Abstract

Numerical modeling is a key tool for understanding deep ocean dynamics, where observations remain sparse, particularly at submesoscales (1–30 km). In this presentation, we use high-resolution basin-scale and regional simulations to investigate how interactions between currents, topography, and mixing shape abyssal circulation and tracer transport. We first examine the generation of long-lived submesoscale coherent vortices (SCVs), which transport tracers and momentum isopycnally from boundary regions into the basin interior, contributing to lateral exchange. We then investigate bottom boundary layer dynamics, focusing on buoyancy balance and the interplay between turbulent mixing, tidal forcing, complex bathymetry, and large-scale circulation. This is done by analysing near-bottom dynamics across multiple timescales, assessing their impact on the density budget, and using passive tracer release experiments to study transport in both depth and density space.