“The strongest solar flare for sun cycle 25, which started
in December 2019, peaked on Tuesday, May 14, 2024.”
How Solar Storms That Bring Northern Lights Can Also Cause Tech Chaos
by Sarah Mohamad  /  May 21, 2024

“Last weekend, a series of powerful solar storms brought the northern lights to the Bay Area and much of the world, illuminating the night skies with a mesmerizing display of color. As well as causing the aurora borealis, these solar storms also have the potential to bring widespread disruption to Earth’s electrical systems — something that originally happened all the way back in 1859 during one of the largest geomagnetic storms recorded in history. One of the biggest solar storms in history happened in September 1859, just a few months before the solar maximum — the peak of the 11-year solar cycle — of 1860.

The storm, also known as the Carrington Event, was after British astronomer Richard Carrington, who first observed a “white light flare” while looking for sunspots. The geomagnetic storm that ensued in the next 17 hours caused chaos to that era’s version of the World Wide Web and shocked telegraph operators around the globe, who found their networks disrupted and even saw fires in multiple telegraph stations throughout Europe and North America. According to contemporary newspaper reports, for hours, telegraph operators were even able to use the overflowing current present in the air to continue working their unplugged telegraph machines. One Portland operator reportedly said the machines worked “better than with our batteries on.”

“NASA’s Solar Dynamics Observatory captured these images of the solar flares — as seen in the bright flashes in the left image (May 8 flare) and the right image (May 7 flare). The image shows 131 angstrom light, a subset of extreme ultraviolet light that highlights the extremely hot material in flares and is colorized in orange. (NASA SDO)

But the solar storm also created spectacular auroral displays in places beyond the usual polar latitudes, as far as south as Mexico and Hawaii. In the northeastern U.S., the northern lights were so bright that people reported using the storm’s glow to read the newspaper at night. A report from the Sonoma County Journal in September 1859 described the beautiful view of the auroras seen in California as “exhibiting every hue from blood red to the faintest golden yellow, and extending from the horizon to the zenith in all directions.” Scientists today believe that multiple coronal mass ejections (CMEs) hit Earth during the Carrington Event, arriving in the Earth’s atmosphere in just 17 hours — a journey that usually takes several days.

Luckily for us, solar storms like the Carrington Event only happen once every few centuries. So the likelihood of it happening during our lifetime is slim, according to Andrew Fraknoi, astronomer and professor at the University of San Francisco’s Fromm Institute. “But, it could happen,” he said. How would such an event today impact us, and are we prepared? “Today, we are in a much more vulnerable place than they were in 1859,” Fraknoi said. And while not at the same scale as the Carrington Event, the solar storm of March 1989 could give a preview of that potential impact. The storm caused a massive power outage of Hydro-Québec’s electricity transmission system, leaving 6 million Canadians in the dark for 9 hours and significantly interfering with the U.S. power grid.

“NASA’s Solar Dynamics Observatory captured images of the two solar flares on May 10 and May 11, 2024. The flares are classified as X5.8 and X1.5-class flares, respectively. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares created from a mixture of SDO’s AIA 193, 171 and 131 channels. (NASA SDO)

2013 report by the National Academy of Sciences estimates that such a storm now could cost one to two trillion dollars in the first year alone and take a decade to recover from. “We’re dependent on GPS satellites, and the power grid is connected in very complicated ways among different parts of the U.S. and parts of North America,” Fraknoi said. “If there were a huge amount of current coming from the sky, it could overwhelm or damage the power grid connections.” The 2013 report lays out the potential disruption on satellites, power grids and infrastructure, as well as the socioeconomic impacts of another Carrington Event happening today. Depending on the scale of the solar storms, disruptions can last for weeks or even years, according to the report.

“If you can imagine a space weather storm strong enough to knock out power from New York down to the Carolinas for weeks, that’s not ‘a bad day’ anymore. That’s a national security risk,” said Bryan Brasher, Project Manager at the Space Weather Prediction Center for the National Oceanic and Atmospheric Administration (NOAA.) Brasher works with the team that predicts space weather events like the recent solar storms we experienced.

If a massive geomagnetic storm like the Carrington Event were to happen today, he said, it could interfere with radio communications and GPS signals and disrupt operations on spacecraft and even pipelines and railroads. But Brasher is optimistic that our understanding of space weather prediction has improved over the last century — and more research is being done to mitigate any catastrophic events that could result from a large solar storm event. “I think today we like to think that by doing our job to provide forecasts and information to these critical system operators, that they will take mitigating factors to help prevent failures,” he said.

