理环境教育部重点实验室(南京师范大学), 江苏 南京 210023
3. 江苏省地理信息资源开发与利用协同创新中心, 江苏 南京 210023
4. 重庆师范大学地理与旅游学院, 三峡库区地表过程与环境遥感重庆市重点实验室, 重庆 401331
基金项目: 国家自然科学基金项目(批准号:41672164、41572151和41571102)资助
详细信息
作者简介: 刘建伟, 男, 27岁, 硕士研究生, 自然地理学专业, E-mail:1007126326@qq.com
通讯作者: 孔兴功, E-mail:kongxinggong@njnu.edu.cn
中图分类号: P597+.2;P426.6收稿日期:2020-01-22
修回日期:2020-05-10
刊出日期:2020-07-30
Characteristics of stable isotope in precipitation of Nanjing in variable scale
Liu Jianwei1,2,3,,Kong Xinggong1,2,3,,,
Zhao Kan1,2,3,
Liang Yijia1,2,3,
Wang Quan4,
Wang Yongjin1,2,3
1. School of Geography, Nanjing Normal University, Nanjing 210023, Jiangsu
2. Key Laboratory of Virtual Geographic Environment(Nanjing Normal University), Ministry of Education, Nanjing 210023, Jiangsu
3. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, Jiangsu
4. Key Laboratory of Surface Process and Environment Remote Sensing in Three Gorges Reservoir Area, School of Geography and Tourism, Chongqing Normal University, Chongqing 401331
More Information
Corresponding author: Kong Xinggong,E-mail:kongxinggong@njnu.edu.cn
MSC: P597+.2;P426.6--> Received Date: 22 January 2020
Revised Date: 10 May 2020
Publish Date: 30 July 2020
摘要
摘要:基于1987年6月至1992年12月全球大气降水同位素观测网(GNIP)数据和2015年1月至2019年6月南京地区大气降水的连续采样数据,探究场降水和月降水δ18O变化的水汽源指示意义。结果表明,南京地区的降水稳定同位素δD的变化范围为-142.50 ‰~+42.91 ‰,δ18O的变化范围为-19.16 ‰~+3.94 ‰,并且利用场降水稳定同位素数据建立了南京地区大气降水方程:δD=7.42 δ18O+8.07(n=330,R2=0.95)。天气尺度上,对单一水汽源场降水氧同位素分析,将水汽来源地主要分为五类(A~E),其降水δ18O平均值分别为-3.66 ‰、-6.65 ‰、-6.45 ‰、-1.64 ‰和-8.97 ‰;在持续性降水过程中,受雨除效应影响,δ18O值呈现逐渐负偏的趋势,水汽源地的变化可能使降水δ18O值波动加剧,其振幅可达11.14 ‰,而水汽源稳定的降水δ18O值波动要相对小的多。在月尺度上,降水δ18O值呈现春季偏正,夏季偏负的特征,d-excess与温度和降水均呈明显反相位关系;这种现象的原因是南京地区不同季节降水水汽来源存在差异,即夏季以印度洋、南海和西太平洋水汽源(B、E类)为主,冬季降水主要来源于欧亚大陆和西风带来的水汽(A、C类),而春季则是西风远源和局地水汽源(C、D类)占优势,这与上述五类降水的δ18O具有很好的对应。
关键词: 南京/
大气降水/
δ18O/
水汽源
Abstract:Nanjing (32.1°N, 118.9°E) is located on the lower reaches of the Yangtze River with an average altitude of 26 m. The mean annual air temperature is 16.9℃ and the average annual precipitation is 1240 mm. It is strongly influenced by Asia monsoon climate characterized with seasonal variations of the wind reversal and alternation of dry and rainy periods. Temperature, the relative humidity and precipitation are monitored in Nanjing Normal University campus, which is located 13 km northwest from Hulu Cave.
Based on 454 stable hydrogen and oxygen isotope data (δ18O, δD), including 67 data for monthly precipitation from 1987 to 1992 and 387 data for daily and monthly precipitation from 2015 to 2019 in Nanjing, the stable isotope in precipitation and water vapor sources in this region were studied. The values of δ18O ranges from -19.16 ‰ to +3.94 ‰, while values of δ18O ranges from -142.50 ‰ to +42.91 ‰. The established Local Meteoric Water Line (LMWL) δD=7.42 δ18O+8.07 (n=330, R2=0.95) based on 330 obtained samples of separate events is similar to the LMWL of Eastern Monsoon China from previous studies.
To study changes in water vapor sources during precipitation events, stable isotope data, NCEP/NCAR data and Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) backward trajectory results during 87 single-source precipitation events and 18 continuous precipitation events in Nanjing were analyzed. The results indicate that there are five different water vapor types (A~E) for the 87 single-source precipitation events:Eurasia continental vapor, Western Pacific and South China Sea vapor, remote westerly vapor, vicinal vapor and Indian Ocean vapor. The average δ18O values of the five types are -3.66 ‰, -6.65 ‰, -6.45 ‰, -1.64 ‰ and -8.97 ‰. According to the water vapor sources, precipitation events can be classified into 2 types:single-source precipitation events and multi-sources precipitation events. The oscillation amplitude of δ18O in multi-sources precipitation events may be much larger than it of the other one. On the monthly scale, the δ18O value of precipitation is lowest in spring especially April while it is highest in summer. The deuterium excess (d-excess) varies with temperature and precipitation in an anti-phase, which indicate that the water vapor sources of precipitation change in different seasons. The water vapor in Nanjing in summer is transported from Indian Ocean, West Pacific and South China Sea (B & E types), in contrast from Eurasian continent and distant westerlies (A & C types) in winter, which is consistent with the δ18O values of five water vapor types.
Key words:Nanjing/
precipitation/
δ18O/
water vapor sources
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