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Showing papers on "Wave height published in 2002"


Journal ArticleDOI
TL;DR: In this article, the authors focused on the North Atlantic region using satellite altimetry and found that wave height anomalies are strongly seasonal and peak in the winter season, and that the strength and geographical distribution of variability is broadly consistent throughout the winter months.
Abstract: Wave climate across the ocean basins can be described using satellite altimetry; here, we concentrate on the North Atlantic region. Waves in the North Atlantic are strongly seasonal and peak in the winter season. The northeastern sector of the Atlantic and adjoining shelf seas also exhibit exceptionally high interannual variability in the winter, with monthly average significant wave height varying by up to a factor of 2 from one year to the next. The strength and geographical distribution of variability is broadly consistent throughout the winter months (December–March). A large fraction of these wave height anomalies is associated with a single pattern of pressure anomalies that resembles the North Atlantic Oscillation (NAO). A predictor based on NAO dependence is “trained” from relatively recent satellite data and then tested against earlier satellite and in situ data. The predictor is successful in large areas of the North Atlantic, confirming a robust relationship between wave height anomalies and the NAO over the last few decades. A substantial rise (up to 0.6 m) in monthly mean wave heights on the northeastern Atlantic during the latter part of the twentieth century is attributable to changes in the NAO. Substantial residual anomalies in wave heights exist after the influence of the NAO has been subtracted; these are partly explained by a second pair of North Atlantic patterns in wave height anomalies and sea level pressure anomalies. This “East Atlantic” pattern is particularly influential in midwinter and affects the southern part of the northeastern sector (including the region of Seven Stones Light Vessel)

250 citations


Journal ArticleDOI
TL;DR: In this paper, a 10-month-long wave/tide dataset from two sites on the Dengie marshes, eastern England, was used to investigate the effect of vegetation cover on wave attenuation.
Abstract: To achieve sustainable coastal management and planning, the interaction between fine-grained - in particular , vegetated - intertidal environments and incoming waves needs to be better understood. Previous studies have established that wave attenuation over saltmarshes can be significantly greater than over unvegetated intertidal surfaces. However, detailed, quantitative information on the effect of marsh elevation in the tidal frame, marsh width, seaward marsh edge configuration (e.g. cliffed versus ramped marshes), seasonal changes in marsh surface roughness (e.g. creek density, vegetation composition) and incident wave conditions, however, has been lacking. Based on a 10-month-long wave/tide dataset from two sites on the Dengie marshes, eastern England, this study addresses the effect of (i) marsh edge topography; (ii) marsh width; (iii) inundation depths; and (iv) seasonal changes in marsh surface vegetation cover on wave height and wave energy dissipation. Directional waves and water levels were recorded at 21 locations across both shallow-sloping and cliffed (cliff height of ca. 1.5m) intertidal profiles. In addition, changes in marsh surface vegetation cover and composition were recorded on a seasonal basis. Wave height attenuation over 310m of the shallow-sloping profile averaged 92 % over the monitoring period. Further analysis shows that the most rapid reduction in wave heights occurs over the most seaward 10 meters of permanent saltmarsh vegetation, where wave height attenuation averaged 2.1% and 1.1% per meter at the shallowsloping and cliffed site respectively. Across the mudflat and the saltmarsh as a whole, wave height dissipation rates were significantly lower with an average of 0.1% and 0.5% per meter respectively. The presence of a saltmarsh cliff increased average wave heights by up to 0.5% per meter. Observed wave height attenuation showed a seasonal pattern at both sites (average wave energy attenuation near the marsh edge was highest in September ‐ November and lowest in March ‐ July) and appears to be linked to the cycle of seasonal vegetation growth. The study provides criteria for the assessment of the wave dissipation potential of marshes characterised by different widths, edge configurations and slopes, variability of water depths, and seasonal variations in vegetation cover/density. ADDITIONALINDEXWORDS: wave attenuation, coastal management, intertidal hydrodynamics, coastal geomorphology

