Dynamic model of ionospheric wind profiles

A statistical analysis of velocity, shear, and wavelength versus altitude has recently been reported for 70 wind profiles observed at midlatitudes between 90- and 150-km altitude. Hines had previously considered theoretically the characteristics of a rotating wind vector with energy supplied from below and viscous loss within the region. The present paper predicts profiles from this model with two assumptions: (1) the viscosity varies from ten-fold molecular viscosity at 90 km (because of turbulence) to its molecular value at all heights above 105 km, and (2) the time constant for supply of energy is semidiurnal. These two assumptions lead to altitude dependence of speed, shear, wavelength, and energy content and dissipation, which are substantially identical to those obtained by the statistical analysis.