A historic polar vortex has been sweeping the nation with brutal temperatures and weather conditions over the past few weeks, hitting the Midwest the hardest.

A polar vortex is a strong circulation of upper-level winds that surrounds the northern pole during the winter. When the circulation weakens or becomes distorted, cold air spills from the Arctic regions southward into the United States.

Marshall Shepherd, director of the University of Georgia’s Atmospheric Sciences Program, said scientists are seeing more instances of the polar vortex weakening.

We think it’s due to a sudden warming of the stratosphere where the ozone layer is,” Shepherd said. “That warming causes a split in the polar vortex and allows for the intrusions of Arctic air.”

While Georgia is feeling some of the cooling effects of the polar vortex, Shepherd said it is nothing compared to the life-threatening conditions in the Midwest, where postal services have been suspended and universities closed.

According to Shepherd, places like Chicago, Minneapolis, parts of Wisconsin, and Indiana have been experiencing the harshest of temperatures, with lows around -30 degrees and windchills ranging from -50 to -70 degrees.

While Athens, along with the rest of Georgia, has avoided most of the intensity of the polar vortex, family members and friends of some University of Georgia students are experiencing the record-breaking cold.

Some scientists have suggested that a warming climate may cause polar vortex episodes to occur more often. Although there have been cold days and cold weeks caused by the polar vortex, Shepherd wants to emphasize that climate change is still happening.

Weather is our mood, and climate is our personality,” said Shepherd. “The two aren’t related.”

Madison Lupo is a senior majoring in journalism and minoring in Spanish in the Grady College of Journalism and Mass Communication at the University of Georgia.