Scientists have observed an unexpected surge in solar activity, potentially indicating a more intense solar maximum than initially predicted. This heightened activity could impact space equipment and navigation systems.
The Solar Cycle and the Gleissberg Cycle
Solar activity naturally fluctuates in an approximately 11-year cycle, transitioning from a quiet state to a solar maximum characterized by increased sunspots and flares. However, a less predictable cycle, the Gleissberg Cycle, influences the intensity of sunspot cycles over 80-100 years.
Recent research suggests the Gleissberg Cycle may be starting a new phase, contributing to the current solar maximum's intensity and making accurate forecasting challenging. Some experts remain skeptical about the influence of the Gleissberg Cycle.
Impact on Earth's Radiation Belts
Researchers are analyzing the flow of protons in Earth's inner radiation belt, which typically decreases as solar activity increases due to interactions with the expanding upper atmosphere. Conversely, proton flow increases during low solar activity.
Analysis suggests this flow has been increasing over the past 20 years and is expected to decrease slightly, indicating the Gleissberg Cycle minimum may have passed. This data is gathered with the help of NOAA satellites, particularly as they pass through the South Atlantic Anomaly (SAA), a region where Earth's magnetic field is weakest.
Rare Helium Isotope Detection
The Solar Orbiter spacecraft has detected record concentrations of helium-3, a rare helium isotope, in plasma flows from the Sun. In late October 2023, the Solar Orbiter detected helium-3 whooshing away from the Sun in concentrations 180,000 times greater than its usual concentration in the Solar atmosphere. Scientists traced it to a quiet region of the Sun with unexpectedly weak magnetic fields, upending previous assumptions about solar particle acceleration.
According to researcher Calvin Adams, average solar activity is expected to increase. Experts suggest that if the Gleissberg Cycle is indeed starting again, the upcoming cycles of solar flares will be as active as the current cycle and might even become stronger as we approach the Gleissberg Cycle maximum, which is still 40-50 years away.