scholarly journals Coastal impacts of Storm Gloria (January 2020) over the north-western Mediterranean

2020 ◽  
Vol 20 (7) ◽  
pp. 1955-1968 ◽  
Author(s):  
Angel Amores ◽  
Marta Marcos ◽  
Diego S. Carrió ◽  
Lluís Gómez-Pujol
Keyword(s):  
Storm Surge ◽  
Wave Height ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Storm Surges ◽  
Western Mediterranean ◽  
Eastern Coast ◽  
Historical Records ◽  
Significant Wave ◽  
Coastal Impacts

Abstract. The ocean component and coastal impacts of Storm Gloria, which hit the western Mediterranean between 20 and 23 January 2020, are investigated with a numerical simulation of the storm surges and wind waves. Storm Gloria caused severe damages and beat several historical records, such as significant wave height or 24 h accumulated precipitation. The storm surge that developed along the eastern coasts of the Iberian Peninsula, reaching values of up to 1 m, was accompanied by wind waves with a significant wave height of up to 8 m. Along the coasts of the Balearic Islands, the storm footprint was characterised by a negligible storm surge and the impacts were caused by large waves. The comparison to historical records reveals that Storm Gloria is one of the most intense among the events in the region during the last decades and that the waves' direction was particularly unusual. Our simulation permits quantification of the role of the different forcings in generating the storm surge. Also, the high spatial grid resolution down to 30 m over the Ebro Delta allows determination of the extent of the flooding caused by the storm surge. We also simulate the overtopping caused by high wind waves that affected a rocky coast of high cliffs (∼15 m) on the eastern coast of Mallorca.

scholarly journals Coastal Impacts of Storm Gloria (January 2020) over the Northwestern Mediterranean

2020 ◽  
Author(s):  
Angel Amores ◽  
Marta Marcos ◽  
Diego S. Carrió ◽  
Lluís Gómez-Pujol
Keyword(s):  
Storm Surge ◽  
Wave Height ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Storm Surges ◽  
Western Mediterranean ◽  
Eastern Coast ◽  
Historical Records ◽  
Significant Wave ◽  
Coastal Impacts

Abstract. The ocean component and coastal impacts of Storm Gloria, that hit the Western Mediterranean between January 20th and 23rd 2020 are investigated with a numerical simulation of the storm surges and wind-waves. Storm Gloria caused severe damages and beat several historical records such as significant wave height or 24-h accumulated precipitation. The storm surge developed along the eastern coasts of the Iberian Peninsula reached values up to 1 m, and were accompanied by wind-waves with significant wave height up to 8 m. Along the coasts of the Balearic Islands, the storm footprint was characterised by a negligible storm surge and the impacts were caused by large waves. The comparison to historical records reveals that Storm Gloria is one of the most intense among the events in the region during the last decades and that the waves direction was particularly unusual. Our simulation permits quantifying the role of the different forcings in generating the storm surge. Also, the high spatial grid resolution down to 30 m over the Ebro Delta, allows determining the extent of the flooding caused by the storm surge. We also simulate the overtopping caused by high wind waves that affected a rocky coast of high cliffs (~ 15 m) in the eastern coast of Mallorca Island.

scholarly journals Wind Wave Growth at Short Fetch

2008 ◽  
Vol 38 (7) ◽  
pp. 1597-1606 ◽  
Author(s):  
T. Lamont-Smith ◽  
T. Waseda
Keyword(s):  
Wind Speed ◽  
Wave Height ◽  
Significant Wave Height ◽  
Field Data ◽  
Wind Wave ◽  
Wind Waves ◽  
Retention Rates ◽  
Horizontal Distance ◽  
Wave Tank ◽  
Significant Wave

Abstract Wave wire data from the large wind wave tank of the Ocean Engineering Laboratory at the University of California, Santa Barbara, are analyzed, and comparisons are made with published data collected in four other wave tanks. The behavior of wind waves at various fetches (7–80 m) is very similar to the behavior observed in the other tanks. When the nondimensional frequency F* or nondimensional significant wave height H* is plotted against nondimensional fetch x*, a large scatter in the data points is found. Multivariate regression to the dimensional parameters shows that significant wave height Hsig is a function of U2x and frequency F is a function of U1.25x, where U is the wind speed and x is the horizontal distance, with the result that in general for wind waves at a particular fetch in a wave tank, approximately speaking, the wave frequency is inversely proportional to the square root of the wind speed and the wavelength is proportional to the wind speed. Similarly, the wave height is proportional to U1.5 and the orbital velocity is proportional to U. Comparison with field data indicates a transition from this fetch law to the conventional one [the Joint North Sea Wave Project (JONSWAP)] for longer fetch. Despite differences in the fetch relationship for the wave tank and the field data, the wave height and wave period satisfy Toba’s 3/2 power law. This law imposes a strong constraint on the evolution of wind wave energy and frequency; consequently, the energy and momentum retention rate are not independent. Both retention rates grow with wind speed and fetch at the short fetches present in the wave tank. The observed retention rates are completely different from those typically observed in the field, but the same constraint (Toba’s 3/2 law) holds true.

