Wave Climate Analysis Research Articles

Multiyear surface wave dataset from the subsurface “DeepLev” eastern Levantine moored station

Abstract. Processed and analyzed sea surface wave characteristics derived from an up-looking acoustic Doppler current profiler (ADCP) for the period 2016–2022 are presented as a dataset available from the public open-access repository of SEA scieNtific Open data Edition (SEANOE) at https://doi.org/10.17882/96904 (Haim et al., 2022). The collected data include full two-dimensional wave fields, along with computed bulk parameters, such as wave heights, periods, and directions of propagation. The ADCP was mounted on the submerged Deep Levantine (DeepLev) mooring station located 50 km off the Israeli coast to the west of Haifa (bottom depth ∼1470 m). It meets the need for accurate and reliable in situ measurements in the eastern Mediterranean Sea as the area significantly lacks wave data compared to other Mediterranean sub-basins. The developed long-term time series of wave parameters contribute to the monitoring and analysis of the region's wave climate and the quality of wind–wave forecasting models.

Wave climate analysis for shoreline management plan in Kelantan, Malaysia

Wave climate analysis for shoreline management plan in Kelantan, Malaysia

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

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

Количество штормов в некоторых морях России: тренды и связь с крупномасштабными атмосферными индексами

Changes in the recurrence of extreme wind waves in the World Ocean are connected with the global climate change. The end of the 20th and the beginning of the 21st centuries are characterized by significant climate warming, the reduction of the Arctic sea ice and changes in the recurrence of various extreme meteorological events. The main motivation of this research is to assess the trends of storm recurrence for the time period from 1979 up to 2020 and to analyze the connection between storminess and large-scale atmospheric circulation indexes. This research contains information about the number of storms that occurred in seven Russian Seas, including the Black, Caspian, Barents, Kara, Bering Seas, the Sea of Okhotsk and the Sea of Japan/East Sea. These seas are located in different climate conditions determined by the Atlantic, Pacific and Arctic oceans. The analysis of wave climate and storm activity is based on the results of wave modelling by WAVEWATCH III with input NCEP/CFSR wind and ice data. The mean plots, maximum, and 95% percentile sig-nificant wave heights are also presented in the research. Significant linear uptrends in the number of storms were found in the Kara, Caspian, Bering, Okhotsk Seas, and in the Sea of Japan. The relationship between the inter-annual variability of the number of storms and large-scale at-mospheric indexes is considered.

Wind Waves Web Atlas of the Russian Seas

The main parameters of wind waves in the World Ocean are connected with global climate change. Renewable energy technologies, intensive shipping, fishery, marine infrastructure, and many different human marine activities in the coastal zone and open sea need knowledge about the wind-wave climate. The main motivation of this research is to share various wind wave parameters with high spatial resolution in the coastal zone via a modern cartographic web atlas. The developed atlas contains information on 13 Russian Seas, including the Azov, Black, Baltic, Caspian, White, Barents, Kara, Laptev, East Siberian, Chukchi, Bering Seas, the Sea of Okhotsk, and the Sea of Japan/East Sea. The analysis of wave climate was based on the results of wave modeling by WAVEWATCH III with input NCEP/CFSR wind and ice data. The web atlas was organized using the classic three-tier architecture, which includes a data storage subsystem (database server), a data analysis and publishing subsystem (GIS server), and a web application subsystem that provides a user interface for interacting with data and map services (webserver). The web atlas provides access to the following parameters: mean and maximum significant wave height, wave length and period, wave energy flux, wind speed, and wind power. The developed atlas allows changing the map scale (zoom) for detailed analysis of wave parameters in the coastal zones where the wave model spatial resolution is 300–1000 m.

