Hindcast Wave Data Research Articles

Numerical Simulation Study of Wind and Wave Energy in Yellow River Delta

This paper simulates the wave condition of Shandong Peninsula and Yellow River estuary with SWAN (Simulating Wave Nearshore) model, which is driven by wind fields from 1996 to 2007. And then hindcasted wave data and the buoy data compared, which shows that hindcasted wave data are validated with buoy data. Finally, wave and wind energy of Yellow River delta are assessed by 12 years hindcasted wave data and the wind data, which is 10m height above the ground level. The result of assessment shows that Yellow River delta has large wave and wind energy potentialities. If the wave energy and wind energy can be used effectively, the pressure of power supply of Dongying will be relieved.

Regional projection of future extreme wave heights around Korean Peninsula

In this study, future changes in regional extreme wave heights around the Korean Peninsula are projected by using the results of an atmosphere general circulation model and a third-generation wave model. The direct use of the model output at each grid point is not appropriate even though high resolution of 20 km is used for the models. Therefore, the model output is grouped into six regions around the Korean Peninsula. The grouping approach is reasonable in assessing climate change effects with alleviated model uncertainty. The extreme wave heights are simulated for two climate periods of 1979–2003 (present climate) and 2075–2099 (future climate). The model results are validated by comparing the simulated wave heights for the present climate with observed and hindcasted wave data. The extreme wave heights for the future climate are then projected for different seasons and in different regions. The 50-year return wave height in summer is projected to increase in most regions, especially in the high-latitude Yellow Sea and the East Sea, while the wave height in winter is projected to decrease in all the regions, especially in the East Sea.

Wave and offshore wind potential for the island of Tenerife

The island of Tenerife, a UNESCO Biosphere Reserve in the Atlantic Ocean, aims to be energy self-sufficient in order to reduce its carbon footprint. To accomplish this goal it should develop the renewable sources, in particular wave and offshore wind energy. The objectives of this work are twofold; (i) to characterize the wave and offshore wind power distribution around the island and (ii) to determine which offshore area is best suited for their exploitation, taking into account the resource and other conditioning factors such as the bathymetry, distance to the coastline and ports, and offshore zoning. To carry out this research, hindcast wave and wind data obtained with numerical models are used alongside observations from meteorological stations. One area, in the vicinity of Puerto de la Cruz, is identified as having great potential for installing a hybrid floating wave–wind farm. Both resources are characterized for the area selected: the wave resource in terms of wave directions, significant wave heights and energy periods; the offshore wind resource in terms of directions and speeds in addition to the seasonality for the both resources. It is found that most of the wave resource is provided by N and NNW waves with significant wave heights between 1.5m and 3.0m and energy periods between 10s and 14s. It follows that the Wave Energy Converters deployed in the area should have maximum efficiency in those ranges. As for the offshore wind resource, most of the energy corresponds to NNE and NE winds with speeds between 9 and 14ms−1, which should be taken into account when selecting the offshore wind turbines.

Black Sea wave energy atlas from 13 years hindcasted wave data

The present study aims to evaluate the wave energy potential of the Black Sea. Wave properties were calculated using 3rd generation Spectral Wave Model for years 1996–2009 by using wind data from European Center for Medium-Range Weather Forecasts (ECMWF). The wave model was calibrated using the wave measurements conducted at five different stations. Wave power atlas displaying time – averaged wave power for entire Black Sea was generated. Also wave power roses and wave power distribution tables in means of periods and heights for different regions were presented. Wave energy found to be decreasing along the coast from west to east. It was found that the most energetic region is the South Western part of the sea. The eastern part of the Black Sea is the least energetic in means of wave power. It was concluded that the most promising location is the Thracian shores of Turkey, especially west side of Istanbul. Beside this, other promising locations in the Black Sea Basin were also evaluated. Annual wave energies (kWh/m) for different regions were presented in this study.

