Polar vortex: what is it and how is it linked to climate change?

Source: The Guardian

Polar vortex: what is it and how is it linked to climate change?

The polar vortex has broken into ‘two swirling blobs of cold air’, bringing the most frigid conditions in decades to the midwest

Oliver Milman in New York
Wed 30 Jan 2019 17.08 GMT

What is the polar vortex?

As its name suggests, the polar vortex is found around the north pole. It’s a band of strong winds, high up in the atmosphere that keeps bitterly cold air locked around the Arctic region. This circulation isn’t considered a single storm, or even a weather pattern as such.

Why is it affecting the US?

Occasionally, the vortex can become distorted and meander far further south than normal. The phenomenon became widely known to Americans during a particularly frigid spell in 2014, when the media first started using the term “polar vortex”. It was also a factor in the “bomb cyclone” that battered the US east coast last year.

This time, the polar vortex has broken in two, bringing the coldest conditions in decades to the midwest US. On Wednesday, Chicago was 10 degrees F colder than Antarctica.

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Is this weather event linked to climate change?

Studies have pointed to a recent increase in instances where the polar vortex has bulged down into heavily populated areas. Scientists are gaining a better understanding of why this is happening, with many identifying climate change as an influence.

There’s some evidence that the jet stream, a meandering air current that flows over North America and Europe, is slowing and becoming wavier as the planet warms. The jet stream interacts with the polar vortex, helping bring numbing temperatures further south.

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Read more: https://www.theguardian.com/us-news/2019/jan/30/polar-vortex-2019-usa-what-is-it-temperatures-cold-weather-climate-change-explained