the polar vortex

基本解释

For the polar vortex area on the Northern Hemisphere, in summer the polar vortex boundary withdraw about 30 latitudes than winter.
冬夏季北半球极涡面积的比较发现夏季和冬季相比极涡边界收缩了近30个纬度。
Besides, the evolutions of the polar vortex, the trough over Bast Asia and the subtropical high prior to Mei-Yu period are also related to the precipitation during Mei-Yu period.
在前期环流演变中发现极涡、东亚槽、副高等对梅雨的丰枯亦有较好的预兆反映。
Meanwhile, planetary waves propagating upwards also affect the polar vortex in the stratosphere, and then affect the Arctic centers of action of the AO.
同时准定常行星波冬季向上传播至平流层并与平流层极涡相互作用从而也影响了北极涛动在北极的活动中心。

极涡
From 1961 to 2006, polar vortex area in the northern hemisphere decreased, and the polar vortex area index was positively correlated with the number of stong wind days.
1961年到2006年,北半球极涡面积呈减少趋势,极涡面积指数与东北地区大风日数呈正相关。