241 citations


Journal ArticleDOI
TL;DR: The analysis of 3 years of data has helped to quantify the global and regional skills, strengths, and weaknesses of different ocean wave forecasting systems as mentioned in this paper, and it is not surprising to find that the center with the lowest wind speed errors also has the lowest wave height errors.
Abstract: The monthly exchange of ocean wave model data has successfully been taking place among five operational weather centers. The data are compared with observations obtained from moored buoys and platforms. The analysis of 3 yr of data has helped to quantify the global and regional skills, strengths, and weaknesses of the different ocean wave forecasting systems. Since the quality of ocean wave forecasts is intrinsically linked to the quality of the forcing wind fields, it is not surprising to find that the center with the lowest wind speed errors also has the lowest wave height errors. The benefit of using a third-generation Wave Model (WAM), for example, is not so tangible in terms of wave height statistics but it is definitively evident in terms of peak periods. Even though WAM has proved to be well suited for global wave forecasting, it is also clear that research is still needed to reduce the model tendency to underpredict some storms when it is forced by operational global wind fields. It appeared that assimilating altimeter wave heights has a positive impact on the model performance. It is also argued that the height of the wind speed observations should be taken into account when assimilating the data or simply when evaluating model performance since it might otherwise introduce a systematic negative bias into the analysis. Last, this exchange of data should continue and possibly extend to other forecasting centers as a tool for model developers but also as a continuous reference for marine forecasters.

230 citations


01 Jan 2002
TL;DR: In this paper, a method for joint probability analysis, using a Monte Carlo simulation approach, based on distributions fitted to water level, wave height and wave steepness, and to the dependence between them, is presented.
Abstract: On coasts with high tidal ranges, or subject to high surges, both still water levels and waves can be important in assessing flood risk; their relative importance depends on location and on the type of sea defence. The simultaneous occurrence of large waves and a high still water level is therefore important in estimating their combined effect on sea defences. Wave period can also be important in assessing run-up and overtopping, and so it is useful also to have information on the joint distribution of wave height and period. Unless the variables are either completely independent or completely dependent, multivariate extremes are difficult to predict directly from observational data, as there may be too few events of the relevant type amongst the observations. In the past, the fitting and extrapolation of the dependence functions between the variables has often involved complicated and/or subjective approaches. This paper presents a method for joint probability analysis, using a Monte Carlo simulation approach, based on distributions fitted to water level, wave height and wave steepness, and to the dependence between them. RESUME

179 citations


Journal ArticleDOI
TL;DR: In this paper, a method for joint probability analysis using a Monte Carlo simulation app is presented, where the authors estimate the joint distribution of wave height and period from a set of observations.
Abstract: On coasts with high tidal ranges, or subject to high surges, both still water levels and waves can be important in assessing flood risk; their relative importance depends on location and on the type of sea defence. The simultaneous occurrence of large waves and a high still water level is therefore important in estimating their combined effect on sea defences. Wave period can also be important in assessing run-up and overtopping, and so it is useful also to have information on the joint distribution of wave height and period. Unless the variables are either completely independent or completely dependent, multivariate extremes are difficult to predict directly from observational data, as there may be too few events of the relevant type amongst the observations. In the past, the fitting and extrapolation of the dependence functions between the variables has often involved complicated and/or subjective approaches. This paper presents a method for joint probability analysis, using a Monte Carlo simulation app...

163 citations


Journal ArticleDOI
TL;DR: In this article, seasonal extremes of wave height in the North Atlantic are analyzed based on a 40-yr (1958-97) numerical wave hindcast using an intensive kinematic reanalysis of wind fields.
Abstract: In this study, seasonal extremes of wave height in the North Atlantic are analyzed. The analysis is based on a 40-yr (1958–97) numerical wave hindcast using an intensive kinematic reanalysis of wind fields. Changes in the ocean wave extremes are identified by performing the Mann–Kendall test, and are further related to changes in the atmospheric circulation (sea level pressure) by means of redundancy analysis. The relationship between sea level pressure and ocean wave extremes is also used to reconstruct the seasonal wave statistics for the last century (back to 1899). Consistent with previous studies, this high-resolution Atlantic wave hindcast also shows that the northeast North Atlantic Ocean has experienced significant multidecadal variations in the last century, and it has indeed roughened in winters of the last four decades. The winter wave height increases are closely related to changes in the North Atlantic oscillation during the last four decades. While showing trend patterns similar to ...

