Statistical characteristics of parameters of sporadic formations in the ionospheric E-region over East Siberia

摘要

Presented are the results of a statistical analysis of the ionospheric sounding data over Irkutsk for 1960-1996. It is shown that sporadic features of type "c" and "f" constitute a stationary process. That is, the lower part of the ionospheric E-region that includes the meteor zone develops a region in which the electron density and its variations are governed by two factors, the interaction or dominant influence of one of which leads to sporadic features of one type and to the decay of the other type. The former, steadily acting type is the prevailing wind regime of this ionospheric region, and the other type is the solar control having a predominant influence in summer. Also, the vertical structure of the horizontal wind has effect not on the formation of type "c" E_s but on its decay for the formation of type "1" E_s. Year-to-year variability of the dynamic wind regime dos not affect the number of type "c" E_s features and its frequency parameters.