For years, scientists have believed that the Sun’s powerful magnetic field, which drives solar storms impacting Earth, originated deep within the star. 

However, a groundbreaking study by researchers from the Massachusetts Institute of Technology and the University of Edinburgh challenges this long-held theory. 

The new findings suggest that the Sun’s dynamo, the process generating the magnetic field, might actually be located much closer to the surface, in the star’s outermost layers.

Study Findings

Published in the prestigious journal Nature, the study provides compelling evidence that the Sun’s magnetic field is generated about 20,000 miles below its surface, rather than the previously assumed 130,000 miles. 

This revelation could revolutionize our understanding of the solar cycle and enhance the accuracy of solar cycle predictions.

“Our results are contributing to understanding the solar cycle better. 

We want to forecast if the next solar cycle will be particularly strong, or maybe weaker than normal,” said Daniel Lecoanet, assistant professor at Northwestern University, in an interview with Down To Earth (DTE).

The Solar Cycle

The Sun’s magnetic field undergoes an 11-year cycle, known as the solar cycle, characterized by the appearance and disappearance of sunspots. 

Sunspots are regions with a much higher magnetic field than the surrounding areas. The cycle begins with few sunspots (solar minimum), reaches a peak with the highest number of sunspots (solar maximum), and then declines again.

Previous models, which assumed that the solar magnetic field was generated deep within the Sun, struggled to predict the strength of upcoming solar cycles accurately. 

The new study’s closer-to-surface dynamo model promises to improve these predictions, similar to how meteorologists forecast hurricanes.

Research Methodology

The research team used numerical simulations to model the Sun’s magnetic fields, incorporating torsional oscillations—cyclical patterns in the flow of gas and plasma within and around the Sun. ‘

Their model aligns with observed solar cycles and suggests that the same physical processes drive both torsional oscillations and the magnetic cycle.

“Our work provides strong evidence that the solar cycle starts near the surface of the Sun in the equatorial region,” noted one of the study’s authors. 

The team hopes to explore further how the solar cycle completes its loop.

Skepticism and Debate

Despite the promising findings, not all experts are convinced. Dibyendu Nandi, a professor at the Indian Institute of Science Education & Research, expressed caution. 

“This is a new and exciting idea, but not a serious contender to the traditional theory yet. The kind of rigorous observational tests that one would expect from a new theory trying to unseat a rather well-tested theory is missing,” he told DTE.

Nandi pointed out that the new model needs to address two critical aspects of the sunspot cycle: the sunspot time series (the periodic rise and fall of sunspots) and the sunspot distribution butterfly diagram, which maps sunspot movements from mid-latitudes towards the equator over the cycle.

Implications of the Study

The study’s publication coincides with the sun’s increasing solar activity as it approaches its solar maximum.

The first full week of May saw multiple large solar flares and coronal mass ejections (CMEs), culminating in the strongest solar storm to reach Earth in two decades on May 14, 2024. These events underscore the importance of accurate solar cycle predictions.

The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center issued warnings to power grid operators and satellite companies to mitigate potential impacts. 

The European Space Agency (ESA) is still assessing the storm’s effects on their technology. Solar storms pose significant risks, including blackouts, satellite disablement, and damage to cell phones and GPS networks.

In extreme cases, they can disrupt power grids. Currently, scientists can forecast the probability of solar eruptions but not their exact timing.

Future of Solar Cycle Prediction

Improving dynamo models is crucial for better forecasting solar cycles. 

As Nandi explained, “A good dynamo model will help predict a solar cycle and not space weather, which determines whether the number of sunspots can create a solar storm or CME in the next couple of days. Think of dynamo prediction as climate and space weather is more like weather.”

The new study by MIT and the University of Edinburgh represents a significant step towards more accurate solar cycle predictions, potentially improving our ability to prepare for and mitigate the effects of solar storms.

The discovery that the Sun’s magnetic field might originate closer to its surface challenges long-standing theories and opens new avenues for research. 

As scientists continue to refine their models, we can look forward to more accurate predictions of solar activity, enhancing our preparedness for the impacts of space weather on Earth.

The Information is Taken from Engadget and Yahoo News