New research suggests that the Sun’s magnetic field originates much closer to the surface than previously thought, a finding that could help predict periods of extreme solar storms like those that hit the earth earlier this month.
The magnetic field appears to be generated 20,000 miles below the surface of the Sun. Previous calculations placed the roots of the process more than 130,000 miles below, the international team reported Wednesday.
The Sun’s intense magnetic energy is the source of solar flares and plasma eruptions known as coronal mass ejections. When directed to Earth, they can create stunning aurora borealis but also disrupt power and communications.
“We still don’t understand the sun well enough to accurately predict” space weather, lead author Geoffrey Vasil of the University of Edinburgh said in an email.
The latest findings, published in the journal Nature, “will be an important step towards finally solving” this mysterious process known as the solar dynamo, added co-author Daniel Lecoanet of Northwestern University.
/ AP
Galileo was among the first astronomers to turn a telescope to the sky and study sunspots in the early 17th century. Solar flares and coronal mass ejections tend to occur near sunspots, Earth-sized dark spots located near the most intense parts of the Sun’s shifting magnetic field.
Vasil and his team developed new models of the interaction between the Sun’s magnetic field and the plasma flow, which changes at different latitudes during an 11-year cycle. They fed their calculations into a NASA supercomputer in Northern California — the same one used in the 2015 movie “The Martian” to verify the best flight path to save the main character. The results suggest a shallow magnetic field and further research is needed to confirm.
The modeling was “very simplistic,” said Ellen Zweibel of the University of Wisconsin-Madison, who was not part of the team, in an accompanying editorial.
The results are interesting and “certainly inspire future studies,” Zweibel said.
Preparing for a “potentially much more dangerous” storm
The new findings should improve long-term solar predictions, allowing scientists to better predict the strength of our star’s future cycles. The Sun is approaching its highest level of activity in the current 11-year cycle, the recent flares.
Powerful solar flares and explosions of billions of tons of plasma earlier this month unleashed violent solar storms that created auroras in unexpected places. The sun came out last week the largest solar flare in almost 20 yearsbut avoided earth.
NOAA Space Weather Prediction Center
It comes just days after an “extreme” G5 geomagnetic storm reached Earth after NOAA’s Space Weather Prediction Center warned of the potential for a severe impact.
A better understanding of the Sun can ensure that “we are prepared for the next storm to hit Earth — potentially a much more dangerous one,” Lecoanet said.
Earth is currently in solar cycle 25, which began in 2020. The last cycle maintained an average length of 11 years and was the weakest solar cycle in a century, the National Weather Service said. Although the current cycle was predicted to be relatively weak and similar to the previous one, NOAA officials noted a “steady increase in sunspot activity” since the beginning.
Li Cohen contributed to this report.