West coast of Antarctica An area of winter sea ice the size of France is missing, raising concerns about endangered penguins, other marine life and global sea levels.
One expert said the loss of ice in the Bellingshausen Sea was “disheartening” and the lack of ice formation could get worse last week there was a heatwave over the continent’s peninsula during the day, the maximum temperature was 15.4 degrees Celsius, more than 20 degrees Celsius above average.
It’s winter in Antarctica, when sea ice expands rapidly around the continent, peaking in September.
However, satellite observations showed that the Bellingshausen Sea – located on the western side of the Antarctic Peninsula and usually covered with ice until June – was almost completely ice-free.
Scientists said the region is missing about 650,000 square kilometers (250,000 square miles) of sea ice compared to the 1991-2020 average. It is an area roughly the size of France and almost ten times the size of Tasmania.
“I’m worried. It’s depressing,” said Dr Will Hobbs, an Antarctic sea ice expert at the University of Tasmania for the Australian Antarctic Programme.
“It’s unusual that it’s June and there’s no sea ice there.”
He said this is the third time in four years that ice cover in the region has been very low. “I don’t think we’ll see sea ice there anymore. It’s over,” he said.
He said sea ice loss is likely linked to changes in the ocean, and scientists are trying to understand whether global warming is having an impact.
He said the region was vital for krill – a key part of the food web for species in the region. Krill usually hid from predators in winter under the ice, where they fed on algae.
On June 10, there was approximately 11.4 million square kilometers of sea ice across the continent, while the long-term average for that day was 12.6 million square kilometers.
Dr Phil Reid, who monitors conditions in Antarctica for the Australian Bureau of Meteorology, said the Bellingshausen Sea had seen “incredible coastal exposure” in winter and summer in recent years.
To the west of that area are the Pine Island and Thwaites glaciers, he said main factors contributing to ice loss and sea level rise on the continent.
He said floating ice shelves in front of glaciers could break up more quickly if protective sea ice is absent for a longer period of time, and this could accelerate ice loss from glaciers, raising global sea levels in the future.
The Bellingshausen Sea Coast was the place tragedy at the end of 2022, when thousands of emperor penguin chicks died during “catastrophic breeding failure” in four colonies.
This event contributed to the UN advisors pushing the genre down two categories on its international endangered species list earlier this year as “threatened.”
Dr Peter Fretwell, a scientist with the British Antarctic Survey who has been documenting penguin declines, said the current loss of sea ice in the region was a “serious problem for penguins, especially emperors”.
“Sea ice forms too late and breaks up too early. This leads to reduced breeding success and longer journeys to molting sites.”
The number of Adelie penguins is also decreasing, and crab seals are forced to migrate in the summer in search of stable ice, he added.
This month, the Antarctic Peninsula witnessed an extreme boost in temperature lasting several days. Hobbs said that while “no one has done the calculations,” it was reasonable to suggest that the heatwave “was made worse by the lack of sea ice.”
Sea ice usually helps frosty warmer air flowing into the region from the north, he added.
Officials with Argentina’s national weather service, Servicio Meteorológico Nacional, said an “extreme temperature event” occurred at the Esperanza base on the northeastern tip of the peninsula, peaking on June 5 and 6.
Maximum temperatures of 15.4 degrees Celsius and 13.4 degrees Celsius respectively were recorded during the period when the average daily maximum was minus 6.2 degrees Celsius. The previous June temperature record of 13.3 degrees Celsius was set on June 12, 1998.