Effects of solar flares on ionospheric TEC over Iceland before and during the geomagnetic storm of 8 September 2017

Abstract

The effects of solar flares on ionospheric total electron content (TEC) over Iceland before and during the geomagnetic storm of September 8, 2017 were studied. Global Positioning Syste (GPS)-TEC data were obtained from dual-frequency GPS sites operated by the University NAVSTAR Consortium at Dyna (65.06°N, −16.6°E) and Kisa (64.7°N, −17.6°E) stations. The findings of this study show that the enhancement of ionospheric TEC was more noticeable over the Kisa station than over the Dyna station during the coronal mass ejection day. However, during the geomagnetic storm day, maximum enhancement of TEC was observed over the Dyna station than over the Kisa station. The values of the ionospheric TEC during the initial phase of the storm were greater than during the main and recovery phases of the storm over both stations. This might be due to the effects of X-class solar flares and shock wave preceding the arriving of interplanetary coronal mass ejections plasma. The spatial gradients of TEC between two nearby stations are similar during the main phase of the storm, but slightly different during the initial and recovery phases of the storm. Finally, solar events have a favorable influence on geomagnetic storm indices and ionospheric observables.