Polar vortex freezes the Midwest

Polar vortex fills headlines across the United States yet few understand this atmospheric phenomenon

Luke Garrett / Editor in Chief / The USD Vista

As the polar vortex swept across the Midwest, media headlines, and political banter this past week, many questions are still left unanswered about this atmospheric phenomena between the record-breaking negative-30-degree temperatures, Trump’s tweets, and this frigid event’s ominous yet intriguing name. What is a polar vortex? Is it the result of climate change? How is it that close to 68 million Americans experienced arctic temperatures? What are frost quakes and sea smoke? To understand such an occurrence, the scientific method comes in handy and goes as such.

Observation: the tangible effects

Midwesterners weren’t the only ones left affected by some of the lowest-recorded temperatures with schools and universities closing, public transportation schedules being altered, and beer delivery in Wisconsin being stopped. The earth, too, felt its wrath. Great plumes of sea smoke rose from the great lakes as if from a chimney, as the frigid air swept over the relatively tepid bodies of water that held above it a thin layer of warm air. This warm air contained evaporated water that was quickly condensed into fog. With the polar vortex moving low temperature over the Midwest’s relatively warm waters, sea smoke abounded last week as its creation is proportional to this difference in temperature. The land was not safe from the polar vortex either, as it induced mini-seismic events through the Middle 48. Frost quakes woke and disturbed Midwesterners with great booming and cracking sounds. Water within the ground froze and therefore expanded, creating stress within the land leading to explosive reliefs of pressure – called cryoseisms.

Theoretical context

Despite the otherworldly effects of the polar vortex, it is a familiar and known occurrence to atmospheric scientists. The existence of these circumpolar westerlies has been known since the 1940s along with its cause: the temperature gradient between the poles and lower latitude. And yes, “these” is the correct pronoun in referring to the polar vortex, as it is in reality made up of two distinct circumpolar westerlies: the stratospheric vortex and the tropospheric vortex. 

The former is seasonal and occurs once the last sun of autumn sets and exists until the first sunrise of spring. It rests solidly in the tropospheric level from  zero to 60 degree latitude and seldom affects its lower cousin, the troposphere vortex, as within the stratosphere there is little to impede its violently cold circumpolar winds. 

The latter rests below the former all year round, and covers a wider girth around the northern hemisphere, being bounded by 50-40 degree latitude. The troposphere vortex, unlike its seasonal sibling, has a more volatile path as the water and land mass below often disturb this circumpolar winds path. In regards to extreme weather, the troposphere vortex is the main actor, although the stratospheric vortex also has potential to play a supporting role.

Questions still unanswered

Weather is a highly unpredictable phenomenon, and by extension the polar vortex, as experienced by Midwesterners last week, is difficult to link to direct causes. Debate over whether climate change played a role has risen as the leading question after last week’s cold spout and a conclusion has not yet been reached. The potential for the boundaries of the troposphere vortex to move equatorward, as was also the case in 2014, is often attributed to localized and short-lived boundary displacements and seen by atmospheric scientists as a normal climatology event. 

Although, some scientists across the world are looking deeper into the potential role of climate change as extreme weather conditions are on the rise. A recent study claims that the warming of the arctic weakens the winterly temperature gradient, thus creating a more chaotic stratosphere vortex. To do this, scientists took circumpolar data compiled over the past 37 years tracking the strength of the stratosphere vortex, anf found that the trend of the weakening stratosphere vortex matched that of the warming trend of the arctic. This is of importance as a weak stratospheric vortex is more susceptible to affect its lower siblings and create extreme weather conditions. 

Torero caught in the freeze

To Ben Freidl, a recent USD graduate and current Master’s student at Northwestern, little else mattered about the polar vortex than staying warm in his studio apartment in Chicago. 

“All I know was that is was negative 20 outside and that was all I needed to know that this was a polar vortex,” Freidl said. ”Northwestern actually canceled classes entirely out of fear as there were reports that you would get frostbite if you were out for longer that 10 minutes. I couldn’t leave my place and I had my heat on, but even then there was ice forming on the inside of the windows.”

As a native San Diegan, this weather was like nothing Freidl had ever experienced, with the daily low rising to only minus 10 degrees on Wednesday, Jan. 30.

“You are talking to a guy who grew up in San Diego so this is next level stuff,” Friedl said. “It is indescribable. It is painful when you walked outside. It hits your nose, then you start tearing up and your tears freeze, then your eyelashes freeze, then everything is frozen all around you.” 

Despite having an unexpectedly productive few days off school and a hint of cabin fever, Friedl’s most enduring sentiment concerning last week’s polar vortex were amazement and warning. 

“My message to San Diegans is stay the hell where you are,” Friedl said. “You are in a good spot.”