Arctic winds from a powerful polar vortex are sweeping ... Arctic air across parts of North America, can disrupt weather ...

A map shared by Jeff Berardelli ... making sure not to leave their skin exposed. A polar vortex is a large area of low ...

A sudden stratospheric warming event reversed the winds that make up the northern polar vortex on March 9. A new animation shows the vortex also moved away from the Arctic towards Europe.

The new Southeast Greenland population, shown as red dots, is located between 60 and 64 degrees north. The map at the right shows the 19 current polar bear subpopulations, with colored dots ...