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Read Full Article (file size: 355708 bytes) Cited by
GEOPHYSICAL RESEARCH LETTERS,
VOL. 35,
L09606,
doi:10.1029/2008GL033407,
2008
Global energy dissipation rate of deep-ocean low-frequency flows by quadratic bottom boundary layer drag: Computations from
current-meter data
Ayon Sen
Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA Westwood High School, Austin, Texas, USA
Robert B. Scott
Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA
Brian K. Arbic
Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA
Abstract
The global energy dissipation rate of deep-ocean low-frequency flows by quadratic bottom boundary layer drag is estimated
in three ways. First, an average over the dissipations computed from the near-bottom velocities recorded by 290 moored current
meters is multiplied by the World Ocean area. Second, near-global maps of surface velocities derived from satellite altimetry
data are used to estimate the bias due to the sparse spatial coverage of the moorings. Third, a relationship between bottom
and surface flows, computed over the mooring locations, is used to estimate global maps of bottom flows from the surface data.
All three methods suggest that at least 0.2 TW of the wind-power input into geostrophic flows is dissipated in deep water
by quadratic bottom drag. Implications for the oceanic overturning circulation, and for oceanic mesoscale eddy dynamics, are
briefly discussed.
Received 24
January
2008;
accepted 1
April
2008;
published 9
May
2008.
Keywords: quadratic bottom drag;
dissipation;
ocean energy budget.
Index Terms: 4520 Oceanography: Physical: Eddies and mesoscale processes; 4512 Oceanography: Physical: Currents; 4532 Oceanography: Physical: General circulation (1218, 1222); 4576 Oceanography: Physical: Western boundary currents.
Read Full Article (file size: 355708 bytes) Cited by
Citation: Sen, A., R. B. Scott, and B. K. Arbic
(2008),
Global energy dissipation rate of deep-ocean low-frequency flows by quadratic bottom boundary layer drag: Computations from
current-meter data,
Geophys. Res. Lett.,
35,
L09606,
doi:10.1029/2008GL033407.
Copyright 2008 by the American Geophysical Union.
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