Structural diversity of the ionosphere at high and middle latitudes in the eastern and western hemispheres as observed by satellite radio tomography

Reconstructions of high- and midlatitude ionosphere applying low- and high-orbiting radio tomography (LORT and HORT) mrthods in different regions are analyzed. LORT reconstructions reflecting local (tens of kms) ionospheric features with various shapes, orientations, and localizations and large-scale (hundreds of kms) formations with regular and irregular structure are presented. HORT demonstrates morphological variety of plasma irregularities spanning hundreds to thousands km. Examples of multi- extrema structures, ionization spots (blobs, patches), variations in locations and depths of ionization troughs, quasi-wave perturbations, high-gradient ionization “walls” are presented. Ionospheric effects of precipitations are discussed. Qualitative comparison between RT reconstructions and DMSP particle flux data is conducted.