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Climate impacts of the Atlantic Multidecadal Oscillation

Authors:
  • Met Office and University of Exeter

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1] The Atlantic Multidecadal Oscillation (AMO) is a near-global scale mode of observed multidecadal climate variability with alternating warm and cool phases over large parts of the Northern Hemisphere. Many prominent examples of regional multidecadal climate variability have been related to the AMO, such as North Eastern Brazilian and African Sahel rainfall, Atlantic hurricanes and North American and European summer climate. The relative shortness of the instrumental climate record, however, limits confidence in these observationally derived relationships. Here, we seek evidence of these links in the 1400 year control simulation of the HadCM3 climate model, which produces a realistic long-lived AMO as part of its internal climate variability. By permitting the analysis of more AMO cycles than are present in observations, we find that the model confirms the association of the AMO with almost all of the above phenomena. This has implications for the predictability of regional climate.
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... Suggested by both observations (Cunningham et al. 2007;McCarthy et al. 2012) and climate models (Liu 2012;Buckley and Marshall 2016), the Atlantic Meridional Overturning Circulation (AMOC) has a rich diversity of variability from interannual to centennial timescales, which acts as an important source of climate variability over the Atlantic and surrounding regions (Sutton and Hodson 2005;Knight et al. 2006;Zhang and Delworth 2006;Zhang and Zhang 2015;Zhang et al. 2019;Ma et al. 2020) and a potential pacemaker for decadal climate predictions (Griffies and Bryan 1997;Zhang and Zhang 2015;Zhang et al. 2019). ...
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... Variabilité inter-annuelleà décennale du SMUSNord. L'impact de l'AMV a puêtre mis enévidence sur des phénomènes météorologiques trés variés[Knight et al., 2006]. Ces auteurs montrent que l'AMV est une composante majeure de l'évolutionà long terme du ventet de la SST dans l'Atlantique Nord. ...
Thesis
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... AMO+ is associated with increased temperatures, decreased precipitation, and greater drought probability. Schlesinger and Ramankutty (1994); Enfield et al. (2001); Knight et al. (2006); Dima and Lohmann (2007) Trenberth (1990); Latif and Barnett (1994); Minobe (1997Minobe ( , 1999; Mantua and Hare (2002) North Atlantic Oscillation NAO poorly defined, typically interannualinterdecadal A localized oscillation in the sea level pressure differential between the Azores High and the Icelandic Low in the northern Atlantic Ocean. ...
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