Bottom dissipation of subinertial currents at the Atlantic zonal boundaries: ATLANTIC ZONAL SUBINERTIAL DISSIPATION

Estimates of the dissipation of subinertial currents due to bottom boundary layer drag at the eastern and western boundaries of the North Atlantic ocean, between 15 N and 60 N, are computed using data from the world's largest archive of ocean current meter time series. We show from these data that a significant proportion of such loss in this region is due to dissipation at the western boundary ocean floor via quadratic bottom boundary layer drag, with an estimated 40–60% (31–47 GW) of the wind input power across the whole basin dissipated by this method. We further show that the majority of this dissipation occurs at shallow depths, <500 m; this has significant implications for the power available for abyssal mixing.