The Geomagnetic Storm Time Response of the Mid Latitude Ionosphere During Solar Cycle 24

This paper mainly assesses the geomagnetic storm time response of the Africa, America, Asia and Europe mid latitude ionosphere in relation to the variability of the total electron content during solar cycle 24. This is carried out by considering the vertical total electron content (VTEC) data derived from the Global Positioning System (GPS), the recent International Reference Ionosphere (IRI 2016) and IRI-Extended to the Plasmasphere (IRI-Plas 2017) models in different geomagnetic storm days during solar cycle 24 (1 June 2013, 17 March 2015, and 28 May 2017). The effects of the 1 June 2013 and 17 March 2015 (2015 St. Patrick's Day) geomagnetic storms which resulted in intensification and fluctuation of the GPS VTEC variations were significantly enhanced in the European sector. On the other hand, the effect of the storm that occurred on 28 May 2017 was mostly pronounced in the American and Asian sectors. Both models are not able to adequately respond to the effects resulting from the geomagnetic storm. The VTEC calculated by the IRI models also generally decrease on most of the hours when the storm on option is applied during the main and recovery phases. Nevertheless, at the Asian station, the IRI-Plas 2017 VTEC values tend to increase on most of the hours during the 2015 St. Patrick's Day storm. Moreover, as a result of enhancement of the VTEC, the satellite signal propagation during the positive geomagnetic storms is largely affected by the VTEC fluctuation.