Journal of Geographical Sciences ›› 2011, Vol. 21 ›› Issue (2): 250-262.doi: 10.1007/s11442-011-0842-9

• Climate Change and Disasters • Previous Articles     Next Articles

Spatio-temporal variability of winter temperature and precipitation in Southwest China

JIANG Xingwen1,2, LI Yueqing2   

  1. 1. College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China;
    2. Institute of Plateau Meteorology, China Meteorological Administration, Chengdu 610072, China
  • Received:2010-10-04 Revised:2010-11-28 Online:2011-04-15 Published:2011-06-15
  • Supported by:

    National Natural Science Foundation of China, No.40875060; No.60832012; Basic Research and Operation Program of Institute of Plateau Meteorology, China Meteorological Administration, No.BROP201017

Abstract:

In recent years, the socio-economic impacts of winter extreme climate events have underscored the importance of winter climate anomalies in Southwest China (SWC). The spatio-temporal variability of surface air temperature (SAT) and precipitation in SWC and their possible causes have been investigated in this paper based on observational data from 1961 to 2010. The results indicate that SAT anomalies in SWC have two dominate modes, one is homogenous, and the other a zonal dipole. The former is caused by the anomalies of East Asian winter monsoon; the latter arises from the anomalies of both subtropical west Pacific high and regional cold air in lower troposphere. The most dominant mode of precipitation anomalies in SWC is homogenous and it has a high correlation with northern hemisphere annular mode (NAM,AO). Neither NAM nor ENSO has significant impacts on SAT in SWC. The anomalies of NAM are associated with the anomalies of tropical circulations, and therefore precipitation over the SWC. When NAM is in positive (negative) phase, the winter precipitation is more (less) than normal in SWC. Winter precipitation increase over the whole SWC is associated with the El Ni?o. However, during La Ni?a winter, the pattern is not uniform. There is an increase in precipitation over the central parts and a decrease in western and eastern parts of SWC. The severe drought in SWC in winter 2010 is more likely caused by anomalies of NAM, not El Ni?o.

Key words: Southwest China, winter 2010, drought, winter monsoon, northern hemisphere annular mode (NAM, AO)