142 citations


Journal ArticleDOI
TL;DR: In this article, a multilayer perceptron neural network with a backscatter and significant wave height as inputs is used to develop an empirical altimeter wind speed model that attenuates the sea-state signature and improves upon the present operational altometer wind model.
Abstract: Globally distributed crossovers of altimeter and scatterometer observations clearly demonstrate that ocean altimeter backscatter correlates with both the near-surface wind speed and the sea state Satellite data from TOPEX/Poseidon and NSCAT are used to develop an empirical altimeter wind speed model that attenuates the sea-state signature and improves upon the present operational altimeter wind model The inversion is defined using a multilayer perceptron neural network with altimeter-derived backscatter and significant wave height as inputs Comparisons between this new model and past single input routines indicates that the rms wind error is reduced by 10%‐15% in tandem with the lowering of wind error residuals dependent on the sea state Both model intercomparison and validation of the new routine are detailed, including the use of large independent data compilations that include the SeaWinds and ERS scatterometers, ECMWF wind fields, and buoy measurements The model provides consistent improvement against these varied sources with a wind-independent bias below 03 m s21 The continuous form of the defined function, along with the global data used in its derivation, suggest an algorithm suitable for operational application to Ku-band altimeters Further model improvement through wave height inclusion is limited due to an inherent multivaluedness between any single realization of the altimeter measurement pair [s o, HS] and observed near-surface winds This ambiguity indicates that HS is a limited proxy for variable gravity wave properties that impact upon altimeter backscatter

135 citations


Journal ArticleDOI
TL;DR: Alternative schemes based on stochastic and neural network approaches along with a three-layered feed forward network are presented for operational prediction of wave heights in India.

132 citations


01 Jan 2002
TL;DR: Mori et al. as mentioned in this paper presented an analysis of a set of available freak wave measurements gathered from several periods of continuous wave recordings made in the Sea of Japan during 1986-1990 by the Ship Research Institute of Japan.
Abstract: This paper presents an analysis of a set of available freak wave measurements gatheredfrom several periods of continuous wave recordings made in the Sea of Japan during 1986–1990 by the Ship Research Institute of Japan. The analysis provides an ideal opportunity tocatch a glimpse of the statistics of freak waves in the ocean. The results show that a well-defined freak wave may occur in the developed wind–wave condition: S(f) f 4 , with single-peak directional spectra. The crest and trough amplitude distributions of the observed seawaves including freak waves are different from the Rayleigh distribution, although the waveheight distribution tends to agree with the Rayleigh distribution. Freak waves can be readilyidentified from the wavelet spectrum where a strong energy density occurs in the spectrum,and is instantly surged and seemingly carried over to the high-frequency components at theinstant the freak wave occurs. 2002 Elsevier Science Ltd. All rights reserved. Keywords: Freak wave; Wave statistics; Wave height distribution; Wavelet analysis; Sea of Japan* Corresponding author. Tel.: +81-471-821-181; fax:+81-471-847-142.E-mail address:mori@criepi.denken.or.jp (N. Mori).

127 citations


Journal ArticleDOI
01 Dec 2002
TL;DR: In this paper, three recently measured wind and wave data sets in the northern part of Chesapeake Bay (CB) are presented, and two very different numerical wave models, Simulation of WAves Nearshore (SWAN) and Great Lakes Environmental Research Laboratory (GLERL), to hindcast the wave conditions against the data sets.
Abstract: Three recently measured wind and wave data sets in the northern part of Chesapeake Bay (CB) are presented. Two of the three data sets were collected in late 1995. The third one was collected in July of 1998. The analyzed wind and wave data show that waves were dominated by locally generated, fetch limited young wind seas. Significant wave heights were highly correlated to the local driving wind speeds and the response time of the waves to the winds was about 1 h. We also tested two very different numerical wave models, Simulation of WAves Nearshore (SWAN) and Great Lakes Environmental Research Laboratory (GLERL), to hind-cast the wave conditions against the data sets. Time series model–data comparisons made using SWAN and GLERL showed that both models behaved well in response to a suddenly changing wind. In general, both SWAN and GLERL over-predicted significant wave height; SWAN over-predicted more than GLERL did. SWAN had a larger scatter index and a smaller correlation coefficient for wave height than GLERL had. In addition, both models slightly under-predicted the peak period with a fairly large scatter and low correlation coefficient. SWAN predicted mean wave direction better than GLERL did. Directional wave spectral comparisons between SWAN predictions and the data support these statistical comparisons. The GLERL model was much more computationally efficient for wind wave forecasts in CB. SWAN and GLERL predicted different wave height field distributions for the same winds in deeper water areas of the Bay where data were not available, however. These differences are as yet unresolved.

92 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe techniques to synthesize deterministic task-related "rogue" waves or critical wave groups for engineering applications, represented by local characteristics like tailored design wave sequences, are integrated in a random or deterministic seaway with a defined energy density spectrum.

