Oceanic hindcast simulations at high resolution suggest that the Atlantic MOC is bistable
Article first published online: 19 JUN 2013
©2013. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 40, Issue 12, pages 3069–3073, 28 June 2013
How to Cite
2013), Oceanic hindcast simulations at high resolution suggest that the Atlantic MOC is bistable, Geophys. Res. Lett., 40, 3069-3073 doi:10.1002/grl.50534., (
- Issue published online: 18 JUL 2013
- Article first published online: 19 JUN 2013
- Accepted manuscript online: 6 MAY 2013 10:11AM EST
- Manuscript Accepted: 3 MAY 2013
- Manuscript Received: 29 APR 2013
- European Commission. Grant Number: FP7-SPACE-2007-1-CT-218812-MYOCEAN
 All climate models predict a freshening of the North Atlantic at high latitude that may induce an abrupt change of the Atlantic Meridional Overturning Circulation (hereafter AMOC) if it resides in the bistable regime, where both a strong and a weak state coexist. The latter remains uncertain as there is no consensus among observations and ocean reanalyses, where the AMOC is bistable, versus most climate models that reproduce a mono-stable strong AMOC. A series of four hindcast simulations of the global ocean at 1/12° resolution, which is presently unique, are used to diagnose freshwater transport by the AMOC in the South Atlantic, an indicator of AMOC bistability. In all simulations, the AMOC resides in the bistable regime: it exports freshwater southward in the South Atlantic, implying a positive salt advection feedback that would act to amplify a decreasing trend in subarctic deep water formation as projected in climate scenarios.