Oceanic surface and internal gravity waves exhibit dispersion, meaning their phase and group speeds vary with frequency or wavelength, distinguishing them from simple non-dispersive acoustic wave propagation in certain media.
The retrieved papers consistently demonstrate that oceanic gravity waves and acoustic-gravity waves possess frequency-dependent phase and group velocities (dispersion). Sound waves in standard fluid approximations travel at a constant speed (non-dispersive except under specific waveguide boundaries or high-frequency/stratified conditions), whereas ocean waves are fundamentally dispersive.