Storm and substorm causes and effects at midlatitude location for the St Patrick s 2013 and 2015 events

Midlatitude locations are unique regions exposed to both geomagnetic storm and substorm effects, which may be superposed on specific events imposing an extra handicap for the analysis and identification of the sources and triggers. We study space weather effects at the midlatitude location of the Iberian Peninsula for the St. Patrick's day events in 2013 and 2015. We have been able to identify and separate storm and substorm effects on ground magnetometer data from San Pablo‐Toledo observatory during storm time revealing important contributions of the Substorm Current Wedge on both events. The analysis of these substorm local signatures have shown to be related to the production of effective geomagnetically induced currents and ionospheric disturbances as measured from Global Navigation Satellite Systems data at MAD2 IGS permanent station and not directly related to the storm main phase. The whole Sun‐to‐Earth chain has been analyzed in order to identify the solar and interplanetary triggers. In both events a high‐speed stream (HSS) and a coronal mass ejections (CME) are involved, though for 2015 event, the HSS has merged with the CME, increasing the storm geoeffectiveness. The enhancement of substorm geoeffectiveness is justified by the effects of the inclined magnetic axes of the Sun and of the Earth during equinox period.
This work has been supported bythe Spanish Ministerio de Economíay Competitividad (MINECO) underprojects AYA2013-47735-P andAYA2016-80881-P. The work at theUniversitat de Barcelona has beensupported by MINECO under theproject AYA2013-42614-P. The workby Antonio Guerrero has beensupported by University of Alcala under the program “Ayuda Posdoctoraldel Programa Propio de Vicerrectoradode Investigación y Transferencia.”Marta Rodriguez Bouza thanks MINECO for her contract in theproject GCL2014-62113-EXP.