Antarctic 'polar vortex' is causing global warming and could cause extreme weather across the globe



As winter approaches in the Southern Hemisphere, experts have warned that a rare warming phenomenon is occurring in the stratosphere, particularly over Antarctica, which could have devastating effects on the entire planet, including extreme weather.

A rare Stratospheric Warming event has begun over the South Pole, with unusually strong anomalies now developing

https://www.severe-weather.eu/global-weather/polar-vortex-stratospheric-warming-event-south-hemisphere-winter-fa/

Rare Sudden Stratospheric Warming event detected over Antarctica - The Watchers
https://watchers.news/2024/07/15/rare-sudden-stratospheric-warming-event-detected-over-antarctica/

According to Andrei Friis, a writer for Severe Weather Europe, a news blog that specializes in information about weather phenomena and known in the meteorological community as ' Recretos ,' stratospheric warming events in the Southern Hemisphere are rare and have only been observed a few times in the past few decades, but their effects are significant and could have ripple effects across the entire planet.

This phenomenon is caused by a polar vortex , a large low-pressure system that forms over the polar regions. Below is an example of a polar vortex shown by Frith, which shows a large vortex that extends from the sky to near the ground.



Relatively common in the Northern Hemisphere, the polar vortex behaves like a very large cyclone and can cover the entire Arctic down to the mid-latitudes.

In addition, the polar vortex can move differently in the stratosphere high in the sky, where there are fewer obstacles and it rotates faster, and in the troposphere near the earth's surface, where it can become unstable due to factors such as topography.



Basically, a strong jet stream creates a stable polar vortex (left) that traps cold air from the Arctic, making the climate in places like North America milder. On the other hand, a disrupted polar vortex (right) can no longer trap the cold air, leading to atmospheric imbalance.



This mechanism is similar to the polar vortex in the Southern Hemisphere, but the Southern Hemisphere is experiencing an unusual problem in 2024. Below is a graph showing the average temperature over the Southern Hemisphere. If you look at the area surrounded by a red frame, you can see that the temperature in the Antarctic atmosphere in July 2024 is rising rapidly.



This is destabilizing the Antarctic polar vortex and warming the Antarctic region, but more seriously, it poses the risk of impacting the Northern Hemisphere as well.



Warming in the Southern Hemisphere affects the entire planet because

the Brewer-Dobson circulation connects the stratospheres of the Earth's northern and southern poles.



A study investigating the warming event that occurred over Antarctica in 2019 suggests that a sudden stratospheric warming (SSW) over Antarctica led to ionospheric anomalies in the Northern Hemisphere, including North America and Europe, that had measurable effects on the Northern Hemisphere during the 2019-2020 winter.

Because the relationship between atmospheric movements and weather phenomena is complex, it is not clear whether this anomaly will have an immediate visible effect, but Frith said, 'Large-scale weather events like SSWs can cause long-lasting high-pressure anomalies over Antarctica. Over the course of weeks or months, these effects may be felt in the Northern Hemisphere.'

in Science, Posted by log1l_ks