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Wave height
About: Wave height is a research topic. Over the lifetime, 5920 publications have been published within this topic receiving 100257 citations.
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TL;DR: In this paper, the authors used zero down-crossing analyses of bed profiles measured by acoustic means along a 4-m transect normal to the ripple crests to estimate wave-generated ripple height, η, and wavelength, λ.
Abstract: [1] Experiments in a large-scale wave flume using regular and irregular waves with periods between 4 s and 6 s and heights between 0.2 m and 1.55 m have examined the formation of wave-generated ripples using sediment beds composed of four grain sizes (D50 = 0.349 mm, 0.329 mm, 0.220 mm, and 0.162 mm) in a water depth of approximately 4 m. Estimates of wave-generated ripple height,η, and wavelength, λ, were obtained using zero down-crossing analyses of bed profiles measured by acoustic means along a 4-m transect normal to the ripple crests. Further information pertaining to λ was obtained from bed images obtained using scanning sonar. The analyses reported here focus on the sequence bedforms that evolved in response to stepwise increases and decreases in wave height. Results show that ripples for the most part are suborbital in nature and do not conform well to empirical equations used frequently to predict η and λ values in the field. On the basis of the present data, two new equations for prediction of η and λ are obtained and their use in field situations where hydrodynamic and sedimentary conditions favor development of suborbital bedforms is recommended.
43 citations
TL;DR: A nonstationary model based on a time-dependent version of the Generalized Pareto Distribution (GPD)-Poisson point process model has been implemented and applied to model extreme wave heights in the Mediterranean basin this paper.
Abstract: A nonstationary model based on a time-dependent version of the Generalized Pareto Distribution (GPD)-Poisson point process model has been implemented and applied to model extreme wave heights in the Mediterranean basin. Thirty-two years of wave hindcast data have been provided by a forecast/hindcast numerical chain model operational at the University of Genoa (www.dicca.unige.it/meteocean). The nonstationary behavior of wave height maxima prompted the modeling of GEV parameters with harmonic functions. Harmonics have been introduced to model seasonal cycles within a year, also taking into account long-term trend and covariates effects. The model has been applied on eight locations corresponding to buoys belonging to the RON (Rete Ondametrica Nazionale), chosen in order to represent best the main features and variability of waves along the Italian coast. The best performing model is chosen among a large set of possible candidates identified by different combinations of wave heights maxima and model parameters. Direct comparison with stationary results has been performed; furthermore, the model has demonstrated a good performance in gathering different seasonal behaviors related to the main meteorological forcing standing on the Mediterranean Sea. Trends related to extreme significant wave heights have also been evaluated in order to offer some insight into decadal-scale wave climate. Results achieved show how the use of a nonstationary statistical model together with the analysis of the main meteorological forcings characterizing the area could prove useful in understanding wave climate related to atmospheric dynamics.
43 citations
TL;DR: In this paper, the effect of the relative angle between the waves and the current can be investigated using circular statistics, showing that local effects can lead to 150-200% increases in wave height when the waves oppose the current.
43 citations
TL;DR: In this paper, a coupled wave and wave-averaged nearshore circulation model was used to predict waves and currents during field experiments conducted near the mouth of San Francisco Bay and nearby Ocean Beach, where field measurements indicate strong spatial variations in current magnitude and direction and in wave height and direction along Ocean Beach and across the ebb tidal shoal.
Abstract: [1] The nearshore circulation induced by a focused pattern of surface gravity waves is studied at a beach adjacent to a major inlet with a large ebb tidal shoal. Using a coupled wave and wave-averaged nearshore circulation model, it is found that the nearshore circulation is significantly affected by the heterogeneous wave patterns caused by wave refraction over the ebb tidal shoal. The model is used to predict waves and currents during field experiments conducted near the mouth of San Francisco Bay and nearby Ocean Beach. The field measurements indicate strong spatial variations in current magnitude and direction and in wave height and direction along Ocean Beach and across the ebb tidal shoal. Numerical simulations suggest that wave refraction over the ebb tidal shoal causes wave focusing toward a narrow region at Ocean Beach. Due to the resulting spatial variation in nearshore wave height, wave-induced setup exhibits a strong alongshore nonuniformity, resulting in a dramatic change in the pressure field compared to a simulation with only tidal forcing. The analysis of momentum balances inside the surf zone shows that, under wave conditions with intensive wave focusing, the alongshore pressure gradient associated with alongshore nonuniform wave setup can be a dominant force driving circulation, inducing heterogeneous alongshore currents. Pressure-gradient-forced alongshore currents can exhibit flow reversals and flow convergence or divergence, in contrast to the uniform alongshore currents typically caused by tides or homogeneous waves.
43 citations
TL;DR: In this paper, the hydrodynamics of a two-body floating-point absorber (FPA) wave energy converter (WEC) under both extreme and operational wave conditions were evaluated for various regular wave conditions.
43 citations