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Nowadays, numerous governments have instituted diverse regulatory frameworks aimed at fostering the assimilation of sustainable energy sources characterized by reduced environmental footprints. Solar, wind, geothermal, and ocean energies were subject to extensive scrutiny, owing to their ecological merits. However, these sources exhibit pronounced temporal fluctuations. Notably, ocean dynamics offer vast energy reservoirs, with oceanic waves containing significant amounts of energy. In the Central American Pacific context, the exploration of wave energy resources is currently underway. Accurate numerical wave models are required for applied studies such as those focused on the estimation of exploitable wave power; and even more so in Central American region of the Pacific Ocean where existing numerical models simulations have so far relied on coarse resolution and limited validation field data. This work presents a high-resolution unstructured wave hindcast over the Central American Pacific region, implemented using the third-generation spectral wave model WAVEWATCH III over the period between 1979 and 2021. The results of the significant wave height have been bias-corrected on the basis of satellite information spanning 2005 to 2015, and further validation was performed using wave buoy and acoustic Doppler current profiler (ADCP) records located in the nearshore region of the Central America Pacific coast. After correction and validation of the wave hindcast, we employed the dataset for the evaluation and assessment of wave energy and its possible exploitation using different wave energy converters (WECs). This evaluation addressed the need to diverse the energy portfolio within the exclusive economic zones of Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador in a sustainable manner. Moreover, a comprehensive analysis was carried out on the advantages of harnessing wave energy, juxtaposed with the imperative of regulatory frameworks and the current dearth of economic and environmental guidelines requisite for development within the region. [ABSTRACT FROM AUTHOR]

This study analyzed the past wave climate of the Black Sea region for the period from 1988 to 2021. The wave field has been simulated using the state-of-the-art, third-generation wave model WAVEWATCH III forced by the ECMWF reanalysis ERA5 winds, with the model resolution being the highest ever applied to the region in a basin-scale climate study. The surface currents provided by the Copernicus Marine Service have been included in the wave model to evaluate wave--current interactions. The wave model results have been validated with respect to satellite and buoy observations, showing that the simulation accurately reproduces the past evolution of the wave field, exceeding 0.9 correlation with respect to satellite data. The inclusion of wave--current interaction has been positively evaluated. Four statistics (significant wave height 5th and 95th percentiles, mean, and maxima) have been used to describe the wave field at seasonal timescale, showing a clear distinction between the Western (rougher sea conditions) and Eastern (calmer sea conditions) sub-basins. Furthermore, the intra-annual wave climate variability has been investigated using a Principal Component Analysis (PCA) and the Mann--Kendall test on significant wave height (SWH). This study represents the first time the PCA is applied to the region, identifying two main modes that highlight distinct features and seasonal trends in the Western and Eastern subbasins. Throughout most seasons, the SWH trend is positive for the Eastern basin and negative for the Western basin. The PCA shows a regime shift with increasing eastward waves and decreasing north and north-eastward waves. Finally, SWH correlation (r) with four Teleconnection indexes (East Atlantic Pattern, Scandinavian Pattern, North Atlantic Oscillation, and East Atlantic/West Russia Pattern) revealed that the strongest r is observed with the Eastern--Atlantic--Western Russia teleconnection, with a peculiar spatial pattern of correlation, and is positive for the northwestern and negative for the southeastern sub-basin. [ABSTRACT FROM AUTHOR]

Nowadays, numerous governments have instituted diverse regulatory frameworks aimed at fostering the assimilation of sustainable energy sources characterized by reduced environmental footprints. Solar, wind, geothermal, and ocean energies were subject to extensive scrutiny, owing to their ecological merits. However, these sources exhibit pronounced temporal fluctuations. Notably, ocean dynamics offer vast energy reservoirs, with oceanic waves containing significant amounts of energy. In the Central American Pacific context, the exploration of wave energy resources is currently underway. Accurate numerical wave models are required for applied studies such as those focused on the estimation of exploitable wave power; and even more so in Central American region of the Pacific Ocean where existing numerical models simulations have so far relied on coarse resolution and limited validation field data. This work presents a high-resolution unstructured wave hindcast over the Central American Pacific region, implemented using the third-generation spectral wave model WAVEWATCH III over the period between 1979 and 2021. The results of the significant wave height have been bias-corrected on the basis of satellite information spanning 2005 to 2015, and further validation was performed using wave buoy and acoustic Doppler current profiler (ADCP) records located in the nearshore region of the Central America Pacific coast. After correction and validation of the wave hindcast, we employed the dataset for the evaluation and assessment of wave energy and its possible exploitation using different wave energy converters (WECs). This evaluation addressed the need to diverse the energy portfolio within the exclusive economic zones of Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador in a sustainable manner. Moreover, a comprehensive analysis was carried out on the advantages of harnessing wave energy, juxtaposed with the imperative of regulatory frameworks and the current dearth of economic and environmental guidelines requisite for development within the region.

This study analyzed the past wave climate of the Black Sea region for the period from 1988 to 2021. The wave field has been simulated using the state-of-the-art, third-generation wave model WAVEWATCH III forced by the ECMWF reanalysis ERA5 winds, with the model resolution being the highest ever applied to the region in a basin-scale climate study. The surface currents provided by the Copernicus Marine Service have been included in the wave model to evaluate wave–current interactions. The wave model results have been validated with respect to satellite and buoy observations, showing that the simulation accurately reproduces the past evolution of the wave field, exceeding 0.9 correlation with respect to satellite data. The inclusion of wave–current interaction has been positively evaluated. Four statistics (significant wave height 5th and 95th percentiles, mean, and maxima) have been used to describe the wave field at seasonal timescale, showing a clear distinction between the Western (rougher sea conditions) and Eastern (calmer sea conditions) sub-basins. Furthermore, the intra-annual wave climate variability has been investigated using a Principal Component Analysis (PCA) and the Mann–Kendall test on significant wave height (SWH). This study represents the first time the PCA is applied to the region, identifying two main modes that highlight distinct features and seasonal trends in the Western and Eastern sub-basins. Throughout most seasons, the SWH trend is positive for the Eastern basin and negative for the Western basin. The PCA shows a regime shift with increasing eastward waves and decreasing north and north-eastward waves. Finally, SWH correlation (ρ) with four Teleconnection indexes (East Atlantic Pattern, Scandinavian Pattern, North Atlantic Oscillation, and East Atlantic/West Russia Pattern) revealed that the strongest ρ is observed with the Eastern–Atlantic–Western Russia teleconnection, with a peculiar spatial pattern of correlation, and is positive for the northwestern and negative for the southeastern sub-basin.

