Propagation speeds of ocean surface waves in shallow water
Abstract
Nonlinear effects on the dispersion relation of waves in shallow water are examined with measurements collected on a mild sloping sandy beach during the recent Sandy Duck experiment. Four arrays of bottom pressure sensors were deployed in depths ranging from 3 - 6 m during August-November, 1997. For each of these arrays, a root-mean-square average wavenumber was estimated as a function of frequency from the cross-spectra of one-hour-long pressure records. The observed wavenumbers are compared to linear finite depth theory predictions and to predictions based on a stochastic formulation of weakly nonlinear Boussinesq equations that incorporate both frequency and amplitude dispersion effects. The observed wavenumbers are generally in agreement with the nonlinear theory predictions and deviate significantly (maximum errors averaged over the spectrum of about 25%) from the linear theory predictions. In high energy conditions with breaking or nearly breaking waves, the effects of amplitude and frequency dispersion tend to cancel, and all components of the wave spectrum travel with approximately the shallow water wave speed. These results are consistent with previous studies.
Collections
Related items
Showing items related by title, author, creator and subject.
-
Advanced Concepts and Applications for Predictive Analytics in the Maritime Domain
Johnson, Bonnie W. (Monterey, California: Naval Postgraduate SchoolMonterey, California. Naval Postgraduate School, 2019-12); NPS-19-N019-BNaval tactical operations could take a significant leap in progress with the aid of a real-time automated predictive analytics capability that provides predictions of second and third order effects of possible courses of ... -
Observed kinematics of waves in the surf zone
Constantian, Richard K. (Monterey, California. Naval Postgraduate School, 1999-03);The observed kinematics of waves in the surf zone is examined with extensive measurements from the DUCK94 experiment. Field data used in the study were obtained from vertical stacks of bi-directional current meters and a ... -
A DETERMINISTIC APPROACH TO UNDERSTANDING THE SENSITIVITY OF SURFACE DUCT PROPAGATION TO SOUND SPEED FEATURES IN THE UPPER OCEAN
Zinicola-Lapin, William N. (Monterey, CA; Naval Postgraduate School, 2020-12);A key sound speed feature of the upper ocean is the Mixed Layer Acoustic Duct (MLAD). Acoustic propagation effects due to mean properties of the duct and spatial and temporal variability are thought to be strong functions ...