Energetics of Seamount Wakes, Part 2: Wave Fluxes
Journal of Physical Oceanography
Seamounts are thought to facilitate ocean mixing through unsteady wake processes, and through the generation of internal waves, which propagate away from the seamount and later break. The relative importance of these processes is examined for idealized, isolated seamounts (with characteristic width D and height H) in uniform barotropic flow U. A range of Coriolis parameters f and buoyancy frequencies N are used such that a broad parameter space of low Froude numbers ([Formula: see text]) and
... Rossby numbers ([Formula: see text]) is considered. Results indicate that eddy processes energetically dominate the internal wave energy flux in this range of parameter space. The internal wave field is specifically examined, and partitioned into steady lee waves and unsteady, wake-generated waves. It is found that the lee wave energy flux cannot be explained by existing analytical theories. A lee wave model by Smith (1980) is then extended into the low-Froude number regime and the effect of rotation is included. While strongly stratified experiments have previously indicated that only the top [Formula: see text] of an obstacle generates internal waves, the effect of rotation appears to modify this wavemaking height. Once the [Formula: see text] height is revised to account for rotation, the lee wave energy flux can be reasonably accurately reproduced by the extended Smith (1980) model.