Solar Magnetic Activity Migrating Toward Sun's Surface, Study Reveals

An international research team using helioseismology—the study of sound wave vibrations within the Sun—has discovered that the star's magnetic activity is progressively shifting toward its surface layers within the past solar cycles. The findings, based on analysis of four complete solar cycles, show that structural changes associated with the solar magnetic cycle are becoming increasingly concentrated in regions less than 1,000 kilometers below the Sun's visible surface. This shift in the Sun's internal magnetic dynamics has implications for forecasting space weather events that can disrupt Earth's satellites, communications, and power grids.

Researchers employed helioseismology, which analyzes how sound waves travel through the Sun's interior, to map magnetic changes invisible from Earth. By monitoring oscillation frequencies across nearly four decades of data from six ground-based observatories, the team identified a pattern: magnetic structures that once extended deeper into the Sun are now concentrating in shallower zones closer to the visible surface.

The shift emerged distinctly over the past few solar cycles, suggesting a fundamental reorganization in how the Sun stores and organizes its magnetic energy. Notably, the current cycle shows weaker outward signs of activity despite internal oscillations indicating comparable underlying strength, indicating that surface observations alone may underestimate or mischaracterize solar processes.