scholarly journals VALIDATION OF JASON-2 AND ENVISAT WIND SPEED AND SIGNIFICANT WAVE HEIGHT DATA IN THE INTERTROPICAL ZONE

2013 ◽  
Vol 31 (3) ◽  
pp. 483 ◽  
Author(s):  
Guilherme Colaço Melo Dos Passos ◽  
Nelson Violante Carvalho ◽  
Uggo Ferreira Pinho ◽  
Alexandre Pereira Cabral ◽  
Frederico F. Ostritz
Keyword(s):  
Wind Speed ◽  
Correlation Coefficient ◽  
Wave Height ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Altimeter Data ◽  
Data Set ◽  
Significant Wave ◽  
Wave Measurements ◽  
Satellite Radar

ABSTRACT. The estimates of significant wave height (SWH) and wind speed at 10 meter height (u10) from the Jason-2 and ENVISAT satellites, over the intertropical region, are analysed. Some authors have tested the dependency of satellite radar wind/wave measurements on local environmental conditions, particularly on wave age, with no conclusive results. Our data show that Jason-2 overestimates high values of SWH and underestimates low values, while ENVISAT exhibits the opposite behaviour. The correlation coefficient between buoy measurements and altimeter data is around 0.95, with bias and root mean square error (RMSE) of, 3 and 15 cm respectively. On the other hand, Jason-2 underestimates u10 throughout the whole measured range, while ENVISAT overestimates throughout the whole range for speeds over 3 m/s. The correlation coefficient is around 0.90, with bias and RMSE around 0.20 cm and 1.5 m/s, respectively. The altimeter estimates in the intertropical region are similar to those obtained with global coverage, hence the sensitivity to sea state to extract wind speed and wave height is not so obvious in our data set. Therefore, the results indicate that the algorithms employed have a fair enough performance in the intertropical region.Keywords: wind waves, wind speed, altimeter, Jason-2, ENVISAT. RESUMO. As estimativas de altura significativa de onda (SWH) e de intensidade do vento a 10 metros de altura (u10) dos altímetros dos satélites Jason-2 e ENVISAT, obtidas na região intertropical, são analisadas. Alguns trabalhos apontam para uma possível dependência da esbeltez das ondas, e portanto do estado de mar, para extração de u10 e SWH, o que tornaria os algoritmos empregados dependentes da localidade. Os resultados aqui obtidos mostram que o Jason-2 em geral superestima altos valores de SWH e subestima baixos valores, enquanto que para o ENVISAT a tendência encontrada é a inversa. Foram obtidos coeficientes de correlação entre a SWH de boias e dos altímetros em torno de 0,95, e bias e erro médio quadrático (RMSE) de aproximadamente 3 e 15 cm, respectivamente. Em relação à u10, o Jason-2 subestima ligeiramente os valores, independente da faixa de intensidade do vento, enquanto que o ENVISAT os superestimam em quase todas as faixas de intensidade, exceto para ventos menores que 3 c/s. Os coeficientes de correlação se encontram em torno de 0,90, com bias e erro médio quadrático de, respectivamente, aproximadamente 0,20 cm e 1,5 c/s. Os resultados indicam que o desempenho na região intertropical é similar aos resultados obtidos empregando medições globais, que são altamente concentradas em altas latitudes no Hemisfério Norte. O efeito da condição do estado de mar para extração de SWH e u10, caso seja importante, não aparenta ser considerável no conjunto de dados aqui empregado. Portanto, os resultados apontam para um desempenho bastante aceitável de tais algoritmos quando empregados na região intertropical.Palavras-chave: altura significativa de ondas, intensidade do vento, altimetria, Jason-2, ENVISAT.

scholarly journals Characteristics of high monsoon wind-waves observed at multiple stations in the eastern Arabian Sea

2017 ◽  
Author(s):  
M. M. Amrutha ◽  
V. Sanil Kumar
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Arabian Sea ◽  
Wind Waves ◽  
Surface Wind ◽  
Wave Model ◽  
Spatial Distance ◽  
Significant Wave ◽  
Eastern Arabian Sea ◽  
Crest Height