The Sri Lankan Port City project provides land for urban construction through land reclamation, a large number of dredgers, traffic vessels, and cargo ships are employed during the construction process. Therefore, it is necessary to simulate the wave field during the construction process to evaluate the influence of waves on engineering ships. Based on GFS sea surface wind field data and GEBCO water depth data, the wave numerical models Wave Watch III and SWAN were nested in multiple layers to establish a numerical simulation system suitable for wave field in the Port City area of Sri Lanka. The system was verified by comparing with the measured data. Based on this system, numerical analysis was conducted on the wave field in the Port City construction area at different construction stages. The trend of wave height, period and direction in the whole construction process of typical construction site was obtained. This paper provides an effective method for the numerical simulation of wave fields in nearshore waters, and provides an important reference basis for the reasonable arrangement of engineering ship operation window and the improvement of construction efficiency. [ABSTRACT FROM AUTHOR]

The wind stress is a measure of the intensity of air-sea momentum transfer and functions as a sea surface drag to resist the atmospheric flow. The wind stress generates the sea state but also depends on the sea state. Under the action of a tropical cyclone (TC), however, the sea state is extremely severe and highly uncertain, particularly under shallow water conditions. It can hardly be regarded as a direct consequence of the wind speed only. This study investigates the spatial variation of the wind stress under the action of a TC moving from deep to shallow waters by coupling the well-known WaveWatch III (WWIII) model with the extended atmospheric wave boundary layer model (eAWBLM), which has been well developed in recent years. An idealized TC is first introduced as the forcing wind to pursue the objective of the study. The sea state that affects the wind stress is shown to include the total wind wave energy, the high-frequency wave energy dissipation due to fluid viscosity, the energy dissipation due to wave breaking, the wave age, the mean wave steepness, and the misalignment of wind and wave directions. It is demonstrated that the wind stress reaches relatively large values in the front-left quadrant of the TC covered region in both deep and shallow waters. The time delay of the ocean surface responding to wind forcing results in younger and steeper waves in the left and rear quadrants of the TC, which leads to relatively large values of the surface drag coefficient. The surface drag coefficient decreases if the wind and the dominant wave directions are misaligned. The numerical model is also applied to the study of Hurricane Ivan (2004) generated ocean waves and satisfactory results are obtained owing to a more accurate evaluation of the wind stress by considering its dependence on the sea state. [ABSTRACT FROM AUTHOR]

Oceanic general circulation models (OGCMs) are important tools used to investigate mechanisms for ocean climate variability and predict the ocean change in the future. However, in most current ocean models, the impact of sea surface waves as one of the most significant dynamic processes in the upper ocean is absent. In this study, the Stokes drift and the vertical mixing induced by nonbreaking surface waves derived from the wave model (WAVEWATCH III) are incorporated into a Climate System Ocean Model, and their effects on an ocean climate simulation are analyzed. Numerical experiments show that both physical processes can improve the simulation of sea surface temperature (SST) and mixed layer depth (MLD) in the Southern Hemisphere. The introduction of Stokes drift effectively reduces the subsurface warm bias in the equatorial tropics, which is caused by the weakening of vertical mixing in the equatorial region. The nonbreaking surface wave mainly reduces the temperature bias in the Southern Ocean by enhancing mixing in the upper ocean. For the MLD, the Stokes drift mainly improves the simulation of the winter MLD, and the nonbreaking surface wave improves the summer MLD. For MLD south of 40° S in summer, the introduction of nonbreaking surface waves resulted in a reduction of 11.86 m in MLD bias and 7.8 m in root mean square errors (RMSEs), respectively. For winter subtropical MLD in the Southern Hemisphere, considering the Stokes drift, the MLD bias and RMSEs were reduced by 2.49 and 5.39 m, respectively. Adding these two physical processes simultaneously provides the best simulation performance for the structure of the upper layer. The introduction of sea surface waves effectively modulates the vertical mixing of the upper ocean and then improves the simulation of the MLD. Thus, sea surface waves are very important for ocean simulation, so we will further couple a sea waves model in the Chinese Academy of Sciences Earth System Model (CAS-ESM) as part of their default model component. [ABSTRACT FROM AUTHOR]

In recent decades, acceleration of coastal erosion has been observed at many key sites of the Arctic region. Coastal dynamics of both erosional and accretional stretches at Kharasavey, Kara Sea, was studied using multi-temporal remote sensing data covering the period from 1964 to 2022. Cross-proxy analyses of the interplay between coastal dynamics and regional (wave and thermal action) and local (geomorphic and lithological features; technogenic impact) drivers were supported by cluster analysis and wind–wave modelling via the Popov–Sovershaev method and WaveWatch III. Ice-rich permafrost bluffs and accretional sandy beaches exhibited a tendency towards persistent erosion (−1.03 m/yr and −0.42 m/yr, respectively). Shoreline progradation occurred locally near Cape Burunniy (6% of the accretional stretch) and may be due to sediment flux reversals responding to sea-ice decline. Although the mean rates of erosion were decreasing at a decadal scale, cluster analysis captured a slight increase in the retreat for 71% of the erosional stretch, which is apparently related to the forcing of wind–wave and thermal energy. Erosional hotspots (up to −7.9 m/yr) occurred mainly in the alignment of Cape Kharasavey and were predominantly caused by direct human impact. The presented study highlights the non-linear interaction of the Arctic coastal change and environmental drivers that require further upscaling of the applied models and remote sensing data. [ABSTRACT FROM AUTHOR]

Knowledge of wave climate is essential for efficient management of the world's coastal areas. Senegal is a relevant case, given its high coastal vulnerability to energetic wave conditions. This study investigates wave climates along the coastal zone of Senegal based on a new high-resolution hindcast covering the period 1980–2021. This study evaluates the average, seasonal, and extreme values for the significant wave heights (Hs), periods (Tm02/Tp), and mean directions (DIR). In boreal winter, the wave climate is dominated by swells coming from the North-Atlantic lows. In contrast, in boreal summer, the Southern Coast (from Dakar to Casamance) is exposed to swells generated in the South Atlantic Ocean. Throughout their refraction around the Dakar Peninsula, NW swells rotate by ~100° from NW to SW, while their Hs is roughly halved when reaching the Southern Coast of Senegal. Over the studied period, trends in Hs are weak (~0.6 cm.decade−1) on the Northern Coast and double on the Southern Coast (~1.2 cm.decade−1), mostly due to an increase during boreal summer (2 cm.decade−1). The wave periods show weak trends (~0.05 s.decade−1), and DIRs show weak counterclockwise rotation (−1°.decade−1). These trends are explained by the main climate modes of the Atlantic Ocean (NAO/EA during winter, SAM during summer) and are important for future research and long-term monitoring of the Senegalese Coast. [ABSTRACT FROM AUTHOR]

A 40‐year hindcast of the wave conditions in the Arabian Gulf, the elongated basin between the Arabian Peninsula and Iran, is described. The input wind fields were derived from the ERA5 reanalysis by the European Centre for Medium‐Range Weather Forecasts for the period 1979–2019. Extensive comparisons with scatterometer data suggested a direction‐dependent wind calibration with a strong influence on the underestimation of offshore blowing winds. The dominant wave patterns in the basin are described together with the characteristics of the related winds. After characterizing the possible meteorological conditions, the corresponding wave fields were hindcast using the WAVEWATCH III model. Extensive validation against altimeter data shows an almost unitary fit and a 0.02‐m bias; a comparison with measured data strongly demonstrates that the general patterns and conditions were well reproduced. The wave physics was also analysed, revealing the crucial role of their dynamic generation in the investigated area domain. The very shallow nature of some limited coastal zones suggests that locally focused studies, with more detailed and specific physics, are required for the best description of the waves in these areas. [ABSTRACT FROM AUTHOR]

