Sporadic plasma perturbations in the E region of the terrestrial ionosphere

Abstract

Sometimes (sporadically) in the ionosphere, at the heights of the E region (altitudes of 90 - 140 km), a very dense (more than 106 electrons/ions per cubic centimeter) layer appears capable of effectively reflecting radio waves of sufficiently high frequencies and with very little absorption. The ES layer is usually very thin, several hundred meters, extended horizontally by hundreds of kilometers and are clouds of increased ionization of pancake-like form, consisting, as a rule, of long-lived metal ions, the time of its spreading in the presence of only ambipolar diffusion is tens of hours. During this time, the layer can shift horizontally due to neutral winds by several hundred kilometers.