Abstract:

Using daily meteorological data from 1951 to 2008 on 112 stations of seven provinces in southern  China，the Maximum Difference Normalization Data Analysis Method was used to develop a Comprehensive Index System(CIS) which could reflect the temporal and spatial distribution of the freezing weather happened in southern China.The index system defined the freezing day，the freezing process at single station，freezing index and regional consecutive freezing process，finally the freezing process was classified based on the fraction of Comprehensive Freezing Index，the annual starting and ending data and geographical range in consecutive freezing process were given.Results show that：(1)The five serious regional consecutive freezing disasters happened in southern China are in 2008，1955，1984，1964 and 1957，especially in early 2008，and the number of frost days and Freezing Index decreased obviously during 1951~2008；(2)The most extreme freezing weather happened in Guizhou Province，next in Anhui，Hunan and Hubei Province.The freezing weather showed better correlation with the altitude，i.e.，the higher of the altitude the more extreme of the frozen；(3)In southern China，ice storm happened mainly in Guizhou province and in southern Hunan province while other regions are snowfall.The Comprehensive Synoptic Weather Index proposed in this paper is comparable in spatialtemporal variation，and can well describe the spatialtemporal variation of the freezing weather