Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection

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 util...

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Main Authors: Yushi Morioka, Syukuro Manabe, Liping Zhang, Thomas L. Delworth, William Cooke, Masami Nonaka, Swadhin K. Behera
Format: Article
Language:English
Published: Nature Portfolio 2024-11-01
Series:Communications Earth & Environment
Online Access:https://doi.org/10.1038/s43247-024-01783-z
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author Yushi Morioka
Syukuro Manabe
Liping Zhang
Thomas L. Delworth
William Cooke
Masami Nonaka
Swadhin K. Behera
author_facet Yushi Morioka
Syukuro Manabe
Liping Zhang
Thomas L. Delworth
William Cooke
Masami Nonaka
Swadhin K. Behera
author_sort Yushi Morioka
collection DOAJ
description 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.
format Article
id doaj-art-44cdb753fb3c4f33a7d75536070e3d12
institution Kabale University
issn 2662-4435
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publishDate 2024-11-01
publisher Nature Portfolio
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series Communications Earth & Environment
spelling doaj-art-44cdb753fb3c4f33a7d75536070e3d122024-11-10T12:44:01ZengNature PortfolioCommunications Earth & Environment2662-44352024-11-015111110.1038/s43247-024-01783-zAntarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convectionYushi Morioka0Syukuro Manabe1Liping Zhang2Thomas L. Delworth3William Cooke4Masami Nonaka5Swadhin K. Behera6Application Laboratory, VAiG, JAMSTECAtmospheric and Oceanic Sciences Program, Princeton UniversityGeophysical Fluid Dynamics Laboratory, NOAAGeophysical Fluid Dynamics Laboratory, NOAAGeophysical Fluid Dynamics Laboratory, NOAAApplication Laboratory, VAiG, JAMSTECApplication Laboratory, VAiG, JAMSTECAbstract 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.https://doi.org/10.1038/s43247-024-01783-z
spellingShingle Yushi Morioka
Syukuro Manabe
Liping Zhang
Thomas L. Delworth
William Cooke
Masami Nonaka
Swadhin K. Behera
Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection
Communications Earth & Environment
title Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection
title_full Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection
title_fullStr Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection
title_full_unstemmed Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection
title_short Antarctic sea ice multidecadal variability triggered by Southern Annular Mode and deep convection
title_sort antarctic sea ice multidecadal variability triggered by southern annular mode and deep convection
url https://doi.org/10.1038/s43247-024-01783-z
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