Submesoscales are dynamical features with horizontal scales of 0.1 – 10 km characterized by Ro ~ 1 and are manifested in the upper ocean as vortices, fronts, and filaments with a lifetime of hours to days. They play a key role in the forward energy cascade through frontogenesis and submesoscale instabilities. This study aims to investigate filament dynamics in the Southeast Atlantic, focusing on the filament lifecycle and the instability mechanisms driving the forward cascade during filament decay. A set of high-resolution, realistic model simulations with the ocean model ICON-o, which supports local grid refinement up to ~500 m through a novel configuration called the “SubMesoscale Telescope (SMT)”, is utilized for this study. The normalized relative vorticity field shows an abundance of submesoscale filaments formed by mesoscale strain in between the Agulhas Rings and by boundary-layer turbulence, making the southeast Atlantic an appropriate place to study their dynamics and their interactions with boundary-layer turbulence. We will also test the effect of KPP and K-epsilon parameterization schemes on the extent of vertical mixing induced by these motions in a realistic model setting.