Antarctica’s polar vortex is on the verge of splitting into two for the first time in over 20 years due to a sudden increase in stratospheric temperatures. If this occurs, Antarctica will experience major warming, while Australia and South America can expect an unusually hot summer.
The southern polar vortex is a swirl of winds that moves clockwise, trapping cold air above Antarctica during the Southern Hemisphere winter. Typically, the vortex remains stable at this time of year, with temperatures around -80°C (-112°F). However, this year’s signs indicate increasing instability.
In mid-July, wind speeds slowed from 300 to 230 km/h, allowing cold air to descend and causing a record increase in stratospheric temperatures. Temperatures inside the vortex remained nearly 20°C (36°F) above average. The UK Met Office recorded another slowdown in early August, followed by rapid temperature increases.
As a result, the vortex was pushed out of its place at the South Pole, with cold polar air moving towards Australia, New Zealand, and South America, while warm air moved towards Antarctica, potentially causing a heatwave. If wind speeds remain slow, the vortex could change direction and swirl anticlockwise in a sudden stratospheric warming.
Repeated slowdowns in wind speeds increase the chances of a vortex split and sudden stratospheric warming this year. Small disruptions to the vortex can have a cumulative effect, leading to extreme events.
Source: https://www.wionews.com/science/earths-polar-vortex-in-antarctica-is-set-to-tear-apart-heres-how-it-will-impact-planet-749398