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The Sun has awoken. After coming out of the solar minimum in December 2019 – thus beginning Solar Cycle 25 – our star has been quite active over the last several months, releasing powerful flares. Not even two weeks ago, a major flare and coronal mass ejection (CME) was sent towards Earth, creating days of geomagnetic storms. The road to the solar maximum of 2025 could be full of powerful events.
In an interview with Space.com, Bill Murtagh, a program coordinator at the Space Weather Prediction Center (SWPC) of the National Oceanic and Atmospheric Administration (NOAA), discussed the danger of multiple coronal mass ejections being released one after the other.
In this scenario, even if the CMEs are not incredibly powerful, a series of them would be more difficult to predict and prepare for. These waves of plasma cross the 150 million kilometers between the Sun and the Earth, before slamming into our planet’s magnetic field and then atmosphere. They can damage satellites and electronic devices, as well as mess with radio communication.
"That first CME essentially works its way through the 93 million miles and almost clearing a path out for other CMEs to come in behind it," Murtagh told Space.com. "Sometimes we use the term ‘cannibalising’ the one ahead."
A "cannibal" CME of a certain power could damage critical infrastructures, and getting people ready for it might not be possible. Space weather prediction is notoriously complicated, and knowing how Eath's magnetic field will behave against the uncertain magnetic distribution of a CME requires observations that are not always readily available.
"We have determined for all practical purposes that our worst-case scenario for the extreme geomagnetic storm event scenario will indeed be this," Murtagh added. "It's just that the CMEs were not that big – but that process happened here, where we had back-to-back two, three different CMEs came sweeping in together."
The strongest geomagnetic storm on record is the “Carrington Event” – and if that were to happen today, the damages and danger would be severe. Back in 2009, NASA estimated that the unfolding of such a severe geomagnetic storm would lead to up to 130 million people in the US left without power and with “water distribution affected within several hours; perishable foods and medications lost in 12-24 hours; loss of heating/air conditioning, sewage disposal, phone service, fuel re-supply and so on.”
There have been calls for governments and companies to update current systems to make them more resilient against geomagnetic storms. Insurance market Lloyd’s estimates that the damage from a Carrington level event would be between 0.6 to 2.6 trillion US dollars.
[h/t: Space.com]
