Fig 3 - uploaded by Eugen Rusu
Content may be subject to copyright.
Case study 1. Model system focalization on the Portuguese port of Sines, time frame 1994/02/04/h15. In background the significant wave height scalar fields are represented while in foreground (with black arrows) the wave direction.
Source publication
The objective of the present work is to illustrate the per-formances of the numerical wave models in ocean and coastal environment. Third generation wave models are considered nowadays the most appropriate for such task. These are full spectral models based on the integration on the wave energy (or alternatively wave action) balance equation. In or...
Similar publications
Background: The possible effects of dietary fiber intake on hypertension have not been clarified fully. The association of dietary fiber intake with hypertension risk in midlife women was analyzed in this study.
Methods: Baseline data were obtained from the Study of Women's Health Across the Nation (SWAN). Smooth curve, linear regression, and logis...
Surface current velocities of mesoscale eddies have a unique annular structure, which can inevitably influence surface wave properties and energy distribution. Sensitivity experiments of ideal mesoscale eddies on waves were carried out by the Simulating WAves Nearshore (SWAN) wave model to investigate these influences. In addition, China–France Oce...
Indonesia is located side by side with the Pacific Ocean and the Indian Ocean where there are often tropical cyclones in these two oceans. As was the case some time ago in the Indian Ocean a tropical cyclone of Cempaka and Dahlia occurred which had a significant impact on Indonesian areas. Another impact felt is the disruption of economic activity...
Storm surges and wind waves are ones of the most important hydrological characteristics, which determine dynamics of the Sea of Azov. Extreme storm surges in Taganrog Bay and flooding in the Don Delta can be formed under the effect of strong western winds. In this work the sea level oscillations and wind waves in the Taganrog Bay were simulated by...
A coastal forecasting system was implemented to provide wind wave forecasts over the whole Mediterranean Sea area, and with the added capability to focus on selected coastal areas. The goal of the system was to achieve a representation of the small-scale coastal processes influencing the propagation of waves towards the coasts. The system was based...
Citations
... This was implemented and validated against satellite data and in situ measurements in the entire basin of the Black Sea, and further on, it was focused considering a higher-resolution domain on the coastal area at the mouths of the Danube. This wave model is based on the spectrum concept and solves an advection-type equation in five dimensions (time, geographical, and spectral spaces) [36,37]. As in most of the spectral wave models, the spectrum considered is the action density spectrum (N) and not the energy density spectrum. ...
The entrance in the Sulina channel in the Black Sea is the target area of this study. This represents the southern gate of the seventh Pan-European transport corridor, and it is usually subjected to high navigation traffic. The main objective of the work is to provide a more comprehensive picture concerning the past and future expected dynamics of the environmental matrix in this coastal area, including especially the extreme wind and wave conditions in connection with the possible
navigation risks. The methodology considered assumes analyses performed at three different levels.
First, an analysis of some in situ measurements at the zero-kilometer point of the Danube is carried out for the 15-year period of 2009–2023. Together with the maximum wind speed and the maximum value of the wind gusts, the water level variation was analyzed at this point. As a second step, the analysis is based on wind speed data provided by regional climate models. Two periods, each spanning 30 years, are considered. These are the recent past (1976–2005), when comparisons with ERA5 reanalysis data were also performed, and the near future (2041–2070), when two different models and three climate scenarios were considered. The focus was on the extreme wind speed values, performing comparisons between the past and future expected extreme winds. Finally, the third analysis is related to the wave conditions. Thus, using as a forcing factor each of the wind fields that was previously analyzed, simulations employing a spectral wave model were carried out. The wave modeling system was focused using three different computational domains with increasing resolution towards the target area, and the nearshore wave conditions were evaluated. The results show that both the extreme wind and wave conditions are expected to slightly increase in the future. Especially in the wintertime, strong wind fields are often expected in this area, with wind gusts
exceeding more than 70% of the hourly average wind velocity. With regard to the waves, due to the complex nearshore phenomena, considerable enhancements in terms of significant wave heights are induced, and there is also an elevated risk of the occurrence of rogue waves. This work is still ongoing, and taking into account the high navigation risks highlighted, the next step would be to elaborate the risk assessment of severe shipping conditions, particularly related to the likelihood
or probability of adverse conditions with the potential of generating hazardous situations in this coastal environment.