Wind and wave conditions are limiting factors for economic activity, and it is very important to study the long-term variability of storm activity. The main motivation of this research is to assess the impact of wind variability on the storm activity in the Caspian Sea over the past 42 years. The paper presents the analysis of a number of storms based on the results of wave model WAVEWATCH III and the Peak Over Threshold method. The mean, maximum, and 95th percentile significant wave heights were analyzed by season. The highest waves were in the Middle Caspian Sea in winter. Detailed interannual and seasonal analyses of the number and duration of storm waves were performed for the whole Caspian Sea and its separate regions. Positive significant trends were found in the whole sea. Significant positive trends in the number and duration of storms were found for the North and Middle Caspian. In the South Caspian, the trends were negative and not significant. High correlations were found between the number of storms and events with wind speed > 10–14 m/s and 95th percentile wind speed. Positive trends in the number of storms in the Middle Caspian were caused by positive trends in extreme wind situations. [ABSTRACT FROM AUTHOR]

The ensemble optimal interpolation method was used in this study to conduct an examination of the assimilations of significant wave height (SWH) data from HY-2A satellite altimeter based on the WAVEWATCH III global ocean wave model. The results suggested that the ensemble optimal interpolation method using HY-2A SWH data played a positive role in enhancing the accuracy of the global ocean wave simulations and could effectively improve the deviations of SWH in the simulation processes. The root mean square errors of the NDBC buoy inspections were improved by 7 to 44% after the assimilation, and those of China's offshore buoy inspections were improved by 3 to 11% after the assimilation. It was observed that the farther the buoys were from the shore, the better the effects of the assimilation improvements. The root mean square errors of the Jason-2 satellite data validations were improved by 17% after the assimilation, with monthly improvements of 8–25%. The improvements occurred in most of the global oceans, particularly in the Southern Ocean, the Eastern Pacific Ocean and the Indian Ocean. The results obtained in this research can be used as a reference for the operational applications of China's ocean satellite data in ocean wave data assimilation and prediction. [ABSTRACT FROM AUTHOR]

A regional wave forecasting system in East Asia, including the Korean Peninsula, was built based on WAVEWATCH III using offshore wind forecast data from the Global Data Assimilation Prediction System. The numerical simulations were performed on the sensitivity of the interaction between input wind and wave development. The forecasts for each condition were compared and verified with the observational data of marine meteorological buoys from 1 August to 30 September 2020. The sensitivity conditions were configured to have a specific range of variables related to the directional distribution of input winds (SINA0) and variables indicating the development of input wind–wave (CDFAC) in the ST6. The results were presented by calculating the mean error and root mean square error for all observation points. Overall, as the CDFAC increased, the mean error tended to decrease according to the forecast time and the root mean square error increased. Although the effect of SINA0 at the same CDFAC was insignificant, when SINA0 increased in sections where the significant wave height decreased rapidly, the significant wave height tended to decrease. In addition, the main variables that affect the physical process of wind–wave interaction should be considered to improve wave model forecasting performance and accuracy. [ABSTRACT FROM AUTHOR]

This study analyses the past and future wave climate of Bass Strait and south‐east Australia by comparing two high‐resolution regional wave climate models (RWCMs), respectively forced by the surface wind speed of EC‐Earth3 and ACCESS‐CM2 global circulation models (GCMs) under two emission scenarios (SSP1‐2.6 and SSP5‐8.5). The two RWCMs are verified against long‐term buoy and satellite observations as well as hindcast model data. The comparison with long‐term satellite altimeter observations shows good agreement between the long‐term model climate and the observations. Both RWCMs project a future increase in swell, approaching the coast of Tasmania and mainland Australia, generated from distant storms in the Southern Ocean. However, different projected wave height spatial distributions are found in the coastal regions, affected by local synoptic weather events and by the coarse resolution of the GCMs winds. We also show that the long‐term wave climate in the domain is impacted by the Southern Annular Mode. As low‐pressure systems are projected to move southward, especially in the SSP5‐8.5 scenario, the swells approaching south‐east Australia are projected to be longer and more energetic in the future. The combination of more energetic swell systems and a counterclockwise rotation in peak wave direction, projected by both RWCMs, may influence the coastal equilibrium, impacting critical coastal locations. Plain Language Summary: Two regional wave climate models (RWCMs) are used to study future wave conditions of Bass Strait and south‐east Australia by the end of the 21st century, under the Paris Agreement mid‐emission scenario (SSP1‐2.6) and a high‐emission scenario (SSP5‐8.5). The RWCMs are extensively validated against model and observational datasets, showing generally good agreement. The results indicate that Bass Strait and the coastal regions of eastern Victoria are dominated by local climate systems. However, both RWCMs show that swell approaching the domain will increase by the end of the 21st century. The long‐term wave climate variability in the domain is impacted by the poleward movement of low‐pressure systems in the Southern Hemisphere. Key Points: Two high‐resolution regional wave climate models (RWCMs), EC‐Earth3 and ACCESS‐CM2, are extensively validated against multiple datasetsBoth RWCMs project longer and more energetic swells approaching south‐east Australian coasts by the end of the 21st centuryThe changes in the wave climate are directly correlated with a projected increasing trend in the Southern Annular Mode Index [ABSTRACT FROM AUTHOR]

Numerical wave models have been developed to reproduce the evolution of waves generated in all directions and over a wide range of wavelengths. The amount of wave energy in the different directions and wavelength is the result of a number of physical processes that are not well understood and that may not be represented in parameterizations. Models have generally been tuned to reproduce dominant wave properties: significant wave height, mean direction, dominant wavelengths. A recent update in wave dissipation parameterizations has shown that it can produce realistic energy levels and directional distribution for shorter waves too. Here, we show that this new formulation of the wave energy sink can reproduce the variability of measured infrasound power below a frequency of 2 Hz, associated with a large energy level of waves propagating perpendicular to the wind, for waves with frequencies up to 1 Hz. The details are sensitive to the balance between the non‐linear transfer of energy away from the wind direction, and the influence of dominant and relatively long waves on the dissipation of shorter waves in other directions. Plain Language Summary: As the wind blows over the ocean, waves are generated in all directions and over a wide range of wavelengths. The amount of wave energy in the different directions and wavelength is the result of a number of physical processes that are not well understood. Practical models used for marine weather and engineering use a decomposition of the wave field across all these different directions and wavelengths. The sources and sinks of energy of the different components have usually been adjusted to properly represent the total energy, the dominant wavelengths, and mean directions, with generally bad results for the shorter wave energy and its directional distribution. Here, we show that a recently proposed formulation for the energy sink can be adapted to produce realistic levels of short wave energy in all directions, revealing the importance of different evolution time scales for different wave components. Our wave model is validated using a wide range of measurements, including underwater infrasound power that is related to the presence of waves in opposing directions. Key Points: A spectral wave model is adjusted to produce accurate properties for both dominant and short wavesA balance between four‐wave non‐linear interactions and dissipation can explain directional bimodalityDissipation must be very weak for waves traveling at 90° and more from the wind direction [ABSTRACT FROM AUTHOR]

