論文

査読有り
2020年4月

Roles of sea ice–surface wind feedback in maintaining the glacial Atlantic meridional overturning circulation and climate

Journal of Climate
  • Sam Sherriff-Tadano
  • ,
  • Ayako Abe-Ouchi

33
8
開始ページ
3001
終了ページ
3018
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.1175/JCLI-D-19-0431.1
出版者・発行元
American Meteorological Society

During glacial periods, climate varies between two contrasting modes, the interstadials and stadials. These climate changes are often associated with drastic reorganizations of the Atlantic meridional overturning circulation (AMOC). Previous studies highlight the important role of sea ice in maintaining contrasting modes of the AMOC through its insulating effect on the oceanic heat flux and the buoyancy flux (sea ice–buoyancy flux feedback); however, the effect of feedback from the atmosphere remains unclear. Here, the effect of sea ice–surface wind interactions over the North Atlantic Ocean on the AMOC is explored. For this purpose, results from comprehensive atmosphere–ocean coupled general circulation models (AOGCMs) are analyzed. Then, sensitivity experiments are conducted with the atmospheric component of the AOGCM. Last, to explore the impact of modifications in surface winds induced by sea ice on the maintenance of the AMOC, partially coupled experiments are conducted with the AOGCMs. Experiments show that the expansion of sea ice associated with a weakening of the AMOC reduces surface winds by suppressing the oceanic heat flux and increasing the atmospheric static stability. This wind anomaly then causes a weakening of the wind-driven ocean salt transport to the northern North Atlantic and maintains the weak AMOC, therefore working as a positive feedback. It is shown that, together with the sea ice–buoyancy flux and sea ice–surface wind feedback, changes in sea ice and oceanic heat flux sustain the contrasting modes of the AMOC. These results may provide useful information for interpreting the differences in the self-sustained internal oscillations of the AMOC produced by recent AOGCMs.

リンク情報
DOI
https://doi.org/10.1175/JCLI-D-19-0431.1
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85081789624&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85081789624&origin=inward
ID情報
  • DOI : 10.1175/JCLI-D-19-0431.1
  • ISSN : 0894-8755
  • ORCIDのPut Code : 70346515
  • SCOPUS ID : 85081789624

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