Numerical analysis of wave climate driven variations in longshore sediment transport along Mahabalipuram coast, Southeast coast of India

The study examines the impact of wave climate change on the longshore sediment transport rate (LSTR) along Mahabalipuram (a UNESCO World Heritage Site) on the east coast of India. Wave climate changes and LSTR were evaluated using a spectral wave module (MIKE 21 SW) and LITPACK (1951–2020). The hourly integral wave parameters (significant wave height (Hs), peak wave period (Tp), and mean wave direction (Dm)) computed at the study location were used to estimate net and gross LSTR. The average Hs, Tp, and Dm were 0.85 m, 7.34 s, and 118° (E-SE), respectively, resulting in an average net northerly transport of about 0.046 × 106 m3/year, and gross transport of 0.2 × 106 m3/year. It has been shown that the changes in the LSTR are primarily associated with the LST of the seasonal variations that correspond to the seasonal changes in the wave climate. An overall increasing trend in wave climate (0.001 m/yr), net (∼ 320 m3/yr), and gross (∼ 619 m3/yr) LSTR was observed. The gross LSTR showed an increasing trend of about 17.6 % (1951–2020).The net LSTR is northward, except for a few years when the direction of net LST reversed. Understanding the variability in longshore sediment transport at the seasonal, inter-annual, and decadal scales is vital for designing better management plans for a coast.

Global Climatology of Extratropical Cyclones From a New Tracking Approach and Associated Wave Heights From Satellite Radar Altimeter

AbstractExtratropical cyclones (ECs) produce comparable wave heights and hazardous sea states to those under hurricanes. With strong wind speeds and considerably larger diameters, the impact of ECs on the global wave climate is substantial. Because ECs occur more frequently, move more quickly, and exist in a large variety of sizes and shapes, these storms are not as well documented. Here, we present findings from a global EC tracking algorithm aimed at creating an EC database of wave producing storms. We focus on the major ocean basins of extratropical cyclone activity: The North Atlantic, North Pacific, and Southern Oceans. Our tracking algorithm uses mean sea level pressure fields from the European Centre for Medium‐Range Weather Forecasts (ECMWF) high resolution, advanced data assimilating, ERA5 reanalysis over the years 1979–2020. The 42 year‐long data set of thousands of cyclone tracks allows seasonal patterns and longer‐term trends of EC activity to be analyzed in these ocean regions. In addition, we employ 36 years of satellite radar altimeter‐derived significant wave height (Hs) data from 14 inter‐calibrated satellite missions to study the wave climate induced by the identified ECs in each basin. The resulting wave climatology compares well with previous results in the mid to high latitudes. We then analyze average wave heights under different EC characteristics, including cyclone translational speed and maximum winds, which have strong effects on wave height variability. Finally, a brief analysis of EC and wave climate under positive and negative phases of the North Atlantic Oscillation is presented.

Wave Climate and Trends for the Marine Experimental Station of Capo Tirone Based on a 70-Year-Long Hindcast Dataset

Nearshore marine systems provide multiple economic and ecological services to human communities. Several studies addressing the climate change stressors and the inappropriate use of the sea indicate a decline of coastal areas. An extensive monitoring of the most important marine sites and protected areas is crucial to design effective environmental-friendly measures to support the sustainable development of coastal regions. A 70-year-long wave climate analysis is presented to study the climatology of the area belonging to the Marine Experimental Station of Capo Tirone, Italy. The analysis is based on the global atmospheric reanalysis developed by the European Centre for Medium-Range Weather Forecasts, validated through an observed buoy dataset recorded by the Italian Sea Wave Measurement Network. No significant long-term trends have been detected. The need to set up new monitoring stations has been pointed out by means of a hydrodynamic model developed at the regional scale, evaluating the effect of the local morphology on the nearshore wave climate and highlighting the importance of surveying the marine protected area of Capo Tirone located therein.

Comprehensive wave climate analysis of the Uruguayan coast

Comprehensive wave climate analysis of the Uruguayan coast

Analysis of the New Zealand’s Taranaki regional wave climate using high-resolution modelling

