How does NOAA measure solar storms and flares?
NOAA has a five-point scale for rating solar storms from G1 to G5. The storms on Tuesday are predicted to be G1 while those on Thursday could reach G2 levels.
Stronger storms can affect satellite navigation and low-frequency radio navigation but most don’t have much of an impact on the general public.
However, solar storms can increase the chance of seeing the aurora borealis, or the Northern Lights, further away from the North Pole.
Solar flares are measured in five categories with M-class and X-class being the strongest. An X-class flare can release as much energy as 1 billion atom bombs, according to NASA.
What is a coronal hole high-speed stream?
A coronal hole high-speed stream – which is the cause of the latest storms – is different from a Coronal Mass Ejection (CME). Last week, that latter caused solar flares which triggered a G3 solar storm.
While CMEs typically hit the Earth within one to three days, coronal holes can have delayed impacts.
A coronal hole appears as a large black area on the Sun’s surface because it lacks plasma which has instead travelled out into space.
Because of the Sun’s spin, a coronal hole can sometimes hit the Earth twice – the Sun spins every 27 days meaning the coronal hole can strike the Earth in 27-day intervals.