scholarly journals Influence of Storm Tidal Current Field and Sea Bottom Slope on Coastal Ocean Waves during Typhoon Malakas

2021 ◽  
Vol 13 (22) ◽  
pp. 4722
Author(s):  
Meng Sun ◽  
Yongzeng Yang ◽  
Yutao Chi ◽  
Tianqi Sun ◽  
Yongfang Shi ◽  
...  
Keyword(s):  
Orbital Motion ◽  
Ocean Waves ◽  
Coastal Ocean ◽  
Ocean Current ◽  
Analytic Model ◽  
Bottom Slope ◽  
Sea Bottom ◽  
Current Interaction ◽  
Wave Models ◽  
The Impact

Wave–current interaction in coastal regions is significant and complicated. Most wave models consider the influence of ocean current and water depth on waves, while the influence of the gradient of the sea bottom slope is not taken into account in most research. This study aimed to analyze and quantify the contribution of storm tidal currents to coastal ocean waves in a case where sea bottom slope was not ignored. Fourier analysis was applied to solve the governing equation and boundary conditions, and an analytic model for the calculation of the variation of amplitude of wave orbital motion was proposed. Ocean currents affect ocean waves through resonance. In this paper, an implemented instance of this analytic model was given, using the Shengsi area during Typhoon Malakas as an example. The results suggest that vertical variation in the amplitude of wave orbital motion is remarkable. The impact of wave–current interaction is noticeable where the gradient of the sea bottom slope is relatively large.

scholarly journals Spatially Tracking Wave Events in Partitioned Numerical Wave Model Outputs

2019 ◽  
Vol 36 (10) ◽  
pp. 1933-1944 ◽  
Author(s):  
Haoyu Jiang
Keyword(s):  
Grid Point ◽  
Wave Model ◽  
Ocean Waves ◽  
Model Verification ◽  
Analysis Model ◽  
Wave Parameters ◽  
Numerical Wave ◽  
Wave Models ◽  
Spectral Partitioning ◽  
The Impact

AbstractNumerical wave models can output partitioned wave parameters at each grid point using a spectral partitioning technique. Because these wave partitions are usually organized according to the magnitude of their wave energy without considering the coherence of wave parameters in space, it can be difficult to observe the spatial distributions of wave field features from these outputs. In this study, an approach for spatially tracking coherent wave events (which means a cluster of partitions originating from the same meteorological event) from partitioned numerical wave model outputs is presented to solve this problem. First, an efficient traverse algorithm applicable for different types of grids, termed breadth-first search, is employed to track wave events using the continuity of wave parameters. Second, to reduce the impact of the garden sprinkler effect on tracking, tracked wave events are merged if their boundary outlines and wave parameters on these boundaries are both in good agreement. Partitioned wave information from the Integrated Ocean Waves for Geophysical and other Applications dataset is used to test the performance of this spatial tracking approach. The test results indicate that this approach is able to capture the primary features of partitioned wave fields, demonstrating its potential for wave data analysis, model verification, and data assimilation.

Towards a unified framework for maximum wave computation from numerical models: outcomes from the LATEMAR project.

2020 ◽  
Author(s):  
Alvise Benetazzo ◽  
Francesco Barbariol ◽  
Paolo Pezzutto ◽  
Luciana Bertotti ◽  
Luigi Cavaleri ◽  
...  
Keyword(s):  
Numerical Models ◽  
Wave Spectrum ◽  
Wave Model ◽  
Ocean Waves ◽  
Unified Framework ◽  
Sea State ◽  
Large Wave ◽  
Wavewatch Iii ◽  
Wave Models ◽  
The Impact