Understanding the regional wave climate is essential for engineering applications. The last two decades have not been included in assessments of the wave climate of New Zealand’s Taranaki region, where the country exploits offshore oil and gas. To make up for this lack of assessment, we carried out a high-resolution long-term (1979–2018) wave hindcast and examined several aspects of the climate in the region. The hindcast data validation against buoy and satellite data showed good agreement and suitability for wave climate analysis. Seasonal wave distributions reveal a bi-modal pattern, composed of (1) more energetic and long period (13–15 s) westerly–southwesterly swells; and (2) shorter-period (∼8 s) southwesterly wind-seas. These signatures result from the region’s high exposure to swells generated by persistent strong winds blowing over long fetches in the Southern Ocean, and to local storm-associated wind-seas, respectively. The largest waves are found offshore, with mean Hs value reaching 2.83 m, 90th percentile 4.3 m, 99th percentile 6.1 m, and maximum 10.8 m. Storm wave monthly climatologies show that storm peaks are largest in the austral autumn, especially in May, while the number of events is the largest in July. Trends in Hs statistics reveal an increase over the past 40 years, with higher rates at higher percentiles. Storm peaks have also increased, by up to 8 cm/decade, whereas the number of storm events has decreased. In agreement with previous work, we found relationships between Hs and climate patterns. Waves get larger in Taranaki waters during El Nino events, as a result of stronger southwesterly winds, and during negative Antarctic Oscillation phases, as westerly winds displace northward.

Thirty-Nine-Year Wave Hindcast, Storm Activity, and Probability Analysis of Storm Waves in the Kara Sea, Russia

The recurrence of extreme wind waves in the Kara Sea strongly influences the Arctic climate change. The period 2000–2010 is characterized by significant climate warming, a reduction of the sea ice in the Arctic. The main motivation of this research to assess the impact of climate change on storm activity over the past 39 years in the Kara Sea. The paper presents the analysis of wave climate and storm activity in the Kara Sea based on the results of numerical modeling. A wave model WAVEWATCH III is used to reconstruct wind wave fields for the period from 1979 to 2017. The maximum significant wave height (SWH) for the whole period amounts to 9.9 m. The average long-term SWH for the ice-free period does not exceed 1.3 m. A significant linear trend shows an increase in the storm wave frequency for the period from 1979 to 2017. It is shown that trends in the storm activity of the Kara Sea are primarily regulated by the ice. Analysis of the extreme storm events showed that the Pareto distribution is in the best agreement with the data. However, the extreme events with an SWH more than 6‒7 m deviate from the Pareto distribution.

Spatial characteristics of wind and wave parameters over the Sea of Marmara

This study aims to determine long-term spatial variability of wind and wave characteristics over the Sea of Marmara. For this purpose, we produced four different wind and wave datasets for a period of 40 years (1979–2018) using the calibrated and default-setting SWAN models forced with both CFSR and ERA-Interim winds and inter-compared. The performance of these datasets is examined against the wave height measurements of 2015 at the Silivri buoy station and 27-year (1991–2018) satellites data (ENVISAT, ERS-1, ERS-2, JASON-1, JASON-2, JASON-3, SENTINEL-3A, SENTINEL-3B, TOPEX). Then, for wind and wave climate analysis, the spatial distributions of the wind and wave characteristics over the study area are determined in terms of seasonal and annual averages. 40-year averages of 95th and 99th percentile significant wave heights, probabilities of being larger than significant wave heights exceeding a critical value, and 40-year maximum significant wave heights are spatially analyzed. Finally, the calibrated SWAN model using CFSR winds presents the most accurate results. Therefore, the effects of different model inputs and settings on the model results are examined by creating spatial distributions of the biases of the other three model results and comparing them to those of the calibrated model results using CFSR winds. The CFSR forced and calibrated model predicts the largest average wind speed and average wave height in the central regions of the Sea of Marmara in comparison with the other three models. The shores of Kapidag Peninsula and Marmara Island are exposed to be with the highest wave conditions.

Long-Term Analysis of Wave Climate and Shoreline Change along the Gulf of California

The last ten years have shown that Climate Change (CC) is a major global issue to attend to. The integration of its effects into coastal impact assessments and adaptation plans has gained great attention and interest, focused on avoiding or minimizing human lives and asset losses. Future scenarios of mean sea level rises and wave energy increase rates have then been computed, but downscaling still remains necessary to assess the possible local effects in small areas. In this context, the effects of CC on the wave climate in the Gulf of California (GC), Mexico, have received little attention, and no previous studies have tackled the long-term trend of wave climate at a regional scale. In this paper, the long-term trends of the wave height, wave period and wave energy in the GC were thus investigated, using the fifth-generation climate reanalysis dataset (ERA5). The long-term shoreline evolution was also examined from historical Landsat images, so as to identify erosional hotspots where intervention can be prioritized. The results indicate that both the mean and extreme wave regimes in the GC are getting more energetic and that two-thirds of the coast is suffering chronic erosion. A discrepancy between the trends of the wave period and wave height in some regions of the Gulf was also found. Finally, the importance of natural processes, human activity and CC in the shoreline change is highlighted, while addressing the need for future permanent field observations and studies in the GC.

