Yushi Morioka, Syukuro Manabe, Liping Zhang, Thomas L. Delworth, William Cooke, Masami Nonaka, Swadhin K. Behera
{"title":"Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection","authors":"Yushi Morioka, Syukuro Manabe, Liping Zhang, Thomas L. Delworth, William Cooke, Masami Nonaka, Swadhin K. Behera","doi":"10.1038/s43247-024-01783-z","DOIUrl":null,"url":null,"abstract":"Antarctic sea ice exerts great influence on Earth’s climate by controlling the exchange of heat, momentum, freshwater, and gases between the atmosphere and ocean. Antarctic sea ice extent has undergone a multidecadal slight increase followed by a substantial decline since 2016. Here we utilize a 300-yr sea ice data assimilation reconstruction and two NOAA/GFDL and five CMIP6 model simulations to demonstrate a multidecadal variability of Antarctic sea ice extent. Stronger westerlies associated with the Southern Annular Mode (SAM) enhance the upwelling of warm and saline water from the subsurface ocean. The consequent salinity increase weakens the upper-ocean stratification, induces deep convection, and in turn brings more subsurface warm and saline water to the surface. This salinity-convection feedback triggered by the SAM provides favorable conditions for multidecadal sea ice decrease. Processes acting in reverse are found to cause sea ice increase, although it evolves slower than sea ice decrease. Multidecadal Antarctic sea ice anomalies are preceded by wind anomalies associated with the Southern Annular Mode which may induce upwelling and melting, according to a combined approach using prolonged sea ice reconstructions and coupled model simulations","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-11"},"PeriodicalIF":8.1000,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01783-z.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Communications Earth & Environment","FirstCategoryId":"93","ListUrlMain":"https://www.nature.com/articles/s43247-024-01783-z","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Antarctic sea ice exerts great influence on Earth’s climate by controlling the exchange of heat, momentum, freshwater, and gases between the atmosphere and ocean. Antarctic sea ice extent has undergone a multidecadal slight increase followed by a substantial decline since 2016. Here we utilize a 300-yr sea ice data assimilation reconstruction and two NOAA/GFDL and five CMIP6 model simulations to demonstrate a multidecadal variability of Antarctic sea ice extent. Stronger westerlies associated with the Southern Annular Mode (SAM) enhance the upwelling of warm and saline water from the subsurface ocean. The consequent salinity increase weakens the upper-ocean stratification, induces deep convection, and in turn brings more subsurface warm and saline water to the surface. This salinity-convection feedback triggered by the SAM provides favorable conditions for multidecadal sea ice decrease. Processes acting in reverse are found to cause sea ice increase, although it evolves slower than sea ice decrease. Multidecadal Antarctic sea ice anomalies are preceded by wind anomalies associated with the Southern Annular Mode which may induce upwelling and melting, according to a combined approach using prolonged sea ice reconstructions and coupled model simulations
期刊介绍:
Communications Earth & Environment is an open access journal from Nature Portfolio publishing high-quality research, reviews and commentary in all areas of the Earth, environmental and planetary sciences. Research papers published by the journal represent significant advances that bring new insight to a specialized area in Earth science, planetary science or environmental science.
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