Bottom boundary layer in south San Francisco Bay, California

Ralph T. Cheng; Jeffrey W. Gartner; Richard E. Smith

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USGS · 70161962

Bottom boundary layer in south San Francisco Bay, California

Ralph T. Cheng·Jeffrey W. Gartner·Richard E. Smith

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Abstract

Detailed velocity distributions within the benthic turbulent boundary layer were measured by a Broad Band Acoustic Doppler Current Profiler (BB-ADCP) in South San Francisco Bay, California. In "mode 5", the BB-ADCP was able to measure velocity in 5 cm increments. The validation of these measurements was achieved by comparing the BB-ADCP measurements with the velocities measured by a Narrow Band Acoustic Doppler Current Profiler (NB-ADCP) in close proximity. There were thirty-three (33) velocity time-series measured by the BB-ADCP beginning at 7 cm above bed and extending to 175 cm in water column for about two weeks. The velocities from locations at 7 cm and 12 cm above the bed were determined to be of lower accuracy, and they were not used in estimates of friction velocity, u.. The values of u. at 95% confidence level were determined with relative error less than 20%. The time-series of u. varied with velocity outside of the boundary layer, and responded to spring-neap tidal variations. Attempts to use acoustic backscatterance echo intensity to measure suspended sediment concentration showed prom ise, and merit consideration in future studies.

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Journal of Coastal Research Article

Source-reported bounding extent: 37.42906945530329° to 37.8271414168374° latitude; -122.40829467773436° to -121.91940307617188° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

Ralph T. Cheng, Jeffrey W. Gartner, Richard E. Smith. 1997. Bottom boundary layer in south San Francisco Bay, California. https://pubs.usgs.gov/publication/70161962

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