Stable isotope ratios of typhoon rains in Fuzhou, Southeast China, during 2013-2017
Stable isotope ratios of typhoon rains in Fuzhou, Southeast China, during 2013-2017
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2013-2017年福州台风降雨稳定同位素比值
DOI：
10.1016/j.jhydrol.2019.01.017
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发表时间：
2019
影响因子：
6.4
通讯作者：
Jiang Xiuyang
中科院分区：
文献类型：
--
作者：
Xu Tao;Sun Xiaoshuang;Hong Hui;Wang Xiaoyan;Cui Mengyue;Lei Guoliang;Gao Lu;Liu Juan;Lone Mahjoor Ahmad;Jiang Xiuyang
降水中的稳定同位素比值（δ 2 H和δ 18 O）不仅在不同时间尺度上对气候变化有一定的响应，而且与热带气旋（飓风/台风）等极端天气事件有很强的联系。中国东南沿海地区的台风活动相当强烈，带来了大量的水分;因此，有助于该地区的极端降雨。我国东南部地区现有的同位素资料都是月或日时间分辨率的，不足以研究特定地点持续1-2天的台风降水事件。本文收集了2013 - 2017年福州8次台风过程的逐时降水δ 2 H和δ 18 O资料。δ 2 H与δ 18 O的相关系数为δ 2 H = 7.41 δ 18 O + 0.81（R ~ 2 = 0.96，N = 220）。8次台风过程的δ 18 O值变化规律相似，可分为3个阶段。第一和第三阶段δ 18 O正值较多，第二阶段δ 18 O负值较多，呈倒U型变化。第一和第三阶段的δ 18 O正值受再蒸发作用的控制。第二阶段降水的δ 18 O值明显低于福州夏季降水的加权平均值。其中一些数值略低于太平洋表面水汽的数值。第二阶段降水δ 18 O与温度和降水量之间没有明显的相关性。我们推测，18 O的显著亏损主要是由“雨屏效应”引起的，即台风期间雨屏区大尺度对流、高凝结效率和同位素亏损水汽的再循环共同作用，导致δ 18 O值非常负。这些结果表明，稳定同位素比值作为台风水的重要示踪剂。
Stable isotope ratios (δ2H and δ18O) in precipitation not only show a certain response to climate change at different time scales, but also have strong linkages to extreme weather events such as tropical cyclones (hurricanes/typhoons). Typhoon activity in the coastal region of Southeast China is quite intense, bringing huge amounts of moisture; thus, contributing to extreme rainfall in this region. The existing isotope data in Southeast China is available on a monthly or daily temporal resolution, which is inadequate to study 1–2-day-long typhoon rainfall events at a particular location. In this study, hourly rainfall δ2H and δ18O data are collected for eight typhoon events from 2013 to 2017 in Fuzhou, Southeast China. The total correlation between δ2H and δ18O is obtained as δ2H = 7.41 δ18O + 0.81 (R2= 0.96, N = 220). All the eight typhoon events reveal a similar variability pattern in δ18O values which can be divided into three stages. More positive δ18O values occur in the first and third stages, while the second stage is dominated by most negative δ18O values, exhibiting an inverted U-shaped pattern. The positive δ18O values during the first and third stages are governed by re-evaporation. The precipitation during the second stage has distinctly lower δ18O values than the weighted average δ18O of summer precipitation in Fuzhou. Some of these values are slightly lower than those of the water vapor over the Pacific Ocean’s surface. No significant relationship is observed between precipitation δ18O and temperature as well as the amount of precipitation during the second stage. We hypothesize that the significant18O-depletion is mainly caused by the ‘rain shield effect’, which refers to combination of large-scale convection, high condensation efficiency, and recycling of isotopically depleted vapor in rain shield areas leading to very negative δ18O values during typhoon system. These findings suggest the use of stable isotope ratios as important tracers of typhoon water.