Title: The OceanŐs conveyor belt, whatŐs driving it?

Presenter: Natassa Romanou

The Atlantic Meridional Overturning Circulation (better known as AMOC) is the oceanŐs 
conveyor belt: the pathway which carries warm surface waters from the equator polewards 
and, after subduction at high latitudes, returns it southward as a deep, cold, nutrient and 
carbon-rich water mass. Subpolar North Atlantic is dotted with areas where dense water forms 
and sinks, the Labrador Sea being arguably the dominant one. The Labrador Sea Water (LSW), 
that forms there during winter/spring, almost every year, feeds into the deeper extension of 
AMOC.

In this study, we are using ocean observations from neutrally buoyant, deep floats and transect 
measurements in the region to determine the LSW volume that formed monthly over the 
period 2003-2016 and associate it to the intensity of the air-sea fluxes in the region. The LSW 
volume has large interannual variability: during certain years, such as 2008 and 2015 intense 
convection and extended water mass formation took place, while during other years, such as 
2010, deep convection was rather quiescent. MERRA2 reanalysis fluxes explain well the 
temporal signal, but are not always predictive of the magnitude of the new volume formed. 
Changes in storminess in the broader region seem likely to explain these differences.