More than 60 million people in the east of the country are likely to be affected by the severe winter storms that have been hitting the country. The expansion of the polar vortex, an area of extremely cold, rotating air around the Arctic, southwards, is what is causing the current cold spell, which could lower the mercury to as low as -50C (-60F).
The US Gulf Coast and Florida Peninsula are where sub-freezing temperatures can reach.
The polar vortex primarily affects countries situated in the Northern Hemisphere’s mid to high latitudes. Extremely cold weather can occur in these areas.
What is the polar vortex?
Wind speeds of about 155 mph (250 km/h) revolve around the North Pole as the polar vortex spins counterclockwise.
There are two types of polar vortexes – tropospheric and stratospheric.
At the lowest layer of the atmosphere, where the majority of weather phenomena occur, occurs the tropospheric polar vortex. Northern latitudes experience milder weather as a result of the vortex.
A stratospheric polar vortex, which typically forms in the fall but disappears in the spring of each year, is what we are currently experiencing. It is located 10 to 30 miles (16 to 48 kilometers) above the Earth’s surface.
The polar regions are the only places where frigid arctic air can be found when the stratospheric polar vortex remains stable.
The chilly winds, however, extend as far south as Florida when they are in a weakened state beyond their circle around the North Pole.
The polar vortex is weakened by rising warm air from the lower atmosphere, allowing it to expand more widely. Significant weather patterns or phenomena, such as strong winds in mountainous areas or changes in tropical climate systems, can cause this upward movement of warm air.
For climate regulation and the global circulation, both polar vortexes are crucial.
Do cold polar vortexes always occur in our bodies?
The extreme cold temperatures from a weakened polar vortex, although seasonal and cyclical in nature, are not an annual phenomenon. In fact, it wasn’t until 2014 that the term “polar vortex” became widely used.
In the years 2013 and 2014, the polar vortex caused record-breaking snow and cold to swarm Canada and the eastern US, causing one of the regions’ coldest winters.
Major metropolitan areas, including New York, Philadelphia, and Chicago, were blanketed with snow, with accumulations ranking among the top 10 highest in their recorded histories.
The Great Lakes were ice-covered in 92.5% of the polar vortex, which was the second-highest ice cover seen by satellite, according to an article published by NASA in 2015. On March 8, 2014, Lake Michigan’s surface experienced the highest ice coverage of its kind, surpassing 93.3 percent.
This atmospheric pattern was covered extensively in 2014 by numerous news outlets and weather reports, earning it a not-so-secret reputation. The extreme cold, which was a key component of understanding winter weather patterns in the Northern Hemisphere, also gained the public’s attention and made a widely available explanation for the extreme weather conditions.
The polar vortex is impacted by climate change.
Researchers have been trying to determine how much of the polar vortex’s impact on the intensity or frequency of the cold. According to some research, the polar vortex may be impacted by climate change.
Because the planet isn’t warming up in a uniform way, it makes sense that the polar vortex is more likely to be weak due to global warming. According to Steven Decker, the director of Rutgers University’s meteorology undergraduate program, “it’s warming more at the pole, overall decreasing the strength of the polar vortex and the jet stream and making it more susceptible to being dislodged and sent our way.”
Because the Earth doesn’t heat up the same everywhere, causing the polar vortex to weaken as a result of global warming. The polar vortex and the jet stream, a fast-flowing air current in the atmosphere, are both weakened by the North Pole’s faster warming than other locations. This makes it simpler for the vortex to strike out of place and cause colder air to decompress many places, including Europe and North Asia.
The change is “reducing the temperature differences between the warmer mid-latitude and polar regions” according to the authors. This weakens and destabilises the polar jet stream, causing it to dip into lower latitudes, bringing polar air farther south”, Paul Ullrich, an associate professor of regional climate modelling at the University of California, Davis, wrote in a 2021 article.
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