近54 a江苏梅雨演变特征及2014年梅雨监测分析

Evolution characteristics of the Jiangsu plum rain in recent 54 years and its monitoring analysis in 2014

通过对1961—2014年江苏省56个常规气象观测站降水及历年5—8月太平洋副热带高压资料进行了整理、订正及分析,揭示了江苏省梅雨入出梅日期、梅雨量、梅雨强度等特征量的变化趋势及年代际变化差异,并对2014年江苏省梅雨异常进行了分析。研究表明:长江以北和长江以南站点均表现出梅雨强度增强,梅雨期内降水频次和强降水事件频次增多的趋势,其中长江以南的梅雨强度、降水频次和强降水事件频次的变化趋势分别为0.18/(10a)、0.75 d/(站·10a)和0.25 d/(站·10a)较长江以北的变化趋势0.07/(10a)、0.01 d/(站·10a)和0.08 d/(站·10 a)更为明显,年代际变化特征也不尽相同。从2014年梅雨监测来看,长江以北处于空梅年份,长江以南则出现了长度为11 d的梅雨。

According to the daily precipitation data at 56 stations in Jiangsu during 1961-2014 and the western Pacific subtropical high data, the trend and the inter-deeadal variation of Meiyu charactersincluding onset data, ending data, total rainfall and intensity are showed. And analyses are conducted on the abnormality of Meiyu in Jiangsu in 2014. The results shown there are increasing trends of intensity, precipitation frequency and heavy precipitation in the north of Yangtze River and south of Yangtze River. The trends of intensity, precipitation frequency and heavy precipitation are 0. 18/（ 10a）, 0.75 d/（ station. 10a） and 0. 25 d/（ station·10a） in south of Yangtze River. The values in north of Yangtze River are larger than the values of 0. 07/（ 10a）, 0. 01 d/（ station·10a） and 0.08 d/（ station·10a）. Obviously, they are larger in south of Yangtze River than in north. In 2014, Meiyu is empty in the north of Yangtze River and 11 days in the south of Yangtze River.