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利用1954～2001年我国150站日平均气温资料,分析了历年冬季期间(11月1日到次年3月31日)气温方差的变化与北极涛动的关系。发现北极涛动处于较强的正位相时,我国日平均气温方差偏小,反之则偏强。主要是通过影响西伯利亚高压中心区的海平面气压的高频变率而影响我国日气温的波动,季节尺度内异常低温事件(日气温距平<-2σ,σ为各站各冬季日气温距平的标准差)频次与气温方差之间存在反常的关系:温度方差大(小)时,异常低温事件频次下降(上升)。这与气温的非正态分布有关,也明显受北极涛动位相及强弱的影响。近50年来随着北极涛动指数的增强,西伯利亚高压中心区海平面气压方差显著下降(-10.7％/10a),我国日气温的变率也在显著减少(-4.1％/10a),而异常低温事件频次则显著增加(0.16d/10a)。
Based on the daily average air temperature data of 150 stations in China from 1954 to 2001, the relationship between the temperature variance and the Arctic oscillation during the winter (November 1 to March 31) was analyzed. When the Arctic Oscillation was found to be in a strong positive phase, the daily average temperature in China was small, and on the contrary, it was too strong. Mainly through the influence of the high frequency variability of the sea level pressure in the central high-pressure area of Siberia, the daily temperature fluctuation in our country and the abnormal low-temperature event in the seasonal scale (the daily temperature anomaly is <-2σ, σ is the daily temperature anomaly Of the standard deviation) There is an abnormal relationship between frequency and temperature variance: When the temperature variance is large (small), the frequency of abnormal low temperature events decreases (increases). This is related to the non-normal distribution of temperature and is also significantly affected by the phase and strength of the Arctic oscillations. In the recent 50 years, with the increase of the Arctic Oscillatory Index, the sea surface pressure variability in the center of Siberia decreased significantly (-10.7% / 10a), and the daily temperature variability in China also decreased significantly (-4.1% / 10a) The frequency of cold events increased significantly (0.16d / 10a).