Characterization of the Coastal Environment as a Baseline for Alternative Tourism Segments Development in Salinópolis, Pará

Salinópolis in Pará State, Brazil, is a coastal city with a highly seasonal tourism industry. Despite the potentiality of the region, tourism is mainly focused on beach use for recreation. The purpose of this study was to analyze environmental conditions to provide a baseline for development strategies of additional tourism activities, decreasing unwanted impacts, and improving the local economy. We combined wind and pluviosity data, remote sensing, and wave model results for the environmental characterization. Wave climate analysis shows higher waves in the first part of the year, favoring sports like water-surfing. Winds are more intense and parallel to the coast in the second part of the year when rain is low, defining ideal conditions for wind sports, like kitesurfing. Apart from sport activities, appropriately designed beach accesses through mangrove forest would allow a more even distribution of tourists on the beaches. Sustainable walkways projects could include multipurpose structures for beach access and development of ecotourism activities such as environmental education or bird watching. Gastronomic and cultural tourism could also reduce seasonality effects, attracting tourists also during the rainy season.

Characteristics and variability of the nearshore wave resource on the U.S. West Coast

Characterizing the nearshore wave resource at a regional scale poses a great challenge because high-quality wave data are required. This paper presents a detailed analysis of nearshore wave climate and resource characterization on the U.S. West Coast based on a 32-year, regional wave hindcast. Resource characterization closely followed the International Electrotechnical Commission standards. The wave hindcast data were generated from an unstructured-grid SWAN model with approximately 300 m grid resolution in the nearshore region. Statistics of six IEC wave resource parameters at the 50 m water depth were calculated for four sub-regions along the coast, including Washington, Oregon, and Northern and Southern California. Results indicate that the Washington and Oregon coast has a similar nearshore wave resource. The wave resource in Southern California is significantly less than that of the Washington and Oregon coast. Alongshore and cross-shore variabilities of wave power were assessed. Temporal variability, at seasonal, inter-annual, and decadal scales were analyzed. Overall, strong seasonal variation is observed; high wave energy occurs in the winter months and calm seas in the summer. Finally, extreme environmental conditions, i.e., the 100-year extreme environmental contours, for different locations along the West Coast were investigated.

Extreme value analysis of wave climate around Farasan Islands, southern Red Sea

The study investigates extreme value analysis of wave climate around the Farasan islands’ protected coastal zone in the southern Red Sea. It provides an overall idea of the extreme wave conditions in the southern Red Sea, which are influenced by the Indian monsoon and local climates as well as by the effect of complex topography due to the presence of corals and high steepness in the bathymetry. The significant wave height return levels for the select shallow and deep regions around the Farasan islands are estimated using extreme value models; Generalized Extreme Value (GEV) and Generalized Pareto Distribution (GPD). Both block maxima and annual maxima methods are used in the GEV and GPD established with Peak Over Threshold (POT). The GPD method gives more reliable return level estimates compared to GEV. The trend analysis shows that, the trends of near extremes (90th and 95th percentile Hs) are significant in the offshore regions around the Farasan Islands, but not significant in the nearshore regions. The seasonal analysis indicate that the seasonal estimates of extreme Hs are more reliable than annual estimates considering the differences in the seasonal wave generation mechanisms over the region.

