Antarctica: Sea ice at 45-year low



by LORENZO CIOTTI

Antarctica: Sea ice at 45-year low

Antarctica's sea ice extent is at a 45-year low. The negative record was recorded on 21 February, when the minimum annual extension of 1.79 million square kilometers was reached, the lowest documented by satellites since 1979 to date.

These are the results of a study published in the journal Ocean-Land-Atmosphere Research conducted by a team of scientists from Ocean-Land-Atmosphere Research and the State University of New York led by Jiping Liu. This year's minimum sea ice extent is 1.05 million square kilometers below the 1981-2010 average and, moreover, it was reached three days early.

Most of the remaining ice is found in the Weddell Sea, with isolated blocks along the coasts of Princess Astrid and Princess Ragnhild, in the eastern regions of Wilkes Land, and in Pine Island Bay. 1.05 million square kilometers are missing compared to the average calculated in the period 1981-2010.

An area comparable to that of Spain and France. And the record came for the second consecutive year.

Antarctica: Sea ice at 45-year low

The previous negative record was set in 2022 with 1.9 million square kilometres. This was announced by the National Snow and Ice Data Center of the University of Colorado in Boulder with a statement that is still provisional, considering that the change in winds or melting at the end of the season could further reduce the extent of Antarctic ice.

2017 and 2018 saw very small ice extents, respectively the third and fourth lowest so far recorded by satellites. This trend suggests that global warming is now also affecting the ice around Antarctica, but to have a statistically significant confirmation it will be necessary to collect data over a longer period of time.

The sea ice in the Southern Ocean, the scientists explain, shows great variability both seasonally and from year to year. On February 21, 2023, Antarctic sea ice extent reached its seasonal low of 1,788 million square kilometers, setting a new all-time low since the late 1970s.

This negative record is not an isolated fact but is placed in a context that has seen the anomalous shrinkage of the ice extensions since 2017. Scholars are alarmed by the fact that it comes immediately after the previous historical minimum of 1.924 million km2 in 2022.