Abstract
A theoretical model of the spatial spectrum of horizontally distributed thermal microstructure is developed for anisotropic turbulence. A two-term power law representation is obtained for the horizontal temperature spectrum which includes the influence of buoyancy and convective forces and which applies in a wavenumber range between internal waves and dissipation. The form of the spectrum is TBC(k) = A1k−5/3+A2k−3 where BC refers to bouyancy-convective and k is wavenumber. The coefficients A1 and A2 are functions of depth through their dependence on the total rate of energy dissipation, the total rate of dissipation of temperature variance and the Brunt-Väisälä frequency. Companion experimental data from 54 long horizontal tows at depths between 97.5 and 1454 m at two widely separated stations near Bermuda support the theoretical predictions.
