Physical backgrounds and origin of the idea -- Concept of the PC index -- Unified procedure for on-line calculation of the 1-min PCN and PCS indices -- Validation of the unified procedure -- Differences in summer and winter PC indices and their physical reasons -- Response of PC index to sudden pulses in the solar wind dynamic pressure -- PC index as an indicator of the substorm development -- PC index as an indicator of the magnetic storm development -- PC index as an input to monitor the disturbances in the polar ionosphere -- Relationship between magnetic activity in the polar cap and atmospheric processes in the winter Antarctica -- Solar wind - magnetosphere coupling in the light of the PC dynamics.

This book demonstrates that the method, based on the ground polar cap magnetic observations is a reliable diagnosis of  the solar wind energy coming into the magnetosphere Method for the uninterruptive monitoring of the magnetosphere state (i.e. space weather). It shows that the solar wind energy pumping power, can be described by the PC growth rate, thus,  the magnetospheric substorms features are predetermined by the PC dynamics. Furthermore, it goes on to show that the beginning and ending of magnetic storms is predictable. The magnetic storm start only if the solar energy input into the magnetosphere exceeds a certain level and stops when the energy input turns out to be below this  level.