The record-breaking warming in the Antarctic stratosphere in the month of July disrupted the polar vortex and affected global weather patterns.
This event was a little different from the frequent warmings of the Arctic and is likely to have impacted the weather phenomena and ozone levels in the Southern Hemisphere.
The warming started in the stratosphere, nearly 30 kilometres above the continent’s icy surface, in July 2024.
In the month of July, the temperatures in the stratosphere above Antarctica remain around minus 80 degrees Celsius (minus 112 degrees Fahrenheit).
The scientists recorded 15°C temperature in the middle of the stratosphere on July 7, which set the record of the warmest July temperatures seen in the stratosphere in the Antarctic region.
On July 22, the temperature decreased only to rise to 17°C (31°F) on August 5.
Here’s how stratospheric warming impacted the polar vortex
NASA’s Goddard Space Flight Centre’s atmospheric scientists, Lawrence Coy and Paul Newman, were surprised to find this sudden stratospheric warming.
Coy and Newman worked on data assimilation and looked into the models of Earth’s atmosphere created for NASA’s Global Modeling and Assimilation Office (GMAO).
“The July event was the earliest stratospheric warming ever observed in GMAO’s entire 44-year record,” said Coy.
The scientists said that the westerly winds, which were present in this layer of the atmosphere, loop across the South Pole in winter and form what is called as the polar vortex.
However, this symmetric circumpolar flow was disrupted, which led to a weakening of the winds and the flow to alter its shape.
The polar vortex, instead of circulating the South Pole, turned elongated and the winds weakened, which caused considerable stratospheric warming over Antarctica.
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The researchers have been investigating what was the origin of disturbances which led to the disruption of the stratosphere.
“Variations in sea surface temperatures and sea ice can perturb these large-scale weather systems in the troposphere that propagate upwards,” said Newman. “But the attribution of why these systems develop is really difficult to do,” he added.
Scientists observed that the sudden warming events in the stratosphere were connected to higher concentrations of ozone over Antarctica.
They observed that the change of circulation led to stratospheric warming events in which ozone is drawn from other latitudes toward the polar region.
(With inputs from agencies)