(Washington) The extent of the sea ice in Antarctica reached a new low in late February, marking a melting record since the start of satellite measurements 45 years ago, the American reference observatory announced on Monday.
Antarctic sea ice melts in summer and recovers in winter. In mid-February, the American National Snow and Ice Data Center (NSIDC) announced that even before the end of the summer, it had melted more than in 2022, already breaking its record.
But the melting continued, and this time the sea ice “probably reached its minimum extent for the year, at 1.79 million square kilometers, on February 21, 2023”, the observatory said.
He said, however, that this figure was “preliminary” and that “continued melting conditions could push the ice extent further down”. A formal announcement is expected in early March.
The melting of sea ice has no immediate impact on sea level, because it forms by freezing the salt water already present in the ocean.
But “lower sea ice extent means that ocean waves will hit the coasts of the ice sheet, further reducing ice barriers around Antarctica,” researcher Ted Scambos, contributor to Antarctica, said in a statement. the NSIDC.
However, the ice cap – a thick freshwater glacier that covers Antarctica – is particularly monitored by scientists because it contains enough water to cause a catastrophic rise in the level of the oceans if it were to melt.
Moreover, the white pack ice reflects the sun’s rays more than the darker ocean, and its loss thus accentuates global warming.
In February 2022, the Antarctic sea ice had dropped below 2 million square kilometers for the first time. The years 2017 and 2018 had also reached a very low extent (third and fourth lowest).
“The declining sea ice trend could be a signal that global warming has finally affected the ice floating around Antarctica, but it will take several more years to be sure,” said Ted Scambos.
The effect of global warming on the Arctic sea ice, where temperatures are rising much faster than on the rest of the Earth, is already well proven.