Variation Of Wave Height Research Articles

Wave Spectra Analysis on the Spatiotemporal Variability of Sea States under Distinct Typhoon Tracks in a Semienclosed Sea

Abstract The dynamics of typhoon-induced waves in semienclosed seas become an interesting topic with the increase of typhoon intensity. Based on the calibrated Simulating Waves Nearshore (SWAN) model, wave dynamics were investigated under distinct typhoon tracks [e.g., Matmo (2014), Rumbia (2018), and Lekima (2019)] in the Bohai Sea. Distributions of significant wave heights (SWHs) are affected by the typhoon wind fields and are directly related to the typhoon tracks. The classical JONSWAP wave spectra were adopted for the analysis of sea states (e.g., wind seas or swells) to further explain variations in wave heights. Results indicate that the dominant sea state with higher energy experiences significant spatiotemporal variability under distinct tracks. For typhoons passing through the central part of the Bohai Sea (e.g., Rumbia), high-energy waves are observed under swell-dominated and mixed sea states, which are subjected to the fetch limitation in the semienclosed sea and rapid changes in typhoon winds. The high energy waves induced by other typhoons passing along the edges of the Bohai Sea correspond to the wind-sea-dominated sea state. Spatiotemporal variability of the sea state exhibits a high correlation with its position relative to the typhoon center. Therefore, a reference frame based on the radius of the maximum wind speed was established to discuss the sea states in this semienclosed sea. Further investigations reveal that swells (wind seas) dominate the regions within the radius of the maximum wind speed (elsewhere), and the double-peaked wave spectra tend to appear in the left quadrants.

Historical change and variability of spectral wind wave climate in the New York Bight

AbstractThe sea surface is a complex superposition of various wave systems, thus, analysing their characteristics provides more meaningful and accurate information compared to conventional integrated wave parameter approaches. The concept of wave family—a population of wave systems within a specific region in spectral space—provides the foundation for investigating the long‐term climatology of wave systems. This study adopts a wave family approach to investigate the climatology of wave systems and their long‐term climate controllers at the location of a coastal buoy in the western North Atlantic Ocean. The frequency‐direction wave spectrum is constructed for a historical 20‐year period by applying the Maximum Entropy Method on directional buoy measurements acquired from the National Data Buoy Center station 44025, located in the New York Bight. The two‐dimensional wave spectrum is partitioned, using the watershed partitioning algorithm, and the occurrence distribution of spectral partitions is calculated to identify predominant wave families. Each of the four identified wave families carries unique characteristics based on spatial formation and duration of propagation prior to arrival at the study site. The study quantifies long‐term trends and variability in wave height of each wave family on a monthly, seasonal and annual level, and their relative importance to the bulk sea‐state climatology. The nexus between the bulk or wave family seasonal wave heights and the climate indices is quantified to identify the wave climate controllers in the study area.

The Effect of Different Swell and Wind-Sea Proportions on the Transformation of Bimodal Spectral Waves over Slopes

In the laboratory experiment, 1:25 scaled models are constructed to investigate the effect of different swell and wind-sea proportions on the wave transformation. The source of the wave spectrum is related to the wave conditions in the Gulf of Guinea. Swell from the westerlies and local wind-sea forms the bimodal spectral waves in the region. To better understand the transformation of bimodal spectral waves, a series of wave conditions are measured by the wave gauges in a wave flume. Based on the wave spectrum at the Bight of Benin, the wave transformation along the slopes and variations of different swell proportions are analyzed. The result of the wave height variations shows that the slope and swell proportion play a significant role in the maximum wave height, and the wave height has an upward trend with a large swell proportion. The analysis of wave nonlinearity is conducted, showing that the large swell proportion in the wave spectrum leads to a more significant nonlinearity before wave breaking. Combining the variations of wave height and wave nonlinearity, the influence of bimodal spectral waves on nearshore wave prediction, shoreline change, marine operations, and structure design is discussed.

