Global response of Magnetic field and Ionosonde observations to intense solar flares on 6 and 10 September 2017

¹ Kyushu Institute of Technology, Iizuka, Japan
² International Center for Space Weather Science and Education, Kyushu University, Fukuoka, Japan
³ National Institute of Technology Kagoshima College, Kirishima, Japan

^* Corresponding author: fujimoto@ces.kyutech.ac.jp

Abstract

Intense X-ray fluxes during solar flares are known to cause enhanced ionization in the Earth’s ionospheric D, E and F region. This sudden change of ionospheric electron density profile is serious problem to radio wave communication and navigation system. The ground magnetograms often record the sudden change in the sunlit hemisphere during the enhanced X-ray flux, due to the sudden increase in the global ionospheric current system caused by the flare-induced enhanced ionospheric conductivity. These geomagnetic field disturbances are known as ‘‘solar flare effects’’ (SFEs) or geomagnetic crochets [Campbell, 2003]. The typical SFE is increase variation on the equatorial magnetic data. On Ionosonde observation during solar flare event, the High-Frequency (HF) radio wave blackout is often detected in ionogram due to the sudden disturbance in ionosphere. Two intense X-class solar flares occurred on 6 and 10 September 2017. We investigated the magnetic field and Ionosonde responses to the intense solar flare events. Dayside magnetic field variations sudden increased due to the ionospheric disturbance resulting from solar flare. There is no response in night side magnetometer data. The magnitude of SFE (magnetic field) is independent of solar flare x-ray magnitude. We found HF radio wave blackout in ionogram at dayside Ionosonde stations. The duration of blackout is dependent of latitude and local time of Ionosonde stations. There is the different feature of ionogram at night side.