Algorithm for Detecting an Extreme Solar Flare of September 6, 2017 from its Geomagnetic Precursors

Abstract

The efficiency of the previously developed algorithm for predicting extreme solar flares from their geomagnetic precursors has been tested on the example of a series of class X flares recorded on September 6, 2017. Over the past few years, these events of the solar flare activity are seen as the most intense. The algorithm consists in comparing the total histograms of the normalized number of synchronization moments for oscillations of long-period pulsations in the horizontal component of the geomagnetic field with extreme solar flare events in the intervals preceding them. The result of the algorithm is that extrema of histograms were detected a few days before the development of intense solar flares and can be considered as markers of the expected extreme flare activity. The study confirms the possibility of using the previously proposed algorithm for a short-term forecast of solar flare activity.