Stratospheric warming brings icy cold temperatures

After the disintegration of the polar vortex in the Arctic stratosphere, an icy easterly wind blows in Central Europe. IAC professor Daniela Domeisen explains the connection between why Siberian conditions currently prevail in Europe, while New Yorkers can enjoy summery warmth.

After a rather mild winter so far, we feel it right now: the temperatures in Zurich have fallen noticeably and will continue to drop considerably below zero degrees Celsius next week due to a flood of icy air from the east, in the mountains below minus ten degrees Celsius. It is likely that the cold easterly winds will reach the British Isles and France. For the time being, there is no mild westerly wind in sight that would drive away the cold.

Icy cold in Europe

This change in weather is associated with a remarkable phenomenon in the Arctic stratosphere: Usually in winter, a huge cold air vortex rotates over the Arctic at an altitude of 30 to 50 kilometers.. About a week ago, this vortex spun off into two smaller ones. Meanwhile, milder air from lower latitudes entered the Arctic stratosphere.