The storm hit a G4-level severity thanks to a powerful coronal mass ejection flung out from the sun, sparking the aurora australis, or southern lights.
The strongest solar storm for years slammed into the Earth’s atmosphere on Sunday, sparking an extremely powerful geomagnetic storm.
The geomagnetic storm triggered by the coronal mass ejection from the sun was classified as a « severe » or G4 storm, and led to auroras lighting up the skies across New Zealand.
This marks the strongest geomagnetic storm seen on Earth since September 2017.
« The 23 March CME arrived at around 24/1411 UTC. Severe (G4) geomagnetic storming has been observed and is expected to continue through the remainder of the 24 March-UTC day and into the first half of 25 March, » NOAA Space Weather posted to X, formerly Twitter, on Sunday evening.
CMEs are enormous clouds of solar plasma that are flung out from the sun during periods of activity, often as a result of realigning magnetic fields at a sunspot. This plasma travels through space at immense speeds of up to 6.7 million miles per hour, which can collide with the Earth. This CME was associated with an X1-class solar flare that erupted from the sun at the same time, on March 22.
When CMEs hit the Earth, they interact with the ionosphere, leading to a geomagnetic storm. These are classed on a scale from G1 (minor) to G5 (extreme), making a G4 storm the second-highest level of severity.