In this study, the state-of-the-art third generation spectral wave models WAVEWATCH III and SWAN have been used to predict waves for the Barcelona Bay (Spain) and for the south shoreline of the Mediterranean Sea (Algerian coast). We used two different nesting strategies in order to reach the local scale, the one-way and two-way nesting systems down method for the period from January to March 2017. The wave models were forced by the hourly wind data from the CFSR (CFSv2) global atmospheric model and by the hourly current from the hydrodynamic model NEMO during the simulation period. The high-resolution wave parameters (mainly significant wave height (SWH)) were compared to in situ buoy and altimeter data. At shallow water, results suggest that WW3 and SWAN nested grids describe variability of wave parameters, mainly the SWH, with good accuracy. With regional data remotely sensed along track altimeter, results showed that SWH at the WW3 nested grid is in good agreement with SARAL and Jason-2 data. Both nesting systems can be used as a platform to provide accurate, high-resolution coastal forecasts. [ABSTRACT FROM AUTHOR]

This study assesses the performance of different source term packages of WAVEWATCH III (WWIII, V-6.07) wave model for various wave conditions in the Indian Ocean (IO). Eight simulations of WWIII were made for the year 2017, four using default source term packages (ST2, ST3, ST4, and ST6) and another four by tuning the wind–wave interaction parameter (β) in the ST4 and ST6 schemes. The simulated wave outputs are compared with in-situ and altimeter wave fields over a wide range of weather conditions. All wave simulations have significant errors in low wind speeds (e.g., in pre-monsoon season) compared to medium (e.g., post-monsoon) and strong (e.g., monsoon season) winds which is independent of the error in the forecast wind. Overall, the ST4 scheme reproduces well the wave characteristics in all seasons and different conditions of IO, while the ST6 scheme is best suited for cyclonic weather conditions for wave simulation. Changing the WWIII parameterization schemes based on wind conditions is not a practical option for a timely wave prediction for a basin like the IO, where varied wave patterns exist year-round, owing to the full spectrum of wind conditions. Instead, this study advocates selecting a scheme that works well in all conditions, like ST4, and tuning it to suit well in cyclonic conditions. [ABSTRACT FROM AUTHOR]

Ocean wave swell generated in the vicinity of Campbell Island in the Southern Ocean is tracked along Great Circle paths across the Pacific Ocean. Data from a wave buoy at Campbell Island provides data on the directional spectrum in the generation region. The swell is measured at locations along a series of 19 Great Circle paths across the Pacific using Sentinel-1 SAR and CFOSAT satellite data. The WAVEWATCH III spectral wave model is used as a diagnostic tool to investigate the physical processes active in the swell propagation and decay. The results indicate that present day spectral wave models over-estimate the decay rate of swell. Although these models contain source terms to represent swell decay and negative wind input, these terms still largely remain tuning parameters. The data indicates that further research is required to adequately represent the observed magnitudes of the swell decay. In addition, the data show that currents have only a small impact on the observed swell decay and that islands can have a major impact. Such island impacts are poorly represented by spectral wave models.

A high-resolution third-generation wave model based on unstructured grids, WAVEWATCH III (WW3), was used to study the projected future wave climate of Bass Strait and south-east Australia under two different greenhouse gas emission scenarios (SSP1-2.6 and SSP5-8.5). The wave model, forced with winds from the Australian ACCESS-CM2 Global Climate Model, shows good agreement with coastal long-term buoy observations and an independent WW3 hindcast dataset over the historical period 1985–2014. The projected mean significant wave height ( H s ) for SSP5-8.5 by the end of the twenty-first century (2071–2100) shows a robust increase for the majority of the domain, but a decrease in nearshore regions, mainly due to projected decreases in local wind speed. The increase in H s for SSP1-2.6 is relatively small. Seasonal variations show that H s (SSP5-8.5) is primarily influenced by Southern Ocean swell in spring and winter and local winds prevail in summer and autumn. Hs percentiles show a stronger increase in extreme wave climate for SSP5-8.5 than for SSP1-2.6. Extreme value H s for SSP1-2.6 shows a projected decrease in western regions of the domain and an increase in the east. Extreme value H s for SSP5-8.5 shows a decrease in the nearshore areas of Victoria. This study shows that projected wave climate changes in south-east Australia may have potential implications for Tasmanian and Victorian coastline stability. [ABSTRACT FROM AUTHOR]

The internal energy distribution of waves can be described using ocean-wave spectra. In many ways, obtaining wave spectra on a global scale is critical. Surface waves investigation and monitoring onboard the Chinese-French oceanography satellite is the first space-borne instrument for detecting wave spectra specially, which was launched on October 29, 2018. It can avoid the shortage of synthetic aperture radar detection results while still having some problems, especially with the effects of speckle noise. In this study, a method to suppress the speckle noise is proposed. First, the empirical formula for background speckle noise is established. Second, many spatio-temporal representative fluctuation spectra are classified and averaged. Third, rational transfer function filtering is used to obtain speckle noise close to the along-track direction. Finally, a signal-to-noise ratio threshold is used to suppress the abnormal speckle noise. This method solves the problems existing in previous denoising methods, such as excessive denoising in the along-track direction and the inability of some abnormal noises to be denoised in the two-dimensional directional wave spectra. [ABSTRACT FROM AUTHOR]

Offshore platforms have become lucrative in the oil and gas industries due to their capabilities, which are exposed to harsh environmental hazards that affect the Structural Integrity. The scope of this study represents a risk assessment strategy for evaluating the structural integrity and proposed a framework for the Risk-Based Underwater Inspection to implement Structural Integrity Management for a fixed offshore jacket platform. The jacket platform is adopted for the Non-linear Quasi-Static Analysis (Push-over) using relevant code criteria. Regarding the required site-specific meteorological and oceanographic parameters, wave is simulated using WAVEWATCH III, third-generation version 4.18, considered input data and uncertain parameters. The Long-Term Load Distribution parameters are localized to determine the Probability of Failure due to the extreme wave loading action, and the platform structural damage rate is obtained by referring to the latest available underwater inspection carried out in the understudied oilfield. Moreover, the platform's structural failure may lead to safety, environmental, and economic impacts, which are the essential factors for evaluating the Consequence of Failure. Finally, the risk level is estimated by ranking the Probability and Consequences of Failure in the risk matrix, and resulting from the risk analysis, the framework for the Risk-Based Underwater Inspection is carried out. • Wave is Simulated using WAVEWATCH III to acquire the Metocean Data. • Platform is exposed to Extreme Environmental Loads to estimate Failure Probability. • The Long-Term Load Distribution parameter is localized for the studied region. • Members' Damage Probability is derived from Underwater Inspection in the Oilfield. • Consequence of Failure considers Safety, Environmental, and Economic impacts. [ABSTRACT FROM AUTHOR]

Oceanic general circulation models (OGCMs) are important tools used to investigate mechanisms for ocean climate variability and predict the ocean change in the future. However, in most current ocean models, the impact of sea surface waves as one of the most significant dynamic processes in the upper ocean is absent. In this study, the Stokes drift and the vertical mixing induced by nonbreaking surface waves derived from the wave model (WAVEWATCH III) are incorporated into a Climate System Ocean Model, and their effects on an ocean climate simulation are analyzed. Numerical experiments show that both physical processes can improve the simulation of sea surface temperature (SST) and mixed layer depth (MLD) in the Southern Hemisphere. The introduction of Stokes drift effectively reduces the subsurface warm bias in the equatorial tropics, which is caused by the weakening of vertical mixing in the equatorial region. The nonbreaking surface wave mainly reduces the temperature bias in the Southern Ocean by enhancing mixing in the upper ocean. For the MLD, the Stokes drift mainly improves the simulation of the winter MLD, and the nonbreaking surface wave improves the summer MLD. For MLD south of 40° S in summer, the introduction of nonbreaking surface waves resulted in a reduction of 11.86 m in MLD bias and 7.8 m in root mean square errors (RMSEs), respectively. For winter subtropical MLD in the Southern Hemisphere, considering the Stokes drift, the MLD bias and RMSEs were reduced by 2.49 and 5.39 m, respectively. Adding these two physical processes simultaneously provides the best simulation performance for the structure of the upper layer. The introduction of sea surface waves effectively modulates the vertical mixing of the upper ocean and then improves the simulation of the MLD. Thus, sea surface waves are very important for ocean simulation, so we will further couple a sea waves model in the Chinese Academy of Sciences Earth System Model (CAS-ESM) as part of their default model component.

