Why Geomagnetic Storms Are Increasing: The Science Behind Solar Activity

“Sorry, it’s going to be a bit before your card goes through,” said a young, stressed-out shopkeep atop Mount Hood, Oregon in May, “The aurora is killing our internet today.” The customer ahead of me tapped on the counter impatiently as the card reader slowly attempted to connect. “Any chance you have cash on you?”

“Nope.” said the customer, a young, blonde woman dressed in REI brand hiking gear head to toe. Behind her, I switched my weight from one hip to the other. It was going to be a while for the poor folks behind us. I didn’t have cash either.

“Bummer,” replied the shopkeeper, “This solar storm is messing up everything on the mountaintop. Sorry about that.”

As we in line did our best to wait patiently, we struck up a conversation about that geomagnetic storm, with folks sharing their experience of the gorgeous sky the night before and relaying suggestions of the best spots to look at without light pollution. We all concluded that this once-in-a-lifetime event for our latitude was worth the wait in line and the slow credit card systems.

But, then, this once-in-a-lifetime event happened again in July — and again a couple ofweeks back in mid-August. Confused by the contradiction, I wondered, “Why on Earth does this keep happening?”. To discover an answer to the mystery, I spent way too long reading about (and then, later, nerding out about) the lovely G-type yellow dwarf at the center of our system (the sun!). Here’s what I discovered.

Understanding Geomagnetic Storms

Solar Weather (The Sun is a Deadly Laser)

To understand what’s going on with our planet, we must take a step back and explore how our local star works: Good Ol’ Sol (Our sun!). The sun isn’t just this big, constant fire in space, it’s a dynamic, massive object that undergoes a mind-boggling amount of chemical reactions each second (Seriously, 9.3 x 10³⁷ nuclear reactions each second. The amount is so large that it’s imperceivable.). The energy that is released from these reactions, which primarily turn hydrogen into helium, is the reason our little blue planet can support life — incredible, right?

Along with an insane number of reactions within, lovely Sol has an intense magnetic field surrounding it. This magnetic field fluctuates wildly, due to a combination of factors including the aforementioned reactions and the pull between Sol and all the celestial bodies that orbit it. With all this writhing and swirling, the magnetic field occasionally tangles on itself. This tangling causes a build-up of pressure that, when it snaps and releases, radiates energy that is “more than a million times greater than the energy from a volcanic eruption on Earth”. Thus, an energy-blasting solar flare is born.

With many of these solar flare events, only radiated energy is thrust out from Sol but, occasionally, with particularly strong tangles, more material is flung along with it. We call these CMEs: Coronal Mass Ejections. A CME, like a solar flare, is a large expulsion of energy — but that energy in question is a little different. With CMEs, instead of radiation, the sun expels both plasma and a bit of its own magnetic field. As a result, CMEs also travel out from the sun a bit slower.

Scientists are still working out much about these two sun phenomena and how related the two are to each other. At the moment, we do know that they aren’t dependent on one another to occur, however.

On top of these phenomena, Sol has its very own sort of constant weather: called solar wind. Created by the outermost atmosphere of reactions on the sun, this wind is the result of extreme heat causing surface plasma to escape Sol’s strong gravity and travel out into the universe. Due to the same forces that cause CMEs and solar flares, these winds can vary in speed. With the right conditions, solar wind can make its way across the solar system and hit Earth, causing similar geomagnetic events and, occasionally, causing gorgeous auroras to form. Usually, regular solar wind isn’t a problem because of our own magnetic field.

Earth’s Magnetic Field (Oh Look, There’s a Blanket!)

Thankfully, our lovely little planet isn’t defenseless to these powerful forces from Sol. If that were the case, solar weather could be much more deadly — destroying our atmosphere and making it impossible for Earth to sustain life. But we don’t have to worry about that — we have the Magnetosphere! The magnetosphere is a fancy term for the region of space around Earth that feels the effects of its magnetic field. It’s an ever-shifting force outside of our planet that acts as a shield to keep us safe from solar wind and other space weather. When solar weather hits this field, the magnetosphere deflects and wiggles away the particles so that they bounce off or flow around Earth.

It isn’t a perfect shield, however. Sometimes, solar wind can break through our magnetosphere. The magnetosphere on our planet, much like the magnetic field on the sun, isn’t a stationary wall, but an ever-shifting force that surrounds us, shifting and warping as solar winds hit it. Because of this, our magnetosphere can be penetrated by solar weather in the right conditions, especially when they interact with weaker spots. When this manages to happen, that’s when we see geomagnetic storms, auroras, and other similar phenomena.

Historical Perspective

Praise the Sun!

Auroras have long been a fascination — finding their way into a wide variety of early legends and delighting or terrifying those who witnessed them. Even before we understood the science behind what caused the phenomenon (the theory was officially developed in the early 1900s), we recorded its effects and the strange ways it meddled with devices powered by electricity.

One of the strongest events we know of, The Carrington Event of 1859, had auroras all over the world, even visible to people who lived near the equator. Closer to the poles, in the Northern United States, newspapers of the time reported that the auroras made the sky so bright that some folks were woken up and began to prepare breakfast “because they thought it was morning.” After this event, which was later identified as a CME by studying magnetometer readings recorded that night, Sol seemingly quieted down. Since this event (that happened in solar cycle 10), the sun has been relatively quiet.

Looking at historical data of geomagnetic events (below), we can see that, despite some counts of total storms appearing marginally higher in some years over others, this increase and decrease of solar events is fairly normal and occurs in a sort of pattern.

Truly, the increase in solar event frequency recently is likely because of its current state in its cycle.

