COMPARATIVE ANALYSIS OF DIFFERENCES IN THE MAIN GEOMAGNETIC INDICES ON THE DAYS OF QUIET AND DISTURBED EARTH’S MAGNETIC FIELD

Geomagnetic indices are used by researchers in helio-geophysics, heliobiology and space medicine. For planners of investigations aimed at studying the geomagnetic effects on humans it is critical to choose proper indices for accurate data acquisition. To obtain information on intercorrelations, differences and/or identity of the geomagnetic indices on the days of quiet and disturbed magnetic field, we made analysis of public records provided by Russian and international geo-monitoring centers. Also, database of the GEFEST monitoring project was used. The results showed that all geo-indices intercorrelated only on the days of the quiet or disturbed field (r is in the interval between 0.73 and 0.97). There was no overlap of correlations registered on different days. DST-index had strong correlations with other indices (r is in the interval between 0.77 and 0.93) on the days of disturbed field only. Significant differences were found after comparison of local and planetary, and regional and planetary indices registered at one and the same time. For planned investigations it is important to select a proper type of index that will characterize GM disturbance in accordance with goals of an investigation. We believe that indices measured in a geographic region are the best for assessment of the geomagnetic field effects on humans.