Diapycnal mixing and tracer dispersion in a terrain-following coordinate model

• Effective diapycnal mixing is quantified in realistic high-resolution simulations using passive tracer experiments and online diagnostics of effective diapycnal mixing • Effective diapycnal mixing is close to parameterized values over the abyssal plain but can be larger above steep ridge slopes • Numerical mixing is minimized by smoothing topography and effective mixing aligns closely with parameterized mixing