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TitleFlow and mixing near a glacier tongue: A pilot study
Publication TypeJournal Article
Year of Publication2011
AuthorsStevens, C.L., Stewart C.L., Robinson N.J., Williams M.J.M., and Haskell T.G.
JournalOcean Science
Pagination293 - 304
Date Published2011
ISSN18120784 (ISSN)
KeywordsAcoustic Doppler Current Profiler, background level, Energy dissipation, flow velocity, glacier, hydrodynamics, Microstructure, Mixing, Richardson number, shear, velocity profile
AbstractA glacier tongue floating in the coastal ocean presents a significant obstacle to the local flow and so influences oceanic mixing and transport processes. Here acoustic Doppler current profiler and shear microstructure observations very near to a glacier tongue side-wall capture flow accelerations and associated mixing. Flow speeds reached around 40 cm s-1, twice that of the ambient tidal flow amplitude, and generated vertical velocity shear squared as large as 10-5 s-2. During the time of maximum flow, turbulent energy dissipation rates reached 10-5 m2 s-3, around three decades greater than local background levels. This is in keeping with estimates of the gradient Richardson Number which dropped to ∼1 during maximum flow. Associated vertical diffusivities estimated from the shear microstructure results were substantial, reflecting the influence of the glacier on velocity gradients. © Author(s) 2011.

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