Prediction of the space weather disturbances

Abstract

Little-known mechanisms of formation of /spl Delta/f/sub 0/F2 ionospheric positive peaks during 6-8 hours before T/sub 0/ (onset of the expansion phase of an isolated substorm) are considered in details. They are connected with an impact of the high-speed particles in the foreshock region of solar wind on the Earth's magnetosphere. Here, the main feature is an entirely different channel of solar wind penetration in the ionosphere. This channel realizes the transmission of energy through the entry layer into the inner magnetosphere and through the day-time cusp into the ionosphere as distinct from the classical channel which describes all three substorm phases, namely, through the magnetospheric tail, plasma sheet and auroral ionosphere. The ionospheric effect due to a cusp and magnetospheric entry layer manifests most likely at high latitudes (polar cap and auroral oval). Enhancement of /spl Delta/f/sub 0/F2 values can be used for prediction of the near Earth disturbance onset and accordingly of space weather problems concerning operation of cosmic apparatus and systems of communications, orientation, and navigation.