It’s the dead of winter in Antarctica, but for the past several weeks, the Antarctic Peninsula has been experiencing an unprecedented heatwave. Researchers are sounding the alarm after temperatures soared well above average earlier this month, smashing the previous winter heat record.
Temperatures at Argentina’s Esperanza base, situated in Hope Bay at the tip of the Antarctic Peninsula, reached 59.7 degrees Fahrenheit (15.4 degrees Celsius) on June 6, scientists told The Guardian. That’s 3.6 degrees F (2 degrees C) higher than the previous record-high winter temperature logged at the base in 1998. According to France 24, two other Argentine research stations on the peninsula—Marambio and San Martin—also logged record-breaking temperatures between June 5 and 6.
“This is absolutely crazy,” Raúl Cordero, a climate scientist and assistant professor at the University of Groningen in the Netherlands, told The Guardian. Esperanza’s new temperature record is about 36 degrees F (20 degrees C) above normal for this time of year, he explained. “That is a huge anomaly.”
A brutal heatwave in a rapidly warming region
Climate change is driving up temperatures around the world, but the Antarctic Peninsula is one of the fastest-warming places on Earth. In fact, it’s been warming five times faster than the global average. The peninsula has experienced more warming since 1950 than anywhere else in the Southern Hemisphere, with an average temperature increase of almost 5.4 degrees F (3 degrees C).
The reasons why are complex, but one of the main drivers is sea ice loss. When ice melts, it exposes the darker ocean surface, which has a lower albedo and therefore absorbs more heat from the Sun. This drives up regional temperatures and, in turn, accelerates ice melt, creating a feedback loop that has supercharged Antarctic warming.
The temperatures recorded on the Antarctic Peninsula this month underscore the consequences of this rapid warming trend. Scientists at the Esperanza base logged the June 6 temperature record during a winter heatwave that caused the maximum daily temperature to remain stubbornly above freezing for three consecutive weeks, The Guardian reports.
Snow and ice disappearing
This relentless warmth has caused “large areas in the far north of the white continent to remain free of snow,” Cordero told France 24. He described it as “an unusual scene in the Antarctic landscape during winter.”
Thomas Caton Harrison, a polar climate scientist at the British Antarctic Survey, told the outlet that a “surprising amount” of precipitation has been falling as rain rather than snow. “This has implications for polar ecosystems such as penguin colonies,” he said, adding that “it poses a challenge to my colleagues working on Antarctic bases because a lot of liquid rain has been falling and creating runoff and ice.”
Chilean glaciologists Luis Muñoz and Natalia Mestre climbed the 1,600-foot (500-meter) peak of the Collins glacier on King George Island last Wednesday and discovered rain melting the ice. “There was a direct impact on the glacier, which should be receiving snow now,” Muñoz told The Guardian. “It should not be suffering ablation at this time of the year. This is obviously not good for the glacier.”
These researchers are working at the frontline of the climate crisis, documenting the rapid transformation of Antarctica amid rising global temperatures. Winter heatwaves like this one will only become more frequent and intense as the Antarctic Peninsula continues to warm, so this new winter heat record may not hold for long.
