Flow and mixing near a glacier tongue: a pilot study

A 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 a...

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Bibliographic Details
Published in:Ocean Science
Main Authors: Stevens, CL, Stewart, CL, Robinson, NJ, Williams, MJM, Haskell, TG
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Gesellchaft MHB; The Authors 2011
Subjects:
Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
Oceanography
MCMURDO-SOUND
SEA-ICE
PLATELET ICE
ANTARCTICA
PARAMETERIZATION
MICROSTRUCTURE
DISSIPATION
NUMBER
FLUXES
McMurdo Sound
Antarc*
Antarctica
Sea ice
Online Access:http://hdl.handle.net/2292/19138
https://doi.org/10.5194/os-7-293-2011
Description
Summary:A 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) m(2) s(-3), around three decades greater than local background levels. This is in keeping with estimates of the gradient Richardson Number which dropped to similar 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.

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