In The Astrophysical Journal, a University of Michigan-led study details how the Sun’s magnetic field evolves as it moves through space, providing insight into solar wind acceleration. Using data from Parker Solar Probe and a rare alignment of Solar Orbiter, researchers observed that the Sun’s magnetic field changes from sharp oscillations to smooth waves, causing the surrounding solar wind to pick up speed. The discovery could enhance predictions of space weather, which affects Earth’s technology and infrastructure.
Observations from the Aligned Solar Probe
According to reports, the study focused on magnetic switchbacks – sharp turns in the Sun’s magnetic field. These events affect the solar wind, a stream of charged particles that can disrupt power grids, communications systems, and satellites. Parker Solar Probe, located within 30 solar radii (rs) of the Sun, and Solar Orbiter, located at 130 rs, provide comparative measurements of magnetic fields and plasma moments.
The findings showed that the magnetic switchbacks became smoother in the microstream with 30 percent fewer reversals as one moved outward, while the surrounding proton velocity increased by 10 percent. Researchers attribute this to magnetic relaxation, where magnetic energy is converted into kinetic energy, causing the solar wind to accelerate.
Insights for space weather forecasting
According to Top Soni, research fellow in climate and space science at the University of Michigan and corresponding author of the study, this is the first direct observation of switchback magnetic energy decreasing with distance. The collaboration between Parker Solar Probe and Solar Orbiter has been important for understanding the Sun’s magnetic processes, he said in the report.
Mojtaba Akhavan-Tafti, an associate research scientist at the University of Michigan, highlighted the broader implications in his statement, saying the magnetic switchbacks reveal the Sun’s dynamic energy processes and their impact on the solar system. The researchers aim to investigate whether magnetic energy transfer also produces heat, potentially solving a mystery about the heating of the solar wind.