Accurate description of the wind energy input into ocean waves is crucial to ocean wave modeling and a physics-based consideration on the effect of wave breaking is absolutely necessary to obtain such an accurate description. This study evaluates the performance of an improved formula recently proposed by Xu and Yu (2020), who took into account not only the effect of breaking but also the effect of air-flow separation on the leeside of steep wave crests in a reasonably consistent way. Numerical results are obtained through coupling an enhanced atmospheric wave boundary layer model with the ocean wave model WaveWatch III (v5.16). The coupled model has been extended to be valid in both deep and shallow waters. Duration-limited waves under controlled normal conditions and storm waves under practical hurricane conditions are studied in details to verify the improved model. Both the representative wave parameters and the parameters characterizing the wave spectrum are discussed. It is shown that the improved source-term package for the wind energy input and the wave energy dissipation leads to more accurate results under all conditions. It performs evidently better than other standard source-term options of ST2, ST4 and ST6 embedded in WaveWatch III. It is also demonstrated that the improvement is particularly important for waves at their early development stage and waves in shallow waters. [ABSTRACT FROM AUTHOR]

Significant wave height (SWH) in shallow waters is assessed by generating two wave hindcasts; the first uses ERA-Interim wind fields and the second one from ERA5 to quantify the improvement of the ERA5 surface winds on the SWH representativeness, both in deep and shallow waters along the Chilean coastline. Additionally, wind field predictions from the Global Forecast System (GFS) were used to assess the representativeness of shallow waters. Oceanographic buoys were used to validate SWH in deep waters, while Acoustic Doppler Current Profiler (ADCPs) was equipped to measure waves in shallow waters. Energy spectrums coupling Wavewatch III and Simulating Waves Nearshore (SWAN) models were transferred to evaluate the performance of shallow water simulations. In general, the SWH from both wave hindcasts showed good performance. Nonetheless, those forced by ERA5 presented a better qualitative comparison of sea state temporal variability, which increased the correlation coefficients (>0.9), coefficients of determination (>0.8), and minor errors (RMSE, MAE, and BIAS) compared to oceanographic buoys and ADCPs. Additionally, in simulations forced by GFS, the temporal variability of the waves in shallow waters was successfully reproduced. Nevertheless, an increase in the RMSE, MAE, and BIAS error was statistically verified compared to ERAInterim and ERA 5. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of climate change on coastal dynamics along the Adriatic Italian coast, with reference to the period 2021–2050 considering the IPCC RCP 4.5 and 8.5 scenarios. The wave datasets are obtained by forcing a spectral wave model with ERA5 wind fields corrected with a procedure that makes them suitable for the investigated semi-enclosed basin where local meteorological events occur at scales of a few kilometers. The wave climate changes between the historic run (1981–2010) and the future scenarios are studied in terms of mean values, percentile and extreme waves in 120 virtual buoys along the coasts. Moreover, a morphological equivalent wave is computed for all the datasets to highlight the consequences of climate change on coastal sediment transport. Along the Adriatic Italian coast, a small decrease in the significant wave heights is found, both for mean and extreme values, and the sediment transport is reduced. However, significant deviations along the coast are highlighted and the longshore sediment transport even reverses its direction in some locations for the future scenarios. [ABSTRACT FROM AUTHOR]

Knowledge of wave climate is essential for efficient management of the world’s coastal areas. Senegal is a relevant case, given its high coastal vulnerability to energetic wave conditions. This study investigates wave climates along the coastal zone of Senegal based on a new high-resolution hindcast covering the period 1980–2021. This study evaluates the average, seasonal, and extreme values for the significant wave heights (Hs), periods (Tm02/Tp), and mean directions (DIR). In boreal winter, the wave climate is dominated by swells coming from the North-Atlantic lows. In contrast, in boreal summer, the Southern Coast (from Dakar to Casamance) is exposed to swells generated in the South Atlantic Ocean. Throughout their refraction around the Dakar Peninsula, NW swells rotate by ~100° from NW to SW, while their Hs is roughly halved when reaching the Southern Coast of Senegal. Over the studied period, trends in Hs are weak (~0.6 cm.decade−1) on the Northern Coast and double on the Southern Coast (~1.2 cm.decade−1), mostly due to an increase during boreal summer (2 cm.decade−1). The wave periods show weak trends (~0.05 s.decade−1), and DIRs show weak counterclockwise rotation (−1°.decade−1). These trends are explained by the main climate modes of the Atlantic Ocean (NAO/EA during winter, SAM during summer) and are important for future research and long-term monitoring of the Senegalese Coast.

Wind and wave conditions are limiting factors for economic activity, and it is very important to study the long-term variability of storm activity. The main motivation of this research is to assess the impact of wind variability on the storm activity in the Caspian Sea over the past 42 years. The paper presents the analysis of a number of storms based on the results of wave model WAVEWATCH III and the Peak Over Threshold method. The mean, maximum, and 95th percentile significant wave heights were analyzed by season. The highest waves were in the Middle Caspian Sea in winter. Detailed interannual and seasonal analyses of the number and duration of storm waves were performed for the whole Caspian Sea and its separate regions. Positive significant trends were found in the whole sea. Significant positive trends in the number and duration of storms were found for the North and Middle Caspian. In the South Caspian, the trends were negative and not significant. High correlations were found between the number of storms and events with wind speed > 10–14 m/s and 95th percentile wind speed. Positive trends in the number of storms in the Middle Caspian were caused by positive trends in extreme wind situations.

