贵州省铜仁市雨季开始期演变特征及环流分析

通过1961—2012年铜仁市各站的逐日降雨量统计出雨季开始期,利用EOF和小波分析方法,得出铜仁市雨季开始期的空间分布特征及时间演变特点:铜仁雨季开始期主要是各地一致偏早(晚)型,其次是西北部与东南部雨季开始期呈反位相变化;雨季开始期偏晚年份为1975、1976、1986、1988、1995、1996、2005、2007、2011年,偏早年份为1961、1977、1989、1990、1993、2002、2008年;1985年之后,雨季开始期2～4 a变化周期显著。同时,利用NCEP/NCAR月平均北半球500 hPa环流资料,分析铜仁雨季开始期偏早年与偏晚年的3—5月之间的环流差异,让政府决策部门和公众对铜仁市雨季开始期时空演变特征有较为清晰的认识,也为更好预测雨季开始期奠定基础。

Beginning Period Evolution Characteristcs of Rainy Season and the Circulation Analysis in Tongren City of Guizhou

The spatial distribution and the temporal evolution characteristics of the beginning of the Tongren rainy season are analysed through using EOF and wavelet analysis method based on the daily stations rainfall statistics during 1961 to 2012. There are the following results： the beginning of Tongren rainy season is the unity of late （early） type, following by the anti - phase change of the northwest and southeast. The late years of the beginning rainy season incfuding： 1975,1976,1986,1988 ~ 1995,1996,2005,2007,2011, the early years is 1961,1977, 1989,1990,1993,2002,2008. The beginning of Tongren rainy season has a noteworthy 2 -4 year cycle. At the same time, Using the NCEP/NCAR monthly mean 500hPa circulation data in Northern Hemisphere, the 6irculation differences from March to May of the for the government decision -making beginning of the rainy season period are demonstrated, which is the foundation and a better understanding of the be~innin~ rainv season to the oeoole.