Abstract. The growth and decay of surface wind-waves during one-month period in a typical Indian summer monsoon is investigated based on the data collected at 9 to 15 m water depth at 4 locations in the nearshore waters of the eastern Arabian Sea covering a spatial distance of ~ 350 km. The significant wave height varied from 0.7 to 5.5 m during the data collection considered in the analysis. The heights of waves during the measurement period often exceed 3 m. The most extreme wave height is 1.50 to 1.62 times the significant wave height and the most extreme crest height of the wave is 1.23 to 1.35 times the significant wave height of the same 30-minutes record. The average ratio of crest height of the wave to the height of the same wave is 0.58 to 0.67. The height of waves having maximum crest height is smaller than the maximum wave height during 30 minutes period. Measured waves are predominantly swell, but since the majority of wave generation during the monsoon is adjacent to the study area and the wind–wave coupling is strong, wave periods are rarely above 15 s. The numerical wave model could estimate the wave height reasonably well during the wave growth compared to the wave decay period. Hovmöller diagrams show a considerable spatial variability in the wave and wind pattern in the Indian Ocean during the high wave event at the eastern Arabian Sea.

Joint probability of storm surge and wave along Hainan Island based on bi-variate copulas analysis

2020 ◽  
Author(s):  
Meng Cheng ◽  
Weihua Fang
Keyword(s):  
Probability Distribution ◽  
Storm Surge ◽  
Wave Height ◽  
Significant Wave Height ◽  
Probability Distributions ◽  
Joint Probability ◽  
Hainan Island ◽  
Joint Probability Distribution ◽  
Significant Wave ◽  
Surge Height

<p>Tropical cyclones (TCs) often bring multiple hazards to offshore and onshore areas, including wind, rainfall, riverine flood, wave and storm surge. These hazards usually interact with each other and cause greater amplified hazard intensity. In the coastal areas, wave may damage coastal defense system like sea walls and dykes, and overtopping storm surge could hence become severe flooding due to the breach of the dykes. The probability distributions of wave and surge, as univariate respectively, have been studies and used in the design in various research. However, far less investigations on their joint probability distribution have been carried out in the past.</p><p>In this study, the dataset of hourly surge height, and significant wave height of 89 TC events impacting along Hainan Island during 1949~2013 was obtained, which are simulated numerically with ADCIRC and SWAN respectively. Following that, 4 types of probability distributions for univariate were used to fit the marginal distribution of storm surge and wave. Secondly, Frank, Clayton and Gumbel Copula were tried to construct the joint probability distribution of wave and surge, and the optimal Copula was determined by K-S test and AIC, BIC criteria. Based on the optimal Copula selected for each area of interest, the joint return period of wave and surge was estimated.</p><p>The results show that, 1) the annual maximum value of the storm surge height and significant wave height of Hainan Island has a relatively obvious geographical distribution regularity. 2) GEV and Gumbel are the most optimal distribution for storm surge height and significant wave height respectively. 3) Clayton Copula is the best model for fitting joint probability of storm surge and wave. The estimated joining probability distribution can help the determination of design standard, and typical TC disaster scenario development.</p>

On Long Term Statistics of Ocean Storms Starting From Partitioned Sea States

2017 ◽  
Author(s):  
Valentina Laface ◽  
Felice Arena ◽  
Christophe Maisondieu ◽  
Alessandra Romolo
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Storm Events ◽  
Significant Wave ◽  
Open Sea ◽  
Storm Duration ◽  
Two Parameters ◽  
Actual Seas

The paper proposes an analysis of ocean storms carried out starting from significant wave height time series of HOMERE sea-states hindcast database based on WAVEWATCH III model. Considering that wave spectra often exhibit multiple peaks due to the coexistence of wind waves and swells, here sea states are described by partitioned sea states that can be interpreted physically as representing independent wave systems. The analysis presented here in the paper deals with the contribution of swells to the storm peaks and on how they influence the long term statistics. The sensitivity of return values of significant wave height to swell contribution is investigated via an application of the Equivalent Triangular Storm Model (ETS). The ETS model provides analytical solution for the calculation of the return period R(Hs>h) of a sea storm whose maximum significant wave height exceeds a given threshold h. The approach of ETS consists in substituting each actual storm with an ETS described by two parameters: the storm intensity, that is the triangle height and it is equal to the maximum significant wave height during the actual storm; the storm duration, that is achieved imposing the equality between the maximum expected wave height of actual and equivalent storms. It has been experimentally proved that the actual storm and associated ETS are statistically equivalent because they have the same maximum significant wave height and the same probability P(Hmax>H) that the maximum wave height exceeds a given threshold H. The sequence of ETSs obtained in this way represents the equivalent sea, while the sequence of actual storms is the actual sea. The equivalent and actual seas present the same wave risk because they are characterized by the same number of storm events, each of them with the same intensity and the same P(Hmax>H). For the proposed analysis a set of four points from open sea to the coast is considered in area of the Gulf of Biscay (France). The results show that the contribution of swells is more significant for the storms of small and medium intensity and decreases for increasing storm intensities. Further return values variability neglecting swell is less than 7% at any point for return periods up to 100 years.

