Sub-Hourly Variability of Stable Isotopes in Precipitation in the Marginal Zone of East Asian Monsoon
Sub-Hourly Variability of Stable Isotopes in Precipitation in the Marginal Zone of East Asian Monsoon
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东亚季风边缘区降水稳定同位素的亚小时变化
DOI：
10.3390/w12082145
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发表时间：
2020-07
期刊：
影响因子：
3.4
通讯作者：
Du Qinqin
中科院分区：
文献类型：
--
作者：
Han Tingting;Zhang Mingjun;Wang Shengjie;Qu Deye;Du Qinqin
中纬度地区的同位素数据通常是按年、月和日时间尺度提供的，但很少能用于个别降水事件中分小时尺度上发生的变化。为填补这一空白，我们采集了9次降水事件的亚小时(每10分钟)序贯样本，并分析了2019年6-10月在兰州、中国西北部的各次降水事件的δ18O值。δ2H和δ18O的序列气象水线相关方程为δ2H=7.33δ18O+9.78(R2=0.97，N=170)。所有事件在初期(垂直灰虚线之前)具有相似的递减变率模式，而在后期(垂直灰色虚线之后)，δ18O负值占主导地位，呈现不同的模式。在大多数事件中，δ18O值的变化约为1-5‰。我们发现，δ18O值在事件内主要表现为三种模式，即“V”字型、“L”型和递减型。正的δ18O值在初始阶段受再蒸发控制。相对湿度对降水事件的δ18O值没有影响，这主要是因为干燥和温暖的条件有利于研究区雨水的蒸发。降水同位素特征的变化与区域气候密切相关。对降水样品的连续分析表明，δ-18O值的快速变化与不同的水汽来源和输送路径有关。一个富含重同位素侵入的新气团可以改变事件内的同位素组成。
Isotope data at mid-latitude locations are commonly available on annual, monthly, and daily timescales; however, they are rarely available for the variations occurring on the sub-hourly scale within individual precipitation events. To fill this gap, sub-hourly (every 10 min) sequential samples were collected for nine precipitation events, and the δ18O values of the individual events were analyzed from June to October 2019 in Lanzhou, Northwest China. The Sequential Meteoric Water Line (SMWL) correlation between δ2H and δ18O is δ2H = 7.33 δ18O + 9.78 (R2 = 0.97, N = 170). All events had a similar decreasing variability pattern in the initial period (before the vertical gray dotted line), while during the later period (after the vertical gray dotted line), negative δ18O values dominated, exhibiting a different pattern. Variations in the δ18O values were about 1–5‰ during most intra-events. We found that δ18O values mainly exhibit three patterns in the intra-event, namely a “V”-shaped pattern, an “L”-shaped pattern, and a decreasing pattern. Positive δ18O values are controlled by re-evaporation in the beginning period. Relative humidity has no effect on the δ18O values of precipitation events, mainly because dry and warm conditions are conducive to the evaporation of rainwater in the study region. The changes in the isotopic characteristics of precipitation are closely linked to the regional climate. The continuous analysis of precipitation samples revealed that the rapid change of δ18O values is related to different moisture sources and transport paths. A new air mass with enriched heavy isotope intrusion can change the isotopic composition in the intra-event.
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影响因子：
6.4
作者：
W. Ren;T. Yao;Shi-you Xie;Youhai He
通讯作者：
W. Ren;T. Yao;Shi-you Xie;Youhai He
影响因子：
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作者：
V. Barras;I. Simmonds
通讯作者：
V. Barras;I. Simmonds
影响因子：
5
作者：
R. Srivastava;R. Ramesh;Naveen Gandhi;R. A. Jani;Ashutosh Singh
通讯作者：
R. Srivastava;R. Ramesh;Naveen Gandhi;R. A. Jani;Ashutosh Singh
风暴事件期间通过同位素监测识别不同的水分源
影响因子：
3.8
作者：
Li;Jie;Tao;Tao;Pang;Zhonghe;Tan;Ming;Kong;Yanlong;Duan;Wuhui;Zhang;Yuwei
通讯作者：
Yuwei
影响因子：
6.4
作者：
Luhua Xie;G. Wei;W. Deng;Xiaoli Zhao
通讯作者：
Luhua Xie;G. Wei;W. Deng;Xiaoli Zhao