“A Japanese auroral drawing showing an observation at Okazaki on 4 February 1872, as reproduced with courtesy of Shounji Temple”

Here’s a list of other large geomagnetic storms that disrupted technology in parts of the U.S. These storms may not necessarily have caused disruptions in California, but sightings of the aurora were visible in the region during most of these storms:

  • November 1882: A report in the SF Examiner in 1882 mentions interruptions to telegraphic communications in places like New York, Chicago, and Boston, with sightings of the aurora visible from Mendocino. “The hues are deep crimson, shading to light green on the horizon. It lasted several hours,” wrote the Examiner.
  • May 1921: A powerful solar storm known as the New York Railroad Storm caused a fire near the Grand Central Terminal in New York. There were reports of damages to telegraph systems in Europe and the Southern Hemisphere. Reports of aurora sightings in San Francisco, Oakland, and Santa Clara were described as “brilliant hued skies,” according to the San Francisco Chronicle.
  • August 1972: Solar flares and coronal mass ejections (CMEs) caused solar storms that disrupted communication grids and satellite communications in North America, with reports saying it caused the accidental detonation of a number of U.S. naval mines near North Vietnam.
  • March 1989: Although no technological disruptions occurred here in California, a “night sky glow” that “varied in color from a whitish green to a brilliant red” was seen in Napa, Solano, Mendocino and San Luis Obispo, according to SF Examiner.
  • October 2003: Also known as “the Halloween solar storms,” this event caused interruptions to satellite-based systems and communications and aircraft were advised to avoid high altitudes near the polar regions. Again, aurora was visible in California as reported by Santa Cruz Sentinal: “A mysterious light that appeared to fall from the sky over the Santa Cruz Mountains had many residents calling emergency dispatchers Thursday night.”

“A view of the northern lights in Sonoma County on May 10, 2024”

To understand space weather, we have to look at the (literal) star of the show: the sun. While this big ball of hot gas is more than 90 million miles away, its influence on Earth and our environment is massive. The sun’s dynamic and complex body continuously emits charged particles into space called solar wind, which astronomer Fraknoi describes as “kind of like a breeze of particles from the sun. It goes in all directions from the sun, and it always comes toward the Earth,” he said. “There’s a complex magnetic field woven throughout the sun,” Fraknoi said, thanks to these charged particles and the rotation of the sun.

And as the magnetic field rotates with the sun, it stretches, twists and snaps like a rubber band. When that snap happens, particles and energy from the sun are released into space, causing a giant flash of light called a solar flare — which travels at the speed of light in all directions and takes about eight minutes to reach Earth. But when a larger amount of those same particles is released, that’s called a coronal mass ejection (CME) — which Fraknoi describes as “blobs of charged particles” hurled out in space. CMEs take one to three days to reach Earth — and unlike solar flares that appear as a flash of light, CMEs look more like explosions in space.

“NASA’s Solar Dynamics Observatory captured this imagery of solar flares from May 7–8, 2024. The imagery shows 131 Angstrom light, a subset of extreme ultraviolet light. (NASA SDO)

Solar flares almost always precede a CME. And because it can take days for a CME to reach Earth, flares let the team at Space Weather Prediction Center at NOAA send out early warnings to the masses, Fraknoi said. Most times, these CMEs from the sun are pointed towards random directions in space. “But every once in a while, the coronal mass ejection is pointed toward Earth,” Fraknoi said. And when it is, that’s when we get a strong geomagnetic storm. Brasher said he likes to think of solar flares like the flash at the end of a cannon when it shoots off — and “you can think of the cannonball as being like a CME,” he said. “It’s massive, it has weight. It travels much slower than the speed of light — and most importantly, has a direction component to it.”

The Earth also has its own magnetic fields that function as a “protective bottle” known as a magnetosphere. The Earth’s magnetosphere is weaker in the north and south poles, noted Fraknoi — making places like Alaska and Antarctica great spots to see the aurora more regularly. When charged particles flowing from the sun get caught up in the Earth’s magnetic field, it energizes the atmosphere’s molecules (like nitrogen and oxygen), excites them and creates a colorful display of light we know as the aurora, or the northern lights. The different colors we see from Earth — the hues of green, red, purple, and blue — depend on which molecule is being excited by the charged particles and on how much energy is being exchanged.

