WEER
Noord-Amerika in de greep van arctische luchtstroom
January 30, 2019 -
De polaire vortex brengt voor de tweede keer sinds 2014 dodelijk koud
weer in grote delen van de Verenigde Staten.
It all started with misplaced Moroccan heat. In December, the normally super chilly air temperatures 30km above the North Pole rapidly rose by about 70 degrees Celsius, thanks to air flowing in from the south. It’s called “sudden stratospheric warming.”
That warmth split the polar vortex, leaving the pieces to wander, said Judah Cohen, a winter storm expert for Atmospheric Environmental Research, a commercial firm outside Boston.
Americans were introduced to the polar vortex five years ago. It was in early January 2014 when temperatures dropped to minus minus 27C in Chicago and meteorologists, who used the term for decades, started talking about it on social media.
This outbreak may snap some daily records for cold and is likely to be even more brutal than five years ago, especially with added wind chill.
Scientists are debating whether polar vortexes are occurring more frequently, and if this is due to climate change.