Internal Lee Waves Control Deep Ocean Turbulent Mixing in the Antarctic Circumpolar Current at 50°E

Abstract Full‐depth (Surface‐to‐bottom) turbulent kinetic energy dissipation (TKED) observed with fast‐response thermistors across the Antarctic Circumpolar Current (ACC) at 50E is compared with the energy flux of bottom‐generated internal waves estimated with high‐resolution multibeam bathymetry. Turbulent kinetic energy dissipation is here found to be locally balanced with the energy flux of internal lee waves generated through the interactions between quasi‐steady deep currents and small horizontal‐scale bottom topography, except in the region where the energy flux of internal tides over relatively large topographic roughness is dominant. The suppression of the lee‐wave energy flux due to the co‐existence with tides is not large. The agreement is different from previous observations across the ACC performed in Drake Passage and Kerguelen Plateau, where the energy flux overestimated TKED. Linearity with relatively low steepness in the present observation is suggested to be the cause of the balance.