scholarly journals WAVE AND SEAFLOOR SPECTRA PREDICTIONS WITH THE COUPLED SWAN-NSEA MODELING SYSTEM

2020 ◽  
pp. 57
Author(s):  
Allison Penko ◽  
Erick Rogers ◽  
Joseph Calantoni
Keyword(s):  
Underwater Acoustics ◽  
Roughness Parameter ◽  
Wave Model ◽  
Wave Spectra ◽  
Dynamic Feedback ◽  
Layer Model ◽  
Sediment Wave ◽  
Coastal Morphology ◽  
Wave Forcing ◽  
Biologic Activity

The existence and evolution of bedforms on the seafloor have significant effects in the areas of oceanography, marine geophysics, and underwater acoustics including the transport of sediment, wave energy attenuation, and seabed sonar scattering and penetration. Here, we present a wave-seafloor modeling system that couples a spectral seafloor boundary layer model (NSEA) with an operational wave model (SWAN) that includes the dynamic feedback between the predicted wave spectra and the wave generated bedforms on the seafloor through a bottom roughness parameter. NSEA is a seafloor spectral model that uses hydrodynamic input forcing forecasted by the wave model SWAN to predict the evolving seafloor spectra given a sediment grain diameter and an estimation of the biologic activity. The system can be used to determine the spatially and temporally varying bottom roughness under given wave forcing important for coastal morphology and acoustic applications.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/u66k6lZbEbw

scholarly journals Influence of Time and Frequency Domain Wave Forcing on the Power Estimation of a Wave Energy Converter Array

2020 ◽  
Vol 8 (3) ◽  
pp. 171
Author(s):  
Fadia Ticona Rollano ◽  
Thanh Toan Tran ◽  
Yi-Hsiang Yu ◽  
Gabriel García-Medina ◽  
Zhaoqing Yang
Keyword(s):  
Power Systems ◽  
Wave Energy ◽  
Time Domain ◽  
Power Output ◽  
Wave Model ◽  
Phase Information ◽  
Wave Forcing ◽  
Marine Renewable Energy ◽  
Wave Energy Converters ◽  
Averaged Model

Industry-specific tools for analyzing and optimizing the design of wave energy converters (WECs) and associated power systems are essential to advancing marine renewable energy. This study aims to quantify the influence of phase information on the device power output of a virtual WEC array. We run the phase-resolving wave model FUNWAVE-TVD (Total Variation Diminishing) to generate directional waves at the PacWave South site offshore from Newport, Oregon, where future WECs are expected to be installed for testing. The two broad cases presented correspond to mean wave climates during warm months (March–August) and cold months (September–February). FUNWAVE-TVD time series of sea-surface elevation are then used in WEC-Sim, a time domain numerical model, to simulate the hydrodynamic response of each device in the array and estimate their power output. For comparison, WEC-Sim is also run with wave energy spectra calculated from the FUNWAVE-TVD simulations, which do not retain phase information, and with wave spectra computed using the phase-averaged model Simulating WAves Nearshore (SWAN). The use of spectral data in WEC-Sim requires a conversion from frequency to time domain by means of random superposition of wave components, which are not necessarily consistent because of the linear assumption implicit in this method. Thus, power response is characterized by multiple realizations of the wave climates.

Assimilation of ERS SAR wave spectra in an operational wave model

1998 ◽  
Vol 103 (C4) ◽  
pp. 7887-7900 ◽  
Author(s):  
Lars-Anders Breivik ◽  
Magnar Reistad ◽  
Harald Schyberg ◽  
Jens Sunde ◽  
Harald E. Krogstad ◽  
...  
Keyword(s):  
Wave Model ◽  
Wave Spectra

scholarly journals Assimilation of decomposed in-situ directional wave spectra into a numerical wave model on typhoon wave

2013 ◽  
Vol 1 (4) ◽  
pp. 3967-3989
Author(s):  
Y. M. Fan ◽  
H. Günther ◽  
C. C. Kao ◽  
B. C. Lee
Keyword(s):  
Data Assimilation ◽  
Forecast Accuracy ◽  
Wave Model ◽  
Sequential Data ◽  
Wave Spectra ◽  
Typhoon Wave ◽  
Independent Observations ◽  
Directional Wave ◽  
Numerical Wave

Abstract. The purpose of this study was to enhance the accuracy of numerical wave forecasts through data assimilation during typhoon period. A sequential data assimilation scheme was modified to enable its use with partitions of directional wave spectra. The performance of the system was investigated with respect to operational applications specifically for typhoon wave. Two typhoons that occurred in 2006 around Taiwan (Kaemi and Shanshan) were used for this case study. The proposed data assimilation method increased the forecast accuracy in terms of wave parameters, such as wave height and period. After assimilation, the shapes of directional spectra were much closer to those reported from independent observations.

