Dissipation and Diffusion by Turbulence and Irregular Winds near 100 km

Abstract

A review is given of some recent measurements of the following energy balance parameters in the 90–110 km height region: ε0, the viscous dissipation of kinetic energy by shears in the mean winds; εd, the viscous dissipation of kinetic energy by shears in the turbulent winds; εs, the transfer of kinetic energy from the mean motion to the turbulent motion; εg, the transfer of turbulent kinetic energy to potential energy by buoyancy action; and εw, the rate of dissipation of wave energy of tides and irregular winds interpreted as gravity waves. Some measurements of the growth rates of globular structure on chemical release clouds and the growth rate of interglobular distances are presented. These data indicate that the diffusion mechanism is a mixture of the 〈v2〉t2 variation expected for the diffusion of a point from its initial position with the εdt3 variation expected for the variation of the separation between pairs of points.