Rotation of wind direction with altitude as obtained from vapor-trail observations

Abstract

A sequence of four vapor‐trail wind observations taken over a 6‐hour period above Kauai, Hawaii, is presented. The wind observations, covering part or all of the 90‐ to 180‐km region, are shown, because they so closely corroborate specific features documented by other vapor‐trail experiments at other locations. These features include the rotation of direction with height, vertical wavelengths of proper magnitude, and downward phase propagation with time. These features are consistent with results expected from the motion of upward propagating waves. The wave period appears to be semidiurnal, but a diurnal period is not excluded.

Generation of mesoscale <I>F</I> layer structure and electric fields by the combined Perkins and <I>E<sub>s</sub></I> layer instabilities, in simulations

“…As argued below, the southward wind leads to southwestward propagation of frontal structures in the E s layer. On the other hand, the sense of the tidal rotation can sometimes be reversed (Smith, 1972), which would place the E s layer in a northward wind. A northward wind would result in northeastward propagation of frontal structures.…”