‘Space tornadoes’ could cause geomagnetic storms, but these phenomena aren’t easy to study

Weather forecasts are a powerful tool. During hurricane season, for example, meteorologists create computer simulations to predict how these destructive storms form and where they might move, helping prevent damage to coastal communities. When you’re trying to predict space weather rather than storms on Earth, creating these simulations becomes a bit more complex. To simulate space weather, one would need to place the sun, planets, and the vast empty space between them in a virtual environment, also called a simulation box, where all the calculations would take place.

Space weather is very different from the storms you see on Earth. These events originate from the sun, which ejects bursts of charged particles and magnetic fields from its surface. The most powerful of these events are called interplanetary coronal mass ejections, or CMEs, which travel at speeds approaching 1,800 miles per second (2,897 kilometers per second).

To put this into perspective, a single CME could move a mass of matter equivalent to all of the Great Lakes from New York to Los Angeles in just under two seconds, almost faster than it takes to call it “space weather.”

When these CMEs hit Earth, they can cause geomagnetic storms, which manifest in the sky as magnificent auroras. These storms can also damage key technological infrastructure, for example by interfering with the flow of electricity in the power grid and causing transformers to overheat and fail.

To better understand how these storms can cause so much damage, our research team created simulations to show how storms interact with Earth’s natural magnetic shield and trigger the dangerous geomagnetic activity that can shut down power grids.

In a study published in October 2025 in The Astrophysics Journalwe modeled one of the sources of these geomagnetic storms: small vortices resembling tornadoes, resulting from an ejection from the sun. These vortices are called flux ropes, and satellites have previously observed small flux ropes, but our work has uncovered how they are generated.

The challenge

Our team began this research in the summer of 2023, when one of us, a space weather expert, spotted inconsistencies in space weather observations. This work revealed that geomagnetic storms occur during periods when no solar flares are expected on Earth.

Baffled, the space weather expert wanted to know if there could be space weather events smaller than coronal mass ejections and not coming directly from solar flares. He predicted that such events could occur in the space between the Sun and Earth, rather than in the Sun’s atmosphere.

An example of smaller space weather events is a magnetic flux rope: bundles of magnetic fields wrapped around each other like a rope. Its detection in computer simulations of solar flares would provide insight into where these space weather events might form. Unlike satellite observations, in simulations you can go back in time or follow an event back to see where it came from.

So he interviewed the other author, a leading simulation expert. It turned out that finding smaller space weather events wasn’t as simple as simulating a large solar flare and letting the computer model run long enough for the flare to reach Earth. Current computer simulations are not intended to resolve these small events. Instead, they are designed to focus on large solar flares, because these have the most effects on terrestrial infrastructure.

This deficit was quite disappointing. It was like trying to predict a hurricane with a simulation that only shows global weather trends. Because you can’t see a hurricane at this scale, you would miss it completely.

These larger-scale simulations are called global simulations. They study how solar flares form on the surface of the sun and propagate through space. These simulations treat charged particle flows and magnetic fields floating in space as fluids to reduce computational cost, compared to modeling each charged particle independently. It’s like measuring the overall temperature of water in a bottle, instead of tracking each water molecule individually.

Since these simulations are computational phenomena that occur in such a large space, they cannot resolve all the details. To cost-effectively resolve the vast space between the sun and planets, researchers divide the space into large cubes, analogous to the two-dimensional pixels of a camera. In the simulation, these cubes each represent an area 1 million miles (1.6 million kilometers) wide, high, and wide. This distance is equivalent to approximately 1% of the Earth-Sun distance.

The search begins

Our search began with what seemed like a hunt for a needle in a haystack. We were studying old global simulations, looking for a small transient drop – which would mean a flux rope – in an area of ​​space hundreds of times wider than the sun itself. Our first searches turned up nothing.

We then focused on simulations of the May 2024 solar flare. This time, we specifically looked at the region where the solar flare collided with a silent stream of charged particles and magnetic fields, called the solar wind, ahead of it.

There it was: a distinct system of magnetic flux strings.

But our enthusiasm was short-lived. We couldn’t tell where these flux ropes were coming from. The modeled flux ropes were also too small to survive, eventually collapsing as they became too small to resolve with our simulation grid.

But that was the kind of clue we needed: the presence of flux ropes where the solar flare collided with the solar wind.

To solve the problem, we decided to fill this gap and create a computer model with a finer grid size than previous global simulations used. Since increasing the resolution across the entire simulation space would have been prohibitively expensive, we decided to increase the simulation resolution only along the flow string trajectory.

The new simulations could now resolve features spanning distances six times the Earth’s diameter of 8,000 miles (or 128,000 kilometers) out to tens of thousands of miles, nearly 100 times better than previous simulations.

Make the discovery

Once we designed and tested the simulation grid, it was time to simulate the same solar flare that led to the formation of these flux ropes in the less fine-grained model. We wanted to study how these flux ropes formed and how they grew, changed shape, and eventually ended in the narrow wedge surrounding the space between the Sun and Earth. The results were astonishing.

The high-resolution view revealed that the flux ropes formed when the solar flare hit the slower solar wind that preceded it. The new structures possessed incredible complexity and strength that persisted far longer than expected. In weather terms, it was like watching a hurricane spawn a series of tornadoes.

We found that the magnetic fields in these vortices were strong enough to trigger a major geomagnetic storm and cause real problems here on Earth. But more importantly, the simulations confirmed that there are indeed space weather events that form locally in the space between the Sun and Earth. Our next step is to simulate the impact of such tornado-like solar wind characteristics on our planet and infrastructure.

Watching these flux ropes in simulation form so quickly and moving toward Earth was exciting, but worrying. This was exciting because this discovery could help us better plan for future extreme space weather events. This was at the same time worrying because these flux ropes would only appear as a small blip in today’s space weather monitors.

We would need multiple satellites to directly observe these flux ropes in more detail so that scientists can more reliably predict if, when and in what orientation they might affect our planet and what the outcome might be. The good news is that scientists and engineers are developing next-generation space missions that could solve this problem.

This article is republished from The Conversation under a Creative Commons license. Read the original article.