<p>Reliable prediction of oceanic waves during severe marine storms has always been foremost for offshore platform design, coastal activities, and navigation safety. Indeed, many damaging accidents and casualties during storms were ascribed to the impact with abnormal and unexpected waves. However, predicting extreme wave occurrence is a challenging task, at first, because of their inherent randomness, and because the observation of large ocean waves, of primary importance to assess theoretical and numerical models, is limited by the costs and risks of deployment during severe open-ocean sea-state conditions.</p><p>In the context of the EU-based Copernicus Marine Environment Monitoring Service (CMEMS) evolution, the LATEMAR project (https://www.mercator-ocean.fr/en/portfolio/latemar/) aimed at improving the modelling of large wave events during marine storms. Indeed, at present, operational systems only provide average and peak wave parameters, with no information on individual waves whatsoever. However, developments of the state-of-the-art third-generation wave models demonstrated that using the directional wave spectrum moments into theoretical statistical models for wave extremes, forecasters are able to accurately infer the expected shape and likelihood of the maximum waves during storms.</p><p>The main purpose of the activity is therefore to provide the wave models WAM and WAVEWATCH III with common procedures to explicitly estimate the maximum wave heights for each sea state. LATEMAR achieved this goal by: performing an extensive assessment of the model maximum waves using field observations collected from an oceanographic tower; comparing WAM and WAVEWATCH III maximum wave estimates in the Mediterranean Sea; investigating the sensitivity of the maximum waves on the main sea state parameters. All model developments and evaluations resulting from this research project will be directly applicable to the wave model forecasting systems to expand their catalogue.</p>

scholarly journals Coupling of wave and circulation models in coastal-ocean predicting systems: a case study for the German Bight

2015 ◽  
Vol 12 (6) ◽  
pp. 3169-3197
Author(s):  
J. Staneva ◽  
K. Wahle ◽  
H. Günther ◽  
E. Stanev
Keyword(s):  
Extreme Events ◽  
German Bight ◽  
Wind Wave ◽  
Wind Waves ◽  
Ocean Waves ◽  
Coastal Ocean ◽  
Prediction Errors ◽  
State Variables ◽  
Nonlinear Feedback ◽  
The Impact

Abstract. This study addresses the impact of coupling between wind wave and circulation models on the quality of coastal ocean predicting systems. This is exemplified for the German Bight and its coastal area known as the Wadden Sea. The latter is the area between the barrier islands and the coast. This topic reflects the increased interest in operational oceanography to reduce prediction errors of state estimates at coastal scales, which in many cases are due to unresolved nonlinear feedback between strong tidal currents and wind-waves. In this study we present analysis of wave and hydrographic observations, as well as results of numerical simulations. A nested-grid modelling system is used to producing reliable nowcasts and short-term forecasts of ocean state variables, including wind waves and hydrodynamics. The data base includes ADCP observations and continuous measurements from data stations. The individual and collective role of wind, waves and tidal forcing are quantified. The performance of the forecast system is illustrated for the cases of several extreme events. Effects of ocean waves on coastal circulation and sea level are investigated by considering the wave-dependent stress and wave breaking parameterization. Also the effects which the circulation exerts on the wind waves are tested for the coastal areas using different parameterizations. The improved skill of the coupled forecasts compared to the non-coupled ones, in particular during extreme events, justifies the further enhancements of coastal operational systems by including wind wave models.

scholarly journals Strongly Coupled Assimilation of a Hypothetical Ocean Current Observing Network within a Regional Ocean-Atmosphere Coupled Model: An OSSE Case Study of Typhoon Hato

2021 ◽  
Author(s):  
Luke Phillipson ◽  
Yi Li ◽  
Ralf Toumi
Keyword(s):  
Coupled Model ◽  
Ocean Currents ◽  
Hf Radar ◽  
Ocean Current ◽  
Coastal Current ◽  
Strongly Coupled ◽  
Ocean Atmosphere ◽  
Atmospheric Observations ◽  
Surface Drifters ◽  
The Impact

AbstractThe forecast of tropical cyclone (TC) intensity is a significant challenge. In this study, we showcase the impact of strongly coupled data assimilation with hypothetical ocean currents on analyses and forecasts of Typhoon Hato (2017). Several observation simulation system experiments were undertaken with a regional coupled ocean-atmosphere model. We assimilated combinations of (or individually) a hypothetical coastal current HF radar network, a dense array of drifter floats and minimum sea-level pressure. During the assimilation, instant updates of many important atmospheric variables (winds and pressure) are achieved from the assimilation of ocean current observations using the cross-domain error covariance, significantly improving the track and intensity analysis of Typhoon Hato. As compared to a control experiment (with no assimilation), the error of minimum pressure decreased by up to 13 hPa (4 hPa / 57 % on average). The maximum wind speed error decreased by up to 18 knots (5 knots / 41 % on average). By contrast, weakly coupled implementations cannot match these reductions (10% on average). Although traditional atmospheric observations were not assimilated, such improvements indicate there is considerable potential in assimilating ocean currents from coastal HF radar, and surface drifters within a strongly coupled framework for intense landfalling TCs.

