The use of solar wind measurements for the analysis and prediction of geomagnetic activity

Some aspects of using the E-parameter (Poynting's vector of the solar wind) for the analysis and prediction of geomagnetic activity are considered. It is demonstrated that the reliability of measurements of the solar wind is high for the large-scale events that cause magnetic storms. The probability of using doubtful data related to the solar wind increases in the analysis of magnetic substorms and can be as high as 50%. The epsilon -parameter can also be employed for the short-term qualitative prediction of geomagnetic activity from the solar wind measurements.