Journal ArticleDOI
TL;DR: In this paper, a non-dimensional sediment flux index is formulated which describes the tendency towards net onshore or offshore transport and the strength of that tendency, and a formulation of suspended sediment transport across bars is obtained by linking the flux index with a parameterization of the sediment concentration/distribution in the water column.

01 Jan 2002
TL;DR: The Mighty Whale is a floating wave power device based on the Oscillating Water Column (OWC) principle, which converts wave energy into electric energy, and produces a relatively calm sea area behind.
Abstract: Mighty Whale is a floating wave power device based on the Oscillating Water Column (OWC) principle. It converts wave energy into electric energy, and produces a relatively calm sea area behind. The open sea tests were begun in September 1998 in Gokasho Bay, Nansei Town, Mie Prefecture. Measurements collected since then include performance data in typhoon seasons. This paper presents the measurements of wave energy absorption, floating body motion, and wave height dissipation. It is expected that these results will be useful in the design of offshore wave power devices in the future.

Journal ArticleDOI
TL;DR: The problem of describing the distribution functions of tsunami wave heights is discussed in this article, where data on runup heights obtained in field surveys of several tsunamis for the last decade are used to calculate the empirical distribution functions.
Abstract: The problem of describing the distribution functions of tsunami wave heights is discussed. Data on runup heights obtained in field surveys of several tsunamis for the last decade are used to calculate the empirical distribution functions. It is shown that the log-normal distribution describes the observed data well. This means that the irregular topography and coastline are major factors which influence the height distribution. The power distribution related with the geometric decay of the propagated wave is a good approximation for one event (Sulawesi, January 1, 1996) only. Results of a numerical simulation of the tsunami event in the Japan (East) Sea on July 12, 1993 are presented. It is shown that the computed wave height distribution, obtained by using the runup correction in the framework of nonlinear shallow-water theory, is in good agreement with the observed height distribution. Simulations are used to study the transformation of the distribution function on different distances from the source.

Journal ArticleDOI
TL;DR: In this paper, a long-term average of data provided a precise climatology of surface temperature, wind speed, and wave height for locations along and offshore along the west coast of Canada and the adjacent United States.
Abstract: Time series of sea surface temperature, wind speed, and significant wave height from meteorological buoys off the west coast of Canada and the adjacent United States are long enough and of sufficient quality to be useful for studying interannual variability and trends. Long-term averages of data provide a precise climatology of surface temperature, wind speed, and wave height for locations along- and offshore. Data from many of the buoys suggest a warming trend, but only three buoys show statistical significance, and sheltered buoys show no increases. Both the wind speed and the wave height data show an increasing trend with more statistical significance. Future data from these buoys should benefit from better calibration and a wider variety of sensors, as well as from longer time series.

Journal ArticleDOI
TL;DR: In this article, the authors derived a joint distribution of the height and the period of the wave in a Gaussian process for a tubular offshore platform with respect to static pushover, and then combined the derived distributional models into a Rosenblatt transformation.

Journal ArticleDOI
TL;DR: In this article, the authors demonstrate that, similar to video imagery, time-exposure X-band (∼3 cm wave length) radar images contain alongshore, breaking-related high-intensity bands that can be used to compute the location of the underlying sandbar crests.

Journal ArticleDOI
TL;DR: In this article, numerical simulations of gravity waves with high-order nonlinearities in two-dimensional domain are performed by using the pseudo spectral method, which increases kurtosis, wave height distribution and H max /H 1/3 in deep water and decreases these wave statistics in shallow water.

Journal ArticleDOI
TL;DR: In this paper, the wave height distribution with Edgeworth's form of a cumulative expansion of probability density function (PDF) of surface elevation is investigated, and the results show that a non-Gaussian model of wave distribution reasonably agrees with experimental data.

Journal ArticleDOI
TL;DR: In this article, a comparison of four different numerical wave prediction models for hindcast wave conditions in Lake Michigan during a 10-day episode in October 1988 is presented, and the results show that while the individual model predictions deviate from the measurements by various amounts, they all tend to reflect the general trend and patterns of the wave measurements.

