EQUATORIAL IONOSPHERIC F REGION IRREGULARITILES AND ITS CHARACTERISTICS AT EAST ASIA SECTOR:A REVIEW

Equatorial ionospheric F region irregularities show different features at various longitudes and latitudes. Still, their diurnal,seasonal and solar cycle variations are local related. Irregularities are primarily nighttime effects with two diverse kinds: bubble irregularity associated with range spread F and bottomside sinusoidal irregularity related with frequency spread F. The generation development and decay processes of these irregularities spread are of leading values in the understanding of the basic features of low latitude ionospheric physical phenomena.The bubble irregularity and sometimes BSS irregularity result in the strong VHF/UHF scintillations which cause many problems in satellite communication. In this review paper we will outline recent progresses of irrdgularity studies in both theoretical researches and experimental ovservations with much attention paid to the east Asia sector.