... This was implemented and validated against satellite data and in situ measurements in the entire basin of the Black Sea and further on it was focused considering a higher resolution domain on the coastal area at the mouths of the Danube. This wave model is based on the spectrum concept and solves an advection type equation in fifth dimensions (time, geographical and spectral spaces) [36,37]. As in most of the spectral wave models, the spectrum considered is the action density spectrum (N) and not the energy density spectrum, because in the presence of the currents, the action density is conserved while the energy density is not. ...
The target area of the present study is the entrance to the Sulina channel in the Black Sea, the zero-kilometer of the Danube River. This represents the southern gate of the seventh Pan-European transport corridor and is subjected to high navigation traffic. The coastal environment at the Danube’s mouth is very often subjected to strong environmental conditions inducing high risks for navigation hazards. From this perspective, the objective of the present work is to provide a more comprehensive picture concerning the past and future expected dynamics of the environmental matrix in this area, including especially wind and wave conditions. An analysis of some in situ measurements performed at the zero kilometer of the Danube is first carried out for the 15 years 2009-2023. A second analysis is based on data provided by regional climate wind models. Two 30-year periods are considered, the recent past (1976-2005), when also comparisons with ERA5 reanalysis data were performed, and the near future (2041-2070), when two different models and three climate scenarios were considered. Finally, using as a forcing factor each of the wind fields before analyzed, simulations with a spectral wave model were carried out and the nearshore wave conditions were evaluated. The results show that both extreme wind and wave conditions are expected to be slightly enhanced in the future. Strong wind fields are characteristic in this area, with wind gusts exceeding on average with more than 70% the maximum hourly averaged wind speed. As regards the waves, due to the complex nearshore phenomena, considerable enhancements in terms of significant wave heights are induced. Furthermore, there is also a high risk of rogue wave’s occurrence.
... On the wave model, there are multiple ways of using third generation wave models in order to study the wave forecast and climate. The most commonly used third-generation wave models by scientists are SWAN, WAM and Wave Watch 3. The The primary strategies of wave simulation in the coastal zones and in the open sea were discussed before in other scientific studies [1]. In another study, numerical wave model, satellite data and in-situ data were analysed with regards to the significant wave height and showed good relation between datasets [2]. ...
Significant wave height (H s ) data are essential in different scientific studies regarding coastal and marine environments, coastal management, various economic activities nearshore and offshore, as well as in the use of marine renewable energy, oil and gas offshore platform operation and security, safety of personnel and equipment. The current paper presents an analysis of the significant wave height parameter for the particular case of the Black Sea basin. In order to achieve this analysis, satellite altimetry measurements from five different satellites taken from the IMOS (Integrated Marine Observing System) database were used and compared with the results of SWAN model simulations in order to assess the accuracy of simulated H s values. The analysis was performed on data available for a period of 3 years, from 2018 to 2020. The comparison of the simulated significant wave height with data measured by altimetry satellites showed a good correlation of 0.8. The obtained results bring a contribution with regards to a better insight and knowledge into the characteristics of wind waves in the Black Sea.
... The Black Sea has a horizontal circulation defined by gyres (cyclonic and anticyclonic currents directed by the force of the wind). Occasionally, the Rim Current has a width of tens of km and a maximum speed of 0.8-1 Nd or 40-50 cm/s, which sometimes reaches values up to 1.6 Nd or 80-100 cm/s [29,[32][33][34][35][36]. ...
The present study aims to outline a general overview of the wind energy potential along the Romanian coast of the Black Sea, using the weather data provided by the Maritime Hydrographic Directorate covering a 13-year time interval (2009-2021). The data obtained from seven automatic weather coastal stations distributed along the Romanian perimeter were used to evaluate the wind regime, highlighting the Black Sea's complex marine environment. The analysis based on the evaluation of the wind parameters per each station registered on the total period revealed that the overall wind characteristics are similar, resulting in no significant variations depending on the station's location. Moreover, the climatic picture of the Black Sea can be interpreted as two seasons, winter and summer, a conclusion based on the analysis made of the seasonal and monthly variation of the wind aspects. Subsequently, the outcomes obtained in this research imply that the Romanian Black Sea coast has the potential to be a good location for wind energy development due to the strong winds that blow in the region.
