“拉尼娜”非典型影响下的新疆2021/2022年冬季气温

2021/2022年冬季新疆大部气温偏高，影响新疆冷空气活动频次少，并非拉尼娜事件对新疆冬季气温的典型影响特征。成因分析表明：2021/2022年冬季北极涛动（AO）为正位相，欧亚中高纬度500 h Pa位势高度西高东低，新疆上空700 hPa南风距平优势明显。2021/2022年冬季“拉尼娜”非典型影响新疆气温的原因主要来自于东部型弱拉尼娜事件对北大西洋涛动（NAO）和亚洲极涡面积的非典型影响，而对亚洲极涡面积的非典型影响是来自东部型拉尼娜事件对冬季AO的不确定性影响，冬季AO正位相有利于新疆气温正距平。2月300 hPa区域纬向风异常偏弱，削弱了NAO正位相对新疆气温的影响；70°E以东中纬度高度场负距平是冬季气温阶段性变化的原因之一。

The atypical influence of La Nina on winter temperatures in Xinjiang 2021 / 2022

In the winter of 2021 / 2022, the temperature in most parts of Xinjiang is high, and the frequency of cold air activities in Xinjiang is less . It is not the typical influence characteristic of the La Nina event on the winter temperature in Xinjiang. The results show that the dynamic of the Arctic oscillation(ao) is the positive phase in the winter of 2021/2022.The potential of 500hpa in Eurasia is high in the west and low in the east, and the south wind over Xinjiang at 700hpa is obvious. The atypical influence of the temperature in Xinjiang in winter 2021 / 2022 by the eastern weak La Nina event is mainly derived from the atypical effect on the North Atlantic oscillation (nao) and the polar vortex area in the Asian region. However,the atypical effect on the polar vortex area is the uncertain effect from the eastern La Nina event on the winter AO. The winter AO is conducive to the positive temperature in Xinjiang. The abnormally weak latitude wind in February 300hpa weakens the influence of NAO positive position on Xinjiang temperature; the east of 70°E is one of the reasons for the periodic change of temperature in winter.