“The Earth’s magnetosphere deflects most solar energy and particles, but occasionally, some make it down into the auroral ovals at the North and South poles. (NOAA)

If the northern lights are most common around the poles, how do we see them all the way here in the Bay Area? During strong geomagnetic storms like the one we experienced over a week ago — usually when a CME is involved — the aurora that is usually only visible in those polar regions is now supercharged and distributed even more geographically, making them visible in places you don’t normally see them. While many were lucky enough to clearly see the recent aurora caused by one of the largest solar storms in over 20 years, folks who weren’t so fortunate shared memes on social media about their FOMO, with one user calling this elusive glow the “aurora fogealis.” But if that was you, there’s still hope. Experts say we might see more auroras in the next couple of years, thanks to the sun’s cycle.

The sun undergoes an eleven-year solar cycle, with solar activity rising and falling. We are currently approaching the peak of the solar cycle, also known as the solar maximum. During this period, space weather events like solar flares and CMEs can happen more often. “During the solar cycle, the sun’s magnetic field goes from being really uniform and easy to getting really complicated, intertwined and complex,” Brasher said. Scientists predict these solar storms will reach their peak in 2025. But sometimes, the biggest storms can hit years after the solar maximum.”
How Colorado’s space weather forecasters predicted the recent solar storm
by Sam Brasch / May. 17, 2024

“Night skies lit in green and purple dazzled viewers across the Northern Hemisphere last weekend.  The widespread aurora was the side effect of a powerful geomagnetic storm, which had the potential to wreak havoc on satellites and power systems. It appears, however, that most people will remember the event as their first glimpse of a galactic light show usually reserved for communities at far higher latitudes.  Shawn Dahl, a space weather forecaster at the nation’s Space Weather Prediction Center in Boulder, takes some credit for the relative lack of problems.

By carefully monitoring the sun, he said his office at the National Oceanic and Atmospheric Administration was able to give key sectors—like airlines and power grid operators—a six-hour warning about the incoming rush of charged particles. “They were able to avoid any power loss, meaning a blackout across entire states in this particular instance,” Dahl said. “We’ve already received feedback that our support was absolutely critical to maintaining their operations during this event.”  That success, he said, proves the importance of his dimly lit office just below the Boulder Flatirons. The operation looks like mission control for humanity’s great battle against the sun.

“Ken Tegnell points out the sunspot responsible for the burst
electromagnetic activity around the Earth earlier this month”

Screens blanket the walls with satellite images of the gaseous orb, its churning surface rendered in pink, yellow, and green. Another monochrome picture shows a black disk surrounded by the solar corona, a crown of pulsating plasma usually only visible during a full eclipse.  Those monitors will continue to pick up evidence of major electromagnetic storms over the next few years. That’s because 2025 marks the peak of the next solar maximum, a period of heightened activity occurring every 11 years.

As the celestial body grows more turbulent, Dahl said the planet is at greater risk of a “benchmark” solar storm like the 1859 Carrington Event. Historical records suggest the storm triggered brilliant auroras above Colorado, which were bright enough to trick miners into thinking the sun had risen on a cloudy day. Some even started making coffee and breakfast at 1 a.m.  A similar event could have far more serious impacts on modern society. A severe electromagnetic storm could induce currents along transmission lines, knocking out major sections of the power grid. Airline passengers could experience unsafe levels of radiation. GPS systems could fail to operate amid the magnetic eruption.

At the same time, the rise in solar activity could cause Earth’s atmosphere to expand, dragging satellites out of orbit and sending them crashing toward the surface.  “That’s what we’re trying to avoid here, but there will be a point in time where one of these events— even though we’re mitigating it — may be unmanageable, which is why our government continues to be involved,” Dahl said. The Carrington Event, Dahl said, was five to 10 times more powerful than the most recent solar storm, but the arrival nevertheless provided an opportunity for the prediction center to test its procedures.

Ken Tegnell, another forecaster at the prediction center, said the first sign of trouble was a cluster of sunspots 16 times the diameter of Earth labeled active region 3664. Early last week, it sprayed half a dozen coronal mass ejections. While the direction of those eruptions wasn’t immediately clear, he said satellites indicated the pulses were headed directly toward Earth a few days later.

