![Space storm alerts: Three views of the sun with explosions on it, seen from the side, face on, and around the whole sun.](https://earthsky.org/upl/2024/07/sun-images-NASA-Goddard-Space-Flight-Center-Jhelioviewer.jpg)
- When space storms hit Earth, they can damage power grids and disrupt communications. Our sun is now at the peak of its 11-year cycle, sending more plasma and radiation our way.
- Scientists said new insight into active regions on the sun will allow precise space storm alerts. By understanding the height at which a magnetic field becomes unstable leading to an ejection of sun stuff, they can now predict the speed of that ejecta and when it will hit Earth.
- Being able to analyze these active regions in three dimensions means scientists can provide crucial warnings, which will help protect technology back on Earth.
The Royal Astronomical Society published this original article on July 19, 2024. Edits by EarthSky.
Studying active regions on the sun
Space storms could soon be forecast with greater accuracy than ever before thanks to a big leap forward in our understanding of exactly when a violent solar eruption may hit Earth. Scientists say it is now possible to predict the precise speed a coronal mass ejection (CME) is traveling at and when it will smash into our planet … even before it has fully erupted from the sun.
CMEs are bursts of gas and magnetic fields spewed into space from the solar atmosphere. They can cause geomagnetic storms that have the potential to wreak havoc with terrestrial technology in Earth’s orbit and on its surface. That’s why experts across the globe are striving to improve space weather forecasts.
Advancements such as this one could make a huge difference in helping to protect infrastructure that is vital to our everyday lives, according to researchers at Aberystwyth University in Wales. They presented their findings on July 19, 2024, at the Royal Astronomical Society’s National Astronomy Meeting in Hull, U.K.
The scientists made their discovery after studying specific areas on the sun called active regions. Active regions have strong magnetic fields where CMEs are born. The researchers monitored how these areas changed in the periods before, during and after an eruption.
![Diagram: Cross-sections of small and middle-sized eruptions, and much bigger large eruption.](https://earthsky.org/upl/2024/07/3-CME-stages-Royal-Astronomical-Society.jpg)
Critical height of active regions
A vital aspect they looked at was the “critical height” of the active regions. This is the height at which the magnetic field becomes unstable and can lead to a CME.
Lead researcher Harshita Gandhi of Aberystwyth University said:
By measuring how the strength of the magnetic field decreases with height, we can determine this critical height.
This data can then be used along with a geometric model which is used to track the true speed of CMEs in three dimensions, rather than just two, which is essential for precise predictions.
Our findings reveal a strong relationship between the critical height at CME onset and the true CME speed.
This insight allows us to predict the CME’s speed and, consequently, its arrival time on Earth, even before the CME has fully erupted.
![Diagram: dense loops from the sun in blue, red and yellow.](https://earthsky.org/upl/2024/07/magnetic-field-lines-sun-Royal-Astronomical-Society.png)
Gaining knowledge toward more precise space storm alerts
When these CMEs hit the Earth they can trigger a geomagnetic storm. Geomagnetic storms are capable of producing stunning auroras, often referred to in the Northern Hemisphere as the Northern Lights.
But the storms also have the potential to disrupt vital systems we rely on daily, including satellites, power grids and communication networks. And that’s why scientists worldwide are working hard to improve our ability to better predict when CMEs will hit Earth.
This requires knowing a more accurate speed of the CME shortly after it erupts from the sun to better provide advance warnings of when it will reach our planet.
Accurate speed predictions enable better estimates of when a CME will reach Earth, providing crucial advance warnings. Gandhi said:
Understanding and using the critical height in our forecasts improves our ability to warn about incoming CMEs, helping to protect the technology that our modern lives depend on.
Our research not only enhances our understanding of the sun’s explosive behavior but also significantly improves our ability to forecast space weather events.
This means better preparation and protection for the technological systems we rely on every day.
Bottom line: A new understanding of the heights of unstable magnetic fields in active regions on the sun will lead to more precise space storm alerts, helping to protect technology on Earth.