Presenter: Margarita Markina (University of Oxford)

Description:
Atlantic Meridional Overturning Circulation (AMOC) is an important component of climate system and understanding what governs its variability is essential for improving climate predictability. Recent mooring observations from OSNAP (Overturning in the Subpolar North Atlantic Program) reveal large variability in overturning circulation in the subpolar latitudes on monthly to interannual time scales. It has been shown that AMOC variability is dominated by overturning in the eastern subpolar gyre, however the relative importance of buoyancy loss in different regions remains uncertain. Apart from that, variability in local and remote wind forcing also plays an important role in mediating variability in buoyancy fluxes and watermass transformation and creating density anomalies. In this study, we aim to attribute recent variability in overturning and gyre circulation in OSNAP array to the surface wind and buoyancy forcing using high-resolution (1/12˚) targeted sensitivity experiments with the regional configuration of MITgcm for the North Atlantic. We conduct a range of sensitivity experiments where we apply changes to surface buoyancy fluxes and wind stress patterns and explore the response of the AMOC to these changes on different time scales.