March 7, 2021: If you heard of a polar vortex, you might know it has something to do with very cold weather.
What is a polar vortex?
A polar vortex is a low-pressure area a wide expanse of swirling cold air that is parked in polar regions.
During winters, this expands at the North Pole, sending cold air southward. This happens fairly regularly and is often associated with outbreaks of cold temperatures in the United States.
What causes a polar vortex?
Sometimes this low-pressure system, full of arctic air, air weaken and travel from its usual position.
As this system weakens, part of the Polar vortex can break off and migrate south, bringing plenty of cold air with it. Areas as far south as Florida may experience article weather as result.
When the low-pressure system is strong and healthy, it keeps the jet stream travelling around Earth in a circular path.
The jet stream is a band of reliably strong wind that plays a key role in keeping colder air north and warmer air south. But when the vortex weakens, part of the weakened low-pressure system can break off.
This breaking off process is what causes a polar vortex.
Without that strong low-pressure system, the jet stream does not have enough force to maintain its usual path.
It becomes wavy and rambling. When high pressure system gets in its way, a collection of cold air pushes south, along with the rest of the Polar vortex system.
Why it is important
For the first time in two decades, temperatures in the US are so cold that scientists and meteorologists are addressing it a polar vortex causing dangerously cold conditions with wind chill values as low as 60 degree below zero.
According to Sam Houston State University, a polar vortex is formed during the Polar winter when stratospheric air moves in a circular motion, with an area of relatively still air in its centre. The temperature in the vortex is approximately -130 ° F (-80°C), which assist in the formation of polar stratospheric clouds. It is the most dangerous when it weakens as it creates.
More acute winter conditions lead to extreme frigid weather conditions in the eastern US.
Some are quick to blame this extreme cold on global warming and the decline of Artic Sea ice. In the Arctic, the temperature has increased at twice the rate as the rest of the globe and could increase by another 14 degrees F by the end of this century.
The warming atmosphere along with new weather pattern extremes is causing Artic sea ice at an alarming rate 12 per cent per decade that suggests the Artic will be ice free by 2030.
Sea ice forms and melts in sea water, as opposed to land-based ice such as glaciers, ice sheets and icebergs and it plays a critical role in global ocean circulation.
Sea ice is generally moderated by sunlight. It grows in the winter and melts in the summer but there are other factors at play in the decline of ice in the Arctic Ocean.
Warm ocean currents travel north from the equator and usher in warmer and warmer water, making sea ice growth difficult.
Arctic sea ice is an important component of the global climate system.
The Polar ice caps help to regulate global temperature by reflecting sunlight back into space.
White snow and ice at the poles reflect sunlight, but a dark ocean absorbs it. The impact of an ice-free Arctic is far reaching and could be a trigger for abrupt, cataclysmic climate change in future.
Although it is difficult to see exactly how sea ice decline will impact the local and global environment, basic understanding of the Arctic as well as recent observation give us a good idea of how things might change.