Communications Earth & Environment volume 4, Article number: 314 (2023 ) Cite this article
In February 2023, Antarctic sea ice set a record minimum; there have now been three record-breaking low sea ice summers in seven years. Following the summer minimum, circumpolar Antarctic sea ice coverage remained exceptionally low during the autumn and winter advance, leading to the largest negative areal extent anomalies observed over the satellite era. Here, we show the confluence of Southern Ocean subsurface warming and record minima and suggest that ocean warming has played a role in pushing Antarctic sea ice into a new low-extent state. In addition, this new state exhibits different seasonal persistence characteristics, suggesting that the underlying processes controlling Antarctic sea ice coverage may have altered.
Antarctic sea ice is a critical component of the global climate system1,2,3. Climatologically, Antarctic sea ice reaches its annual minimum in mid-February to early March. Sea ice coverage in January and February 2023 broke monthly and daily sea ice extent records for this time of year4. On 10 February 2023, sea ice coverage broke the record daily minimum of 1.91 million square kilometres set one year earlier on 21 February 20224,5. On 19 February 2023, a new minimum Antarctic sea ice extent of 1.77 million square kilometres was observed4, 1.02 million square kilometres (36%) less than the 1979-2022 average daily minimum sea ice coverage.