NSIDC - For 3rd Straight Year, Antarctic Sea Ice Cover Falls Below 2 Million Square Kilometers
For the third year in a row, sea ice coverage around Antarctica has dropped below 2m sq km a threshold which before 2022 had not been breached since satellite measurements started in 1979. The latest data from the US National Snow and Ice Data Center confirms the past three years have been the three lowest on record for the amount of sea ice floating around the continent.
Scientists said another exceptionally low year was further evidence of a regime shift, with new research indicating the continents sea ice has undergone an abrupt critical transition. Antarcticas sea ice reaches its lowest extent at the height of the continents summer in February each year. On 18 February the five-day average of sea ice cover fell to 1.99m sq km and on 21 February was at 1.98m sq km. The record low was 1.78m sq km, set in February 2023.
EDIT
Antarcticas sea ice reaches its peak each September, but last years maximum extent was the lowest on record, easily beating the previous record by about 1m sq km. Scientists were shocked at how much less ice regrew last year, falling well outside anything seen before. Coverage appeared to recover slightly in December as the refreeze progressed, but then fell away again to the current levels.
There are no reliable measurements of how thick Antarctic sea ice is, but Ariaan Purich, a climate scientist specialising in Antarctica and the Southern Ocean at Monash University, said it was possible the ice that did regrow was thinner than usual.
EDIT
https://www.theguardian.com/world/2024/feb/24/antarctica-sea-ice-reaches-alarming-low-for-third-year-in-a-row