... Wave dissipation due to whitecapping is the least certain term among the source terms in a spectral wave model and can significantly affect the results (Rusu, 2011). Therefore, the effects of two available SWAN whitecapping formulations (Komen and Westhuysen) on wave ...
A coupled Flow-Wave-Sediment model was used to study hydrodynamics, sedimentation, and bottom boundary
layer (BBL) dynamics over the Sandy Point Dredge Pit (SPDP; a potential sand mining site in the Louisiana shelf,
northern Gulf of Mexico) during fair weather summer conditions (July and August 2015). The Delft3D modeling
system on a curvilinear computational grid with spatial resolution between 10 m and 2.8 km was used. The flow,
wave, and sediment transport models were evaluated using water level, current speed, wave parameters, and
sediment concentration. During this period, the wind over the Louisiana shelf is characterized as low energy with
the prevailing direction from southeast to the southwest, which corresponds to small wave heights (Hs < 1.2 m)
and small wave periods (Tm < 4 s). The relatively shorter waves resuspended sediments only in very shallow
areas along the Mississippi Birdfoot Delta. Simulations with and without the SPDP showed that the presence of
the pit could decrease the speed of surface currents by as much as 19%, while its effect on wave characteristics
was minor. The northward current produced by the prevailing winds transported the discharged sediments from
the Mississippi River contributed 60% of the sedimentation over the SPDP. Sediment re-suspension inside the
BBL of the SPDP occurred during the days that more energetic waves propagated over the shelf. As a result,
sediments from the Mississippi River significantly increased the sediment concentration near the bottom of and
throughout the water column above the SPDP.
... The SWAN model and other third-generation wave models need the careful calibrations for the numerical basic setting parameters and the key parameters of the source and sink terms before the high accuracy modelling (Amoudry and Souza, 2011;Rusu, 2011;Allahdadi et al., 2017). One common method to determine the numerical basic setting parameters is by implementing the sensitivity analysis for each parameter (Allahdadi et al., 2019). ...
... Due to the paucity of observations and the lack of access to long-term data, which resulted in the lack of access to wave climate estimation over recent years, more attention has been devoted to the use of numerical wave models and resulting wave spectra to evaluate wave climate. Proper implementation of the wave model is imperative (Rusu, 2011). Wave models use wind as the forcing function for the generation of wind-waves in water bodies; hence, a proper understanding of wind characteristics must be obtained. ...
Wind-wave characteristics are one of the most important factors in the design of coastal and marine structures. Hence, accurate estimation of wave parameters is crucial. In this paper, we examined the performance of a third-generation spectral wave model, MIKE 21 SW, in estimating wave parameters in the Iranian southeastern coasts over 1 year in 2016 using unstructured triangular mesh. The simulated wave conditions at the southern open boundary and the wind field variable in time and space of the Weather Research and Forecasting model with a spatial resolution of 0.1 and a temporal resolution of 1 hr were used for evaluating the model. To improve the model's performance, it was calibrated and validated by adjusting white-capping coefficients. The output data including significant wave height (Hs), peak wave period (Tp), and mean wave direction were compared with the data measured by acoustic Doppler current profiler at three stations of Pasabandar, Pozm, and Meydani on the southeastern coast of Iran. The results revealed that the scatter index for Hs at three stations after calibration was 0.232, 0.363, and 0.684, respectively. Moreover, the results for mean wave direction were 0.149, 0.181, and 0.288, respectively. The mean model errors for Hs were 0.003 m, 0.233 m, and 0.399 m, respectively, and this error was typically calculated for Tp and mean wave direction at Pasabandar station 0.12 s and 3.80°, respectively. The finding shows a more accurate prediction of Hs estimation with an appropriate correlation coefficient in three stations with a low bias and upstream. Comparison of the period of modeling waves with measurement data shows the appropriate accuracy of modeling results. According to the climate modeling results, waves from the north wind (Shamal wind) with periods of less than 8 s and waves from the southwest (Monsoon) with periods of more than 10 s are well distinguishable.
... The model configuration was as follows. The numerical scheme for the non-stationary mode was BSBT, whereas SORDUP was implemented for the stationary climate [11]. The bottom friction was defined by Collins [12], and depth-induced wave breaking and whitecapping were set as the default [13]. ...
