also: きょくか
noun
polar vortex; polar cell
Meteorological term for a large-scale cyclone near the poles. 極渦 usually refers to the polar vortex, while 極細胞 (polar cell) is a related but distinct concept; the source groups them together.
極渦が南下すると、寒波がやってくる。
When the polar vortex moves south, a cold wave arrives.
成層圏の極渦は冬に強まる。
The stratospheric polar vortex strengthens in winter.
極細胞 (polar cell) is a component of atmospheric circulation, while 極渦 (polar vortex) is a specific cyclonic feature. They are distinct in meteorology.
Compound of 極 (pole) and 渦 (vortex, whirlpool). The reading きょくうず is the standard combination; きょくか is a less common alternative reading of the same kanji.