Journal of Geographical Sciences ›› 2007, Vol. 17 ›› Issue (2): 212-220.doi: 10.1007/s11442-007-0212-9

• Climate and Environmental Change • Previous Articles     Next Articles

Reconstruction of the starting time series of rainy season in Yunnan and the evolvement of summer monsoon during 1711–1982

YANG Yuda1, MAN Zhimin1, ZHENG Jingyun2   

  1. 1. Center for Historical Geography Studies of Fudan University, Shanghai 200433, China|
    2. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
  • Received:2006-09-25 Revised:2006-12-20 Online:2007-06-25 Published:2007-06-25
  • Supported by:

    Knowledge Innovation Program of CAS, No.KZCX3-SW-321-3; Key Project of the Ministry of Education of China, No.01JAZJD770008

Abstract:

According to the textual research into the historical documents dominated by ar-chives yearly, as well as the verification with several other kinds of data, the later or earlier starting time of the rainy seasons in Yunnan during 1711–1982 has been reconstructed. The analysis indicates that there are obvious fluctuations in the starting date of the rainy seasons in Yunnan in a year or years, and long fluctuation on the decadal scale. The rainy season comes earlier in the early 18th century, later in the 19th century and earlier again in the 20th century. This reflects to a certain degree the gradual change of the summer monsoon in Yunnan. There exists an obvious quasi-3 years cycle, which is related to El-Nino’s quasi-3 years cycle, and a 11.3-year cycle which is notably related to the 11-year cycle of the solar activity of starting date of the rainy seasons in Yunnan. Meanwhile, the dissertation finds that the El-Nino is very important to the starting date of the rainy seasons in Yunnan. The starting date of the rainy seasons in Yunnan often comes later or normally in the year of El-Nino. However, there is an obvious imperfect period in such influence, which in turn may mean that there is a certain fluctuation in the effect of ENSO on Asian summer monsoon.

Key words: Yunnan, Qing Dynasty, starting date of rainy season, summer monsoon, ENSO