The 11-Year Solar Cycle

One of the main reasons we’re seeing such an uptick in solar events recently is due to the current state of the sun’s magnetic field. The magnetic field of the sun goes through an 11-year cycle. Roughly every 11 years, the magnetic field flips so that the north and south poles swap places. Halfway between this transition, the sun is at its solar maximum. At this stage, it has the most sunspots and is also at its most active.

It just so happens that scientists believe 2024 is a solar maximum year — a relatively early solar maximum. We are currently in roughly the middle of Solar Cycle 25, which started near the end of 2019. So, all that activity we’ve seen this year is due to the reactivity of this part of Sol’s magnetic field’s reactivity.

Also of note, the four sun cycles that preceded it, cycles 21–24, were uncharacteristically calm compared to the recorded average. So, for anyone under 45, the last couple of years have seemed rather strange — with far more activity than any of us youngsters have seen. But, in actuality, what we’re experiencing is pretty regular for the sun.

Factors Behind the Increase

Has the Sun Been Acting Odd Recently?

The sun has, indeed, been remarkably active in the last year — it’s the most active year in the previous two decades.

Of course, it isn’t all the cause of the position of our sun in the galaxy, we’ve also gotten much better at detecting notable solar events in the last few decades. A host of satellites to measure the happenings of Sol, paired with a quicker news cycle brought on by our lovely pal, the internet, can make it seem like these solar events are in overdrive. If we were able to report on (or tweet about) sun events in the same frequency as we do now fifty, one hundred, or even a thousand years ago, we’d have a much better perception of the regular pattern of our sun.

In addition, with how much our societies have grown to rely on technology, it’s more noticeable when these storms hit, as they interrupt processes like electricity and the internet. No longer are only telegraph operators subject to power surges, we all notice the effects acutely! Before light pollution was significant enough to block out the sky for us modern humans, the most notable impact of these events was a light display in the sky which, though stunning, and occasionally inspirational to legend, was likely less disruptive to the day-to-day.

Impacts of Geomagnetic Storms

The effects that geomagnetic storms have are, most notably, their ability to damage powered devices. One of the greatest risks of these is harm to satellites, particularly due to how necessary it is for sea-faring and air-faring vessels to accurately predict where they are and where other crafts are with GPS tech. Inaccurate navigation readings can be dangerous if not addressed in cases like air travel, and even when they aren’t life-threatening, can disrupt industries that rely on them.

There have also been numerous cases in which these events harmed power grids that weren’t equipped to deal with the out-of-character power surges that the storms brought on. Where most of these cases resulted in blackouts, there have been instances where fires were ignited by the surges and even some ancient reports of operators of telegraph machines being shocked.

Of course, any risk to our power grid can pose threats to those who rely on power to survive. Those kept alive by medical machinery are particularly at risk. Additionally, should a power grid failure occur on a particularly hot or cold day, that could also pose a risk for those who are sensitive to temperature. And, if a geomagnetic storm, universe forbid, harms a power grid too severely, we may say crises emerge from extended periods of lack of power in power-dependent communities.

Human Health: As Above, So Below

Though less discussed, these sorts of solar weather events can also be a huge risk for astronauts in orbit around Earth. As these events increase the amount of radiation in space, they can cause significant health risks — the horrific ones you’d expect with high radiation exposure. Thankfully, the ISS works closely with agencies that monitor solar weather events and can inform astronauts when they need to retreat to zones of the station that are made to be better shielded against radiation. With our ability to quickly detect this sort of phenomenon, our astronauts can employ an abundance of caution when Sol emits radiation.

Additionally, there’s a growing body of research that indicates these sorts of disruptions can impact the psychological health of us people down on the surface of the Earth, too. One particular study in 2005, titled Geomagnetic Storms and Their Influence on the Human Brain Functional State, found that some patients were more likely to feel weak, indisposed, and experience headaches during geomagnetic storms. EEG investigations in the study saw functional brain differences as well!

Preparing for the Future

Luckily, the potential negative effects of solar storms aren’t inevitable. With the development of new technologies, we will better be able to predict when they will occur and prevent our tech from being affected by them. We are already lightning-fast at identifying these events. With NOAA’s Space Weather Prediction Center, we’re able to predict whether storms will occur with reasonable accuracy up to three days before they hit Earth. This much time to prepare allows operators to temporarily power down their satellites (or power stations) to prevent damage to them, should the need arise.

There’s still a long way to go, however. Though we can predict when a storm will arrive, we’ve yet to crack the code on how to tell how severe each of these events are, and whether they’ll affect us down on Earth. With limited ideas about severity, and not many geomagnetic surge protectors set up in our power grids, we still have a notable vulnerability to the storms.

Though the probability of a grid-destroying geomagnetic storm is low, it’s odd that we haven’t prioritized much development in preparing our electricity systems. Such preparation is notably costly, but the cost to be prepared is far lower than what it would cost to repair the damage done by such an event.

With these initiatives, it’s paramount that the entire globe collaborates. The more we know, and the more knowledge we share, the better we’ll be able to efficiently improve our defenses against the effects of solar weather affecting our planet.

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Slowly, but surely, the little loading dots on the card reader blinked in a line until a checkmark appeared. The young Mount Hood shopkeeper sighed a breath of relief that made her dyed bangs float upwards as the machine dutifully spit out a short receipt.

The REI-clad customer grabbed the receipt and happily strolled off, souvenir in hand, equally relieved she wouldn’t have to wait any longer.

The shopkeeper leaned towards me with a wide grin — my turn to order, “Sorry for the wait — it’s worth it though, dontcha think? That Aurora is gorgeous.”

I returned her grin, “God, yeah. What an incredible view.”

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Crossposted from Medium :)