Midwest colder than usual, thanks to polar vortex

February 6, 2014 6:17 AMComments Off

Story by Avery Gregurich

Unpredictable. Erratic. Fickle.

These are all words used to describe a typical Iowa winter.

But this year, Iowa’s frosty winter has been a study in dependability.

“The statewide average temperature-both highs and lows-since Oct. 1 has been 29.9 degrees,” the Des Moines Register recently reported. “The 120-year average for that period is 34.2 degrees.”

Iowa is not the only state undergoing a bone-chilling winter, though.

The first week of the New Year found nearly all land area east of the Rocky Mountains in a state of dangerously low temperatures and high amounts of snow fall. Meteorologists and news anchors began warning their viewers of the polar vortex that was upon them.

What is a polar vortex?

A polar vortex is a “strong, counter-clockwise circular flow in the vicinity of the poles,” said David Courard-Hauri, the director of environmental science and policy program at Drake University. “This flow is powered by the difference in temperature between the pole and the temperate zone.”

At the meeting of these two zones, there is an area called the “arctic front,” Courard-Hauri said. While the “air over Iowa is the temperate air, sometimes the arctic front moves far enough south to cover us, and we get very cold air.”

And that’s not the worst of it.

“Sometimes behind the arctic front there is an even colder region of air that has formed over the pole and is cycling rapidly,” Courard-Hauri said. “That is the polar vortex.”

In the past, the difference in temperature between the two areas has kept the polar vortex closer to the pole.

“What has been happening recently,” Courard-Hauri said, “is that the difference in temperature between the poles and temperate regions is still very large, but it is less large than it has been in the past, presumably due to climate change.

“That means that the vortex itself weakens, and rather than flow in a nice, tight circle, the arctic front kind of meanders around more than usual.”

This meandering has led the vortex to dip further south, causing the frigid temperatures in Iowa and the rest of the area east of the Rocky Mountains.

Drake students from throughout the Midwest have noticed the change in temperature both here in Iowa and in their home states.

Benjamin Bovard, a junior finance and law, politics and society double major, is a Minnesota native.

“It has been a lot colder than usual in Des Moines this winter, and there seems to be less snow on the ground than in past years,” Bovard said.

His home state has also felt the effects of the polar vortex.

“In Minnesota, this winter it has been much colder,” Bovard said. “At one point over winter break it was around -45 degrees with the wind chill.”

Anna Chott, a junior environmental science and environmental policy double major, is from St. Louis, Mo. She has resided in Des Moines for three years and said that this winter has been particularly bitter.

“The last two winters were much less bitter than this one,” Chott said.

Chott also said that while St. Louis’ winter has been “noticeably warmer than in Des Moines,” there has been “more snow in St. Louis than usual.”

“They rarely get much snow, but this year it sounds like they’ve gotten more snow than Des Moines,” Chott said.

The Minnesotan Bovard remained optimistic despite the icy temperatures.

“It’s going to get warmer sooner or later,” Bovard said.

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