Impact of vertical mixing parameterizations on internal gravity wave
spectra in regional ocean models
Abstract
We present improvements in the modeling of the vertical wavenumber
spectrum of the internal gravity wave continuum in high-resolution
regional ocean simulations. We focus on model sensitivities to mixing
parameters and comparisons to McLane moored profiler observations in a
Pacific region near the Hawaiian Ridge, which features strong
semidiurnal tidal beams. In these simulations, the modeled continuum
exhibits high sensitivity to the background mixing components of the
K-Profile Parameterization (KPP) vertical mixing scheme. Without the KPP
background mixing, stronger vertical gradients in velocity are sustained
in the simulations and the modeled kinetic energy and shear spectral
slopes are significantly closer to the observations. The improved
representation of internal wave dynamics in these simulations makes them
suitable for improving ocean mixing estimates and for the interpretation
of satellite missions such as the Surface Water and Ocean Topography
(SWOT) mission.