影响我国冬季温度的若干气候因子

Several Climate Factors Influencing the Winter Temperature over China

综合分析了西伯利亚高压、北极涛动、ENSO和西太平洋遥相关型(WP)在年际和年代际时间尺度上对中国冬季温度的影响,结果表明在年际尺度上,WP和西伯利亚高压都对温度有显著影响,WP的影响主要存在于中国东部从东北南部至广东沿海一带大陆边缘区,而西伯利亚高压的影响范围则大得多,几乎涵盖了除黄河长江上游部分地区外的整个中国。在年代际尺度上,北极涛动和ENSO都与东亚冬季风有关联,北极涛动比ENSO的影响范围大,除长江上游沿江地区外的其他地区基本上都是关联区,ENSO与温度的关联区位于35°N以北的整个北方及长江中下游地区。

Recently, many studies have described the relationship between winter temperature in China and some climate systems including the Siberian high （SH）, the Arctic Oscillation （AO）, ENSO and the western Pacific teleconnection pattern （WP）. For example, during the past 100 years the winter temperature in China has been closely related to the intensity of SH which may be possibly influenced by global warming. The winter temperature in China also changes in phase with AO which is an important mode in boreal winter. In addition, ENSO exhibits the greatest influence on the interannual variability of the global climate. Li et al （2007） also pointed out that temperature in the east of the marginal areas in China is well associated with WP. In these studies, however, only one single factor instead of the joint effects of two or more is usually considered. Many meteorological variables are in fact influenced by many factors at the same time and the true relationship cannot be indicated when only considering the simple correlation coefficient between two variables. Until now, the relationship of many factors and their effects on temperature are still unknown. Therefore, it is necessary for us to do some researches on temperature by using the partial correlation coefficient. It is assumed that there are three random variables X1, X2 and X3, which submit Gaussian distribution. The variable X2 and X3 are related to X1. According to statistic theory, the partial correlation coefficient ρ12.3 is the correlation coefficient between X1 and X2 when X3 is constant, which means that the influence of X3 has to be eliminated when the relationship between X1 and X2 is considered. In addition, the variations on the interannual and interdecadal timescales are considered separately in this study. After subtracting by 9-year running mean, which is regarded as the interdecadal components, the remains are referred to as the interannual components. In this paper, the effects of SH, AO, ENSO and WP on the winter temperature in China on the interannual and interdecadal timescales are investigated by using the partial correlation analysis. The results show that the western Pacific teleconnection pattern and the Siberian high have significant influence on winter temperature in China on the interannual timescale. The western Pacific teleconnection pattern mainly influences the east of marginal areas from the south of Northeast China to coastal cities in Guangdong Province. The region associated with the Siberian high covers almost the entire China except for the upper reaches of the Yangtze River and the Huanghe River, which is larger than that associated with the western Pacific teleconnection pattern. However, the temperature is strongly affected by AO and ENSO on the interdecadal timescale. The area under the impact of ENSO includes North China and the mid- and lower reaches of the Yangtze River. Compared with ENSO, AO affects larger areas including the entire mainland exeent for some re,ions in the upper reach of theYangtze River.