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- Author or Editor: Jim Gunson x
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Abstract
From in situ measurements taken over several sea-breeze cycles off a beach in southwest (SW) Australia, the evolution of the one-dimensional spectrum of wave energy is observed to have a distinctive spectral shape. During the land-breeze phase of the cycle, lower rates of dissipation of wave energy are seen at high frequencies compared to midrange frequencies above the remnant wind-sea peak. A simulation of waves was performed using the Simulating Waves Nearshore (SWAN) model and produced the same spectral evolution, by generating longshore modes, as seen in the observations. The performance of whitecapping schemes available in SWAN was assessed, and the Alves–Banner scheme was found to best simulate the observed growth and decay of the wave spectra. During the onshore phase of the sea-breeze cycle, local wave growth is duration limited, and during the offshore land-breeze phase, wave growth is fetch limited. From an examination of the modeled two-dimensional spectra it is found that quadruplet interactions play a key role in spreading high-frequency wave energy in frequency and direction space.
Abstract
From in situ measurements taken over several sea-breeze cycles off a beach in southwest (SW) Australia, the evolution of the one-dimensional spectrum of wave energy is observed to have a distinctive spectral shape. During the land-breeze phase of the cycle, lower rates of dissipation of wave energy are seen at high frequencies compared to midrange frequencies above the remnant wind-sea peak. A simulation of waves was performed using the Simulating Waves Nearshore (SWAN) model and produced the same spectral evolution, by generating longshore modes, as seen in the observations. The performance of whitecapping schemes available in SWAN was assessed, and the Alves–Banner scheme was found to best simulate the observed growth and decay of the wave spectra. During the onshore phase of the sea-breeze cycle, local wave growth is duration limited, and during the offshore land-breeze phase, wave growth is fetch limited. From an examination of the modeled two-dimensional spectra it is found that quadruplet interactions play a key role in spreading high-frequency wave energy in frequency and direction space.
Abstract
The Australian marine research, industry, and stakeholder community has recently undertaken an extensive collaborative process to identify the highest national priorities for wind-waves research. This was undertaken under the auspices of the Forum for Operational Oceanography Surface Waves Working Group. The main steps in the process were first, soliciting possible research questions from the community via an online survey; second, reviewing the questions at a face-to-face workshop; and third, online ranking of the research questions by individuals. This process resulted in 15 identified priorities, covering research activities and the development of infrastructure. The top five priorities are 1) enhanced and updated nearshore and coastal bathymetry; 2) improved understanding of extreme sea states; 3) maintain and enhance the in situ buoy network; 4) improved data access and sharing; and 5) ensemble and probabilistic wave modeling and forecasting. In this paper, each of the 15 priorities is discussed in detail, providing insight into why each priority is important, and the current state of the art, both nationally and internationally, where relevant. While this process has been driven by Australian needs, it is likely that the results will be relevant to other marine-focused nations.
Abstract
The Australian marine research, industry, and stakeholder community has recently undertaken an extensive collaborative process to identify the highest national priorities for wind-waves research. This was undertaken under the auspices of the Forum for Operational Oceanography Surface Waves Working Group. The main steps in the process were first, soliciting possible research questions from the community via an online survey; second, reviewing the questions at a face-to-face workshop; and third, online ranking of the research questions by individuals. This process resulted in 15 identified priorities, covering research activities and the development of infrastructure. The top five priorities are 1) enhanced and updated nearshore and coastal bathymetry; 2) improved understanding of extreme sea states; 3) maintain and enhance the in situ buoy network; 4) improved data access and sharing; and 5) ensemble and probabilistic wave modeling and forecasting. In this paper, each of the 15 priorities is discussed in detail, providing insight into why each priority is important, and the current state of the art, both nationally and internationally, where relevant. While this process has been driven by Australian needs, it is likely that the results will be relevant to other marine-focused nations.
