Solar storms may briefly dampen precipitation in parts of North America
A University of New Hampshire study links geomagnetic storms to short-term drops in rain and snow in some regions, especially after stronger events.
By Tom Brennan · Health & Medicine Correspondent
2 min read
Solar storms may briefly reduce rain and snow in parts of North America, according to a University of New Hampshire study published in Geophysical Research Letters. The findings point to a short-term connection between space weather and terrestrial weather that could help researchers improve climate modeling.
Joachim Raeder, professor emeritus of physics at the University of New Hampshire and author of the study, examined how weather patterns changed in the hours and days after solar activity sent radiation and energetic particles toward Earth. Raeder said scientists have long recognized that the sun affects the atmosphere over its roughly 11-year cycle, but the new work identifies a stronger response that can appear within a day of a solar storm.
The study combined 67 years of space weather records with atmospheric data that has become available more recently, according to the university. Raeder used computer models and anomaly mapping methods to look for departures from normal weather patterns after geomagnetic storms.
The analysis found notable declines in precipitation after solar storms in some areas, including the Rocky Mountains in the western United States and the Hudson Bay region of Canada, according to the university. The study also found that stronger solar storms were associated with larger shifts.
Season appeared to matter. Raeder reported that large solar storms occurring in summer or winter were more likely to reduce precipitation than storms that happened in spring or fall.
The work also examined wind speed, temperature, radiation and surface pressure. The university said those signals were significant in some places, but they were more scattered and local, making broad conclusions harder to draw.
Raeder’s paper does not present solar storms as a direct tool for day-to-day forecasting. The atmosphere is complex, and the study describes clues about possible links rather than a complete explanation of how a geomagnetic storm changes weather at the surface.
One pathway discussed in the study involves electromagnetic radiation from solar flares reaching the lower atmosphere through the polar vortex, the zone of low pressure and cold air around the poles. Raeder suggested that route may be more plausible than another proposed explanation in which solar activity changes cosmic rays and, in turn, affects cloud formation.
The university said the findings could help researchers better account for solar storms in climate models. Raeder’s study, titled “Regional and Seasonal Effects of Geomagnetic Storms on Terrestrial Weather,” was published in Geophysical Research Letters with the DOI 10.1029/2025GL121097.
This story draws on original reporting from Phys.org.