The objective of this paper was to characterize swell conditions in the coastal zone of the South Shetland Islands, where our preliminary analyses evaluated potential locations for the Colombian scientific station. The Simulating Waves Nearshore (SWAN) spectral model was implemented for the Bransfield Strait. The boundary conditions were selected by a cluster analysis of the wave climate from global hindcasting obtained with the WAVEWATCH III model. Some comparisons between the model and wavemeter measurements were made. The results demonstrated that optimal sea state conditions for the scientific base are present in the South Bay, Livingston Island.
... Following the Persian Gulf, this region is the second-largest reservoir of oil and natural gas and has considerable deposits of coal and, of course, a traditional adherence to fossil fuels [1] . At the same time, it is renowned for the potential of its substantial renewable in hydropower, solar, and wind energy, and altogether [1][2][3][4][5][6][7] , these factors raise awareness whenever climate change generate concern. The Black Sea is cut off from the world's ocean through its unique particularities. ...
... The Black Sea's general circulation features consist mainly of the cyclonic Rim current, drifting along the continental slope, and various cyclonic and anticyclonic mesoscale eddies located inside the primary current or between it and the shore [4,13] . Nevertheless, the mesoscale eddies emerge along the borderline of the basin, as part of the Rim structure. ...
... Given the lack of consistent data for sea surface salinity, typically climatological datasets are utilized instead. However, they failed to replicate the vertical Black Sea thermohaline structure, such as the cold intermediate layer's properties, realistically, but are suitable for operational forecasting (CMEMS, [4] ). The second category includes stand-alone ocean models with distinct relaxation plots to climatological or observational sea surface temperature and sea surface salinity time series. ...
Having as target the semi-enclosed basin of the Black Sea, the primary purpose of the existing paper is to present an overview of its extensive physical features and circulation patterns. To achieve this goal, more than five decades of data analysis-from 1960 to 2015-were taken into consideration and the results were validated against acknowledged data, both from satellite data over the last two decades and in-situ measurements from first decades. The circulation of the Black Sea basin has been studied for almost 400 years since the Italian Count Luigi Marsigli first described the 'two-layer' circulation through the Bosphorus Strait in the year 1681. Since climate change projections for the Black Sea region foresee a significant impact on the environment in the coming decades, a set of adaptation and mitigation measures is required. Therefore more research is needed. Nowadays, the warming trend adds a sense of immediate urgency because according to the National Oceanic and Atmospheric Administration's National Centre for Environmental Information, July 2020 was the second-hottest month ever recorded for the planet. Its averaged land and ocean surface temperature tied with July 2016 as the second-highest for the month in the 141-year NOAA's global temperature dataset history, which dates back to 1880. It was 0.92°C above the 20th-century average of 15.8°C, with only 0.01°C less than the record extreme value measured in July of 2019.
... Its source term includes wave generation; dissipation and quadruplet wave-wave interactions; and dissipation due to bottom friction, triad wave-wave interactions and depth-induced breaking. In this model, the action balance equation is utilized instead of the energy balance equation since the action density N (defined as N = E/σ) is conserved during wave propagation [35]. The action balance equation in the Cartesian coordinate system can be expressed as: ...
Short-term wave forecasts are essential for the execution of marine operations. In this paper, an efficient and reliable physics-based machine learning (PBML) model is proposed to realize the multi-step-ahead forecasting of wave conditions (e.g., significant wave height Hs and peak wave period Tp). In the model, the primary variables in physics-based wave models (i.e., the wind forcing and initial wave boundary condition) are considered as inputs. Meanwhile, a machine learning algorithm (artificial neural network, ANN) is adopted to build an implicit relation between inputs and forecasted outputs of wave conditions. The computational cost of this data-driven model is obviously much lower than that of the differential-equation based physical model. A ten-year (from 2001 to 2010) dataset of every three hours at the North Sea center was used to assess the model performance in a small domain. The result reveals high reliability for one-day-ahead Hs forecasts, while that of Tp is slightly lower due to the weaker implicit relationships between the data. Overall, the PBML model can be conceived as an efficient tool for the multi-step-ahead forecasting of wave conditions, and thus has great potential for furthering assist decision-making during the execution of marine operations.