Extreme waves in the Caribbean Sea: spatial regionalization and long-term analysis

The extreme wave height distribution in the Caribbean Sea is studied using a new method based on the maximum basin-wide aggregate of significant wave height, Hs, values per month. Besides, by means of the Self-Organizing Maps (SOM) technique, we identify coherent geographical regions with similar extreme wave height variability in the Caribbean Sea. Our findings revealed three primary regions: the eastern side with comparatively lower values, the central region with intermediate values, and the western side with the highest extreme wave heights. The study also examines the wind forcing conditions driving the spatial and temporal variability of the extreme waves, highlighting the influence of the low-pressure belt dynamics as well as the role played by the Caribbean Low-Level Jet (CLLJ) index, and the impact of cold fronts and hurricanes on extreme wave heights. Additionally, we explore the relationship between the extreme wave height distribution and climatic indices, such as the Atlantic Multidecadal Oscillation (AMO), the Atlantic Meridional Mode (AMM), the North Atlantic Oscillation (NAO) and the Oceanic Niño (ONI). The results reveal that the spatial distribution of extreme wave heights in the Caribbean Sea is mostly ruled by the influence of the CLLJ, with correlations close to 80%. In addition, significant correlations were observed between the extreme wave heights and the ENSO in the central Caribbean, as well as positive correlations between the extreme wave heights and NAO in the eastern part of the basin, and significant values of correlation with the negative phases of AMO and AMM in the whole basin. We show that, unlike conventional (or broadly used) methods deployed to identify extreme wave height, such as percentile 99th, Hs99, our methodology allows a further assessment of the wind and climate forcing conditions associated with the extreme wave events. Although, we acknowledge that the method here presented has limitations to capture extreme wave height outliers, it has the advantage of being used concomitant with the wind forcing to develop multivariate wave climate analysis at basin scale, and could be extended to a more local scale when studying coastal processes.

Multipole solution with nonlinear pressure loss for oblique waves action on a submerged partially perforated semi-circular breakwater

This study is an extension of the research on semi-circular breakwater based on Lyu et al. (2020). This time, we focus on the changes in the flow field when waves obliquely interact with the axis of the partially perforated semi-circular breakwater, as well as the nonlinear effects resulting from variations in wave height to some extent. The analytical solution of the flow field is still obtained using the multipole expansion method based on potential flow theory and the method of separation of variables. The analytical solution for oblique incidence is primarily achieved through the cylindrical form of the Bessel equation. Separately considering viscous effects and potential flow, we estimate the impact of wave height variation on the perforated boundary through the quadratic pressure loss term. By employing an iterative solving approach, we comprehensively discuss the influence of wave height, water depth, perforation form, and oblique incidence angle on the flow field and the forces acting on the breakwater.

Characteristics of vortex evolution around a cylindrical oscillating water column device: An experimental study

The utilization of oscillating water column (OWC) converters with existing hydraulic/coastal structures has emerged as a crucial approach for the development of economically viable and environmentally sustainable green power generation devices. Integrating OWC converters into offshore wind turbine (OWT) monopiles is a promising solution in wind power industrialization. This paper presents an experimental investigation of the flow characteristics of an OWT-OWC system under regular wave conditions, focusing on the evolution of vortex structures. Particle image velocimetry (PIV) is employed to measure the flow field surrounding the OWC converter under different wave heights and wave period conditions. Based on the measured velocity field data, the evolution of vortices is examined using the Q-criterion. The results indicate that the wave period significantly affects the flow patterns. Specifically, an increase in wave period enhances the three-dimensional nature of the flow field. The vortices outside the OWC chamber are observed to connect and form a three-dimensional vortex ring, hindering efficient wave energy conversion. Conversely, the variation in wave height exhibits limited impact on the flow field evolution. However, as the wave height increases, the vortex strength and asymmetry experience a significant rise, making it difficult to form a stable three-dimensional vortex ring. Moreover, based on optimal geometric design considerations, it is recommended to increase the lateral angle and height of the sidewall openings to prevent vortex ring formation and minimize obstructions, while ensuring the structural safety of the OWT.

Stochastic dynamic analysis of floating bridges exposed to inhomogeneous and irregular waves

As future floating bridges gets longer, the likelihood of significant inhomogeneous wave conditions across them increase. Consequently, a proper assessment of the effects of inhomogeneous wave conditions is needed. In this paper, we present an approach to model inhomogeneous sea states by representing the stochastic process using generalized harmonic decomposition, retaining the coherency inherent in Airy wave theory. The methodology is applied to a concept model of a floating bridge to cross the Bjørnafjord in Norway, which is more than five kilometres wide. The paper emphasizes on frequency-domain simulation, but the required steps to generate time-domain representations are given. To suggest what might be critical considerations in design, the response effects due to some selected conceptual inhomogeneities are highlighted. For varying wave heights alone, it is found that it is likely conservative to approximate the inhomogeneous sea state as homogeneous by assuming the harshest conditions across the full width of the strait. By modulating the mean wave angle of a 100-year swell sea state, a spherical wave front matching the curvature of the bridge girder is found to produce significantly more severe response than the homogeneous reference swell; an increase of 14% of the maximum axial force response is found. Furthermore, a proper treatment of the coherency for swell sea states is found to be crucial, in contrast to typical wind sea conditions.

