Abstract
Idealized numerical simulation is used to explore energy sinks for lee waves
trapped in their bottom-intensified generating flow. In addition to the loss to
explicit dissipation and reabsorption predicted by linear wave action
conservation, indirect dissipation due to a nonlinear forward cascade by
parametric subharmonic instability represents a significant sink that
substantially reduces reabsorption. The partition of lee-wave energy loss
between reabsorption and (explicit plus indirect) dissipation is independent of
subgridscale damping parameterization. Remote dissipation of freely propagating
internal waves generated by shear instability at the lee-wave critical layer
proves to be small. A general parameterization for lee-wave dissipation of the
balanced flow requires a more complete exploration of the parameter space.