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...
Published in: | Ocean Science |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Gesellchaft MHB; The Authors
2011
|
Subjects: | |
Online Access: | http://hdl.handle.net/2292/19138 https://doi.org/10.5194/os-7-293-2011 |
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. |
---|