Observation of wave propagation in ice using stereo imaging in the Sea of Okhostk

2021 ◽  
Author(s):  
Alberto Alberello ◽  
Takehiko Nose ◽  
Tsubasa Kodaira ◽  
Keita Nishizawa ◽  
Filippo Nelli ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Wave Attenuation ◽  
Wind Waves ◽  
Arctic Basin ◽  
Ocean Waves ◽  
The Arctic ◽  
Camera System ◽  
The Sea Of Okhotsk ◽  
Wave Models ◽  
Seasonal Ice Zone

<p>Sea ice seasonally covers the Sea of Okhotsk, a marginal Arctic basin nested between Russia and Japan, but its extent is predicted to decrease by 40% by 2050 leaving larger ice free areas over which waves can form. In the highly dynamical seasonal ice zone, i.e. where waves and ice interact, ice formation and breakup, and wave attenuation mutually affect each other via complex feedback mechanisms. To shed light into these interactions, wave measurements were conducted in the winter seasonal ice zone in the Southern Okhotsk Sea, North of Hokkaido, from onboard the P/V Soya using a stereo camera system. Data show that wave energy penetrates even in high ice concentration (>85%), where contemporary wave models predict complete attenuation of wind waves. Consistently with physical experiments and field observations of waves in the Arctic and Antarctic marginal ice zones, the measurements also show that the ice cover is more effective in attenuating short wave components and, consequently, the dominant wave period in ice is significantly increased compared to corresponding open ocean waves. The present data can inform calibration of wave models in the rapidly evolving seasonal ice zone in the Sea of Okhotsk.</p>

A Path Analytic Model of the Relationship between Event Involvement and Sponsors Recall

2015 ◽  
pp. 66-81
Author(s):  
Anish Yousaf ◽  
Anil Gupta
Keyword(s):  
Emerging Economies ◽  
Analytic Model ◽  
Premier League ◽  
Gender Characteristics ◽  
Path Analytic ◽  
The Impact ◽  
The Relationship ◽  
Highly Involved

This chapter empirically examines the importance of involvement in accurate sponsor identification in Indian Premier League (IPL) and explores the involvement differences between gender characteristics. The study aims to: (1) validate Kyle et al. (2004) involvement scale in context of IPL, (2) examine involvement differences according to gender characteristics, and (3) explore the impact of individuals' involvement on their ability to recall sponsors. Findings of the study reveal that involvement differences do exist among gender characteristics and individuals' levels of involvement significantly impact their ability to recall sponsors, as it was found that highly involved individuals recall more sponsors. These findings have implications for marketers investing in sponsorship-linked marketing in emerging economies.

scholarly journals ANALISIS PENGARUH INTERKONEKSI DISTRIBUTED GENERATION (PLTSA SUWUNG) TERHADAP RUGI-RUGI DAYA DAN KEANDALAN PADA PENYULANG SERANGAN

2015 ◽  
Vol 14 (2) ◽  
pp. 27
Author(s):  
I Made Gusmara Nusaman ◽  
I Wayan Sukerayasa ◽  
Rukmi Sari Hartati
Keyword(s):  
Distributed Generation ◽  
Power Plants ◽  
Flow Analysis ◽  
Ocean Waves ◽  
Load Flow ◽  
Ocean Current ◽  
Total Power ◽  
Small Scale ◽  
Renewable Energy Resources ◽  
Power Losses

The distributed generation technology or in this case abbreviated DG is a kind of power plants with small scale which prioritizes the utilization of renewable energy resources such as wind, water, solar, geothermal, ocean waves (Wave Energy), ocean currents (Ocean Current Energy), biomass, and biogass to produce the electrical energy with range of power generation between 1 kW-10 MW. One of the DG in Bali and still in operation is the garbage power plant which located in Suwung, South Denpasar. An analysis has been done using load flow analysis and reliability assessment to determine the effect of DG interconnection against the power losses and the level of reliability on the Serangan feeder. Based on the research that has been done, DG intercon-nection on the Serangan feeder decrease the power losses and increase the reliability and it can visible from the acquisition of SAIFI and SAIDI index which decreased. The best location of DG interconnection to get low of the power losses and the high level of reliability is at 97% from the total length of the feeder. At that location the power losses is decrease as big as 4.5 kW or 11.25% of the total power lossess without the DG interconnection and decrease of the SAIFI and SAIDI index respectively to 0.1 failure/customers/year and 1.4150 hour/ customer/year

scholarly journals VISIR-1.b: ocean surface gravity waves and currents for energy-efficient navigation

