Atmospheric Disturbance Caused Temperature Surge in Antarctica

The Antarctic is experiencing higher temperatures than expected

Eyal Bartov / Alamy

Since early September, air temperatures in Antarctica have soared beyond 35°C (63°F), accompanied by a significant reduction in wind speeds, with ozone depletion halting unexpectedly.

This scale of change is typically anticipated only every two decades, according to Martin Zicker from the University of New South Wales, Sydney, Australia. However, such phenomena appear to be occurring with increasing frequency, with similar transient disruptions noted last year, alongside more severe occurrences in both 2019 and 2002.

Jucker observes that four of these events have appeared within just 25 years, indicating ongoing unpredictable shifts in the global climate system.

Typically, air temperatures in Antarctica hover around -55°C (-67°F), but have been unrelentingly rising to -20°C (-4°F) since September 5th. Although still extremely cold, this shift has resulted in the polar vortex winds decreasing relatively gently to 100 km/h.

While this warming event has not yet met the formal criteria for sudden stratospheric warming, Jucker notes that for that classification to apply, the winds need to cease entirely—not just for weeks but in response to the warmth itself. He warns that the repercussions in the Southern Hemisphere could be dramatic over the ensuing months.

Initially, Australian meteorologists forecast a wetter spring than normal, but they are now signaling potential impacts from a powerful system over western Australia, likely pushing the region into warmer and drier conditions.

Unusual weather patterns may persist. Jucker indicates that one possible scenario could see a return of the polar vortex, bringing atmospheric temperatures back to their typical averages.

Conversely, the temperature anomaly might continue, with expectations of further increases up to 20°C (36°F). This could lead to erratic weather in the higher latitudes of the Southern Hemisphere.

The reason behind this anomaly remains unclear scientifically, but Jucker asserts that it’s almost guaranteed that rising sea surface temperatures in the Pacific Ocean, possibly increasing by 1°C (1.8°F) to 3.6°F, are connected.

“The presence of three significant typhoons in the Pacific can be traced to these warmer sea temperatures,” remarks Jucker. “We’ve witnessed markedly strange weather patterns over the last two years, coinciding with this substantial rise in ocean temperatures.”

Edward Dodridge from the University of Tasmania in Hobart, Australia, emphasizes the array of extreme changes occurring at the southernmost point of the globe. Recent years have seen a dramatic deceleration in sea ice loss, heatwaves, widespread breeding failures among Emperor Penguin colonies, and shifts in Antarctic circulation.

“Antarctica continues to astonish us,” he notes. “While each change is noteworthy on its own, my primary concern is witnessing shifts that not only reinforce themselves but also ripple through various components of the Antarctic ecosystem.”

“The loss of summer sea ice facilitates the fracturing of ice shelves, which in turn accelerates ocean warming. This warmer seawater melts the remaining ice shelves at an increased rate.”

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Source: www.newscientist.com