scholarly journals Can Rogue Waves Be Predicted Using Characteristic Wave Parameters?

2018 ◽  
Vol 123 (8) ◽  
pp. 5624-5636 ◽  
Author(s):  
A. D. Cattrell ◽  
M. Srokosz ◽  
B. I. Moat ◽  
R. Marsh
Author(s):  
Odin Gramstad ◽  
Elzbieta Bitner-Gregersen ◽  
Erik Vanem

We investigate the future wave climate in the North Atlantic with respect to extreme events as well as on wave parameters that have previously not been considered in much details in the perspective of wave climate change, such as those associated with occurrence of rogue waves. A number of future wave projections is obtained by running the third generation wave model WAM with wind input derived from several global circulation models. In each case the wave model has been run for the 30-year historical period 1971–2000 and the future period 2071–2100 assuming the two different future climate scenarios RCP 4.5 and RCP 8.5. The wave model runs have been carried out by the Norwegian Meteorological Institute in Bergen, and the climate model result are taken from The Coupled Model Intercomparison Project phase 5 - CMIP5. In addition to the standard wave parameters such as significant wave height and peak period the wave model runs provided the full two-dimensional wave spectrum. This has enabled the study of a larger set of wave parameters. The focus of the present study is the projected future changes in occurrence of extreme sea states and extreme and rogue waves. The investigations are limited to parameters related to this in a few selected locations in the North Atlantic. Our results show that there are large uncertainties in many of the parameters considered in this study, and in many cases the different climate models and different model scenarios provide contradicting results with respect to the predicted change from past to future climate. There are, however, some situations for which a clearer tendency is observed.


2021 ◽  
Author(s):  
Elzbieta M. Bitner-Gregersen ◽  
Odin Gramstad

Abstract Traditionally, wave parameters and their statistics has been derived from time series measurements of wave elevation. Recently, due to introduction in oceanography of stereo video camera systems, increasing attention has started to be given to spatial wave data and statistics. The present study is addressing temporal and spatial statistics of nonlinear waves giving focus to individual wave parameters. A directionally spread rogue-prone sea state observed in the North Sea is used as an example in the analysis which is based on numerical HOSM (Higher Order Spectral Method) simulations. The nonlinear order in the HOSM solver is set to M = 3, which includes the leading order nonlinear dynamical effects, including the effect of modulational instability. The following wave parameters are investigated: surface elevation, wave crests and wave troughs. The results demonstrate that the maximum spatial crest in a wave record can be up to 70% higher than the temporal crest. Further, the study indicates that the Gram-Charlier series can be used to fit the probability density function of surface elevation. It discusses applicability of the methodology based on the Gram-Charlier series for approximation of distributions of individual wave parameters of extreme and rogue waves and recommends further exploitation of this methodology. The results are discussed in the context of marine structures’ design.


Author(s):  
Elzbieta M. Bitner-Gregersen ◽  
Odin Gramstad

Abstract In the past, it was most common to derive wave parameters and their statistics from time series of wave elevation. The duration of the wave records has been usually restricted to 20 or 30 minutes. Recently, increasing attention has started to be given to spatial wave data and wave statistics, particularly due to introduction in oceanography of stereo camera systems for collecting space–time ensemble of sea surface elevation. Using numerical linear, 2nd and 3rd order simulations this study compares temporal and spatial statistics of wave parameters. The 3rd order wave data are simulated by a numerical solver based on the Higher Order Spectral Method (HOSM) which includes the leading order nonlinear dynamical effects, accounting for the effect of modulational instability. The Pierson-Moskowitz and the JONSWAP spectrum with different gamma parameters are used in the analysis. Sea states with wave steepness where rogue waves were recorded in nature are considered. Consequences of using temporal contra spatial statistics are discussed in perspective of marine structures’ design. Functional dependency between wave parameters characterizing occurrence of rogue waves in unidirectional wave field is proposed.


