Momentum and Buoyancy Contributions to Atlantic Ocean Circulation Variability

Abstract:

Untangling the drivers of Atlantic climate variability is complicated due to the combined contributions and still-debated relative influence of wind forcing, buoyancy forcing, and intrinsic ocean dynamics. The partitioning and efficacy of these forcings can generate variations with very different spatial characteristics and timescales in different regions of the Atlantic basin. In this presentation, we will show the extent to which momentum and buoyancy forcing contribute to variations in the horizontal ocean circulations, meridional oceanic heat transport, and the overturning circulation in the Atlantic. Different from prior ocean-only model experiments, we utilize coupled model experiments in which air-sea heat and freshwater fluxes are freely evolving and consistent between the atmosphere and ocean model components. We will also show what characteristics can be linked to the basin-scale, buoyancy-driven AMOC in our model and how adding in wind-driven effects on the ocean circulation impact these characteristics. Time permitting, we will attempt to address potential issues in the detectability of basin-scale AMOC variations in the subpolar versus subtropical gyres.