“Polar Vortex” is 2014′s Newest Buzzword

In this past few days the word Polar Vortex and Arctic Blast are tending in news and in social media all over. 

Much of the United States has plunged into a deep freeze from record low temperatures. One of the coldest Arctic outbreaks in two decades has plunged into country, bringing bitterly cold temperatures to the Midwest, South and East. 

The bitter chill gripping North America is a result of Arctic air that has spilled southwards, and global warming may be a cause. As tundra-like temperatures and wind chills as cold as 70 below zero fan out across the country, everyone is blaming the "polar vortex”.

What is a polar vortex? What distinguishes it?

Polar Vortex: A polar vortex is basically a great swirling pool of extremely cold air located tens of thousands of feet in the atmosphere. Basically an arctic cyclone, it ordinarily spins counterclockwise around the north and south poles.

When the vortex weakens, the air starts heading southwards, bringing exceptional snow and chill to middle latitudes.

A polar vortex (also known as a polar cyclone, polar low, or a circumpolar whirl) is a persistent, large scale cyclone located near either of a planet's geographical poles.

On Earth, the polar vortex are located in the middle and upper troposphere and the stratosphere. They surround the polar highs and lie in the wake of the polar front. These cold-core low-pressure areas strengthen in the winter and weaken in the summer due to their reliance upon the temperature differential between the equator and the poles.Unlike a hurricane, these are frigid polar winds, circling the Arctic at more than 100 miles per hour.

Last month, European scientists reported that the volume of sea ice in November was around 50 percent greater compared with a year earlier, following a recovery in the Arctic summer. 

Where on Earth can this happen?

The polar vortex can lead to major cold air outbreaks in any portion of the Northern Hemisphere -- North America, Europe and Asia. This will lead to cold snaps in multiple locations, though not always.

"Temperatures across half the U.S. are plummeting like a rock. So what is this mysterious marvel and why is it invading America? The polar vortex is a prevailing wind pattern that normally keeps extremely cold air bottled up toward the North Pole. Occasionally, though, the vortex weakens, allowing the cold air to pour down across Canada into the U.S. In addition to bringing cold, the air mass can push the jet stream that typically flows from the Pacific Ocean across the U.S. much farther south as well."

How dangerous is a polar vortex distortion as compared to a tornado or hurricane?

Completely different type of systems. A cold air outbreak caused by the polar vortex is much more widespread and lasts longer than a single storm. With the widespread drop in temperature, however, you can see significant winter storms develop, especially when the cold air is initially advancing into a previously warm region -- much like the nor'easter this past week.

What Caused the Polar Vortex to Move?

i. Polar vortices are weaker during summer and strongest during winter. Volcanic eruptions in the tropics lead to a stronger polar vortex during the winter for as long as two years afterwards. 

ii. The Arctic vortex is elongated in shape, with two centers, one normally located over Baffin Island in Canada and the other over northeast Siberia. In rare events, when the general flow pattern is amplified (or meridional), the vortex can push farther south as a result of axis interruption, such as during the Winter 1985 Arctic outbreak. 

iii. The Antarctic polar vortex is more pronounced and persistent than the Arctic one; this is because the distribution of land masses at high latitudes in the Northern Hemisphere gives rise to Rossby waves which contribute to the breakdown of the vortex, whereas in the Southern Hemisphere the vortex remains less disturbed.

iv. The vortex is threatening temperatures as low as minus 30 degrees Fahrenheit in the Plains and in the negative 20s and negative teens farther into the Midwest.

v. According to the National Weather Service, the Upper Midwest, where some of the lowest temperatures are occurring, is currently more than 98 percent snow-covered. The Upper Great Lakes region is 100 percent snow-covered, and the Midwest is more than 76 percent covered.

Is it a side effect of global warming and should we expect more events like this?

This is a hotly researched topic. In short, yes, it could be. It seems counter intuitive that global warming could cause significant cold snaps like this one, but some research shows that it could. We know that different types of extreme weather can result from the overall warming of the planet, melting of the Arctic Sea ice, etc. This includes extreme distortions of the jet stream, which can cause heat waves in summer and cold snaps in winter. 

So, When Will the Cold Air Stop?

When the strong air from the Eastern Pacific weakens and falls apart, the polar vortex will retreat and go back into place near the North Pole.

Until then, temperatures across the northern Plains and Midwest will continue to be life-threateningly cold, shattering some all-time low record highs.