Electron flux alert issued on September 11, 2026

An alert was issued by NOAA SWPC on September 11, 2026, after the electron 2 MeV integral flux exceeded 1,000 pfu. The alert remains in effect, continuing from September 10, 2026 at 13:04 UTC. The maximum recorded 2 MeV flux was 1,391 pfu at 04:55 UTC on September 11, 2026.

Exceeding the 1,000 pfu threshold for 2 MeV electron integral flux indicates enhanced levels of energetic particles in Earth’s outer radiation belt. Such conditions can create increased hazards for spacecraft and satellite operations by contributing to deep dielectric charging and interfering with satellite electronics. These alerts are critical for operational planning by satellite operators and impacted industries. There were no corresponding enhancements in proton flux, which remained at background levels according to official data.

The increased electron flux was not linked to elevated solar flare activity, as solar activity remained low with only weak C-class flares observed in the relevant period. The overall solar wind conditions and geomagnetic field were largely stable, with no significant geomagnetic disturbances reported.