Frequency-domain hydroelastic stress analysis of floating structures under spatially inhomogeneous wave field

This paper presents a frequency-domain method for the stress analysis of flexible floating structures exposed to a spatially inhomogeneous wave field. A hydroelastic model is developed for the continuous structure, wherein discrete rigid modules are connected by elastic beams with equivalent stiffness. The inhomogeneous wave field is divided into wave regions characterized by constant wave parameters. By assigning distinct wave parameters to modules based on their respective positions, the global hydroelastic equation is established to capture the wave inhomogeneity. To compute the stress, external loads in the hydroelastic equation, comprising hydrodynamic and hydrostatic restoring pressures, as well as inertia forces, are mapped onto the finite element model of the continuous structure, enabling stress calculation by the quasi-static method. Variations in wave directions and heights along the longitudinal direction of the structure are introduced with the aim of exploring the effect of the wave inhomogeneity on the stress. A deliberately flexible barge is constructed to evaluate the stress resulting from global structural vibrations. The results demonstrate a significant contribution of wave inhomogeneity to the stress, particularly during structural resonance frequencies. Moreover, an exclusive phenomenon is observed whereby the inhomogeneous wave field induces stress due to anti-symmetric vibrations under beam sea conditions.

Effects of Terrain near Taiwan Island on Typhoons with Different Tracks and Typhoon Waves

The terrain, such as Taiwan Island, have been shown to have complex effects on typhoons and the associated typhoon waves. Terrain effects change with typhoon tracks. In this study, three types of typhoon tracks (northern, middle and southern) were defined according to the relationship between the typhoon tracks and Taiwan Island. Typhoons on these three tracks and typhoon waves were simulated using the Weather Research and Forecasting–Simulating Waves Nearshore model. In each type of typhoon, a control case without the Taiwan topography was simulated to compare with real cases. The results showed that typhoons on different tracks were affected by the terrain of Taiwan Island in different ways. Taiwan Island had weakening, decelerating and deflective effects on typhoons. The ranking for the weakening effect was middle track (81%) > southern track (69%) > northern track (3%). The decelerating effect was 7% in the northern track and 25% in the southern track. The deflective effect of the terrain makes typhoons on the northern (southern) track deflect toward the south (north). When a typhoon on a middle track passed over Taiwan Island, a new center of low pressure would replace the former center and make the track discontinuous. In addition, the influence of typhoons on regions near Taiwan Island changed with the typhoon’s tracks. The influence ranking of typhoons in Taiwan Island was the middle track > southern track > northern track, which was consistent with that of typhoons in the Taiwan Strait and opposite to that of typhoons in Fujian Province. The influence ranking of typhoons on the Taiwan Strait was the opposite of the typhoon intensity ranking, which suggests that the intensities of wind and waves in the strait were more related to typhoon tracks than typhoon intensity. The variations in the significant wave height were similar to those of the wind speed, but there was a time lag (2 h) between them due to the wave growth process and swells. In addition, the significant wave height distribution sometimes differed from the wind speed distribution under the influence of swells and terrain.

Significant wave height prediction based on the local-EMD-WaveNet model

This research constructed the innovative Local-EMD-WaveNet, a multi-channel neural network model, specifically designed for the prediction of significant wave height (SWH) at a singular point. It leverages Local Empirical Mode Decomposition (EMD) on significant wave heights in Ghanaian waters, integrating the derived decomposition results with wind speed data. This compiled data is then channeled into the model, which exploits the capabilities of dilated causal convolution to capture and analyze the time-series characteristics integral to future SWH predictions. The model ingeniously embeds EMD within the training process, treating the decomposed sub-waves and wind speed sequences as unique channels along the “depth” dimension. Following the application of dilated causal convolution, these channels are systematically “stacked”. Compared to conventional LSTM and direct data incorporation methods, Local-EMD-WaveNet consistently outperforms, especially in long-term predictions. The model exhibited significant improvements in Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) during 48 and 56 time-step predictions, marking increases of 27.3% and 23.5%, respectively, outshining both WaveNet and LSTM. Particularly in situations with larger wave height variations, Local-EMD-WaveNet accurately captures waveforms' peaks and troughs. These results validate Local-EMD-WaveNet as a reliable wave forecasting tool with considerable potential in ocean engineering and maritime applications.

