1) Frozen Chicago
Image Courtesy: Shawn, Twitter
2) Frozen Cherry:
Image Courtesy: Twitter
3)Â Frozen Tundra Beyond Milwaukee
Image Courtesy: Getty Images
4) Cold Commute
Image Courtesy: Getty Images
5) Lake Michigan
Image Courtesy: Getty Images
What is a polar vortex?
It is a circulation of strong, upper-level winds that normally surround the northern pole in a counterclockwise direction i.e. a polar low-pressure system. It is not a single storm but the winds keep the bitter cold air locked in the Arctic regions of the Norther Hemisphere.
Scientific American writes that:
“More and more Arctic sea ice is melting during summer months. The more ice that melts, the more the Arctic Ocean warms. The ocean radiates much of that excess heat back to the atmosphere in winter, which disrupts the polar vortex. Data taken over the past decade indicate that when a lot of Arctic sea ice disappears in the summer, the vortex has a tendency to weaken over the subsequent winter.”
Washington Post weather editor Jason Samenow described the polar vortex this way:
“We’re talking about a huge sprawling area of circulating cold air originating from the North Pole. It’s a low-pressure center, and typically during the winter months it resides up there. At times, some tentacles of it will slip southward and bring cold air outbreaks into the U.S., but this year, we’re seeing a huge chunk of it, most of it descending into the U.S.”
When was it identified?
The polar vortex was first described as early as 1853 and this phenomenon appears during the winter time in the northern hemisphere. The sudden stratospheric warming (SSW) was discovered in 1952 with radiosonde observations at altitudes higher than 20km.
Is polar vortex dangerous as compared to a tornado or hurricane?
All the of them are completely different type of systems. If a cold air outbreak is caused by polar vortex, it is more widespread and lasts longer than a single storm. When the cold air is initially advancing into a warm region, significant winter storms develop. At such temperatures, exposed flesh can freeze in five minutes, and some vehicles may not start.
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