Complex sounding of the ionosphere during the intense magnetic substorm

The magnetic substorm effects on the ionosphere and radio propagation conditions are discussed. The vertical and oblique ionospheric sounding data were used for the study. The characteristic features at high latitudes were revealed: the Es oblique layers appearance, their multilayer structure and diffuse F-formations as well as the EsMOF changes and multi-hop Es reflections. The processes in the ionosphere were qualitatively similar within 400 km distance southward from Sodankylä. The difference of the processes much more southward (2250 km far) where the reflection point of the mid-latitude radio path lies was revealed.