Corpuscular Radiation and the Ionospheric Anomalies

ABSTRACT

No satisfactory explanations have been forthcoming so far, for explaining some of the well-known anomalies of the ionosphere, e.g. the longitude, the latitude, the winter and other anomalies of the F₂ layer or the continued existence of the F region at night especially in the polar regions during long winter months in the absence of any sunlight. Likewise, no satisfactory explanation has been available for the occurrence of spread F, sporadic E and its world-wide behaviour.

With the discovery of the radiation belts, it has now been established beyond any doubt that the earth is enveloped by charged particles of high energies and flux densities. Recent satellite observations have also shown that the upper atmospheric density profile shows important diurnal and sunspot cycle variations and tends to follow changes in geomagnetic activity. The well-known ionospheric anomalies are explained qualitatively on the basis of interaction between the high energy charged particles precipitating directly and, as a result of leakage from the radiation belts, into the earth's atmosphere. It is shown that like the F₂ layer, sporadic E also exhibits a profound degree of geomagnetic control. The apparent anomalies associated with the F₂ layer and sporadic E are shown to be inter-related due to an inverse correlation which seems to exist between the F₂ layer and sporadic E ionization as both owe their origin to the precipitation of corpuscular radiation into the terrestrial atmosphere.