Upsampling wave temporal resolution: Investigating wave parameters and the influence on WEC power performance

Power production of wave energy converters (WEC) predicted in the time domain utilize wave resource parameters and time-domain hydrodynamic model simulations of the WEC. While the hydrodynamic model provides high temporal resolution of power production (10’s of Hz), the wave resource parameters are often based on frequency-domain calculations with temporal resolution of 30 minutes to an hour. However, real ocean wave conditions vary on much shorter time scales. Relying on frequency-domain calculations will not be sufficient to capture the short-term variability and accurately predict WEC power production for a standardized methodology that follows power system requirements. These requirements need forecasted data with high sampling frequency for accurate energy predictions. Looking specifically at resource characterization, high temporal resolution datasets are not publicly available or do not exist for many coastal locations. Due to data availability, low temporal resolution datasets are being used in a majority of studies to generate representative wave conditions as inputs to numerical simulations. Representative wave conditions are used to generate wave spectrums. The issue with this practice is spectrums are then used to predict the efficiency of systems that will not accurately capture the variability of waves in short timeframes. Creating a standardized methodology to increase the temporal resolution of metaocean conditions to inform model development can provide better forecasting of power production. Random amplitude, Fourier coefficient methods have been suggested for WEC simulations of finite durations to improve the observed variability in wave heights and power production. Variability using this method does increase for finite durations compared to the commonly used deterministic amplitude method. In this paper we will investigate the influence of wave parameters (significant wave height, maximum wave height, and energy period) on the prediction of WEC power production. A better understanding of the influence of these parameters will provide a path towards future standardization methodology for resource inputs for time-domain modeling.

Evolution of Scour Length around Circular Piles Subjected to Irregular Waves Due to Climate Change

Scour is a phenomenon that affects structures deployed in rivers or seas, favoring the transport of sediments around their foundations, which can expose their structural stability. This work aimed to develop a physical model of a mobile bottom to determine the scour-hole extensions around a group of four vertical piles of circular sections subjected to irregular waves. For this purpose, a beach profile and a typical slope were constructed and subjected to 24 h of storm waves, divided into 12 h intervals in the prototype. Additionally, three wave periods were studied according to the Mexican Institute of Transportation wave data and three scenarios of a rise in sea level. The data suggest that the length of the scour hole was greater in the piles in the front for all cases, which may be reflected in a reduction in scour protection costs. The results obtained for the extent of the scour hole suggest a setting of less than four times the pile diameter in most cases. Finally, it is inferred that a rise in sea level by itself is not a decisive factor in the increase in the values obtained; therefore, it is necessary to consider the variations in wave heights and wave periods associated with such increases.

A Comparison of Multiple Approaches to Study the Modulation of Ocean Waves Due To Climate Variability

AbstractUsing multiple approaches, the modulation of climate variability on global ocean waves from 1981 to 2020 is investigated based on a wave hindcast model forced by ERA5 winds. These climate variabilities include El Niño–Southern Oscillation (ENSO), Antarctic Oscillation (AAO), Arctic Oscillation (AO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and Indian Ocean Dipole. Linear regression and composite analysis results indicate that El Niño‐induced low‐pressure systems in December–February (DJF) generate energetic waves in the Pacific Ocean. Positive AAO events are associated with the southward movement of westerlies in the Southern Hemisphere and thus produce long‐period Southern Ocean swell that impacts the South Pacific Ocean. In the Northern Hemisphere, positive AO is associated with strengthening winds which generate larger waves around the Icelandic region. An empirical orthogonal function approach was further undertaken to study interannual variability of significant wave height (Hs) anomalies. In DJF, mode 1 marks the impacts of ENSO and PDO in the Pacific Ocean and AO in the North Atlantic Ocean. Mode 2 is controlled by AO, which is characterized by a dipole pattern in the North Atlantic Ocean. Mode 3 describes the AAO footprints in the Southern Ocean and the eastern Pacific Ocean. In June–August, the leading mode is influenced by AAO and AMO. Mode 2 indicates the importance of ENSO and PDO which exhibit opposite patterns in the Pacific Ocean sector of the Southern Ocean. Finally, a wavelet coherence analysis is conducted on the principal components and climate indexes, which shows their respective evolutions over the time–frequency domain.

