CAPE TOWN, Jan. 20 (Xinhua) -- The South African National Space Agency (SANSA) has confirmed that an extreme geomagnetic storm hit South Africa in the early hours of Tuesday.
According to the SANSA Space Weather Centre, geomagnetic conditions recorded in Hermanus, in South Africa's Western Cape province, briefly reached G5/Extreme levels, with the K-index peaking at 9 at around 2:00 a.m. local time on Tuesday.
The development followed a warning issued by SANSA on Monday that geomagnetic storm conditions over South Africa were expected to intensify 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 on Sunday, Jan. 18, at around 20:00 South African Standard Time (SAST)," the statement said.
According to SANSA, a Solar Flare is a sudden burst of light from the Sun with an immediate impact on the Earth's day side. "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," it added.
In its latest update on Tuesday, SANSA said the expected CME, a cloud of plasma released from the Sun and triggered by the Solar Flare, reached the Earth earlier than anticipated, arriving at about 21:15 SAST on Jan. 19.
"The impact resulted in geomagnetic activity reaching G4/Severe storm levels," SANSA said, adding that the geomagnetic storm was expected to continue through Tuesday, with conditions ranging between G1/Minor and G3/Strong and the possibility of further G4/Severe storm levels.
The event may cause disruptions to high-frequency communications as well as global navigation and satellite systems applications, such as GPS.
"Unlike terrestrial storms, geomagnetic storms largely go unnoticed by people because their effects are felt mainly through technological systems," SANSA added.
In addition to the impact on communications systems, several people in the Western Cape reported seeing the Southern Lights, also known as the Aurora Australis, in the early hours of Tuesday.
According to SANSA, the G-scale, used by space weather centers worldwide, categorizes geomagnetic storms based on their intensity and potential impact and ranges from G1/Minor to G5/Extreme, while the K-index is a standardized global measure, ranging from 0 to 9, that indicates how much the Earth's magnetic field is disturbed. ■
