Silent waves of solar radiation slammed into Earth’s magnetic field at 3 million mph on Monday, Jan. 19.
This type of event is called a geomagnetic storm: a major disturbance of Earth’s magnetosphere that occurs when there is a highly efficient exchange of energy from the solar wind into the space environment surrounding Earth, according to the Space Weather Prediction Center.
“Geomagnetic storm is basically a catch-all term for anything that really changes the Earth’s magnetic field, such as its orientation and strength,” said Ian Hagmann, who teaches Advanced Placement (AP) Physics at Carlmont.
Geomagnetic storms can disrupt navigation systems such as the Global Positioning System (GPS) and create harmful currents in power grids and pipelines. However, they can also create auroras, also known as the northern lights, making them more visible around the world.
For those who work in public safety, a G4 geomagnetic storm is less of a photo opportunity and more of a logistical stress test.
Although geomagnetic storms are considered a “low-impact hazard” by the state, Sherry Constancio, a senior water resources engineer for the California Department of Water Resources, notes that our increasing dependence on technology makes these events more significant.
“One of the biggest issues in any emergency is going to be communications,” Constancio said. “We have backup communication systems that we can put into place that don’t rely on satellites or those things that could be affected by a geomagnetic storm.”
By focusing on the “all-hazards” approach, emergency workers ensure that whether a blackout is caused by a fallen tree or a solar event, the response remains the same.
“We may not plan specifically for a geomagnetic storm,” Constancio said, “but the impacts are things that we train for and plan for every day.”
The Jan. 19 storm was classified as G4, or a severe geomagnetic storm – the second most intense level on the National Oceanic and Atmospheric Administration’s (NOAA) 1-to-5 scale. It was caused by a coronal mass ejection (CME) from the sun and was the largest solar radiation event in over 20 years.
“The sun is going into a kind of maximum in the solar cycle, which means the sun has a lot of solar flares, solar storms, charged particles, and other things that it sends out into the solar system. Charged particles cause magnetic fields, which can then affect other magnetic fields, like Earth’s,” Hagmann said.
One major effect of geomagnetic storms is the auroras they create, which, during these events, can sometimes be visible across the world.
These auroras are caused by solar particles, such as electrons and protons, entering the upper atmosphere. They then crash into gases like oxygen and nitrogen during a process called excitation.
To get rid of excess energy and return to their ground state, the oxygen and nitrogen atoms emit a tiny flash of light, a photon. When billions of these flashes happen at once, they create the glowing curtains we see as auroras.
While this normally happens near the North and South Poles, during a geomagnetic storm, they can sometimes be seen from all over the world.
“When a solar storm comes, it causes the Earth’s magnetic field to shrink because it’s basically getting pressured to straighten down. That means the North Pole is expanding slightly into the field lines,” Hagmann said.
But for most people, the best part of the auroras isn’t the science, but rather, the view.
“I think that a lot of people saw the northern lights as a life-changing experience, so if I had the opportunity to go see them, I would definitely take it,” said Carlmont sophomore Leah Karp. “If I could see them right from my backyard, that would be pretty cool.”
