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

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, J_q. The scales contributing most significantly to J_q 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, J_q is almost as frequently positive (countergradient) as negative (downgradient). In contrast, instantaneous estimates of J_q from microstructure measurements of ϵ or χ are always, by definition, downgradient.