Potentialities and Limitations in Applying Geomagnetic Indices in the Problems of Monitoring Geomagnetically Induced Currents

The application of auroral and wave ultra-low-frequency indices for monitoring geomagnetically induced currents has been analyzed. The potentialities and limitations in the description of hourly average values inherent in geomagnetically induced currents at the Vykhodnoy auroral station through a linear regression relationship constructed based on the indices for a set interval of magnetic local time and season are considered. It has been demonstrated that a two-index approximation provides quite an adequate estimation of time corresponding to the most part current amplification peaks but leads to an underestimation of the strongest peaks. The estimation of geomagnetically induced currents based on the time derivative value of a magnetic field component, integral over a chain of stations is more accurate than its approximation with the use of geomagnetic indices.