AMOC weakening in response to global and regional reductions in aerosol emissions
Rattachement africain : us, gb, no, se, ca, jp, fi. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
In response to continued greenhouse gas (GHG) increases, the Atlantic Meridional Overturning Circulation (AMOC) is expected to weaken through the 21st century. However, AMOC impacts associated with efforts to improve air quality are less well understood. Here, eight models from the Regional Aerosol Model Intercomparison Project are examined to quantify mid-21st century AMOC changes resulting from global and regional anthropogenic aerosol and precursor gas (AA) emissions reductions (industrial and biomass burning), by comparing strong air pollution control shared socioeconomic pathway (SSP1-2.6) to a baseline with weak air pollution control (SSP3-7.0). Global AA reductions and subsequent warming yield multi-model mean AMOC weakening of 6% ( Sv; 1 Sv = 106 m3 s−1) by the last 12 years of the simulation (2039–2050). This is ⅓ of the magnitude of the corresponding weakening associated with the high GHG emissions scenario SSP3-7.0. Of the regional perturbations, combined North American and European AA reductions drive the largest AMOC weakening, followed by combined African and Middle Eastern reductions and then East Asian reductions, with South Asian reductions yielding non-significant weakening. Across these experiments, AMOC weakening is significantly correlated with the North Atlantic Ocean aerosol effective radiative forcing () and aerosol optical depth response (). AMOC weakening under AA reductions is associated with a thermally driven reduction in buoyancy in the subpolar North Atlantic, which is largely driven by surface shortwave radiation increases, consistent with the forcing from AA reductions. Africa + Middle East AA reductions also involve excitation of a negative North Atlantic Oscillation pattern, which contributes to AMOC weakening. Our results show that efforts to improve air quality, particularly around the Atlantic basin but also far away in East Asia, will contribute to future AMOC weakening.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
Où se fait cette recherche
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University of California pays non établi dans la noticeUniversité ou école supérieure
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University of Reading pays non établi dans la noticeUniversité ou école supérieure
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CICERO Center for International Climate Research pays non établi dans la noticeStructure de recherche
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Norwegian University of Life Sciences pays non établi dans la noticeUniversité ou école supérieure
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Stockholm University pays non établi dans la noticeUniversité ou école supérieure
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University of Toronto pays non établi dans la noticeUniversité ou école supérieure
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University of Bristol pays non établi dans la noticeUniversité ou école supérieure
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Lancaster University pays non établi dans la noticeUniversité ou école supérieure
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Japan Meteorological Agency Numerical Prediction Development Center pays non établi dans la noticeInstitution
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Science and Technology Facilities Council pays non établi dans la noticeOrganisme public
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Goddard Institute for Space Studies pays non établi dans la noticeStructure de recherche
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Finnish Meteorological Institute pays non établi dans la noticeOrganisme public
University of California, University of Reading et CICERO Center for International Climate Research, avec 9 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.