AUTHOR=Zhou Yuliang , Zhou Ping , Zhang Yuliang , Wu Chengguo , Jin Juliang , Cui Yi , Ning Shaowei TITLE=Characteristics of Precipitation During Meiyu and Huang-Huai Rainy Seasons in Anhui Province of China JOURNAL=Frontiers in Earth Science VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2021.751969 DOI=10.3389/feart.2021.751969 ISSN=2296-6463 ABSTRACT=

Based on the spatial distribution characteristics of the summer monsoon rain belt, Anhui Province of China is divided into three regions, namely, the south of the Yangtze River region (SYA), the Yangtze-Huai region (YHA), and the north of the Huaihe region (NHA). The western Pacific subtropical high (WPSH) ridge and the number of regional rainy days are adopted to identify the onset and ending dates of Meiyu and Huang-Huai rainy seasons during 1957–2020, using China’s national standard on “Meiyu monitoring indices.” Then precipitation characteristics of these three regions during Meiyu and Huang-Huai rainy seasons are investigated. Finally, the return periods of the precipitation during the northward movement of summer monsoon over Anhui Province are calculated. The results show that there are 7 years without the occurrence of Huang-Huai rainy season, but 8 years with the occurrence of two Meiyu periods and 5 years with two Huang-Huai rainy periods. Thus, there is only one Meiyu period and one Huang-Huai rainy period in the rest 49 years. For the first Meiyu period during 1957–2020, the average onset and ending dates are 14th June and 10th July, respectively, while the corresponding precipitation presents a decreasing tendency from south to north regions in Anhui Province. For the first Huang-Huai rainy period during 1957–2020, the average onset and ending dates are 10th July and 23rd July, respectively, and the corresponding precipitation shows an increasing tendency from south to north regions. For the northward movement of summer monsoon over Anhui Province, the average onset and ending dates are 14th June and 25th July, respectively, and the corresponding precipitation in NHA is close to that in YHA, but less than that in SYA. Annual precipitation in SYA, YHA, and NHA are 999.5, 1010.6, and 618.7 mm, respectively, during the northward movement of summer monsoon over Anhui Province in 2020, and the corresponding return periods are 56.0, 161.6, and 29.2 years, respectively.