Projection of extreme typhoon waves: Case study at Busan, Korea

ABSTRACT Chun, J., Ahn, K., Yoon, J.-T., Suh, K.-D. and Kim, M., 2013. Projection of extreme typhoon wave : Case study at Busan, Korea Several studies predicted that the typhoons will be more intense in the future. Since the intensification makes the wave environments at the coastal zone more extreme, the analysis on the enhancement of typhoon waves is required for the future protection of the coastal zone. Most of the extreme wave analysis is based on the measured or hindcast wave data which does not reflect the future trend of variations. This study discuss the add-on effect of future typhoon intensification on the estimation of extreme waves. Especially, since the extreme waves at Busan port, Korea are generated by typhoons, the trends of the activity and intensity of typhoons on the southern coasts of Korean Peninsula between 1951 and 2010 were analyzed. At the analysis, it was found that there is a trend in the intensity of typhoons. By applying the wavelet analysis, the long-term trend of the intens...

Longshore Sediment Transport on the Northern Coast of the Yucatan Peninsula

This paper presents a qualitative assessment of coastal processes along the northern coast of the Yucatan Peninsula based on a method used to estimate the potential longshore sediment transport. Despite the deep-water low-energy wave conditions (Hs 5 1 m) in the study area, erosion is critical in many locations, including the urbanized stretches of coast. The waves were characterized using a 12 y (1997‐2009) deep-water wave hindcast data (WAVEWATCH III) as forcing for a spectral wind-wave numerical model (MIKE 21 SW) used to propagate the waves to the coast. Simulated time series of significant wave height, peak period, and direction are compared against in situ measurements at 10 m water depth. Numerical results are further employed for estimation of the nearshore wave climate along the coast. Wave conditions are strongly affected by the wide continental shelf in front of the northern Yucatan Peninsula, with an increase in wave energy at the eastern part of the peninsula where the shelf narrows. The nearshore wave climate is employed for the qualitative assessment of potential longshore sediment transport (LITDRIFT model) in the study area. The sediment transport calculations are consistent with both volume impoundment estimations at a groin and dredging estimates at a harbor (235,000 m 3 /y). A net westward potential longshore sediment transport is found along the entire coast, ranging between 220,000 and 280,000 m 3 /y, except west of Holbox, where longshore transport direction is inverted. Based on sediment transport gradients, potential erosion and deposition areas are identified. Erosion/accretion patterns at nonurbanized areas are consistent with field observations. This dominant westward longshore transport suggests an extremely sensitive shoreline to littoral barriers, as supported by observations in the most urbanized areas. These areas show no gradients on longshore sediment transport, whereas beach erosion is a common feature enhanced by littoral barriers. Shore protection should then be oriented toward sediment management strategies.

장기 파랑관측자료 분석 및 천해파 수치실험에 의한 강릉 해역의 천해설계파

In this study, shallow-water design waves are calculated for the return period of 10, 20, 30, and 50 years, based on the extreme value analysis of the wave measurement data at Gangneung beach. These values are compared with the results of SWAN simulation with the boundary condition of the deep-water design waves of the corresponding return periods at the Gangneung sea area provided by the Fisheries Agency (FA, 1988) and Korea Ocean Research & Development Institute (KORDI, 2005). It is found that the shallow-water wave heights at Gangneung beach calculated by the deep-water design waves were significantly less than the observation data. As the return period becomes higher, the significant wave heights obtained by the extreme value analysis becomes higher than those computed by SWAN with the deep-water design waves of the corresponding return periods. KORDI computed the hindcast wave data from January 2004 to August 2008 by WAM with a finer-grid mesh system than those of previous studies. Comparisons of the wave hindcast results with the wave observation show that the reproducibility of the winter-season storm wave was considerably improved compared to the hindcast data from 1979 to 2003. Hereafter, it is necessary to carry out hindcast wave data for the years before 2004 using WAM with the finer-grid mesh system and to supplement the deep-water design wave.

