陕北地区冬季气温的时空变化特征分析

The spatiotemporal variation characteristics of winter temperature in northern Shaanxi Region

根据1960-2009年陕北地区逐月气温资料,运用Mann-Kendall法、小波分析、空间插值等方法,对陕北地区近50年来冬季气温的时空分布特征和突变、周期变化规律进行了分析。结果表明:冬季气温总体上呈现增暖的趋势,其线性增长率为0.55℃/10a,相当于近50年冬季气温升高了2.76℃。冬季气温存在15、10 a和6a左右的周期振荡期,其中15年左右的振荡周期较强。1988年冬季气温发生突变,之后进入偏暖期,1993年后增温趋势更加显著。冬季气温空间分布不均,大致呈现出由南向北逐减的趋势,这种分布与纬度呈较高的负相关关系。

The meteorological data from 1960 to 2009 were analyzed to understand the spatial-temporal characteristics about temperature variation in winter over Shanbei Region,by employing the approach of linear trend analysis as well as Mann-Kendall rank analysis,wavelet analysis and spatial interpolation.It was observed that there was an obvious ascending tendency of winter air temperature from 1960 to 2009 in this region,with a warming rate of 0.55℃/10a in winter.The result indicated that the winter temperature of this region increased by 2.76℃ in the last five decades.Meanwhile,in the last half century,there was typical oscillation such as 6a,10a and 15a in winter temperature variation,particularly,the15a oscillation dominated.During the study period,there was a lowest average winter temperature point in 1967 and a highest one in 2001 with an abrupt change point in 1988,after it a warm stage emerged especially after 1993.Spatial variation of winter temperature indicated that there was an obvious degressive tendency from south to north in the study area,and this distribution has a higher negative correlation with latitude.