Unprecedented S4 Radiation Storm and G4 Magnetic Storm Shake Near-Earth Space

A rare and extremely powerful S4-level solar radiation storm has begun in near-Earth space for the first time in two solar cycles, according to the Solar Astronomy Laboratory of the Space Research Institute of the Russian Academy of Sciences (IKI RAN).

Photo: flickr.com by NASA Goddard Space Flight Center, https://creativecommons.org/licenses/by-sa/2.0/

Solar flare

"The flux of solar protons has exceeded 10,000 units. For the first time in the last two solar cycles, an S4-level radiation storm is occurring in the vicinity of Earth.”

Scientists explained that the historical maximum, approximately 40,000 units, was recorded in the twentieth century. Later, the laboratory уточнено that by 22:25 Moscow time, the proton flux had reached 37,000 units.

According to researchers, this level exceeds the proton intensity observed during the powerful X17.2 solar flare in 2003 and represents the highest radiation level recorded in the twenty-first century.

What an S4 Radiation Storm Means

Two solar cycles correspond to roughly 22 Earth years. Under the classification system developed by the National Oceanic and Atmospheric Administration (NOAA), radiation storms are divided into five categories, from S1, considered weak, to S5, classified as extreme.

Experts emphasized that an S5-level radiation storm has never been observed in recorded history and remains purely theoretical.

Risks for Space, Aviation, and Satellites

Scientists stressed that the ongoing radiation storm poses no threat to life on Earth's surface. The planet's magnetic field and atmosphere fully block solar radiation at high altitudes. If energetic particles were to penetrate to the surface, the consequences for the biosphere would be catastrophic, but this scenario is not occurring.

The main risks affect astronauts, high-altitude flights in polar regions, and satellites. Potential consequences include increased radiation exposure, electronic malfunctions, orientation errors, and reduced efficiency of solar panels.

NOAA also warned of possible disruptions to radio communications and increased navigation errors at high latitudes that could persist for several days.

Planetary Magnetic Storm Reaches G4 Level

Alongside the radiation storm, a powerful planetary magnetic storm has begun on Earth, reaching level G4.33, according to the Solar Astronomy Laboratory of IKI RAN.

"The key question remains whether the highest level, G5, will be reached in the coming hours. Over the past 20 years, such a level has been observed only once, in May 2024.”

Researchers reported that solar wind parameters currently stand close to record values.

Critical Day Forecasted

Earlier, NOAA warned that January 20 would become a critical day due to unfavorable space weather conditions caused by the combination of an intense solar radiation burst and a strong magnetic storm.

Scientists from IKI RAN previously explained that after the strongest solar flare of the year, classified as X19.5 and recorded on January 18, a massive cloud of plasma would reach Earth during the night, triggering magnetic storms and vivid auroras.

According to preliminary forecasts, the most intense magnetic disturbance at level G4 was expected between 9:00 and 12:00 Moscow time, while the probability of an extreme G5-level storm was estimated at 10 percent.

On the evening of January 19, researchers confirmed the onset of the S4 radiation storm, noting that the proton flux of 37,000 units set a new record for the twenty-first century and surpassed levels observed during the major solar event of 2003.