2012 ◽  
Vol 1 (33) ◽  
pp. 85
Author(s):  
Guirec Prevot ◽  
Olivier Boucher ◽  
Maryline Luck ◽  
Michel Benoit

Rubble-mound breakwaters are often pre-designed with empirical formulae allowing the estimation of armour stone size or weight, taking into account the wave conditions (mainly a characteristic wave height and a characteristic period), the type and density of stone or block used, the slope of the mound, the acceptable level of damage, etc. In deep water conditions, the existing formulas are rather well established (e.g. Hudson and Van der Meer formulas among others). They use as input data wave parameters that are well defined (e.g. the significant wave height H1/3 or sometimes the height H1/10) and easily accessible, from in situ measurements or from numerical wave models. In shallow water however, and in particular in breaking wave conditions (where most of the small breakwaters are built), a number of physical processes (refraction, shoaling and breaking) significantly modify the incoming waves. They also lead to changes in the wave height distribution (which can no longer be regarded as being of Rayleightype) and in the shape of the wave spectrum. This, combined with the fact that most of the models used nowadays for nearshore wave propagation are spectral wave models (e.g. SWAN, TOMAWAC, etc.) and thus provide spectral parameters as output (typically the spectral significant wave height Hm0 and the peak period Tp or the mean energetic period Tm-1,0) has raised the question of which characteristic wave parameter should be used in stability formulas for rubble-mound breakwaters in shallow water. This has led to the consideration of more representative wave parameters such as H2% or Tm-1,0 which are sometimes less accessible from existing wave database or numerical modelling studies. The objective of the present study is to review and compare several available methods to calculate armour stone weight in shallow waters, and to provide some insight into the applicability and limitations of these methods based on a series of wave flume experiments.


2002 ◽  
Vol 12 (7) ◽  
pp. 403-412 ◽  
Author(s):  
P. A. Fomin ◽  
K. Mitropetros ◽  
H. Hieronymus ◽  
J. Steinbach

Author(s):  
Fedor Gippius ◽  
Fedor Gippius ◽  
Stanislav Myslenkov ◽  
Stanislav Myslenkov ◽  
Elena Stoliarova ◽  
...  

This study is focused on the alterations and typical features of the wind wave climate of the Black Sea’s coastal waters since 1979 till nowadays. Wind wave parameters were calculated by means of the 3rd-generation numerical spectral wind wave model SWAN, which is widely used on various spatial scales – both coastal waters and open seas. Data on wind speed and direction from the NCEP CFSR reanalysis were used as forcing. The computations were performed on an unstructured computational grid with cell size depending on the distance from the shoreline. Modeling results were applied to evaluate the main characteristics of the wind wave in various coastal areas of the sea.


Author(s):  
Olga Kuznetsova ◽  
Olga Kuznetsova ◽  
Yana Saprykina ◽  
Yana Saprykina ◽  
Boris Divinsky ◽  
...  

Based on numerical modelling evolution of beach under waves with height 1,0-1,5 m and period 7,5 and 10,6 sec as well as spectral wave parameters varying cross-shore analysed. The beach reformation of coastal zone relief is spatially uneven. It is established that upper part of underwater beach profile become terraced and width of the terrace is in direct pro-portion to wave height and period on the seaward boundary but inversely to angle of wave energy spreading. In addition it was ascertain that the greatest transfiguration of profile was accompanied by existence of bound infragravity waves, smaller part of its energy and shorter mean wave period as well as more significant roller energy.


Author(s):  
Wei Tan ◽  
Zhao-Yang Yin

Abstract The parameter limit method on the basis of Hirota’s bilinear method is proposed to construct the rogue wave solutions for nonlinear partial differential equations (NLPDEs). Some real and complex differential equations are used as concrete examples to illustrate the effectiveness and correctness of the described method. The rogue waves and homoclinic solutions of different structures are obtained and simulated by three-dimensional graphics, respectively. More importantly, we find that rogue wave solutions and homoclinic solutions appear in pairs. That is to say, for some NLPDEs, if there is a homoclinic solution, then there must be a rogue wave solution. The twin phenomenon of rogue wave solutions and homoclinic solutions of a class of NLPDEs is discussed.


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