Kshitija Suryawanshi, B. Jena, C. C. Bajish, N. Anilkumar
{"title":"Recent Decline in Antarctic Sea Ice Cover From 2016 to 2022: Insights From Satellite Observations, Argo Floats, and Model Reanalysis","authors":"Kshitija Suryawanshi, B. Jena, C. C. Bajish, N. Anilkumar","doi":"10.16993/tellusa.3222","DOIUrl":null,"url":null,"abstract":"Ever since the abrupt drop in Antarctic sea ice extent (SIE) began in spring of 2016, as opposed to its consistent growth (1.95% decade–1 from 1979 to 2015), the SIE in the satellite era has reached record lows in 2017 and 2022. From spring 2016, the satellite-based SIE remained consistently lower than the long-term mean, with the trend dropping to 0.11% decade–1 from 1979 to 2022. The top record lowest SIE years were observed from 2016 to 2022, corresponding to the warmest years dating back to 1979. With this background, the rare features of Antarctic polynyas reoccurred frequently and the west Antarctic Peninsula remained ice-free throughout 2022. Recently, the SIE dropped to a record low in June 2022, July 2022, August 2022, January 2023, and February 2023, which were 13.67%, 9.91%, 6.79%, 39.29%, 39.56% below the long-term mean value, respectively for months described above. We find that the observed decline in SIE during 2016–2022 occurred due to the combined influences from the intensification of atmospheric zonal waves with enhanced poleward transport of warm-moist air and anomalous warming in the Southern Ocean mixed layer (>1°C). Although the sudden sea ice decline in spring of 2016 occurred corresponding to the transitional climate shift from IPO– (Interdecadal Pacific Oscillation, 2000–2014) to IPO+ (2014–2016), the recent decline after 2016 occurred in a dominant IPO– and Southern Annular Mode (SAM+). CMIP6 models showed a consistent decrease in ensemble-mean SIE from 1979 to 2022. The model trend exhibits similarities to the recent declining trend in SIE from satellite observations since 2016, suggesting a possible shift towards a warmer climatic regime.","PeriodicalId":54433,"journal":{"name":"Tellus Series A-Dynamic Meteorology and Oceanography","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tellus Series A-Dynamic Meteorology and Oceanography","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.16993/tellusa.3222","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Ever since the abrupt drop in Antarctic sea ice extent (SIE) began in spring of 2016, as opposed to its consistent growth (1.95% decade–1 from 1979 to 2015), the SIE in the satellite era has reached record lows in 2017 and 2022. From spring 2016, the satellite-based SIE remained consistently lower than the long-term mean, with the trend dropping to 0.11% decade–1 from 1979 to 2022. The top record lowest SIE years were observed from 2016 to 2022, corresponding to the warmest years dating back to 1979. With this background, the rare features of Antarctic polynyas reoccurred frequently and the west Antarctic Peninsula remained ice-free throughout 2022. Recently, the SIE dropped to a record low in June 2022, July 2022, August 2022, January 2023, and February 2023, which were 13.67%, 9.91%, 6.79%, 39.29%, 39.56% below the long-term mean value, respectively for months described above. We find that the observed decline in SIE during 2016–2022 occurred due to the combined influences from the intensification of atmospheric zonal waves with enhanced poleward transport of warm-moist air and anomalous warming in the Southern Ocean mixed layer (>1°C). Although the sudden sea ice decline in spring of 2016 occurred corresponding to the transitional climate shift from IPO– (Interdecadal Pacific Oscillation, 2000–2014) to IPO+ (2014–2016), the recent decline after 2016 occurred in a dominant IPO– and Southern Annular Mode (SAM+). CMIP6 models showed a consistent decrease in ensemble-mean SIE from 1979 to 2022. The model trend exhibits similarities to the recent declining trend in SIE from satellite observations since 2016, suggesting a possible shift towards a warmer climatic regime.
期刊介绍:
Tellus A: Dynamic Meteorology and Oceanography along with its sister journal Tellus B: Chemical and Physical Meteorology, are the international, peer-reviewed journals of the International Meteorological Institute in Stockholm, an independent non-for-profit body integrated into the Department of Meteorology at the Faculty of Sciences of Stockholm University, Sweden. Aiming to promote the exchange of knowledge about meteorology from across a range of scientific sub-disciplines, the two journals serve an international community of researchers, policy makers, managers, media and the general public.
Original research papers comprise the mainstay of Tellus A. Review articles, brief research notes, and letters to the editor are also welcome. Special issues and conference proceedings are published from time to time.
The scope of Tellus A spans dynamic meteorology, physical oceanography, data assimilation techniques, numerical weather prediction, climate dynamics and climate modelling.