Since the weekend, the United States is experiencing one of its worst winter storms in recent decades, and this has a particular explanation: a polar vortex.
This phenomenon spawned the storm named “Fern,” which left at least 35 people dead in various states and hundreds of thousands without electricity across much of the country.
This particular atmospheric phenomenon is characterized by releasing Arctic air to lower latitudes.
Currently, this same phenomenon is affecting the United States, which does not yet foresee that this week the states with below-zero temperatures will return to more normal numbers.
In response, various cities reached climate emergency status while transportation chaos persisted with thousands of flights canceled.
An anomaly with unprecedented impact: what is a polar vortex
The cold front extended from Texas to New England. This brought snow to places where this phenomenon is extremely unusual, transforming the American landscape.
Mississippi Governor Tate Reeves emphasized the severity: “We haven’t seen a storm of this magnitude, in terms of ice, since 1994.” The explanation lies in a polar vortex anomaly.
This system of low pressures and cold air exists permanently at both Earth’s poles.
Although the term seems modern, its first record dates back to 1853 in the Living Age magazine, according to data from the NOAA.
It is characterized by air masses located in two different atmospheric layers: the troposphere, up to 12 km high, and the stratosphere, from 12 to 50 km.
These systems rotate counterclockwise, confining the densely cold air at the poles.
Why the Arctic air descended south and affected the United States
The current chaos is due to the cold air, usually “locked” by the vortex, being released to lower layers.
NASA explained that the intrusion of warm air masses can destabilize the system.
When the frigid air collides with the warm southern air, the mass rises. Dangerous storm fronts then form, causing extreme snowfalls.
“Normally, the vortex spins quietly and has little effect on our climate, but occasionally it moves or stretches south over North America, bringing with it a cold surge,” explained Jennifer Francis, senior scientist at the Woodwell Climate Research Center, to the AFP agency.
Judah Cohen, a researcher at MIT, agreed: “There is clearly a strong relationship between stretched vortex events and extreme winter weather here in the U.S.”
The scientific debate on climate change
The scientific community is analyzing whether global warming alters the frequency of these events. The positions present important nuances:
- Jennifer Francis suggests that Arctic warming favors these anomalies more often
- Judah Cohen points out that sea ice loss “loads the dice” in favor of these phenomena
- Meteorologist Jason Furtado considers it too soon to establish a definitive connection due to a lack of historical data
The National Weather Service warned that frostbite is possible in just 10 minutes outdoors. Hundreds of schools, colleges, and universities in the affected areas were closed.
While the debate continues, millions of people remain under the influence of a destabilized polar vortex.
The phenomenon transformed the American map into a landscape of ice and emergency with no recent precedents.