A Mixed Layer Model with Surface Wave Forcing.

1997 ◽  
Author(s):  
Albert J. Plueddemann ◽  
Robert A. Weller ◽  
James F. Price
Keyword(s):  
Surface Wave ◽  
Mixed Layer ◽  
Layer Model ◽  
Wave Forcing ◽  
Mixed Layer Model

WAVERYS : A CMEMS global wave reanalysis during the altimetry period

2020 ◽  
Author(s):  
Stephane Law Chune ◽  
Lotfi Aouf ◽  
Alice Dalphinet ◽  
Bruno Levier ◽  
Yann Drillet
Keyword(s):  
Large Scale ◽  
Surface Current ◽  
Wave Model ◽  
Grid Resolution ◽  
Wave System ◽  
Wave Spectra ◽  
Ocean Reanalysis ◽  
Wave Data ◽  
Directional Wave ◽  
Wave Reanalysis

<p><strong>As part of the Copernicus Marine Core service, WAVERYS is the multi-year wave reanalysis that aims to provide global wave data with a grid resolution of 1/5°. The wave reanalysis covers the period of 1993-2018 and provides 3-hourly classical integrated wave parameters describing the sea state at the ocean surface. The wave model used is the V4 version of the model MFWAM, which is driven by atmospheric forcing (winds and ice fraction) from ECMWF ERA5 reanalysis. This latter has showed a significant improvement regarding to the previous reanalysis ERA-Interim. WAVERYS includes the assimilation of altimeters wave data available during the period starting from Topex-Poseidon until Sentinel-3A missions. Directional wave spectra from Synthetic Aperture Radar (SAR) of Sentinel-1A and 1B missions are also assimilated. This is the first time that such directional wave spectra are used in a global wave reanalysis.</strong></p><p><strong>Further, WAVERYS uses a 3 hour surface current forcing provided by ocean reanalysis GLORYS12 implemented by Mercator-Ocean in the frame of Copernicus Marine Service with a grid resolution of 1/12°. The wave reanalysis is high skilled for ocean regions with dominant wave-currents interactions. Preliminary validation tests have shown improvement by 15% in scatter index for large scale high currents areas. This paper will give detailed characteristics of the wave system and will insist on the benefits of taking into account ocean currents and a physics calibrated for realistic swell propagation.</strong></p><p> </p>

scholarly journals OBSERVATIONS OF HORIZONTAL AND VERTICAL SEDIMENT FLUXES ON A SANDBAR IN THE SUSPENDED AND SHEET FLOW LAYERS

2018 ◽  
pp. 30
Author(s):  
Ryan S. Mieras ◽  
Jack A. Puleo ◽  
Dylan Anderson ◽  
Daniel T. Cox ◽  
Tian-Jian Hsu ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Surf Zone ◽  
Breaking Waves ◽  
Suspended Load ◽  
Bed Load ◽  
Sheet Flow ◽  
Coastal Morphology ◽  
Sediment Fluxes ◽  
Wave Forcing ◽  
Transport Component

The majority of prior sandbar migration studies have been conducted from the morphological standpoint, whereby, (i) bathymetric profiles are recorded over periods of time ranging from days to decades, at frequencies ranging from hourly to yearly (Ruessink et al., 2003), and (ii) hydrodynamic observations typically consist of far-field wave and environmental conditions. Subsequent modeling efforts have generally focused on tuning parameters in the sediment transport formulations (suspended load and bed load) to maximize model skill in predicting observed beach profiles over time (Fernández-Mora et al., 2015; Hoefel and Elgar, 2003). However, little emphasis at the operational level has been placed on tuning coastal morphology models to the true relative contributions of the physical processes (e.g. suspended load, bed load and/or sheet flow) that drive the changing bathymetry. This is due, in part, to the lack of detailed sediment transport observations (field and lab) under realistic wave forcing conditions and spatially variable bathymetry. Such a modeling approach leads to the improper quantification (magnitude and/or direction) of each modeled sediment transport component under skewed-asymmetric and/or breaking waves, often observed in the surf zone. The present study aims to better understand the physical mechanisms responsible for driving cross-shore sediment transport over a sandbar by quantifying (a) the vertical exchange of sediment at the near-bed interface (i.e. pick-up layer), and (b) intra-wave horizontal sediment fluxes in the suspended load and sheet layers.

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