Abstract：Personal diary is a precious proxy data for historical weather and climate reconstruction with high resolution. According to the index of rainfall days recorded in the diary named Zhashanxueren Diary in Shanghai area during AD 1800-1813 in the early nineteenth century when diaries are relatively deficient,this paper reconstructs the characteristics of Meiyu during this period.We distinguish the recorded rainfall days for 5 precipitation grades by which the instrumental daily precipitation of Shanghai Longhua station during AD 1951-1998 is distinguished,so the precipitation of Meiyu and the precipitation in flood season during AD 1800-1813 can be reconstructed according to the regression relationship between rainfall days for 5 grades and precipitation of Longhua station. The results show that:(1)During AD 1800-1813,the average starting date of Meiyu was 10th,June, the ending date was 7th,July, the rainfall days was 20.1 days,the duration of Meiyu was 27.1 days,the precipitation was 257.3 mm,and the precipitation in flood season was 669.5 mm.The annual starting and ending dates of Meiyu were similar with that reconstructed by Yu Xue Fen Cun, but the precipitation of Meiyu was different. (2)As a whole,comparing with meteorological observation data of every 10 years at Longhua station during AD 1951-1998,it is found that the average starting and ending dates of Meiyu during AD 1800-1813 were earlier than present.The rainfall days,duration,and precipitation of Meiyu were a bit larger. The strength of Meiyu was more stronger,and the precipitation in flood season was at moderate level. However,there is no significant difference in the characteristics of Meiyu and the precipitation in flood season between AD 1800-1813 and decadal scale during AD 1951-1998,the characteristics during AD 1981-1990 and AD 1990-1998 are more closer to AD 1800-1813. (3)“Rainfall days, length of Meiyu”as well as the precipitation in flood season have a good correspondence with drought-flood conditions and the spatial distribution characteristics of precipitation indicated by the strength of East Asian Summer Monsoon(EASM),which shows that the used diaries,including the reconstrcution methods and results in the paper are with high reliability.
