Observing Finescale Oceanic Velocity Structure with an Autonomous Nortek Acoustic Doppler Current Profiler

Shcherbina, Andrey Y.; D’Asaro, Eric A.; Nylund, Sven

doi:10.1175/jtech-d-17-0108.1

Cited by 29 publications

(46 citation statements)

References 45 publications

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“…The instrument has a high sampling frequency (up to reach 16Hz depending of chosen configurations) as well as the ability to interleave between two acoustic measurement configurations during a single deployment. Thus, the signature instruments can obtain current velocity, turbulence, and wave data during the same deployment [35].…”

Section: Study Site and Data Collectionmentioning

confidence: 99%

Wave-Turbulence Decomposition Methods Applied to Tidal Energy Site Assessment

et al. 2020

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High levels of turbulence have been proven to substantially increase the blade loadings on tidal turbines, outlining the need of properly characterizing turbulence parameters in tidal energy sites. The presence of long surface gravity waves may cause a significant bias on the estimation of these parameters, which requires wave-turbulence decomposition methods that are currently missing from guidelines. Here, three techniques of decomposing wave and turbulence are tested: the stopband filter (SB), moving average filter (MA), and synchrosqueezing wavelet transform (SWT). The study site, Banks Strait, Tasmania, is a 16 km wide channel that presents high potential for tidal energy generation. Wave peak periods at the study site were found to vary mostly between 7 and 12 s, with maximum exceeding 15 s. Turbulence intensities (TI), turbulent kinetic energy (TKE), and integral scales are quantified. Our results indicate differences between the estimates obtained from each method. The MA highly underestimates turbulence, resulting in TI values which were nearly 50% lower than those obtained from other decomposition methods. While TI and TKE estimated from the SB and the SWT techniques are quite similar, integral length scales are considerably underestimated by the SB. These findings reveal that the SWT is a more reliable method because of the more accurate estimates of turbulence parameters and indicate the need of establishing guidelines which address wave-turbulence decomposition in tidal stream energy site assessments. Despite having shown to be quite a versatile technique, further investigation of its applicability in data from other prospective tidal energy sites is necessary to fully assess the generality of the SWT technique.

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Section: Study Site and Data Collectionmentioning

confidence: 99%

Wave-Turbulence Decomposition Methods Applied to Tidal Energy Site Assessment

et al. 2020

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“…At a typical float profiling speed of 2-5 cm s -1 and 1 Hz ADCP sampling rate, consecutive profiles largely overlap in depth, although over 10-20 minutes, a wider depth range is covered. At the same time, improved single-ping accuracy of HR measurements makes each profile individually meaningful and allows us to resolve time-space variability of small-scale turbulent velocities (Shcherbina et al, 2018). Visualization of the detailed structure of this variability with respect to real depth presents substantial challenges.…”

Section: Lagrangian Float Observationsmentioning

confidence: 99%

“…However, only approximate timing of the observations and intervals between them can be inferred from such a plot. If presentation of the actual timing is important, the standard display may be preferable, as in Shcherbina et al (2018).…”

Section: Lagrangian Float Observationsmentioning

confidence: 99%

Rain and Sun Create Slippery Layers in the Eastern Pacific Fresh Pool

Shcherbina

D’Asaro

Harcourt

2019

Oceanog

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“…While the Acoustic Doppler Current Profiler (ADCP) was deployed for two days in the southern Ie Meulee beside the port's jetty which positioned at the 9 meters depth (Figure 1). ADCP will record the vertical current profile in each layer (every 1 m toward the surface with blanking distance of 0.5 m) (Shcherbina et al, 2018).…”

Section: Methodsmentioning

confidence: 99%

Velocity Components of Currents and Transport Mechanism in the Ie Meulee Waters, Weh Island, Indonesia

Wisha

Wang

2019

J. Kel. Trop.

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Weh Island has become an area of significance in which many developments are ongoing. Ie Meulee region was one of the developed areas where a new fishing port has been built which may impact to coastal instability. This study aims to determine the sea currents regime in the Ie Meulee waters and its relation to the transport mechanism. Field survey was conducted on March 2017 by which Tide Gauge and ADCP have installed within and without the port, respectively. Flow model was also simulated depicting current patterns for four extreme tidal conditions. The elliptical form of zonal and meridional components of current proves that the tidal current role takes place. The speed of tidal current ranged from 0-0.42 m/s and 0-0.85 m/s in the bottom and surface, respectively. The most prominent positive value of current components indicates that the transport mechanism is primarily surface ward during both ebb and flood tides. Reflection and diffraction are identified in the simulation testifying that the emergence of the fishing port has changed the hydrodynamic features. We also founded that the low-speed currents induced sediment settling within the jetty, so that it is essential to conduct regular dredging and bathymetry survey in the surrounding port.

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Observing Finescale Oceanic Velocity Structure with an Autonomous Nortek Acoustic Doppler Current Profiler

Cited by 29 publications

References 45 publications

Wave-Turbulence Decomposition Methods Applied to Tidal Energy Site Assessment

Wave-Turbulence Decomposition Methods Applied to Tidal Energy Site Assessment

Rain and Sun Create Slippery Layers in the Eastern Pacific Fresh Pool

Velocity Components of Currents and Transport Mechanism in the Ie Meulee Waters, Weh Island, Indonesia

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