Studying Powerful Coronal Mass Ejections That Occurred in September 2017, According to Data from the URAGAN Muon Hodoscope

Abstract

At the beginning of September 2017, the Sun was characterized by anomalously high solar activity (SA), which was unusual for the region of the minimum of the 11-year cycle. A great many powerful flares of the M- and X-classes were observed; these were accompanied by powerful coronal mass ejections (CMEs). These events caused strong magnetic storms on the Earth (the Kp index was as high as 8; the Dst index was <−140 nT). In this work, the effect these ejections had on the flux of cosmic rays (CRs) is considered using data from the URAGAN muon hodoscope at the Moscow Engineering Physics Institute. The study is based on an analysis of variations in the cosmic ray muon flux. Results are presented from processing flux intensity via flicker-noise spectroscopy in order to identify geoeffective disturbances of the Earth’s magnetosphere. A predictor that precedes by more than one day the emergence in near-Earth space of disturbances related to CME propagation is obtained.