Impact of Solar Flares on HF Radio Communication at High Latitude

An increase in the solar magnetic field gives rise to the number of visible sunspots in the Earth facing side of the Sun. This tends to impact the Earth's magnetic field. Occurrence of a geomagnetic storm depends on the interaction of magnetic fields of both the Sun (captured in solar wind) and the Earth. The energy of the sun is given out in the form of high-speed solar wind, solar flares, coronal mass ejections (CMEs), solar uV light and energetic particles (MeV). The effect of such geomagnetic storms is borne by the trans-ionospheric message carrying signal and affects both satellite navigation and radio communication systems on Earth. Moreover, the ionosphere, being a refractive and dispersive medium, adds as a source of error to the message signal. Thus, it becomes important to study the effect of space weather activities on GNSS signal and try to overcome its impact. This paper studies the impact of one such solar storm in the mid-high latitude region during the winter solstice of 2015 on GPS and high-frequency airplane communication. A case study of an event that occurred in Stockholm, Sweden on the 4 November 2015 has been investigated using the geomagnetic and satellite geometric parameters, and the total electron content (TEC) variation in the ionosphere. The analysis undertaken in this paper demonstrates the importance of understanding the serious threats solar activity poses to GNSS and its related applications on Earth, which can have rippling effects on industries which are evidently reliable on space technology.