The Pearl River Estuary (PRE) locates in the core region of the Guangdong-Hong Kong-Macao Greater Bay Area, where typhoons, storm surge, and huge wave occur frequently and bring great threats to human life and property. Accurate high-resolution wave forecasting / simulation is crucial to regional economic development and disaster prevention and mitigation. The quality of wave forecasting/simulation depends largely on wind input parameterization. Thus, we build up a nested South China Sea-PRE wave model using the WAVEWATCH III model v6.07 to evaluate the performance of different wind reanalysis and wind input parameterization on the wave simulation in the PRE region. Compared with the CFSR wind data, ERA5 wind data can help better simulate the surface wave in the PRE region. ERA5 wind data combined with the T500 parameterization provides the best results, followed by the ERA5 + T471 combination. The T500 parameterization tunes the wind input for high winds and includes depth-induced breaking, and thus may be more appropriate for depth-limited conditions. For the CFSR wind data, T471f appears to be the optimal parameterization. However, the results produced by the CFSR + T471f combination are not better than those of ERA5+ST6 combination in terms of both root mean squared error and mean absolute error. Moreover, the ST4 source package performs better than the ST6 source package. [ABSTRACT FROM AUTHOR]

The ECHOWAVE hindcast is an open source dataset specially developed for wave climate and energy applications within European Atlantic waters. It provides high resolution (∼ 2. 3 km) fields of wave parameters and spectral data allowing for a detailed characterization of the wave resource within the coastal shelf. This is of importance for depths < 200 m, where most deployment projects of wave energy converters (WEC) take place. Model setup and adjustments, leading to parameterization TUD-165, were specially aimed to improve the sea states' characterization within the North-East Atlantic. The effects on accuracy of these adjustments and extensive validation, were done mainly comparing simulations with significant wave heights (H s) from the European Space Agency CCI Version 3 altimeter dataset. Verification of other wave parameters and the spectral energy comparing with in situ measurements were also included. Results show that TUD-165 helps to reduce about 5% the H s bias of the most frequent waves compared to T475 proposed by Alday et al. (2021), and an overall better performance than ERA5 within the North-East Atlantic. Compared to WAVERYS, ECHOWAVE performs better for H s > 9. 5 m, with constrained bias between −2 to 5%. The accurate estimation of "extreme" waves is important to avoid WECs survivability over-estimations. [Display omitted] • High-resolution wave hindcast specially implemented for European North Atlantic coastal areas. • CCI V3 Altimetry data used for adjustments and validation of the TUD-165 parameterization. • 20-years mean wave energy flux can be underestimated by 20% or more with global models. • ECHOWAVE's high resolution for depths ≤ 200 m, make it a unique database for energy applications. [ABSTRACT FROM AUTHOR]

The wave power in the Gulf of Mexico was analyzed, using 42 years (1979–2020) of simulated data, with ERA-5 winds to force the WAVEWATCH III wave model. The model was successfully validated with three NDBC buoys, 42,055, 42,001 and 42,002. Comparison of significant wave heights obtained from the Jason-2, Cryosat-2, and Saral satellites showed good mean correlation coefficients and root mean squares. The spatial distribution of wave power was studied, as well as its seasonal variability. The region studied has moderate availability of wave power with marked seasonality. A multi-criteria MCA approach, including both sea state and wave energy converters (WECs), was then applied. Nine virtual sites were selected for the study and the AAHPA device gave best results in 7 virtual sites and the Wavestar device in the remaining two. The technology of these two devices, a system of oscillating buoys, is the most viable technology for the Gulf of Mexico.

A regional wave forecasting system in East Asia, including the Korean Peninsula, was built based on WAVEWATCH III using offshore wind forecast data from the Global Data Assimilation Prediction System. The numerical simulations were performed on the sensitivity of the interaction between input wind and wave development. The forecasts for each condition were compared and verified with the observational data of marine meteorological buoys from 1 August to 30 September 2020. The sensitivity conditions were configured to have a specific range of variables related to the directional distribution of input winds (SINA0) and variables indicating the development of input wind–wave (CDFAC) in the ST6. The results were presented by calculating the mean error and root mean square error for all observation points. Overall, as the CDFAC increased, the mean error tended to decrease according to the forecast time and the root mean square error increased. Although the effect of SINA0 at the same CDFAC was insignificant, when SINA0 increased in sections where the significant wave height decreased rapidly, the significant wave height tended to decrease. In addition, the main variables that affect the physical process of wind–wave interaction should be considered to improve wave model forecasting performance and accuracy.

• Hong Kong Observatory operates ocean model in support of marine weather forecasting • Model validation of current and wave forecasts uses moored and drifting buoys data • Downscaling model results serve as benchmark reference for future model enhancement The Hong Kong Observatory has been running an Operational Marine Forecasting System (OMFS) adapted from the Regional Ocean Modelling System (ROMS) coupled with the WaveWatch III and SWAN wave models to provide wave, current and sea temperature forecasts up to 144 h twice a day since December 2021. To facilitate users' interpretation of model forecasts of significant wave height and current speed in coastal predictions and open seas which are of particular significance in high wind situations, model forecasts were validated against moored buoy observations and wave recorder measurements near the shores of Hong Kong and drifting buoy data over the South China Sea, as well as Mercator Ocean model reanalysis in 2022. The validation results showed that the wave forecasts generally agreed well with the buoy observations with coefficient of determination (R2) of around 0.7 and root-mean-square error (RMSE) of less than 0.2 m up to 72 h ahead. The R2 for sea current forecasts ranged between 0.4 and 0.6, and the RMSE was around 8 to 11 cm/s in near shores up to T + 144 forecast hours. Validation against drifting buoy demonstrated that the trend of current forecasts generally agreed well with the measurements. RMSE of surface current forecasts over open seas ranged from 19 cm/s for 24-hour forecast to around 30 cm/s for 144-hour forecast when compared against Mercator Ocean reanalysis. Results from the current downscaling approach could serve as a benchmark reference for HKO to enhance OMFS in the future. In this paper, applications of model forecasts in the provision of marine weather services in Hong Kong are also introduced. [ABSTRACT FROM AUTHOR]

The ensemble optimal interpolation method was used in this study to conduct an examination of the assimilations of significant wave height (SWH) data from HY-2A satellite altimeter based on the WAVEWATCH III global ocean wave model. The results suggested that the ensemble optimal interpolation method using HY-2A SWH data played a positive role in enhancing the accuracy of the global ocean wave simulations and could effectively improve the deviations of SWH in the simulation processes. The root mean square errors of the NDBC buoy inspections were improved by 7 to 44% after the assimilation, and those of China’s offshore buoy inspections were improved by 3 to 11% after the assimilation. It was observed that the farther the buoys were from the shore, the better the effects of the assimilation improvements. The root mean square errors of the Jason-2 satellite data validations were improved by 17% after the assimilation, with monthly improvements of 8–25%. The improvements occurred in most of the global oceans, particularly in the Southern Ocean, the Eastern Pacific Ocean and the Indian Ocean. The results obtained in this research can be used as a reference for the operational applications of China’s ocean satellite data in ocean wave data assimilation and prediction.

