EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Decomposition of the Atlantic Multidecadal Variability in a historical climate simulation

Ioana Colfescu and Edwin Schneider
Ioana Colfescu and Edwin Schneider

The Atlantic Multidecadal Variability (AMV) modulates various climate features worldwide with enormous societal and economic implications, including variations in hurricane activity in the Atlantic, sea-level changes, West African and Indian monsoon rainfall, European climate, and hemispheric‐ scale surface temperature. Leading hypotheses regarding the nature and origin of AMV focus primarily on its links with oceanic and coupled ocean-atmosphere internal variability, and on its response to external forcing. The role of another possible process, that of atmospheric noise forcing of the ocean, has received less attention. This is addressed here by means of historical coupled simulations and diagnostic experiments, which isolate the influences of external and atmospheric noise forcings. Our findings show that external forcing is an important driver of the simulated AMV. They also demonstrate that weather noise is key in driving the simulated internal AMV in the southern part of the (0o-60oN) AMV region, and that weather noise forcing is responsible for up to 10%-20% of the multidecadal internal SST variability in some isolated areas of the sub-polar gyre region. Ocean dynamics independent from the weather noise forcing is found to be the dominant cause of multidecadal SST in the northern part of the AMV region.


How to cite: Colfescu, I. and Schneider, E.: Decomposition of the Atlantic Multidecadal Variability in a historical climate simulation, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22545,, 2020


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