Polar Vortex:
The polar vortex circling the Arctic is swirling in the wrong direction after warming in the upper atmosphere triggered a major reversal event recently.
- The polar vortex is a large area of low pressure and cold air surrounding both of the Earth’s poles. It weakens in summer and strengthens in winter.
- The term “vortex” refers to the counter-clockwise flow of air that helps keep the colder air near the poles.
- Many times, during winter in the northern hemisphere, the polar vortex will expand, sending cold air southward with the jet stream.
- This occurs fairly regularly during wintertime and is often associated with large outbreaks of Arctic air in the United States and Canada.
- Portions of Europe and Asia also experience cold surges connected to the polar vortex.
- The polar vortex extends from the tropopause (the dividing line between the stratosphere and troposphere) through the stratosphere and into the mesosphere (above 50 km).
- Low values of ozone and cold temperatures are associated with the air inside the vortex.
- Jet streams are narrow bands of strong wind that generally blow from west to east all across the globe.
