Rocket studies of sporadic-E ionization and ionospheric winds

Simultaneous observations of positive ion density (by means of positive ion probes) and high-altitude winds (by scattering of sunlight in trails of alkali metal vapour) were made in three rocket firings at Hammaguir, Algeria in order to study the correlation of sporadic-E layers and high-altitude wind shears. On one occasion, a sporadic-E layer was found to occur at 95 km where the E-W component of the wind was zero and the wind shear was in the sense predicted by the theory of Whitehead. However, on two occasions, layers were also observed near 115 km where the E-W wind component was zero, but the wind shear was in the opposite sense. This appears to suggest that some modification of the theory is required.