New Regional Geomagnetic Indices for the Russian Sector of the Geomagnetic Observation Network

It was proposed to introduce new regional geomagnetic indices SME-R and VAR characterizing the values of the geomagnetic field perturbation and its variability (i.e., dB/dt) in the Russian sector at auroral latitudes into space weather studies. The indices are calculated from data of the Russian magnetic stations at geomagnetic latitudes from 40° to 70°. We compared the unofficial and regional indices with the standard planetary indices during some magnetic storms of 2015. In addition to the official IAGA indices Dst/ SYM-H, AE, PC, modified and regional indices SME, PC-n, ULF, EI, Wp (Pi2) were considered. The analysis of these events showed that some auroral activations confidently distinguished by the SME index can be missed by the standard AE index. The discrepancy between the standard PC and the refined PC-n indices reaches 1 mV/m to 2 mV/m during strong perturbations. The variability of the magnetic field characterized by the VAR index is not uniquely related to the level of geomagnetic perturbation characterized by the AE or SME-R indices. The events considered show that the use of planetary indices to estimate regional space weather perturbations can lead to false conclusions. The database of standard, modified, and new regional indices for 2015 is freely available at the FTP site ftp://indexguest:[email protected]/ for testing.