title: The Atlantic Multidecadal Oscillation without a role for ocean circulation.
abstract: The Atlantic Multidecadal Oscillation (AMO) is a major mode of climate variability with important societal impacts. Most previous explanations identify the driver of the AMO as the ocean circulation, specifically the Atlantic Meridional Overturning Circulation (AMOC). Here we show that the main features of the observed AMO are reproduced in models where the ocean heat transport is prescribed and thus cannot be the driver. Allowing the ocean circulation to interact with the atmosphere does not significantly alter the characteristics of the AMO in the current generation of climate models. These results suggest that the AMO is the response to stochastic forcing from the mid-latitude atmospheric circulation, with thermal coupling playing a role in the tropics. In this view, the AMOC and other ocean circulation changes would be largely a response to, not a cause of, the AMO.
authors.affiliation: Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA. aclement@rsmas.miami.edu.
authors.forename: Amy
authors.initials: A
authors.lastname: Clement
authors.affiliation: Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA.
authors.forename: Katinka
authors.initials: K
authors.lastname: Bellomo
authors.affiliation: Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA.
authors.forename: Lisa N
authors.initials: LN
authors.lastname: Murphy
authors.affiliation: Lamont-Doherty Earth Observatory of Columbia University, New York, NY, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Cane
authors.affiliation: Max Planck Institute for Meteorology, Hamburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Mauritsen
authors.affiliation: Max Planck Institute for Meteorology, Hamburg, Germany.
authors.forename: Gaby
authors.initials: G
authors.lastname: Rädel
authors.affiliation: Max Planck Institute for Meteorology, Hamburg, Germany.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Stevens