Flow and mixing near a glacier tongue: A pilot study

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TitleFlow and mixing near a glacier tongue: A pilot studyAbstractA 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. Copyright Author(s) 2011.AcknowledgementsThe authors wish to thank Pat Langhorne, Andy Mahoney, Alex Gough, Robin Robertson, Inga Smith and Melissa Bowen for useful discussions. Brett Grant, Stephane Popinet, David Plew, Brian Stait and Peter Gerring assisted with field work. Laurie Padman and two anonymous reviewers provided highly constructive criticism on the Ocean Science Discussion version of this manuscript. Satellite imagery is courtesy of NASA. Funding and support were provided by The New Zealand Royal Society administered Marsden Fund, Antarctica New Zealand (Events K131/K132) and the New Zealand Foundation for Research Science and Technology (Contract C01X0701). This paper is dedicated to the memory of Don Lewis

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1st AuthorStevens, C.AuthorStevens, C.Stewart, C.Robinson, N.Williams, M.Haskell, T.Year2011JournalOcean ScienceVolume7Number3Pages293-304DOI10.5194/os-7-293-2011URLhttps://www.scopus.com/inward/recor.....36cc35c975d0c61e6fdcb7b13KeywordsAcoustic Doppler Current Profilerbackground levelenergy dissipationflow velocityglacierhydrodynamicsmicrostructuremixingRichardson numbershearvelocity profile, rank5

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TypeArticleCitationStevens, C., Stewart, C., Robinson, N., Williams, M. and Haskell, T. (2011). Flow and mixing near a glacier tongue: A pilot study. Ocean Science, 7(3): 293-304IdentifierStevens2011Relevancerank5

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Stevens, C.

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