Wave-driven sediment transport and beach-dune dynamics in a headland bay beach

This paper presents a comprehensive study of wave refraction, wave and wind driven sediment transport, foredune development and Holocene barrier evolution over a variety of time scales at Moçambique Beach, Santa Catarina State, Southern Brazil. The motivation for this study was to examine the relationships between estimated wave driven sediment transport, medium and long term aeolian transport, foredune development, and Holocene barrier volumes and morphology. An analysis of 2years of wave rider data for the region shows two well defined peaks of frequencies: one of swell waves from the south with a period of 12s, and another peak of sea waves from east-northeast with a period of 7s. Longshore sediment transport rates were calculated using high resolution hindcast wave data for the South Atlantic Ocean, which was calibrated by the measured buoy data. The dominant southerly waves drive a longshore gradient in wave energy from south to north, and nearshore/surf zone sediment transport increases from south to north. Beach grain size is fine in both the south and north, and medium in the center. The combination of grain size and wave energy variations creates a marked alongshore variation in surf zone beach types ranging from low energy dissipative in the south, moderate energy intermediate in the central area to moderate to high energy dissipative in the north. Estimates of aeolian sediment transport, volumetric changes in foredune deposition and total Holocene dunefield volumes were also calculated. Results indicate that the morphological behavior of the foredune profiles reflects the gradients of longshore sediment transport and the exposure to wind energy and aeolian sediment delivery, with a maximum of sediment volume and transport towards, and in the central part and northern end of the barrier. Holocene (0–7000years) barrier volumes vary along the embayment, mimicking the trends in both calculated wave and wind driven sediment transport. The Short and Hesp (1982) model was more suitable in predicting the long term (Holocene) barrier evolution than the size and volume of the foredune. The combination of wide beach, high energy dissipation, maximum sediment supply, and high exposure to strong onshore winds is found in the northern end of the embayment where Holocene subaerial barrier volumes are at a maximum. Overall, this study proves that foredune development is closely related to wind exposure, wave energy and gradients of longshore sediment transport, and that dunefield development reflects the increase downdrift in potential sediment supply from the southern to the northern end of the beach, and the change alongshore from low energy dissipative, through intermediate, to high energy dissipative beach-surf zone environments. This paper significantly extends previous models of beach and dune interactions in that it (i) actually determines wave driven sediment transport for various sections of a long embayment, (ii) relates those transport patterns to surf zone/beach morphodynamic types and variations in alongshore sediment patterns, and (iii) correlates foredune volumes and Holocene barrier volumes (which reflect proxy Holocene onshore transport rates) with wave driven sediment transport rates.

Wave energy pattern around the Madeira Islands

The objective of the present work is to evaluate the patterns of wave power resources around the Madeira Islands. An analysis of the wave climate in the target area is first carried out based on satellite, buoy and hindcast wave data. As a further step, a SWAN based wave prediction system is validated against remotely sensed data over the entire area of the archipelago and this is subsequently used to evaluate the most relevant patterns from the point of view of the spatial distribution of the wave power. The model simulations, which are focused on the two main islands of the archipelago, made also apparent some nearshore locations where significant concentrations of wave energy usually occur. Corresponding to these energy hot spots, diagrams for the bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are designed and the performances of various types of wave energy converters were assessed. According to these evaluations, the efficiency of the wave energy conversion appears to be highly dependent on the distribution of the wave energy along the sea states. The results of the present work show that Madeira Archipelago, and especially the coastal environment of the Porto Santo Island, may be considered appropriate for an efficient extraction of wave energy.

Statistical analysis on extreme wave height

The classical extreme value theory based on generalized extreme value (GEV) distribution and generalized Pareto distribution (GPD) is applied to the wave height estimate based on wave hindcast data covering a period of 31 years for a location in the eastern Arabian Sea. Practical concern such as the threshold selection and model validation is discussed. Estimates of wave height having different return periods are compared with estimates obtained from different distributions. On comparing the distributions fitted to the GEV with annual maximum approach and GPD with peaks over threshold approach have indicated that both GEV and GPD models gave similar or comparable wave height for the study area since there is no multiple storm event in a year. Influence of seasonality on wave height having different return period is also studied.