2019 ◽  
Vol 12 (8) ◽  
pp. 3449-3480 ◽  
Author(s):  
Gianandrea Mannarini ◽  
Lorenzo Carelli
Keyword(s):  
Energy Efficiency ◽  
Gravity Waves ◽  
Ocean Surface ◽  
Surface Gravity ◽  
Ocean Current ◽  
Ship Routing ◽  
Surface Gravity Waves ◽  
Waves And Currents ◽  
The Impact

Abstract. The latest development of the ship-routing model published in Mannarini et al. (2016a) is VISIR-1.b, which is presented here. The new version of the model targets large ocean-going vessels by considering both ocean surface gravity waves and currents. To effectively analyse currents in a graph-search method, new equations are derived and validated against an analytical benchmark. A case study in the Atlantic Ocean is presented, focussing on a route from the Chesapeake Bay to the Mediterranean Sea and vice versa. Ocean analysis fields from data-assimilative models (for both ocean state and hydrodynamics) are used. The impact of waves and currents on transatlantic crossings is assessed through mapping of the spatial variability in the tracks, an analysis of their kinematics, and their impact on the Energy Efficiency Operational Indicator (EEOI) of the International Maritime Organization. Sailing with or against the main ocean current is distinguished. The seasonal dependence of the EEOI savings is evaluated, and greater savings with a higher intra-monthly variability during winter crossings are indicated in the case study. The total monthly mean savings are between 2 % and 12 %, while the contribution of ocean currents is between 1 % and 4 %. Several other ocean routes are also considered, providing a pan-Atlantic scenario assessment of the potential gains in energy efficiency from optimal tracks, linking them to regional meteo-oceanographic features.

Higher Order Wave-Current Elevations in Deep Water

2011 ◽  
Author(s):  
Anne Katrine Bratland ◽  
Ragnvald Bo̸rresen ◽  
Per Ivar Barth Berntsen
Keyword(s):  
Deep Water ◽  
Higher Order ◽  
Irregular Waves ◽  
Ocean Current ◽  
Regular Waves ◽  
Third Order ◽  
Uniform Current ◽  
Current Interaction ◽  
The Waves ◽  
Wave Elevations

Wave-current interaction refers to the interaction between surface gravity waves and ocean current flow. This interaction implies an exchange of energy, i.e. both the waves and the current are affected. The present paper describes the calculation of wave elevations in higher order unidirectional, irregular waves with a uniform current in deep water. Results for regular waves are compared with those obtained for Stokes second and third order waves with uniform current according to the method described by Fenton [1]. The results for higher order wave elevations in irregular waves have been compared with waves and current generated in a model test basin and reasonable agreement has been found.

scholarly journals Performance Evaluation of an IEEE 802.15.4 Wireless Sensor Network on a Coastal Environment

2017 ◽  
Vol 11 (1) ◽  
pp. 98
Author(s):  
Carlos Flores-Cortés ◽  
Raymundo Buenrostro-Mariscal ◽  
Antonio Gurrero-Ibañez ◽  
Fermín Estrada-González ◽  
Jesus Sandoval-Orozco
Keyword(s):  
Ieee 802.15.4 ◽  
Signal Strength ◽  
Ocean Waves ◽  
Coastal Environment ◽  
Wireless Sensor ◽  
Round Trip ◽  
Commercial Activities ◽  
Received Signal Strength Indication ◽  
The Impact ◽  
Round Trip Delay

Wireless Sensor Networks (WSNs) have an enormous potential for investigating oceanographic problems such as the impact of industrial, touristic and commercial activities in coastal areas, among others. However, ocean waves, fog, humidity and other environmental conditions make difficult communication between nodes. This paper presents an evaluation on-site of the performance of an IEEE 802.15.4 WSN. In particular, received signal strength indication, throughput, round trip delay time and the rate of efficiency are evaluated.  Different settings were tested and results shown which settings performed better on these environments.

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