1月北极涛动异常程度特征及其对北半球同期温度的影响

将1月北极涛动（AO）大气遥相关型的强度分为：正常、异常和极端异常3类典型年进行讨论,发现其同期大气环流及其对北半球温度影响存在显著的异同性：当AO呈异常和极端异常时,均表现为东亚大槽、乌拉尔山、贝加尔湖阻塞高压、阿留申低压的持续、稳定异常,但对应极区涡旋的强度、面积及其向南、向北的扩展等有所差异,与NPO、NAO正、负位相对应,致使冷空气在极地和中、高纬度活动范围不同。极端异常年的影响强度和范围较异常年偏大、偏南,高低空配置使冷空气向北半球中低纬度地区延伸,异常低温可扩展至北太平洋暖池区。

Abnormal Characteristics and Its Influence on the Northern Hemisphere Temperature of Arctic Oscillation in January

Based on the analysis of typical Arctic Oscillation (AO) years, this article classifies the January AO strength into normal, abnormal and extreme anomaly categories and investigates the characteristics of the atmospheric circulations associated with these three different AO strength as well as their effects on the North Hemisphere January surface temperature. The results show that the atmospheric circulations associated with these three AO strength and their effects on North hemisphere January surface temperature have significant similarities and differences. When AO is in abnormal or extreme anomaly phases, the similar and typical AO positive and negative phase distribution are observed from the lower troposphere to the tropopause. The atmospheric circulations in 500hPa are shown as the continual and stable east Asia trough, Ural Mountains and Lake Baikal blocking high, and Aleutian low. However, the corresponding intensity, area, southward and northward extension of polar vortex associated with these two AO patterns are different, which caused the different range of cold air activities in the middle and high latitude as well as the polar region. During the extreme anomaly years, the strength and the range of influence of AO are larger and more southward than that in the abnormal AO years, the corresponding configuration of high and low level atmospheric circulations cause the cold air extend to the middle and lower latitude of North Hemisphere, and the abnormally low temperature can extend to the North Pacific warm pool.