Journal ArticleDOI
01 Sep 2002
TL;DR: In this article, high-resolution acoustic measurements were made of suspended sand and bedform dimensions caused by prototypescale waves, both regular and in groups, over a mobile sand bed, in a very large wave channel.
Abstract: High resolution acoustic measurements were made of suspended sand and bedform dimensions caused by prototypescale waves, both regular and in groups, over a mobile sand bed, in a very large wave channel. The changes in wave height at the beginning of the regular waves and within wave groups provides an opportunity to examine the time lag in the response of the sediment. For regular waves suspended sand concentrations lagged the forcing waves with the lag increasing with distance from the seabed. Typically, near-bed (1–2 cm) concentrations reached an equilibrium one to two wave-periods after the waves themselves had reached their steady height while at elevations of 10–15 cm the lag was longer. This lag was interpreted as due to the continual injection of turbulence into the water column from vortex processes associated with the oscillatory wave boundary layer over bedforms. A similar pattern was seen for wave groups, with the sand concentration near the bed lagging by the waves by one to two wave-periods and increasing with distance from the bed. Despite the controlled nature of these prototype-scale suspension experiments, with detailed measurements of bedforms and attempts to achieve ‘equilibrium’ bedforms, considerable variability (730%) in the suspended sand concentration occurred between ‘similar’ forcing conditions, both at a wave-to-wave level and on the scale of groups and longer. The results suggest that considerable variability (a factor of two or more) should be expected in the suspension due to turbulence produced from wave boundary layers in natural environments, where bedforms are frequently continually evolving as the waves change their height, period and direction. A simple wave-average suspended-load model is used to describe the major temporal features of the suspension and to quantify the lag of the suspended sediment in relation to the waves and wave groups. Quantification of the lag is essential for assessing the transport of sand at infra-gravity frequencies. A decay rate of 0.06 s � 1 , applied to antecedent waves, decreased the mean average error (MAE) by a factor of 3 when predicting the suspended load of the repeating wave groups. When tested against five further data sets (including random waves and wave records from the SANDYDUCK field experiment) including the decay rate of 0.06 s � 1 , resulted in a decrease in the MAE of a factor of 1.5–2 (compared to the same model with no lag). The entrainment (pickup) constant in the same model was variable and no consistent pattern was found, although there were suggestions of a link to the location of the measured profile relative to the bedforms. r 2002 Elsevier Science Ltd. All rights reserved.


Journal ArticleDOI
TL;DR: In this paper, a two-dimensional analytical solution is presented to study the reflection and transmission of linear water waves propagating past a submerged horizontal plate and through a vertical porous wall, and the velocity potential in each fluid domain is formulated using three sets of orthogonal eigenfunctions and the unknown coefficients are determined from the matching conditions.

Journal ArticleDOI
TL;DR: In this article, the shape of the spectral spreading function at the Bragg wavelength for the sea-surface gravity waves was determined from a deployment of the HF coastal ocean surface radar (COSRAD) which samples the same patch of water from a range of different angles.
Abstract: The biggest difficulty in extracting wind direction from high-frequency (HF) backscatter ground-wave radar data is in not knowing the fundamental shape of the directional spreading function at the Bragg wavelength for the sea-surface gravity waves. In this paper we present data from a deployment of the HF coastal ocean surface radar (COSRAD) which samples the same patch of water from a range of different angles, allowing us to determine the shape of the spectral spreading function for the Bragg resonant gravity waves. The resulting evaluation of wind direction compares favourably with wind-vane measurements in the vicinity. A routine method for extracting root mean square (rms) wave heights from HF backscatter ground-wave radar spectra has been developed based on the theoretical work of D.E. Barrick. This method is reviewed in the paper and a "best practice" procedure is described for routine production of rms wave heights. Results are shown for a recent deployment of the COSRAD HF radar near Cairns in th...

Journal ArticleDOI
TL;DR: In this article, a new sea state bias modeling approach is presented that makes use of altimeter-derived marine geoid estimates, which directly bin-averages sea height residuals over the wind and wave correlatives.
Abstract: A new sea state bias modeling approach is presented that makes use of altimeter-derived marine geoid estimates. This method contrasts with previous models that require differencing between repeat altimeter passes for SSB isolation, along with complex bivariate inversion, to derive a relation between wind speed, wave height and SSB. Here one directly bin-averages sea height residuals over the wind and wave correlatives. Comparison with the most current nonparametric repeat-pass model shows close agreement and provides a first validation of this simpler and more direct technique. Success is attributed mainly to extensive space and time averaging. Ease in implementation and benefits in working with absolute levels provide much appeal. Further advantages and potential limitations, centered on the need to effectively randomize large sea level anomaly components to expose the bias, are also discussed.

