Acoustically and visually tracked drogue measurements of nearsurface water velocities in Lake Huron, plus observations of a coastal upwelling
MetadataShow full item record
LocationLake Huron (Mich. and Ont.)
KeywordOcean currents; Oceanographic buoys; Acoustic drogue measurements; Nearsurface water measurement
During July and August of 1980 our research group measured nearsurface water velocities near the eastern coast of Lake Huron by tracking drogues using acoustic travel time and compass sighting techniques. The velocity fields appeared to consist of two components. These have been termed: a sub-current, which varied slowly with depth (compared to the deepest drogue depth of 5.2 m) and, in most cases, was apparently in geostrophic balance with the cross shore pressure gradient; and, a surface layer-current (defined by the relative velocity from deeper to shallower drogues) which decayed rapidly with depth and was directed nearly parallel with the wind and waves. There was no discernable relationship between wind speed and relative velocity. There was, however, a direct dependence of relative velocity with estimated surface roughness, suggesting that Stokes drift may have been primarily responsible for the shear. The magnitudes of the observed relative velocities were approximately equal to Stokes drift magnitudes calculated from representative wave energy spectra. Also reported are measurements of current and temperature structure made prior to and following a coastal upwelling.
Suggested CitationTechnical Report: Churchill, James H., Pade, Bert H.-G., "Acoustically and visually tracked drogue measurements of nearsurface water velocities in Lake Huron, plus observations of a coastal upwelling", 1981-10, DOI:10.1575/1912/10288, https://hdl.handle.net/1912/10288
Showing items related by title, author, creator and subject.
Water velocity measurement from near surface to 110 m depth at deepwater dumpsite #106 using acoustically tracked drogues and conventional current meters Churchill, James H.; Pade, Bert H.-G.; Peal, Kenneth R. (Woods Hole Oceanographic Institution, 1981-02)A system has been developed recently at W.H.O.I. for tracking nearsurface drogues equipped with sonobuoys using an acoustic navigation system. Surface and submerged drogues of mean depths ranging from 0.15 m to 4.88 m ...
Churchill, James H.; Pade, Bert H.-G. (Woods Hole Oceanographic Institution, 1980-01)During July 16-19, 1979 currents in Cape Cod Bay from the very near surface to 1.8 m were measured by taking simultaneous bearings on submerged drogues from two anchored vessels. The error in drogue position as a function ...
Tracking near surface drogues using an acoustic travel time technique in shallow, highly stratified water : problems and observations Churchill, James H. (Woods Hole Oceanographic Institution, 1981-05)During July and August of 1980 near surface water velocities of Lake Huron were measured by tracking drogues, equipped with sonobuoys, using an acoustic travel time technique. Prior to these experiments difficulties associated ...