The much-anticipated State of the Climate in 2023 report was released by the National Oceanic and Atmospheric Administration on August 22. Chief researcher at the Council for Scientific and Industrial Research (CSIR), Dr Sandy Thomalla, in collaboration with 14 contributing authors, led the Southern Ocean section of the chapter on Antarctica and the Southern Ocean. The report is a peer-reviewed series published annually as a special supplement to the Bulletin of the American Meteorological Society.
Thomalla and her collaborators assessed the 2023 anomalies (relative to climatology) in key physical and biological Southern Ocean metrics. She says the results for 2023 are intriguing, given the record-low sea ice coverage, which has recently elicited wide media coverage and may reflect alterations in the underlying processes that determine the state of sea ice. This analysis revealed substantial ocean warming with mostly positive anomalies evident in sea-surface temperatures, ocean heat content and air-sea heat flux. These changes may be exacerbated by the warm conditions of the 2023 El Nio, with evidence of impacts on the oceans biochemistry. These significant findings highlight the impact of changing atmospheric-ocean dynamics of particular concern considering the central role that the Southern Ocean exerts in regulating the climate system it plays a key role in buffering the impacts of climate change by absorbing 50% of anthropogenic carbon dioxide and 75% of anthropogenic heat from the oceanic uptake.
The Antarctica and Southern Ocean chapter in the report consists of seven sections involving 52 experts. Shining the spotlight on the Southern Ocean, Thomalla also contributed to the striking cover photo of the chapter that depicts freely moving ice in its waters during the summer of 2015 [EL1] . It has been a privilege to collaborate with international peers and experts working together to produce this important body of work that highlights the susceptibility of this critical ecosystem to change.
Notable key points in the report disclose that, in the Southern Ocean, sea surface temperatures and ocean heat content from the surface were well above average in 2023, marking a continuation of the warming trend observed since 2005. Above-average annual temperatures were observed over most of Africa in 2023 while South Africa had its eighth-warmest year on record since 1951.
This edition of the report will be fully accessible for the first time. Its live launch is a result of the dedicated 592 international experts representing 59 countries and 25 editors. This 34 th edition spans 497 pages and is filled with recent research findings on climate summaries and statistics. As a research publication, it also serves as an authoritative summary detailing global, oceanic, tropical, Arctic, Antarctic, Southern Ocean and regional climate conditions.
