1951～1999年中国降水和气温的SEOF分析

SEOF Analysis on the Precipitation and Temperature in China during 1951-1999

[目的]研究1951～1999年我国降水和气温的季节变化特征。[方法]利用我国气象局提供的160个站1951年1月～1999年2月的月平均降水和气温资料,运用SEOF方法研究了48年我国降水和气温的时空变化特征。[结果]降水的SEOF分析表明,第1模态的SEOF分析表现了我国雨带从南到北的四季推进;从时间系数来看,总体上,20世纪60～70年代我国降水略有减少,70年代后降水是增多的趋势,80年代后降水又是减少的趋势。气温的SEOF分析表明,降水的第1模态和气温的第1模态在空间上配置较好,降水量少的干旱区域,温度变化比较明显,配合时间序列来看,1951～1999年我国气温是偏低;20世纪50年代为低温时期,50～60年代前期气温有所升高,60年代中、后期～70年代初期又进入低温时期,70年代中期至90年代末气温变化相对稳定增大。[结论]该研究为我国气候变化提供理论依据。

[ Objective ] The research aimed to study the seasonal variation characteristics of precipitation and temperature in China during 1951 - 1999. [ Method] Based on the monthly average precipitation and temperature data in 160 stations from January,1951 to February, 1999 which were provided by China Meteorological Administration, the spatial-temporal variation characteristics of precipitation and temperature in China in 48 years were studied by using SEOF method. [ Result ] SEOF analysis of precipitation ： the first modal SEOF analysis showed the four-season propulsion of rain belt in China from south to north. Seen from the time coefficient, as a whole, the precipitation in China slightly decreased during the 1960s- 1970s. After the 1970s, the precipitation had the increase trend and had the decrease trend after the 1980s. SEOF analysis of temperature ： the first modals of precipitation and temperature configured well in the space. In the dry zone where the precipi- tation was less, the temperature variation was obvious. Coordinated with the time sequence, the temperature in China during 1951 - 1999 was low, and it was the low temperature period in the 1950s. The temperature rose during the 1950s - 1960s, and it entered into the low tempera- ture period again from the middle and latter periods of 1960s to early the 1970s. From the metaphase of 1970s to the end of 1990s, the temper- ature relatively stably increased. [ Conclusion] The research provided the theory basis for studving the climate variation in China.