VOA慢速英语:北极上空的暖空气冻结了欧洲

causal –adj. having to do with a cause

jet stream –n. a strong current of fast wind traveling above the earth in one direction

penetrate –v. to go through or into something or someplace

stratospheric - adj. relating to the upper layer of the Earth's atmosphere

anomaly –n. something that is not expected or unusual

perceptions –n. the way a person thinks about a something or someone