In response, the SWPC issued a G4 watch, the highest warning for an incoming solar storm, and predicted it would hit on May 11. The alert marked the first time the office had issued such a severe warning since 2005. As the storm drew closer, the center held a hotline call for key economic sectors vulnerable to solar storms. Dahl credits the early heads-up with giving grid operators hours to shift electricity and protect critical power infrastructure. It also helped airlines reroute some flights away from areas with higher levels of electromagnetic activity, he said.

The center has since tried to collect evidence of any storm impacts. So far, it appears the storm didn’t trigger any major blackouts like the 2003 Halloween Storm, an electromagnetic event that triggered power losses in Sweden and South Africa. Dahl, however, heard the solar storm may have left a mark on his family’s farm in North Dakota. After the event, his nephew called to say his brother-in-law paused their planting operation after their tractor’s GPS systems went haywire. Other farmers reported a similar loss of location services, making it impossible to sow seeds in precision rows without overlaps. “These are the kind of effects and impacts that we’ve been saying are possible with these storms, and, sure as heck, it materialized right in front of my family and others,” Dahl said.”

Solar storm detected in deep sea observatories
“Ocean Networks Canada infrastructure map. ONC operates world-leading observatories in the deep ocean, coastal waters and land of the Pacific, Atlantic and Arctic coasts of Canada, and in the Southern Ocean. ONC’s cabled observatories supply continuous power and internet connectivity to scientific instruments, cameras and 12,000-plus ocean sensors. ONC also operates ocean mobile and land-based assets, including coastal radar. ONC provides continuous live ocean data accessible through the Oceans 3.0 data portal on the ONC website. Credit: University of Victoria”
Solar storm detected in deep sea observatories
by University of Victoria  /  May 16, 2024

“The powerful solar storm driving the aurora borealis over global skies last weekend was also triggering the movement of compasses deep in the ocean, as revealed in new scientific findings shared today by Ocean Networks Canada (ONC), a University of Victoria initiative. ONC’s subsea observatories on the west and east coasts of Canada recorded the temporary distortion of the Earth’s magnetic field on instrument platforms deployed as deep as 2.7 kilometers under the ocean surface, potentially some of the most remote recordings ever captured. The most significant magnetic shift moved the direction of the compass within a range of +30 to -30 degrees and was recorded at a depth of 25 meters at the Folger Passage subsea site, which is part of the ONC NEPTUNE cabled observatory off the coast of Vancouver Island.

Geomagnetic disturbances can pose risks to power grids, satellite networks, and navigation systems as well as impact animals’ own navigational abilities. “The reach of these data recordings kilometers under the ocean surface highlight the magnitude of the solar flare over the past weekend and suggest that the data may be useful for better understanding the geographic extent and intensity of these storms,” says Kate Moran, ONC president and CEO. The discovery of these solar storm magnetic disturbances happened during  control checks. ONC primarily uses compasses to orient its Acoustic Doppler Current Profilers (ADCP) instruments which measure ocean currents.

“Compass data captured by ONC’s major cabled subsea observatories VENUS and NEPTUNE off Vancouver Island, at Burrard Inlet on the Pacific Coast, and at Conception Bay on the Atlantic coast shows the magnetic field distortion occurring during a solar storm from May 10–12 (UTC), 2024. Credit: Ocean Networks Canada”

Alex Slonimer, a scientific data specialist at ONC, was completing a daily check on the data in late March when he first noticed an anomaly in the numbers showing up in the Ocean 3.0 Data Portal. “I looked into whether it was potentially an earthquake, but that didn’t make a lot of sense because the changes in the data were lasting for too long and concurrently at different locations,” Slonimer explains. “Then, I looked into whether it was a  as the sun has been active recently.”

This past weekend’s much larger solar storm event reinforced the observation, he adds, with the peaks in the compass headings closely correlated to the peaks in the visible activity in the aurora. Justin Albert, professor of physics with UVic’s Department of Physics and Astronomy, welcomes the new subsea geomagnetic detections. “The next two years will be the peak of the 11-year . After a decade of relative inactivity, aurora events like this past weekend are likely to become more frequent over the next couple of years, although solar variability makes precise prediction of such events impossible,” says Albert. “ONC’s network might provide a very helpful additional window into the effects of solar activity on the Earth’s terrestrial magnetism.”