Scientists have demonstrated that surface plasma instabilities, not deep interior processes, are the most likely source of the sun's magnetic field.
This finding contradicts long-held beliefs, was made using sophisticated computer simulations, and significantly impacts solar activity prediction.
A Paradigm Shift in Solar Physics
The discovery was published on May 22 in the journal Nature. It shows that instabilities in the plasma throughout the solar surface's outermost layers create the sun's magnetic field. Scientists previously thought the source of this magnetic activity was deep within the sun's core.
Verifying this result could significantly enhance the forecasting of solar storms and flares, which can destroy internet infrastructure, interfere with electrical systems, and harm satellites.
Keaton Burns, an MIT research scientist and co-author of the study, acknowledged that the results might be controversial. He explained that while most of the community has focused on finding dynamo action deep within the sun, their research indicates a different mechanism that better matches observations.
The sun is a giant orb of plasma that moves charged particles around, creating strong magnetic fields. Known as the "convection zone," this active area reaches around 124,000 miles (200,000 kilometers) from the surface.
The magnetic field lines made by the sun's plasma churning and flowing within this zone periodically burst, causing solar flares and coronal mass ejections (CMEs). These explosions have a speed of about millions of miles per hour and have the potential to produce powerful geomagnetic storms if they are directed toward Earth.
Historically, researchers have traced the origins of the sun's magnetic field using 3D simulators, which concentrate on the deep layers of the atmosphere. However, these models frequently lacked sufficient complexity and necessitated high processing power without accurately representing the sun's turbulence.
For this investigation, scientists used helioseismology, a discipline that examines the sun's surface vibrations to deduce interior structures. They simulated the sun's outer plasma flows by utilizing sophisticated algorithms on these observations.
The findings showed that perturbations closely matched the magnetic fields detected outside of the sun's surface in the upper 5% to 10% of its surface. On the other hand, incorporating deeper layers obscured the findings and made them inconsistent with the observed magnetic patterns.
Burns explained that features observed on the sun, such as the corona, sunspots, and solar flares, are all linked to the sun's magnetic field. He noted that their research demonstrates how isolated perturbations near the sun's surface, rather than in the deeper layers, can grow over time and potentially produce the magnetic structures observed.
Implications for Solar Storm Prediction
Now that it is known that the sun's magnetic field may originate from its outer layers, solar storm prediction has new possibilities. Known as solar maximums, these roughly 11-year-long solar cycle activity bursts are marked by powerful flares and CMEs.
Since these occurrences have the potential to interfere with satellite operations, induce radio blackouts, and produce auroras outside of the typical polar regions, accurate forecasting of them is essential.
The present cycle has affected recent solar activity, which has already caused major disruptions like radio blackouts and the downing of Starlink satellites. Burns and his team have developed a novel model that has the potential to improve forecasts and provide more readiness for such geomagnetic occurrences.
The study team, which includes members from MIT, the University of Edinburgh, and other establishments, is still investigating the dynamics of the sun's magnetic field. Their objective is to comprehend the creation of individual sunspots and the entire 11-year solar cycle.
This novel viewpoint on the sun's magnetic activity casts doubt on long-held beliefs and opens the door to creative investigation. Not engaged in the study, Oxford University astronomy professor Steven Balbus said, "This is far from the final word on the problem." "However, it is a fresh and very promising avenue for further study."
As scientists delve deeper into the sun's magnetic mysteries, this discovery marks a significant step towards unraveling the complex mechanisms driving solar phenomena.
Check out more news and information on the Sun in Science Times.