Journal ArticleDOI
TL;DR: In this article, the Durden/Vesecky wave model is combined with the wave height spectral model to analyze recent polarimetric measurements to analyze the azimuthal features, amplitude and phase.
Abstract: Atwo-scale scattering model of the sea developed in terms of wind-generated stochastic processes of the surface-the elevation spectral density of the small-scale structure and the probability density of slopes of the large scale roughness-is combined with the Durden/Vesecky (1) wave height spectral model to analyze recent polarimetric measurements. Ad hoc parameter values are found for the wave model that allow the two-scale model to account for essentially all of the azimuthal features, amplitude and phase, appearing in all four Stokes parameters for the Jet Propulsion Laboratory (JPL) aircraft measurements at 19.35 and 37 GHz (2) and recent Naval Research Laboratory (NRL) aircraft measurements at 10.7 GHz. The excellent agreement provides support for the validation of the approximations of the two-scale model for the range of conditions encountered. The ad hoc parameters of the wave model are developed using the 19.35 and 37.0 GHz data and then tested with 10.7 GHz data. The two- scale model should be useful in studies dealing with simulations and retrievals of surface wind direction from satellite-based polarimetric measurements.

01 Jan 2002
TL;DR: In order to understand the tsunami reduction effect of the coastal permeable structures such as mangrove, coastal forest, wave dissipating block, rock breakwater, houses, with different structure and porosity, the hydraulic experiment was carried out in this article.
Abstract: In order to understand the tsunami reduction effect of the coastal permeable structures as the coastal forest and the artificial wave dissipating structure, the hydraulic experiment is carried out. The hydraulic experiment for the tsunami of two different amplitudes with five kinds of models; mangrove, coastal forest, wave dissipating block, rock breakwater, houses, with different structure and porosity was carried out in order to measure an effectiveness in reducing tsunami disaster. Wave height, the horizontal velocity, and wave pressure were measured for each model case. The measuring points are arranged by considering the impact of the tsunami due to the existence of permeable structure, and the change of tsunami at the front and rear side of a model, and the reduction effect by model conditions was compared. Comparing with the forest case and the artificial structure case, the quantity of reduction on the forest case is smaller than the artificial structure. Although there is the reduction effect by the forest existence and the coastal forest is effective in the damage mitigation by tsunami. Experimental results suggest that the tsunami reduction effect in the water level, the flow velocity and fluid force in the structure back by the permeable structures was fully expectable.

Journal ArticleDOI
TL;DR: In this article, a RANS model for spilling breaking waves is developed, which can be implemented with ship hydrodynamics RANS CFD codes, based on the Cointe & Tulin theory of steady breakers.
Abstract: A RANS model for spilling breaking waves is developed, which can be implemented with ship hydrodynamics RANS CFD codes. The model is based on the Cointe & Tulin theory of steady breakers. The breaker cross section is assumed triangular with maximum height determined by the theoretical/experimental linear relationship with following wave height. Pressure and velocity boundary conditions are imposed on the dividing streamline between the breaker and underlying flow based on the hydrostatic and mixing layer models. An iterative solution procedure provides a unique solution for specified breaking criteria and simulation conditions. The model is implemented using CFDSHIP-IOWA and validated using spilling breaking wave benchmark data for two-dimensional submerged hydrofoils. As with other current RANS codes, wave elevations are under-predicted. However, for the first time in literature, the breaking wave wake is predicted

Journal ArticleDOI
TL;DR: It is shown that training of the network with the help of observed directional wave data could be used to establish dependency of the spreading parameter on more commonly available unidirectional wave parameters derived from, for example, pressure gauge data.
Abstract: The short-term directional spreading of wave energy at a given location is popularly modeled with the help of the Cosine Power model. This model is oriented mainly around value of the spreading parameter involved in its expression. This paper describes how a representative spreading parameter could be arrived at from easily available wave parameters such as significant wave height and average zero-cross wave period, using the technique of neural networks. It is shown that training of the network with the help of observed directional wave (e.g., heave-pith-roll buoy) data could be used to establish dependency of the spreading parameter on more commonly available unidirectional wave parameters derived from, for example, pressure gauge data. It is found that such a procedure involving neural networks is much more accurate and reliable than the conventional approach based on statistical linear regression.

Journal ArticleDOI
TL;DR: In this article, a quasi-linear transform was applied to map the SAR wave spectra into real ocean wave spectras and the azimuth cut-off was then used to model the significant wave height.