What is it?

• A polar vortex is a large area of persistent low pressure, generally located above each of Earth’s polar regions, containing a mass of extremely cold air.

Characteristics of Polar Vortex:

• The direction of the vortex is anti-clockwise.
• Usually exists in the area between the troposphere and the stratosphere.
• The polar vortex helps keep the jet stream stable, preventing cold air from moving south.
• It is strongest in winter and helps the polar region remain cold by keeping the Arctic air confined near the poles.
• When the temperature difference between polar and mid-latitude (temperate) regions is very high, the jet stream becomes extremely strong and flows in a relatively straight path with minimal waviness.
• However, when this temperature contrast weakens, the jet stream loses strength and begins to meander, forming large atmospheric waves known as Rossby waves.
• This leads to :
  • Severe winter storms in the US, Canada, and Europe
  • Unusual cold waves in mid-latitudes

Source: The Indian Express