The African region experienced interruptions in high frequency (HF) communications due to two X-class flares and several M-class flares that were observed.
Five categories — A, B, C, M and X — are used to rank solar flares based on their intensity. A-class are the weakest, while X-class are the most energetic. The impacts of solar flares are immediate due to the flare travelling at the speed of light and reaching Earth within eight minutes.
A CME is a cloud of charged particles from the Sun and can reach Earth between one and three days. CMEs were observed on 8 May and continued till Sunday when the fares trailed off in intensity.
The South African National Space Agency (SANSA), in a space weather alert, said that the sun has an eleven-year solar cycle going from solar minimum to solar maximum. ‘’We are expecting to reach the solar maximum in 2025. As we move closer to solar maximum, we anticipate an increase in the frequency of space weather events”.
SANSA launched its 24/7 operational Space Weather Centre at its facility in Hermanus in November 2022. This state-of-the-art facility operates around the clock to monitor and mitigate the risk of space weather on the African continent. SANSA has been actively studying and forecasting space weather since 2009 and is the only accredited space weather centre in Africa. They provide daily space weather updates at https://spaceweather.sansa.org.za/
SANSA issued several G4 warnings and, for the first time since 2003, one G5 warning was issued on Friday 10 May. The Geomagnetic Storm scale indicates the severity of geomagnetic storms. It is denoted by a G followed by a number from 1 to 5, with 1 being a minor event, and 5 being an extreme event.
A geomagnetic storm occurs when charged particles from the Sun, caused by a coronal mass ejection (CME), interact with the Earth’s magnetic field. The impact of such a storm is mostly on technological systems, however, it is also the origin of the northern and southern lights. There were several reports of Aurora Australis also known as the Southern Lights being visible over the Southern tip of Africa. Reports of Southern light sightings were reported from Gansbaai in the Western Cape and Namibia among others. Auroras are caused by the energetic particles from the Sun as it interacts with the gasses in the upper atmosphere.
Jon Ward, acting Executive Director at SANSA Space Science in Hermanus said that this was the largest geomagnetic storm that has been observed in a very long time.