Whats the difference between “arctic” and “polar” air?
An air mass is simply a large volume of air that has similar temperature and water vapor content throughout. Air masses tend to take on characteristics of the areas where they form. In the case of arctic air, the source region for the air mass is above the Arctic Circle. This cold and dry air tends to only form during the winter. Polar air masses form at high latitudes, but not typically above the Arctic Circle. While not as cold or dry as arctic air, polar air can result in winter storms in the USA as well as welcome relief during hot summer months. Learn more about air masses on this USA TODAY resource page.