This paper presents an efficient algorithm for generating a spherical multiple-cell (SMC) grid. The algorithm adopts a recursive loop structure and provides two refinement methods: (1) an arbitrary area refinement method and (2) a nearshore refinement method. Numerical experiments are carried out, and the results show that compared with the existing grid generation algorithm, this algorithm is more flexible and operable. [ABSTRACT FROM AUTHOR]

The complexity and variability of ocean waves make wave energy harvesting very challenging. Previous research has indicated that wave energy was mainly generated and transferred by wind, but the detailed correlation between wind and wave energy has not been discovered. Wave energy in the Gulf of Mexico (GoM) has high variability with distinct seasonal behavior. However, the underlying reasons for this unique behavior have not been discussed and discovered yet. In this paper, a computer animation-based dynamic visualization method was created to conduct exploratory and explanatory analyses of 36 years of meteorological data in the GoM from the WaveWatch III system to identify preliminary patterns and underlying reasons for the unique behavior of wave energy in the GoM. These preliminary patterns and underlying reasons were further analyzed using Energy Events and Breaks concepts. During both high and low levels wave energy periods, the detailed correlation between wave energy and the wind was analyzed and determined. High level wave power in the GoM was mainly generated by the local inland wind from northern weather patterns, while low level wave power was mainly generated by swells from the Caribbean and the Atlantic oceans, which entered the GoM through the two narrow pathways, the Straits of Yucatan and the Florida Straits. The results from this paper will also be able to help the design, placement, and operation of future wave energy converters to improve their efficiency in harvesting wave energy in the GoM. [ABSTRACT FROM AUTHOR]

Indonesian offshore and coastal areas are vulnerable to swells from Roaring Forties and cyclone disasters. However, the understanding of the characteristics and propagation mechanisms of local disastrous waves is insufficient, posing a threat to the construction, maintenance, and protection of coastal structures. This study establishes a multiple nested wave model based on the third-generation wave model WAVEWATCH III. This model includes sole forcing of Roaring Forties and combined forcing of Roaring Forties and cyclone Ernie to simulate the influence of disastrous waves under the Roaring Forties and tropical cyclones in the Indonesian offshore zone and coasts. The following results are obtained. The Indonesian offshore is prevailed by relatively stable southern to southwestern dominant swells and small wind waves under the impacts of the Roaring Forties without cyclone winds. Long propagating swells originated from the Roaring Forties dominate in nearshore coastal waters with deformed directions and strength because of the shoaling effect. [ABSTRACT FROM AUTHOR]

This paper evaluates the performance of the spectral wave model WAVEWATCH III for the South Atlantic Ocean forced by wind inputs from the most recent reanalyses, NCEP/CFSR and ECMWF/ERA5, combined with two different source terms: ST4 and ST6. A calibration is performed considering 1 year (2012) and 31 simulations, evaluated against altimeter and buoy data through six error metrics and Q-Q plots. Assessment results suggest that both ST4 and ST6 provide good results when WAVEWATCH III is properly adjusted for the wind input. Nevertheless, the wave model presents a positive bias of significant wave height when forced by CFSR winds that requires attention. The investigation in the spectral domain indicates a better performance of wave simulations forced by ERA5 winds, especially for wave periods below 10 s. For wave periods above 10 s, the choice of source term package becomes more important. In this regard, ST4 parameterization combined with ERA5 winds presents the best results for the region. The optimal range of calibration parameters for each wind input and source term package is reported and discussed. [ABSTRACT FROM AUTHOR]

At reconnaissance to feasibility study stages of wave energy development, guidelines and standards recommend wave power assessments to be conducted for long periods of time, albeit at relatively coarse spatial resolutions. However, quite often developers need to make a preliminary site selection based on high-resolution information. Unfortunately, even with abundant computational resources nowadays, running a high-resolution coastal model for more than a decade is still not practical. In this paper, we propose to combine uncertainty estimates from a 21-year-long 1-km-resolution model and a high-resolution (10 m nearshore) coastal model to assess wave energy. Two sites in Japan facing the Pacific Ocean were selected for this study. One site located on the southern coast (site-S) is affected more by the passage of typhoons than another site located on the eastern coast (site-E). The estimated wave power climatology at site-S ranges between 3 and 7 kW m - 1 with an uncertainty of ± 0.27 to ± 0.51 kW m - 1 ; whereas for site-E, the climatology varies between 3 and 9 kW m - 1 with uncertainties of ± 0.12 to ± 0.34 kW m - 1 . In general, the eastern coastal area of Japan is found to offer higher wave power and lower margins of uncertainty than compared with the southern coastal area. [ABSTRACT FROM AUTHOR]

In this study, an integrated wave model from global to coastal scales was developed to improve the operational wave prediction performance of the Korean Meteorological Administration (KMA). In this system, the wave model was upgraded to the WaveWatch III version 6.07 with the improved parameterization of the source term. Considering the increased resolution of the wind input field and the introduction of the high-performance KMA 5th Supercomputer, the spatial resolution of global and regional wave models has been doubled compared to the operational model. The physical processes and coefficients of the wave model were optimized for the current KMA global atmospheric forecasting system, the Korean Integrated Model (KIM), which is being operated since April 2020. Based on the sensitivity experiment results, the wind-wave growth parameter (βmax) for the global wave model was determined to be 1.33 with the lowest root mean square errors (RMSE). The value of βmax showed the lowest error when applied to regional/coastal wave models for the period of the typhoon season when strong winds occur. Applying the new system to the case of August 2020, the RMSE for the 48-hour significant wave height prediction was reduced by 13.4 to 17.7% compared to the existing KMA operating model. The new integrated wave prediction system plans to replace the KMA operating model after long-term verification. [ABSTRACT FROM AUTHOR]

Ocean surface waves tend to be attenuated by interaction with sea ice. In this study, six sea ice models in the third-generation wave model WAVEWATCH III® (WW3) were used to estimate wave fields over the Sea of Okhotsk (SO). The significant wave height (Hs) and mean wave period (Tm) derived from the models were evaluated with open ocean and ice-covered conditions, using SO coastal area buoy observations. The models were validated for a period of 3 years, 2008–2010. Additionally, the impact of sea ice on wave fields was demonstrated by model experiments with and without sea ice. In the open ocean condition, the root-mean square error (RMSE) and correlation coefficient for hourly Hs are 0.3 m and 0.92, and for hourly Tm 0.97 s and 0.8. In contrast, for the ice-covered condition, the averaged RMSE and correlation coefficient from all models are 0.44 m (1.6 s) and 0.8 (0.6) for Hs (Tm), respectively. Therefore, except for the bias, the accuracy of model results for the ice-covered condition is lower than for the open water condition. However, there is a significant difference between the six sea ice models. For Hs, the empirical formula whereby attenuation depends on the frequency relatively agrees with the buoy observation. For Tm, the empirical formula that is a function of Hs is better than those of other simulations. In addition, the simulations with sea ice drastically improved the wave field bias in coastal areas compared to the simulations without sea ice. Moreover, sea ice changed the monthly Hs (Tm) by more than 1 m (3 s) in the northwestern part of the SO, which has a high ice concentration.

Abstract Global wave hindcasts are developed using the third generation spectral wave model WAVEWATCH III with the observation‐based source terms (ST6) and a hybrid rectilinear‐curvilinear, irregular‐regular‐irregular grid system (approximately at 0.25°×0.25°). Three distinct global hindcasts are produced: (a) a long‐term hindcast (1979–2019) forced by the ERA5 conventional winds U10 and (b) two short‐term hindcasts (2011–2019) driven by the NCEP climate forecast system (CFS)v2 U10 and the ERA5 neutral winds U10,neu, respectively. The input field for ice is sourced from the Ocean and Sea Ice Satellite Application Facility (OSI SAF) sea‐ice concentration climate data records. These wave simulations, together with the driving wind forcing, are validated against extensive in‐situ observations and satellite altimeter records. The performance of the ST6 wave hindcasts shows promising results across multiple wave parameters, including the conventional wave characteristics (e.g., wave height Hs and wave period) and high‐order spectral moments (e.g., the surface Stokes drift and mean square slope). The ERA5‐based simulations generally present lower random errors, but the CFS‐based run represents extreme sea states (e.g., Hs>10 m) considerably better. Novel wave parameters available in our hindcasts, namely the dominant wave breaking probability, wave‐induced mixed layer depth, freak wave indexes and wave‐spreading factor, are further described and briefly discussed. Inter‐comparisons of Hs from the long‐term (41 years) wave hindcast, buoy measurements and two different calibrated altimeter data sets highlight the inconsistency in these altimeter records arising from different calibration methodology. Significant errors in the low‐frequency bins (period T>15 s) for both wave energy and directionality call for further model development.