Physical Model Experiment for Estimating Wave Overtopping on a Vertical Seawall under Regular Wave Conditions for On-Site Measurements

Apart from implementing hardware solutions like raising the crest freeboard of coastal structures to efficiently counter wave-overtopping, there is a simultaneous requirement for software-driven disaster mitigation strategies. These tactics involve the swift and accurate dissemination of wave-overtopping information to the inland regions of coastal zones, enabling the regulation of evacuation procedures and movement. In this study, a method was proposed to estimate wave-overtopping by utilizing the temporal variation of wave heights exceeding the structure’s crown level, with the aim of developing an on-site wave measurement system for providing wave-overtopping information in the field. Laboratory model experiments were conducted on vertical seawall structures to measure wave-overtopping volumes and wave runup heights under different wave conditions and structural freeboard variations. By assuming that the velocity of water inundation on the top of the structure during wave-overtopping events is equivalent to the long-wave velocity, an overtopping discharge coefficient was introduced. This coefficient was utilized to estimate the rate of wave-overtopping based on the temporal changes in wave runup heights measured at the top of the structure. Upon reasonably calculating the overtopping discharge coefficient, it was verified that the estimation of wave-overtopping could be achieved solely based on the wave runup heights.

Numerical Modeling of Transient Flow Characteristics on the Top Surface of a Steel Slab Continuous Casting Strand Using a Large Eddy Simulation Combined with Volume of Fluid Model.

In the current study, the transient flow characteristics on the top surface of a steel slab continuous casting strand were numerically investigated using a large eddy simulation combined with volume of fluid (LES + VOF) model. The validation of numerical simulation was verified via nail board measurement in the industrial continuous casting mold. The effects of casting speed on the top surface level profile and the instantaneous distribution of vortex were discussed. The level variation profile migrated after a period of time, moving from one side of the wide face of the mold to the other. The wave height and transient variation degree of the standing wave increased with an increase in the casting speed. The region near the SEN was more likely to promote the formation of vortices. The vortex generation became easier when the vorticity peaks were concentrated on the outer edge of the low-speed confluence area near the submerged entry nozzle. In addition, the effect of surface velocity on the instantaneous level fluctuation was analyzed. The frequency of level fluctuations was highest at 3~4 mm, and the high-frequency range of velocity fluctuation was 20~60 mm/s at 0.9 m/min casting speed for a 1500 mm × 200 mm caster section. The linear relationship between the level fluctuation and surface velocity magnitude was obtained. The present work aimed at evaluating the dynamic problem of the standing wave at the liquid powder-molten steel interface on the top surface of the mold, which is helpful in optimizing the casting parameters for regular casting practice and improving the quality of the steel slabs.

Wave Groups and Small Scale Variability of Wave Heights Observed by Altimeters

AbstractRecent satellite altimeter retracking and filtering methods have considerably reduced the noise level in estimates of the significant wave height (Hs), allowing to study processes with smaller spatial scales. In particular, previous studies have shown that wave‐current interactions may explain most of the variability of Hs at scales 20–100 km. As the spatial scale of the measurement is reduced, random fluctuations emerge that should be associated to wave groups. Here we quantify the magnitude of this effect, and the contribution of wave groups to the uncertainty in Hs measurements by altimeters, with a particular focus on extreme extra‐tropical storms. We take advantage of the low orbit altitude of the China‐France Ocean Satellite (CFOSAT), and the low noise level of the nadir beam of the SWIM instrument. Our estimate of wave group effects uses directional wave spectra measured by off‐nadir beams on SWIM, and signal processing theory that gives statistical properties of the wave envelope, and thus the local wave heights, from the shape of the wave spectrum. We find that the standard deviation of Hs associated to wave groups is a function of satellite altitude, wave height and spectral peakedness. For CFOSAT these fluctuations generally account for about 25% of the variance measured over a 80 km distance. This fraction is largest in storms and in the presence of long swells. When the estimated effect of wave groups is subtracted from the variance of Hs measurements, the remaining variability is higher in regions of strong currents.

