A NASA-led analysis published in Nature challenges the long-standing idea that Earth's geomagnetic response eventually stops intensifying during the strongest solar storms.

Researchers examined more than one million solar-wind measurements from NASA spacecraft operating closer to Earth, including MMS and THEMIS. In those data, upper-atmosphere electric currents continued to strengthen as the solar wind intensified instead of flattening at a presumed saturation point.

The team argues that the apparent ceiling seen in older analyses can be explained by uncertainty. Many solar-wind measurements are taken about a million miles upstream, where the conditions observed do not always match the weaker or stronger flow that ultimately reaches Earth's magnetic shield.

The result matters because geomagnetic currents can disrupt satellites, radio communications and navigation signals. It does not prove that there is no physical limit under every possible condition. The authors say more observations during unusually strong storms are needed, so the finding should be treated as a major revision to the evidence rather than a final risk forecast.

Source: NASA Science ↗

Source: Nature ↗