Momentum transfer between semidiurnal internal waves and subinertial flow at a dissipating surface reflection
Date
2009-08-31T18:09:11Z
Authors
Jenkyns, Reyna L.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Full-depth profile data reveal semidiurnal internal waves radiating from Mendocino Escarpment. Energy- and momentum-fluxes are lost between stations bracketing the first surface reflection to the north. A plausible interpretation is that wave energy is dissipated as a consequence of superposition of incident and reflected waves. Because there are no profiler data in the superposition region, a theoretical approach is used to bridge the gap. Assuming zonal independence, constant stratification and linear decay in the dissipation region, the forcing on the mean equations is evaluated with parameters consistent with Mendocino Escarpment data. Both superposition and dissipation cause momentum-flux divergence forcing. An Ekman-like balance is anticipated with predicted mean zonal flows u~O(1-2 cm/s), comparable to surface wind-forced Ekman currents.
Description
Keywords
internal waves, momentum-flux divergence, internal tide, superposition, Mendocino Escarpment, dissipation