Trend analysis of wave direction and associated impacts on the Catalan coast

The effects of climate change are currently a red-hot issue in the scientific community. However, little attention has been paid to the effects of climate change on the wave climate and, in particular, on wave directionality. In this study, we developed a methodology of trend analysis and extrapolation of mean wave climate. We used the parameters of a typical wave rose: frequencies of wave height intervals and directional sectors. The trend over time was estimated by means of linear regression analysis after applying a transformation according to the nature of the (compositional) data. Then, the wave climate was extrapolated up to 2050 assuming the same previously estimated trend and part of the uncertainty was assessed with the bootstrapping technique. Additionally, to get an idea of the magnitude of the consequences of the identified trends, we carried out an impact assessment, in terms of coastal morphodynamics and harbour operability, comparing the present situation with the extrapolation. To assess the impact on coastal morphodynamics, we compared the gradients of long-shore sediment transport to evaluate possible changes in beach retreat/accretion tendency, and to assess harbour operability, we studied the possible impact on harbour agitation in three port case studies. This study was carried out on the Catalan coast (NW Mediterranean Sea) and was based on 40 nodes of 44 years of wave hindcast data. The main impacts on the wave climate were found to be a reduction in the waves coming from the north and northeast and an increase in events coming from the south. This apparently significant change in directionality could result in changes in the prevailing dynamic pattern along more than 70 % of the Catalan coast (e.g. some apparently stable beaches could become erosive) although these results have associated a large uncertainty and are not statistically significant. On the other hand, harbour agitation is expected to increase with statistical significance (by up to 18 % on average) because the studied ports, like most of Catalonia’s ports, are oriented towards the south-southwest.

Wave hindcast experiments in the Indian Ocean using MIKE 21 SW model

Wave prediction and hindcast studies are important in ocean engineering, coastal infrastructure development and management. In view of sparse and infrequent in-situ observations, model derived hindcast wave data can be used for the assessment of wave climate in offshore and coastal areas. In the present study, MIKE 21 SW Model has been used to carry out wave hindcast experiments in the Indian Ocean. Model runs have been made for the year 2005 using QuickSCAT scatterometer winds blended with ECMWF model winds. In order to study the impact of southern ocean swells, the model has been run in two different domains, with the southern boundary being shifted far south for the Domain 60S model. The model simulated wave parameters have been validated by comparing with buoy and altimeter data and various statistical yardsticks have been employed to quantify the validation. Possible reason for the poorer performance of the model in the Arabian Sea has also been pointed out.

Application of a ship-routing fatigue model to case studies of 2800 TEU and 4400 TEU container vessels

Ship structures will always be subjected to and suffer from fatigue damage and fracture. However, we can become better at utilizing the materials and the structures and operating them more wisely, leading to less maintenance, extended service life and enhanced safety if we can improve the fatigue damage prediction. In this study, a fatigue model useful for ship routing is presented. Similar to the ship-routing design for the expected time of arrival and fuel reduction, the objective here is to demonstrate the possibility and benefits of ship route planning which lead to a reduction in fatigue damage accumulation. In the context of ship fatigue route planning, uncertainty analysis of the fatigue assessments of container ships is discussed. The proposed ship-routing fatigue model is employed in case studies on two container vessels to illustrate the possible benefits to the fatigue safety of ship structures. Sea environments in the application are obtained from hindcast wave data and a spatiotemporal wave model. The results show that the fatigue damage of the studied container ship structures could be decreased by more than 50% if awareness and knowledge of fatigue in ship route planning are employed.

Modeling regional sediment transport and shoreline response in the vicinity of tidal inlets on the Long Island coast, United States

A new numerical model was developed to simulate regional sediment transport and shoreline response in the vicinity of tidal inlets based on the one-line theory combined with the reservoir analogy approach for volumetric evolution of inlet shoals. Sand bypassing onshore and sheltering effects on wave action from the inlet bar and shoals were taken into account. The model was applied to unique field data from the south coast of Long Island, United States, including inlet opening and closure. The simulation area extended from Montauk Point to Fire Island Inlet, including Shinnecock and Moriches Inlets. A 20-year long time series of hindcast wave data at three stations along the coast were used as input data to the model. The capacity of the inlet shoals and bars to store sand was estimated based on measured cross-sectional areas of the inlets as well as on comprehensive bathymetric surveys of the areas around the inlet. Several types of sediment sources and sinks were represented, including beach fills, groin systems, jetty blocking, inlet bypassing, and flood shoal and ebb shoal feeding. The model simulations were validated against annual net longshore transport rates reported in the literature, measured shorelines, and recorded sediment volumes in the flood and ebb shoal complexes. Overall, the model simulations were in good agreement with the measured data.

