Arctic polar vortex area
Arctic polar vortex intensity
500 hPa northern polar vortex
breakup of polar vortex
Circulation indices of polar vortex at 10 hPa
Polar vortex abnormality
Polar vortex oscillation
Stratospheric Polar Vortex
The core of the polar vortex
The splitting of the Polar Vortex
the Stratospheric Polar Vortex
arctic air [= arctic air mass]
bias between the mass center and siffness center