Abstract
In the study, the summer extreme precipitation in South China is divided into early rainy season (MJ) and late rainy season (JA). The percentile method (95%) is used to define the extreme precipitation threshold. Based on the international general definition method of extreme precipitation threshold: percentile method (95%), the extreme precipitation thresholds in flood season before and after South China are defined respectively. The total amount and frequency of extreme precipitation in flood season before and after 1979-2014 are calculated in this paper. The change trend of the two indicators is basically the same, and the two indicators have obvious interannual variation and an upward trend. According to the results of wavelet analysis of extreme precipitation frequency, the frequency of extreme precipitation in the first flood season mainly has a period of 3 - 5 years, while the frequency of extreme precipitation in the later flood season has a significant period of 6 - 8 years. The spatial distribution of extreme precipitation before and after the flood season shows that the extreme precipitation in the former flood season is mainly distributed in the central part of Guangdong, the northeast of Guangxi and the western part of Fujian, and the extreme precipitation in the latter flood season mainly occurs in the southern coastal area. The results show that there are different tropical SST regions affecting the extreme precipitation in South China. The former flood season is mainly the tropical Indian Ocean warm SST, and the latter flood season is mainly the tropical Pacific warm SST. The tropical Indian Ocean SST stimulates the anticyclonic anomaly over the South China Sea, which brings the southwest warm and humid air flow into South China, resulting in the increase of extreme precipitation in the first flood season of South China; the tropical Pacific SST stimulates the cyclonic anomaly over the South China Sea, which reduces the water vapor outflow caused by the seasonal northward jump of the subtropical high in South China, resulting in the increase of extreme precipitation in the later flood season of South China.
Highlights
Frequent occurrences of flooding are one of the most important meteorological disasters in China
Due to the characteristic of seasonal northward jump of East Asian summer monsoon, the rain belt formed by monsoon precipitation mainly concentrated in South China in June, and moved northward to the Yangtze River valley in July (Ding & Chan 2005; Wang 2006; Huang et al, 2012), this will cause 56 months and 78 months in southern China, extreme precipitation reasons are different, this paper studies the summer extreme precipitation in southern China which divided into early rainy season (MJ) and late rainy season (JA)
When we study the extreme precipitation in summer in South China, we divide it into early rainy season and late rainy season
Summary
Frequent occurrences of flooding are one of the most important meteorological disasters in China. South China is located in the East Asian monsoon region, affected by the monsoon, summer precipitation in South China can be divided into early rainy season and late rainy season. Due to the characteristic of seasonal northward jump of East Asian summer monsoon, the rain belt formed by monsoon precipitation mainly concentrated in South China in June, and moved northward to the Yangtze River valley in July (Ding & Chan 2005; Wang 2006; Huang et al, 2012), this will cause 56 months and 78 months in southern China, extreme precipitation reasons are different, this paper studies the summer extreme precipitation in southern China which divided into early rainy season (MJ) and late rainy season (JA). The percentile method is used to characterize the extreme precipitation, and the temporal and spatial variation and abnormal distribution characteristics of the total amount and frequency of extreme precipitation in the early and late rainy seasons in South China are compared and analyzed, the relationship between the variation of extreme precipitation in the early and late rainy season and the anomalies of atmospheric circulation, Pacific Ocean and Indian Ocean SSTA is analyzed, and the possible reasons for the difference between the early and late rainy season extreme precipitation events in South China are discussed, deepening our understanding of summer extreme precipitation in South China will help us to analyze and predict the changes of summer extreme precipitation in South China under the global warming environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
