The Department of Science, Technology and Innovation, together with the South African National Space Agency (Sansa), has advised that geomagnetic storm conditions will likely increase over the next 24 hours with the arrival of an Earth-directed coronal mass ejection (CME).

The CME was triggered by a long duration X1.9 solar flare event on January 18.

A solar flare is a sudden burst of light from the sun with an immediate impact on the Earth’s day side, disrupting high frequency radio communications.

Solar flares are ranked in five categories — A, B, C, M and X — based on their intensity.

A-class flares are the weakest, while X-class flares are the most energetic.

The Africa region was not affected by the high-frequency radio blackout on January 18 as it was observed during nighttime, mostly out of the flare’s impact range.

However, the solar flare triggered a CME, which is a cloud of plasma released from the sun.

This CME is currently travelling from the sun to the Earth and is expected to impact Earth from the early hours of January 20.

This impact will interact with the Earth’s magnetic field and cause a geomagnetic storm. The geomagnetic storm could reach G4 or severe storm conditions.

The G-scale, used by space weather centres globally, categorises geomagnetic storms based on their intensity and potential impact. It ranges from G1 (minor), G2 (moderate), G3 (strong), G4 (severe) and G5 (extreme).

Sansa’s Space Weather Centre expects geomagnetic conditions to increase over the next 24 hours. Unlike terrestrial storms, geomagnetic storms largely go unnoticed by people because their effects are felt mainly through technological systems.

Navigation, communication and electricity networks are the most at risk.

Industries such as aviation and drone operations can be affected by the impact on navigation systems and should take note of the K-Index, a standardised, global measure of geomagnetic activity, showing how much the Earth's magnetic field is disturbed.

Sansa operates a local K-Index from Hermanus that can be tracked at spaceweather.sansa.org.za.