Atlantic Multi-decadal Oscillation covaries with Agulhas leakage

Arne Biastoch1, Jonathan V Durgadoo1, Adele K Morrison2, Erik van Sebille3, Wilbert Weijer4 and Stephen Matthew Griffies5, (1)GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, (2)Princeton University, AOS Program, Princeton, NJ, United States, (3)Imperial College London, Grantham Institute, London, SW7, United Kingdom, (4)Los Alamos National Laboratory, Los Alamos, NM, United States, (5)Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States
Abstract:
The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, ‘Agulhas leakage’, forms a chokepoint for the overturning circulation in the global ocean. By combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870-2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a tantalizing correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. This is relevant for climate in the North Atlantic.
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