TROPICAL GEOGRAPHY ›› 2018, Vol. 38 ›› Issue (5): 651-659.

Change and Influencing Factors of δ18O in the Precipitation of Typhoon “CHAN-HOM” at Eastern Coastal Cities in China

SUN Xiaoshuang1，CUI Mengyue1，HONG Hui1，WANG Xiaoyan1， DONG Jinguo3，LEI Guoliang1,2，JIANG Xiuyang1,2

1. （1．Collegeof Geographical Sciences，Fujian Normal University，Key Laboratory of Humid Subtropical Eco-geographical Process， Ministry of Education，Fuzhou 350007，China；2．Institute of Geography，Fujian Normal University，Fuzhou 350007，China； 3．School of Geographic Science，Nantong University，Nantong 226000，China）
• Online:2018-09-05 Published:2018-09-05

Abstract:

In order to discuss the change of stable isotopic in extreme weather precipitation, the stable isotope data of Taipei (TP), Wenling (WL), Haining (HN) and Nantong(NT) in the eastern coastal cities of China were applied during the impact of typhoon Chan-hom in 2015, analyzing the spatiotemporal changes of stable isotopes in precipitation. This study reveals characteristics of precipitation isotopes composition at the four sites during typhoon. The average value of δ18O in the “CHAN-HOM” precipitation at TP was -4.40‰, which was the highest value. The lowest value of δ18O precipitation was -9.80‰ at WL. The average values of δ18O precipitation at HN and NT were -8.83‰ and -7.88‰, respectively, which were between those of TP and WL. The pattern of precipitation δ18O at the four sites expressed negative and gradually stable. The rainout effect of precipitation δ18O was obvious. Isotope ratios reveal that the precipitation δ18O decreased inward typhoon’s center and d-excess values increased. The water vapor sources were primarily from moist maritime air mass. At stage one of TP precipitation the δ18O was relatively heavy, the water vapor mixed local evaporation water vapor and was influenced by external circulation of the typhoon. The TP precipitation at stage two and WL precipitation were affected by the single water vapor mass and δ18O value gradually decreased. The distance between HN and the typhoon center was similar to that between NT and typhoon center, and the two cities had the same water vapor source, so that their precipitation δ18O fluctuations were close to each other.