Researches on the motion and flooding process of a damaged passenger ship in regular and irregular beam waves

The motion and flooding process of a damaged passenger ship in regular and irregular beam waves are investigated experimentally and numerically at zero forward speed. Experiments are carried out on the intact and damaged ship models with varied wave periods and different wave steepness in regular and irregular waves. The water height inside the damaged compartments and ship's roll are measured and compared to the numerical results from the potential flow method with a flooding model based on the modified Bernoulli's equation. Experiments are conducted to verify numerical method's capability of predicting ship's motion under unsteady condition in the irregular wave. The results indicate that the potential flow method can accurately estimate ship roll and internal water height, but it fails to capture the multi-frequency characteristic of wave height variation in large-wave-steepness cases. The flooding into the side damaged opening increased the period of ship's roll and the roll amplitude increased with increasing wave steepness in both ship states. The roll amplitude of the damaged ship is smaller than that of an intact one under same condition in both regular and irregular wave, although the maximum rolling angle can exceed the latter under certain conditions. More nonlinear effects throughout the flooding process, as well as unsteady effects in irregular waves, should be added to improve the accuracy of the numerical method.

Numerical Simulation of the Beach Response Mechanism under Typhoon Lekima: A Case Study of the Southern Beach of Chudao

Typhoons play an important role in beach evolution. The storm surge and large waves caused by typhoons can cause significant changes in beach morphology in a short period of time. The mechanism of beach evolution and profile changes during typhoons is significantly different from that under non-typhoon dynamic conditions. The XBeach numerical model provides an effective tool for predicting the response of sandy coasts to typhoons. This study is based on field-collected long-term beach profile elevations and grain size data, which were used to establish a two-dimensional XBeach model for simulating the morphological evolution of Cudao Island Beach under Typhoon Lekima. The GSA (Generalized Sensitivity Analysis) method was used to determine the sensitivity order of several important parameters in this modeling. Four different moments of wave height variation were selected during the typhoon process to analyze and study beach evolution. The results show that Chudao South Beach is always in a state of erosion during the typhoon period. The wave water increase is apparent in the nearshore wave-breaking area. The beach shoulder in the northeastern part of the beach is short, and the profile, with a short length, responds quickly to the typhoon. The eroded sediment is mainly deposited in the lower part of the intertidal zone or even transported outside of the wave-breaking zone, and a small part is transported to the shore and deposited in the high-tide zone. The continuous sediment transport along the coast of Chudao Beach is an important factor that influenced the evolution of each profile during Typhoon Lekima.

Wave climate and energy resources in the Mariana Islands from a 42-year high-resolution hindcast

A high-resolution wave hindcast from 1979 to 2020 was developed for Guam and the Commonwealth of the Northern Mariana Islands, which are influenced by mesoscale and synoptic weather systems from the western Pacific Rim to the Central Pacific. The spectral wave modeling utilized structured global and unstructured regional grids with improved resolution in nearshore waters, where wave resources development is most feasible. The hindcast demonstrates its capability in capturing multi-modal seas through reproduction of bulk and partitioned wave parameters derived from altimetry and buoy measurements. The local wave climate is influenced by the year-round trade winds and tropical cyclones as well as seasonal monsoons, frontal systems, and mid-latitude high- and low-pressure systems. The strong intra-annual variation of the significant wave height and power flux reflects transitions between local and distant weather systems, which account for the diverse wave conditions comprised of short-period wind waves, intermediate-period seas, and long-period swells around the islands. Among the Pacific island regions, spectral partitioning is particularly important for describing the dominant wave components by period and direction with pertinent information conducive to energy resources characterization and coastal zone management in the Mariana Islands.

The effect of the operational environment on the survivability of passenger ships

The in-force probabilistic framework for passenger ship survivability assessment covers collision hazards. The framework primarily pertains to a static approach. Nonetheless, more complex dynamic analyses usually employ the same damage definitions, adding besides the breach characteristics, the environmental condition selection or, more precisely, the irregular wave environment necessary to simulate the damage scenarios. The traditional dynamic approaches to survivability consider only the significant wave height sampled from statistical formulations, with the wave period deriving from a constant steepness assumption. However, wave height and period influence ship dynamics in waves differently, especially concerning survivability after damage. Therefore, aiming at a direct assessment of ship survivability and the probability of loss of lives determination in realistic operational scenarios, it is essential to properly study the influence of combined variations of wave height and periods and their occurrence. The present study proposes a methodology for dynamic simulations in site-specific conditions derived from the Global Wave Statistics. The study documents the process in two critical collision damages for a reference passenger ship, using wave height and period combinations typical of the main sea areas of interest for passenger ships and performing a sensitivity analysis on the simulations needed to evaluate survivability. This enhanced analysis allows identifying the limiting environmental conditions for the critical damage cases, including the effect of heading variations, determining the ship’s survivability to specific damage in an operational area.