Global morphology of ionospheric scintillations.

A radio wave traversing the upper and lower atmosphere of the earth suffers a distortion of phase and amplitude. When it traverses drifting ionospheric irregularities, the radio wave experiences fading and phase fluctuation which vary widely with frequency, magnetic and solar activity, time of day, season, and latitude. This review has the objective to organize the experimental and theoretical studies which have been employed in an attempt to isolate the variables. Questions of global morphology are discussed along with scintillation examples, signal characteristics, frequency dependence, fading spectra, and geometrical considerations. Spread F and scintillations are considered, and equatorial scintillations are investigated. Attention is given to equatorial scintillations, middle-latitude scintillation, the high-latitude region, and an empirical model of global scintillation behavior.