Influence of Reclamation on Hydrodynamic Environment in Bohai Bay

2013 ◽  
Vol 726-731 ◽  
pp. 3262-3265
Author(s):  
Xin Zhao ◽  
Qun Sun
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Numerical Results ◽  
Bohai Bay ◽  
Wave Fields ◽  
Significant Wave ◽  
Swan Model ◽  
Coastline Change ◽  
Hydrodynamic Environment

The SWAN model was used to simulate the effect of the coastline change caused by the reclamations on the wave fields in Bohai Bay. The numerical results in the year of 2000 had been compared with that of 2010 to study the influence of the sea reclamations on the wind waves in Caofeidian area. The results show that the significant wave height has a declining trend due to the reclamation and decreased in value of 0.1 to 0.4m in 2010. The magnitude of the decrease of the significant wave height in winter is larger than that in summer. The significant variations of wave fields are occurred in the harbor basin and tide channel.

scholarly journals Global coastal attenuation of wind-waves observed with radar altimetry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marcello Passaro ◽  
Mark A. Hemer ◽  
Graham D. Quartly ◽  
Christian Schwatke ◽  
Denise Dettmering ◽  
...  
Keyword(s):  
Wave Height ◽  
Energy Flux ◽  
Wave Energy ◽  
Annual Cycle ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Wave Climate ◽  
Radar Altimetry ◽  
Significant Wave ◽  
The Mean

AbstractCoastal studies of wave climate and evaluations of wave energy resources are mainly regional and based on the use of computationally very expensive models or a network of in-situ data. Considering the significant wave height, satellite radar altimetry provides an established global and relatively long-term source, whose coastal data are nevertheless typically flagged as unreliable within 30 km of the coast. This study exploits the reprocessing of the radar altimetry signals with a dedicated fitting algorithm to retrieve several years of significant wave height records in the coastal zone. We show significant variations in annual cycle amplitudes and mean state in the last 30 km from the coastline compared to offshore, in areas that were up to now not observable with standard radar altimetry. Consequently, a decrease in the average wave energy flux is observed. Globally, we found that the mean significant wave height at 3 km off the coast is on average 22% smaller than offshore, the amplitude of the annual cycle is reduced on average by 14% and the mean energy flux loses 38% of its offshore value.

Interannual variability of ocean surface waves in the Southeast Pacific

2020 ◽  
Author(s):  
Catalina Aguirre ◽  
Diego Becerra ◽  
Marcelo Godoy ◽  
Diego Silva
Keyword(s):  
South America ◽  
Interannual Variability ◽  
Wave Height ◽  
Significant Wave Height ◽  
Wind Waves ◽  
Austral Summer ◽  
Ocean Surface ◽  
Positive Phase ◽  
Significant Wave ◽  
Southeast Pacific

<p>Ocean surface (wind-driven) waves continuously shape the coastal environment and play a relevant role in ocean-atmosphere interaction processes. They are also important in operational aspects of ports and have significant energy potential. This research is focused on the interannual variability of the wind waves in the Southeast Pacific, particularly its relationship with the Southern Annular Mode (SAM) and El Niño Southern Oscillation (ENSO). We used a 38-year wave simulation (1979-2016) performed using the Wavewatch III model forced with surface winds and ice concentration from the ERA-Interim reanalysis. Additionally, a cyclone tracking software was used to analyze the trajectories of the extratropical storms which generate the wind waves that reach the coast of western South America. Time series statistics, such as correlation and composites analysis, have been applied to both wave parameters (such as significant wave height and mean period) and directional spectra. Results show a significant and positive correlation between the SAM and the significant wave height and the mean period of the wind waves. However, local storms in central Chile, which are the most damaging extreme wave events for coastal infrastructure, are less frequent during the positive phase of the SAM. Furthermore, a trend analysis shows an increase of the significant wave height during the last decades, which is consistent with the trend toward the positive phase experienced by the SAM. On the other hand, the wave energy of remote origin that travels from the North Pacific toward the Southeast Pacific, which is maximum during the austral summer, shows a significant relationship with the extreme El Niño events. These energetic swells events that reach the coast of western South America during the austral summer are more intense and frequent during the warm phase of ENSO.</p>

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