Evolution of Antarctic Sea Ice Ahead of the Record Low Annual Maximum Extent in September 2023

• Published in: Geophysical Research Letters
• Main Authors: Jena, Babula, Kshitija, S., Bajish, C.C., Turner, John, Holmes, Caroline, Wilkinson, Jeremy, Mohan, Rahul, Thamban, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2024
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; Ice Shelf; Ross Ice Shelf; Ross Sea; Sea ice; Weddell Sea
• Online Access: http://nora.nerc.ac.uk/id/eprint/537188/; https://nora.nerc.ac.uk/id/eprint/537188/1/Geophysical%20Research%20Letters%20-%202024%20-%20Jena%20-%20Evolution%20of%20Antarctic%20Sea%20Ice%20Ahead%20of%20the%20Record%20Low%20Annual%20Maximum%20Extent.pdf; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL107561

The 2023 Antarctic sea ice extent (SIE) maximum on 7 September was the lowest annual maximum in the satellite era (16.98 × 106 km2), with the largest contributions to the anomaly coming from the Ross (37.7%, −0.57 × 106 km2) and Weddell (32.9%, −0.49 × 106 km2) Seas. The SIE was low due to anomalously warm (>0.3°C) upper-ocean temperatures combined with anomalously strong northerly winds impeding the ice advance during the fall and winter. Northerly winds of >12 ms−1 in the Weddell Sea occurred because of negative pressure anomalies over the Antarctic Peninsula, while those in the Ross Sea were associated with extreme blocking episodes off the Ross Ice Shelf. The Ross Sea experienced an unprecedented SIE decrease of −1.08 × 103 km2 d−1 from 1 June till the annual maximum. The passage of quasi-stationary and explosive polar cyclones contributed to periods of southward ice-edge shift in both sectors.