MODELING SHORELINE RESPONSE AND INLET SHOAL VOLUME DEVELOPMENT ON LONG ISLAND COAST, UNITED STATES

A new numerical model was developed to simulate regional sediment transport, shoreline response in the vicinity of tidal inlets, and inlet shoal volume growth based on the one-line model of shoreline change combined with the reservoir concept for volumetric evolution of inlet shoals. Sand bypassing onshore and sheltering effects on wave action from the inlet bar and shoals were taken into account. The model was applied to unique field data from the south coast of Long Island, United States, including inlet opening and closure. The simulation area extended from Montauk Point to Fire Island inlet, including Shinnecock and Moriches Inlets (Figure 1). A 20-year time series of hindcast wave data at three stations along the coast were used as input data to the model. Several types of sediment sources and sinks were represented, including beach fills, groin systems, jetty blocking, inlet bypassing, and flood shoal and ebb shoal feeding. The model simulations were validated against annual net longshore transport rates reported in the literature, measured shorelines, and recorded sediment volumes in the flood and ebb shoal complexes. Overall, the model simulations were in good agreement with the measured data.

Trend analysis of wave storminess: wave direction and its impact on harbour agitation

Abstract. In the context of wave climate variability, long-term alterations in the wave storminess pattern of the Catalan coast (northwestern Mediterranean Sea) are analysed in terms of wave energy content and wave direction, on the basis of wave hindcast data (from 44-year time series). In general, no significant temporal trends are found for annual mean and maximum energy. However, the same analysis carried out separately for different wave directions reveals a remarkable increase in the storm energy of events from the south, which is partly due to a rise in the annual percentage of such storms. A case study of Tarragona Port (on the southern Catalan coast) highlights the importance of including changes in wave direction in the study of potential impacts of climate change. In particular, an increase in the frequency of storms from the south leads to greater agitation inside the Port.

Trend analysis of the wave storminess: the wave direction

Abstract. In this paper changes in the wave pattern of the Catalan coast are analyzed in terms of wave storminess and wave direction based on series of 44 years of hindcast wave data. The analysis is performed employing two different techniques: one resulting from the combination of regression and bootstrapping and the other applying a Bayesian method. Although the trends are, in general, null, in some locations there are clear changes in the wave directional frequencies. These changes can significatively affect coastal hydrodynamics and morphodynamics.

Global P, PP, and PKP wave microseisms observed from distant storms

Microseisms are the continuous background vibrations of the Earth observed between earthquakes. Most microseism studies have focused on low frequency energy (0.05–0.5 Hz) propagating as surface waves, but in the microseism spectrum there is also energy that propagates as body waves (P‐waves). Using array analysis on southern California stations we show that these body waves are generated in the ocean from distant storms and propagate deep within the Earth's mantle and core as P, PP and PKP phases. Comparisons with ocean wave hindcast data identify several distinct source regions in both the northern and southern hemispheres. Analyses of these body waves demonstrate that microseisms often have a strong P‐wave component originating from distant locations.

Estimate of global sea-air CO2 flux with sea-state-dependent parameterization

Although the annual global sea-air CO2 flux has been estimated extensively with various wind-dependent-k parameterizations, uncertainty still exists in the estimates. The sea-state-dependent-k parameterization is expected to improve the uncertainty existing in these estimates. In the present study, the annual global sea-air CO2 flux is estimated with the sea-state-dependent-k parameterization proposed by Woolf (2005), using NOAA/NCEP reanalysis wind speed and hindcast wave data from 1998 to 2006, and a new estimate, −2.18 Gt C year−1, is obtained, which is comparable with previous estimates with biochemical methods. It is interesting to note that the averaged value of previous estimates with various wind-dependent-k parameterizations is almost identical to that of previous estimates with biochemical methods by various authors, and that the new estimate is quite consistent with these averaged estimates.

A method for spatial calibration of wave hindcast data bases

In the last years, new tools have been developed to describe wave climate. In particular, wave hindcast models allow a very detailed description in time and space. However, the data bases generated from these models require calibration with instrumental observations. In this work, a methodology for spatial calibration of wave hindcast data bases is developed. It is based on an Empirical Orthogonal Function decomposition and a non-linear transformation of the spatial–time modes. The method is applied to monthly long-term distribution of significant wave height in the Western Mediterranean. The calibration (transformation of the modes) is carried out using existing buoys in the area. After calibration, the validation with satellite data shows that this methodology is useful to better define wave climate from hindcast data bases.