The Quest for Kρ—Preliminary Results from Direct Measurements of Turbulent Fluxes in the Ocean

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  • 1 College of Oceanography, Oregon State University, Corvallis, Oregon
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Abstract

Simultaneous measurements of vertical velocity fluctuations, w′, and temperature fluctuations, T′, on scales of three-dimensional turbulence yield a direct measure of the turbulent heat flux, Jq. The scales contributing most significantly to Jq are tens of centimeters or about 10 times larger than the scales contributing to the turbulent kinetic energy dissipation for the data examined. A limited sample indicates that, instantaneously, Jq is almost as frequently positive (countergradient) as negative (downgradient). In contrast, instantaneous estimates of Jq from microstructure measurements of ε or χ are always, by definition, downgradient.

Abstract

Simultaneous measurements of vertical velocity fluctuations, w′, and temperature fluctuations, T′, on scales of three-dimensional turbulence yield a direct measure of the turbulent heat flux, Jq. The scales contributing most significantly to Jq are tens of centimeters or about 10 times larger than the scales contributing to the turbulent kinetic energy dissipation for the data examined. A limited sample indicates that, instantaneously, Jq is almost as frequently positive (countergradient) as negative (downgradient). In contrast, instantaneous estimates of Jq from microstructure measurements of ε or χ are always, by definition, downgradient.

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