Scientific Calendar Event



Starts 5 Oct 2017 11:30
Ends 5 Oct 2017 12:30
Central European Time
ICTP
Common Area, exSISSA bldg. 2nd floor
Via Beirut 2/4
The ongoing decline of Arctic sea ice exposes the ocean to anomalous surface heat and
freshwater fluxes, resulting in positive buoyancy anomalies that can affect ocean
circulation. In this study, we use an optimal flux perturbation framework and
comprehensive climate model simulations to estimate the sensitivity of the Atlantic
meridional overturning circulation (AMOC) to such buoyancy forcing over the Arctic and
globally, and more generally to sea ice decline. It is found that while on decadal
timescales flux anomalies over the subpolar North Atlantic have the largest impact on
the AMOC, on multi-decadal timescales (longer than 20 years) flux anomalies in the
Arctic become more important. These positive buoyancy anomalies spread to the North
Atlantic, weakening the AMOC and its poleward heat transport. Therefore, the Arctic
sea ice decline may explain the suggested slow-down of the AMOC and the “Warming Hole”
persisting in the subpolar North Atlantic.