Engineering, Civil
; Geosciences, Multidisciplinary
; Water Resources
WOS研究方向:
Engineering
; Geology
; Water Resources
英文摘要:
Stable isotope ratios (delta H-2 and delta O-18) 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 delta H-2 and delta O-18 data are collected for eight typhoon events from 2013 to 2017 in Fuzhou, Southeast China. The total correlation between delta H-2 and delta O-18 is obtained as delta H-2 = 7.41 delta O-18 + 0.81 (R-2 = 0.96, N = 220). All the eight typhoon events reveal a similar variability pattern in delta(18)Ovalues which can be divided into three stages. More positive delta O-18 values occur in the first and third stages, while the second stage is dominated by most negative delta O-18 values, exhibiting an inverted U-shaped pattern. The positive delta O-18 values during the first and third stages are governed by re-evaporation. The precipitation during the second stage has distinctly lower delta O-18 values than the weighted average delta O-18 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 delta O-18 and temperature as well as the amount of precipitation during the second stage. We hypothesize that the significant O-18-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 delta O-18 values during typhoon system. These findings suggest the use of stable isotope ratios as important tracers of typhoon water.
1.Fujian Normal Univ, Sch Geog Sci, Minist Educ, Key Lab Humid Subtrop Ecogeog Proc, Fuzhou 350007, Fujian, Peoples R China 2.Fujian Normal Univ, Inst Geog, Fuzhou 350007, Fujian, Peoples R China 3.Guangzhou Univ, Innovat Ctr, Guangzhou 510006, Guangdong, Peoples R China 4.Guangzhou Univ, Minist Educ, Key Lab Waters Safety & Protect Pearl River Delta, Guangzhou 510006, Guangdong, Peoples R China 5.Natl Taiwan Univ, Dept Geosci, High Precis Mass Spectrometry & Environm Change L, Taipei 106, Taiwan 6.Natl Taiwan Univ, Res Ctr Future Earth, Taipei 10617, Taiwan
Recommended Citation:
Xu, Tao,Sun, Xiaoshuang,Hong, Hui,et al. Stable isotope ratios of typhoon rains in Fuzhou, Southeast China, during 2013-2017[J]. JOURNAL OF HYDROLOGY,2019-01-01,570:445-453