Geomagnetic Storm Predicted to Reach Earth This Friday

A series of M-class solar flares, recorded between October 5 and 6, launched a coronal mass ejection (CME) towards the planet. NOAA models indicate that the front of the plasma cloud is expected to reach Earth's magnetosphere in the early hours of October 9, generating a G1 to G2 level geomagnetic storm.

How the CME Was Detected and Its Speed

The M1.4-class eruption occurred in sunspot region AR4549, near the center of the solar face pointed towards Earth. Space observatories identified the event using X-ray sensors and coronagraphs, measuring the cloud's initial speed at about 560 km/s, according to the Solar Influences Data Analysis Center in Belgium.

Arrival Predictions and Intensity

The WSA-ENLIL heliospheric model, used by NOAA, estimates that the leading edge of the CME will reach Earth around 2 AM (Brasília time) on October 9, with a margin of error of a few hours. The alert issued by NOAA's Space Weather Prediction Center (SWPC) classifies the storm as moderate (G2), corresponding to a Kp index of ≈ 6.

Possible Effects on Technologies

During G1 to G2 events, brief radio blackouts may occur in sunlit areas, isolated voltage fluctuations in high-latitude power grids, and minor atmospheric drag requiring adjustments for low-Earth orbit satellites. Temporary drops in GPS and other navigation accuracy are also reported in similar situations.

Auroras at Lower Latitudes

G2-level storms have previously allowed auroras to be observed in regions as far south as New York and Idaho. If the CME's magnetic field orientation favors energy entry into the atmosphere, the luminous spectacle could be visible at lower latitudes than usual, although there is no guarantee of occurrence in specific locations.

Outlook for the Coming Days

In addition to the CME expected to arrive on Friday, regions AR4549 and AR4545 remain Earth-facing, increasing the likelihood of further eruptions. Coronal holes advancing across the solar face may release fast solar winds, suggesting another period of elevated geomagnetic activity forecast for Sunday, October 11.

With information from O GLOBO, Estadão, Brasil 247.