Analysis of wave climate and trends in a semi-enclosed basin (Persian Gulf) using a validated SWAN model

Results from a spectral wave model of the Persian Gulf for a long-term period (32-year) are used to describe and quantify the seasonal wave climate and trends. The model is forced by a wind reanalysis dataset and validated against a set of field measurements and altimeter data from various satellite missions. The results revealed the existence of a more energetic wave (higher Hm0 and larger TP) zone located at the southern regions of the Gulf that is linked to the predominant and stronger north-westerly winds. The wave heights and periods are intensified in winter (Hm0>2.7m and TP > 8s for the 99th percentile) followed by spring. The waves conditions are milder in autumn. The analysis of wave climate trends throughout the region clearly show an overall slight positive trend (0–0.2%/year) in mean Hm0, which is associated with long-term positive trends in wind speed. There is generally a positive trend in the mean significant wave height during winter (0–0.8%/year), spring (0–0.6%/year) and autumn (0–1.0%/year), and negative during summer (0–0.8%/year). The results indicate that the more statistically significant results are at the areas with larger magnitude of trends.

Wave climate analysis in the ice-free waters of Kara Sea

Sea surface waves in the Kara Sea can vigorously generate and grow owing to the increasing ice cover reduction in recent years. This study aims to quantitatively determine the wave climate in the ice-free waters of Kara Sea based on the ECMWF ERA-Interim dataset. Wave parameters, such as the mean and extreme significant wave heights (SWH), periods (MWP), and their trends, roses and co-occurrences are adequately investigated. The optimal years from 2005 to 2018 are chosen when the summer ice-free extent continuously maintains at the maximum. Results reveal that the SWH and MWP are slightly higher in September than in August. The largest waves predominantly occur in the zone of 77∘N-79∘N and 67∘E-80∘E. The temporal linear trends of SWH and MWP are estimated but not statistically significant in most zones. The mean SWH and MWP remain stable with small fluctuations, while the extreme ones show a noticeable interannual variation. In addition, roses of SWH and MWP indicate that in the northern zone directions from SSW to NNW are predominant, while in the southern zone ones from NW to NE are prevalent. Moreover, the co-occurrences of simultaneous SWH and MWP are put forward. The SWH of 0.5–2.5 m with MWP of 4–7 s largely occur in the northern zone, while the SWH of 0.5–2 m with MWP of 3–6 s mainly appear in the southern zone.

A 39-year high resolution wave hindcast for the Chinese coast: Model validation and wave climate analysis

A new wave database has been built over the period of 1979–2017, which can provide wave parameters with high spatial (1 km along Chinese coast) and temporal (1 h) resolutions. Buoy data and satellite altimeter data are used to evaluate the accuracy of the wave hindcasts. Wave climate analysis is the next stage in which the yearly/seasonal maximum, 100-year return period and mean wave characteristics are analyzed. The maximum of the significant wave height (SWH) in summer and autumn are larger than those in the other seasons, while the seasonal mean values in autumn and winter are larger. Severe wave events analysis reveals the maximum values of the 99th percentile SWH (approximate 6 m) are located around Taiwan Island. The average durations for the events during typhoons are 20–30 h with SWH 2–3 m above the 99th percentile SWH. In contrast, the durations are 10–15 h with intensities less than 1 m in winter. For long-term trends, the 99th percentile SWH increases in most part of the Chinese seas, of 0.5–3 cm per year. The changes in times and durations over the past 39 years are not obvious, but the intensity increases approximate 6 cm per year along typhoon tracks.

Long-Term Estimation of Wave Climate Variability in the Western Bay of Bengal

The ocean plays a major role in climate change, and its impact has an extreme effect on the process of coastal and other activities around the globe. The comprehensive analysis of long-term wave climate is carried out at selected locations in the western Bay of Bengal (BoB), by observing the distribution of significant wave height (SWH) using monthly averaged satellite and WAM model for 20 years (1996–2015). The data used in this study were compared with two in situ buoy observations obtained from the National Institute of Ocean Technology (NIOT), Chennai, India. The satellite and wave model (WAM) data show a good correlation with both in situ buoy observations. The probability distribution functions indicated a significant increase in the higher range of SWH during the recent decade. The analysis of 20-year SWH indicates a positive trend with significant annual and semiannual periodicities. The northwestern bay depicts higher energy in the annual cycle, whereas the southwestern bay exhibits equal contributions from annual and semiannual cycles. The study also reveals that the increasing trends in local SWH in the western BOB are modified due to the number of tropical cyclones as well as the migrating swells generated in the southern Indian Ocean.