Global wave hindcasts are developed using the third generation spectral wave model WAVEWATCH III with the observation‐based source terms (ST6) and a hybrid rectilinear‐curvilinear, irregular‐regular‐irregular grid system (approximately at 0.25°×0.25°). Three distinct global hindcasts are produced: (a) a long‐term hindcast (1979–2019) forced by the ERA5 conventional winds U10 and (b) two short‐term hindcasts (2011–2019) driven by the NCEP climate forecast system (CFS)v2 U10 and the ERA5 neutral winds U10,neu, respectively. The input field for ice is sourced from the Ocean and Sea Ice Satellite Application Facility (OSI SAF) sea‐ice concentration climate data records. These wave simulations, together with the driving wind forcing, are validated against extensive in‐situ observations and satellite altimeter records. The performance of the ST6 wave hindcasts shows promising results across multiple wave parameters, including the conventional wave characteristics (e.g., wave height Hs and wave period) and high‐order spectral moments (e.g., the surface Stokes drift and mean square slope). The ERA5‐based simulations generally present lower random errors, but the CFS‐based run represents extreme sea states (e.g., Hs>10 m) considerably better. Novel wave parameters available in our hindcasts, namely the dominant wave breaking probability, wave‐induced mixed layer depth, freak wave indexes and wave‐spreading factor, are further described and briefly discussed. Inter‐comparisons of Hs from the long‐term (41 years) wave hindcast, buoy measurements and two different calibrated altimeter data sets highlight the inconsistency in these altimeter records arising from different calibration methodology. Significant errors in the low‐frequency bins (period T>15 s) for both wave energy and directionality call for further model development. Plain Language Summary: Ocean surface waves are fundamentally important for ocean engineering design, ship navigation, air‐sea exchange of gas, heat, momentum and energy, upper ocean dynamics, and remote sensing of the ocean. Spectral wave modeling is an indispensable tool to estimate sea state information. In this study, we present new global wave hindcasts developed using the state‐of‐the‐art model physics and numerics and the modern reanalysis winds and satellite sea ice records. It is demonstrated through validation against in‐situ observations and altimeter records that the global wave hindcasts perform well across multiple parameters. Meanwhile, intercomparisons of wave height from the long‐term hindcast, buoys, and altimeters reveal inconsistency and potential inhomogeneity in these different data sets. The wave hindcasts we developed, in combination with global wave databases published previously, will form a large ensemble of realizations of historical evolution of sea states simulated with distinct wave physics and wind forcing, which will help quantify sea states in real oceans more accurately. Key Points: Global wave hindcasts using the observation‐based source terms are developed and validated against extensive observationsThe wave hindcasts show promising performance across multiple parameters, including wave height, period, and high‐order spectral momentsIntercomparisons of wave height from the hindcast, buoys, and altimeters highlight the inconsistency and inhomogeneity in these data sets [ABSTRACT FROM AUTHOR]

Bordering the Bay-of-Bengal, Bangladesh, India, Sri Lanka, Indonesia, and Myanmar possess significant potential for harnessing wave energy to address their growing energy crisis. This study aims to comprehensively characterize wave energy resources in the exclusive economic zones of the Bay-of-Bengal's littoral countries. The study utilizes 13 years of wave hindcasts obtained from WAVEWATCH-III, a widely used third-generation numerical wave model. Various approaches for characterizing wave energy resources were employed, including site accessibility analysis and extreme event analysis, which were overlooked in prior studies on Bay-of-Bengal. The research revealed that the mean wave energy flux in the Bay-of-Bengal is higher (16–39 kW/m) during the summer-monsoon season (July–October) and lower (2–12.5 kW/m) during the post-monsoon season (November–February). Consequently, the summer-monsoon season is deemed appropriate for energy harvesting, while the post-monsoon season is ideal for wave energy converter installation, servicing, or maintenance. The sea-state analysis demonstrated that the significant wave height and energy period of the most frequent and energetic sea-states in the Bay-of-Bengal range from 0.5 to 3.5 m and 4–16 s, respectively. Based on considerations of annual energy storage, resource stability, and wave energy converter survivability, the locations in the exclusive economic zones of Sri Lanka, Indonesia, and India's Andaman and Nicobar Islands were identified as the most suitable for constructing wave power plants. The research findings presented herein can assist local authorities and stakeholders in the energy sector by facilitating a comparison of wave energy resources across different locations and determining the most suitable sites for wave power plant construction that align with their energy needs and goals. Additionally, the results can aid wave energy converter developers in planning tests in the Bay-of-Bengal, maintaining their devices, and evaluating potential sites for opportunities and risks. [ABSTRACT FROM AUTHOR]

This study characterizes the spatio-temporal wave variability along Southwestern Nigerian coastal and shelf areas in the Gulf of Guinea. This is to provide further insight into the hydrodynamic factors that influence geomorphologic changes on the low-lying coast. Reanalysis wind-field datasets are employed to generate hourly wind forcing for an unstructured WAVEWATCH III model to simulate some bulk wave parameters. The model is validated against data from offshore buoys and satellite altimetry at selected locations near the coast. Results show that the waves have an annual average of significant wave height (H s), peak period (T p), and wind speed (u) of ∼0.5 m, 4.1 s, and 3.9 m/s, respectively. They exhibit seasonal spatial variability that is highest in the peak rainy season from July to September (Av. H s : 0.56–0.79 m; Av. T p : 4.68–5.18 s; Av. u : 4.30–5.22 m/s) and lowest in the early dry season from November to January (Av. H s : 0.26–0.34 m; Av. T p : 3.37–3.80 s; Av. u : 3.25–3.50 m/s). Also, the monthly averaged wave power varies from 0.2 to 2.8 kW/m annually. However, a maximum H s of 2.2 m that generated power of 9.4 kW/m for 11.1 s was recorded during the peak of the rainy season in August. Overall, waves with relatively low intensity, which can be classified as smooth to moderate, propagate from the southwest direction and decrease towards the coast. The higher H s and T p recorded during the peak of rainy and end of dry seasons are attributed to the influence of far-away swells. A comparative assessment indicates that the Barrier-Lagoon coast is highly controlled by waves, while the Mahin mud coast, which witnesses frequent flooding events that degrade its shoreline, has little wave influence. Thus, local subsidence that increases the relative sea level is suggested to be taking place at sections of the muddy coast. This information is crucial for the sustainable engineering design and management of low-lying coasts. • The SW Nigerian coastal and shelf area is characterized by smooth to moderate waves. • The waves exhibit seasonal variations that are strongest at the peak of rainy seasons. • The Barrier-Lagoon shelf has relatively stronger waves that can be harnessed. • Complex hydrodynamic interactions control geomorphological changes in the area. • Mahin coastal degradation is aggravated by alterations in local geomorphology. [ABSTRACT FROM AUTHOR]