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Chris Bassett

Senior Mechanical Engineer

Email

cbassett@uw.edu

Phone

206-543-1263

Research Interests

Passive noise studies, acoustic scattering, sea ice, marine renewable energy, fisheries acoustics, anthropogenic noise

Biosketch

Chris applies passive and active acoustic techniques to a variety of underwater applications. Some of his previous and ongoing studies include fisheries acoustics; high-frequency scattering from sea ice, crude oil, and physical oceanographic processes; measurements of anthropogenic noise; and ambient noise studies.

Department Affiliation

Ocean Engineering

Education

B.S. Mechanical Engineering, University of Minnesota, 2007

M.S. Mechanical Engineering, University of Washington, 2010

Ph.D. Mechanical Engineering, University of Washington, 2013

Videos

Connecting to the Ocean's Power: Marine Energy Research at APL-UW

The U.S. Navy's support of the University of Washington, one of the nation's preeminent research universities, leverages APL-UW capabilities with university academic expertise to address a wide range of topics in marine energy through experimentation and evaluation in laboratory settings and field deployments of prototype systems.
Companion to the technical report, APL-UW TR 2301.

5 Jul 2023

Turbulence Generated by Tides in the Canal de Chacao, Chile

At a proposed tidal energy conversion site in southern Chile, APL-UW researchers are measuring the magnitude and scales of turbulence, both to aid in the design of turbines for the site and to understand the fundamental dynamics of flows through the channel.

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7 Mar 2013

Principal Investigator Jim Thomson chronicled all phases of the Chilean experiment through posts to the New York Times 'Scientist at Work' blog.

Sound Sounds: Listening to the Undersea Noise in Puget Sound

Doctoral student researcher Chris Bassett is analyzing a long time series of ambient noise data from Puget Sound. Vessel traffic is the most significant noise source, but breaking waves, precipitation, biology, and sediment moving on the seabed are other common underwater noise sources. The research is being pursued in conjunction with a program to assess the environmental impacts from a tidal energy conversion system placed on the seafloor.

13 Mar 2012

Publications

2000-present and while at APL-UW

Statistics of bubble plumes generated by breaking surface waves

Derakhti, M., J. Thomson, C. Bassett, M. Malila, and J.T. Kirby, "Statistics of bubble plumes generated by breaking surface waves," J. Geophys. Res., 129, doi:10.1029/2023JC019753, 2024.

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17 May 2024

We examine the dependence of the penetration depth and fractional surface area (e.g., whitecap coverage) of bubble plumes generated by breaking surface waves on various wind and wave parameters over a wide range of sea state conditions in the North Pacific Ocean, including storms with sustained winds up to 22 m s-1 and significant wave heights up to 10 m. Our observations include arrays of freely drifting SWIFT buoys together with shipboard systems, which enabled concurrent high-resolution measurements of wind, waves, bubble plumes, and turbulence. We estimate bubble plume penetration depth from echograms extending to depths of more than 30 m in a surface-following reference frame collected by downward-looking echosounders integrated onboard the buoys. Our observations indicate that mean and maximum bubble plume penetration depths exceed 10 and 30 m beneath the surface during high winds, respectively, with plume residence times of many wave periods. They also establish strong correlations between bubble plume depths and wind speeds, spectral wave steepness, and whitecap coverage. Interestingly, we observe a robust linear correlation between plume depths, when scaled by the total significant wave height, and the inverse of wave age. However, scaled plume depths exhibit non-monotonic variations with increasing wind speeds. Additionally, we explore the dependencies of the combined observations on various non-dimensional predictors used for whitecap coverage estimation. This study provides the first field evidence of a direct relation between bubble plume penetration depth and whitecap coverage, suggesting that the volume of bubble plumes could be estimated by remote sensing.

Motion tracking of fish and bubble clouds in synthetic aperture sonar data

Marston, T.M., B.R. Hall, C. Bassett, D.S. Plotnick, and A.N. Kidwell, "Motion tracking of fish and bubble clouds in synthetic aperture sonar data," J. Acoustic. Soc. Am., 155, 2181-2191, doi:10.1121/10.0025384, 2024.

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21 Mar 2024

Data captured by a Synthetic Aperture Sonar (SAS) near Mobile Bay during the 2021 Undersea Remote Sensing experiment funded by the Office of Naval Research reveals near surface bubble clouds from wave breaking events and a large aggregation of fish. Tools developed for using SAS data to image hydrodynamic features in the water column were applied to observations of the bubble clouds and fish aggregation. Combining imagery and height data captured by the sonar array with a detection and tracking algorithm enables the trajectories, velocities, and behavior of fish in the aggregation to be observed. Fitting the velocity and height data of the tracked objects to a Gaussian mixture model and performing cluster analysis enables an estimate of the near-surface ambient velocity via observation of the movement of the bubble traces and the general direction of motion of the fish aggregation. We find that the velocity traces associated with bubbles are consistent with ambient currents as opposed to the direction of propagating wave crests while velocities of fish indicate relatively large, pelagic species.

The structure and dynamics of an estuarine tidal intrusion front

Geyer, W.R., D.K. Ralston, M.C. Haller, C. Bassett, and D. Honegger, "The structure and dynamics of an estuarine tidal intrusion front," J. Geophys. Res., 129, doi:10.1029/2023JC020371, 2024.

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1 Feb 2024

Tidal intrusion fronts are surface convergences that occur at constrictions in estuaries during the flood tide, separating incoming higher-salinity water from lower-salinity, stratified estuarine water. Previous observations of tidal intrusion fronts describe a V-shaped planform, with the apex of the V pointing into the estuary, however the significance of this structure has not been previously explained. Observations near the mouth of the James River estuary during the flood tide reveal the development of a quasi-steady, V-shaped front. Considering a reference frame oriented normal to the front, the velocity and density structure are consistent with gravity-current dynamics, but the oblique orientation of the front relative to the impinging flow indicates strong, along-front shear, which results from vorticity produced by flow separation at the lateral boundaries as well as topographic torque from upstream. The combination of convergence and along-front shear leads to enhanced mixing, as revealed by acoustic backscatter images of shear instability and persistent subcritical gradient Richardson number in the frontal zone. Oblique fronts such as this tidal intrusion front are common features of estuaries, and they play an important role in vertical exchange due to subduction and mixing of surface water.

More Publications

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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