Skies across Iceland, northern Scandinavia, and parts of the northern United States erupted in green and red curtains of light on January 10 as a moderate geomagnetic storm slammed into Earth’s magnetic field. The aurora pushed far enough south to reach New York and Idaho, regions that rarely witness the northern lights.
NOAA’s Space Weather Prediction Center recorded the storm at G2 level on its five-point scale. Peak activity hit between 18:00 and 21:00 UTC when the planetary Kp index climbed to 7, according to measurements from the UK Met Office.
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Solar Blast Triggers the Storm
The source traced back to January 8, when Active Region 4334 on the sun’s surface unleashed a coronal mass ejection. This explosive burst of solar plasma traveled 93 million miles through space before colliding with Earth’s magnetosphere 48 hours later.
The Heartland magnetometer in the central United States detected the impact at 20:13 UTC on January 10. The instrument registered a sudden magnetic impulse of 47 nanoteslas, marking the exact moment the solar material struck.
Solar wind speeds spiked from a baseline of 500 kilometers per second to 646 km/s within hours. By the storm’s peak, velocities reached between 670 and 780 km/s, nearly double normal conditions.
Where the Lights Appeared
Viewers across both hemispheres reported aurora sightings during the storm’s most active period:
Northern locations: Iceland, Greenland, northern and central Scandinavia, Alaska, northern Canada, northern tier U.S. states including areas near New York City and Boise.
Southern locations: Tasmania, New Zealand’s South Island.
The displays reached down to 55 degrees geomagnetic latitude, a threshold that brings auroras to populated areas far from the Arctic and Antarctic circles. Photographers in Scotland and northern Michigan captured vibrant greens and purples dancing overhead.
How Geomagnetic Storms Create Auroras
When a coronal mass ejection reaches Earth, its embedded magnetic field interacts with our planet’s magnetosphere. The key factor is the orientation of the interplanetary magnetic field’s north-south component, called Bz.
A southward-pointing Bz essentially opens a door in Earth’s magnetic defenses. Solar particles stream down magnetic field lines toward the poles, slamming into oxygen and nitrogen molecules in the upper atmosphere at altitudes between 60 and 200 miles.
These collisions transfer energy to atmospheric gases. When the excited molecules return to their normal state, they release photons. Oxygen produces the familiar green glow at lower altitudes and red at higher altitudes. Nitrogen contributes blues and purples.
Infrastructure Takes a Hit
Power grid operators across northern regions monitored systems closely during peak storm hours. G2 storms can trigger voltage alarms and stress transformers, particularly in high-latitude electrical networks where geomagnetically induced currents flow more readily through long transmission lines.
Satellite operators made precautionary adjustments to spacecraft orientation. Increased atmospheric drag during geomagnetic storms causes satellites in low Earth orbit to slow down, throwing off position predictions used for collision avoidance and ground tracking.
GPS signals degraded in polar regions, with effects extending into mid-latitudes. Aviation routes over the North Atlantic and Arctic experienced high-frequency radio blackouts, forcing some flights to use alternative communication methods.
Activity Continues This Week
The January 10-11 storm has passed, but space weather remains unsettled. A large coronal hole rotated into position facing Earth on January 16. These regions of open magnetic field lines on the sun’s corona act like fire hoses, spraying high-speed solar wind streams into space.
NOAA forecasters expect G1 (minor) geomagnetic storm conditions through January 18, with brief G2 (moderate) intervals possible when the solar wind’s magnetic field orientation turns favorable. High-latitude regions from Reykjavik to Fairbanks continue seeing regular aurora activity.
Current solar wind speeds hover around 670 to 750 km/s, well above the 400 km/s average. The interplanetary magnetic field strength remains elevated but has shown mostly northward orientation, which limits geomagnetic coupling.
Viewing Opportunities Ahead
Aurora chasers should monitor NOAA’s 30-minute forecast model, which uses real-time solar wind data from satellites positioned 1 million miles upstream of Earth. The model provides location-specific visibility predictions.
Best viewing requires three elements: active geomagnetic conditions, clear skies, and darkness away from light pollution. Look toward the northern horizon if you’re south of the Arctic Circle, or overhead if you’re inside the auroral oval.
The sun remains in an active phase of its 11-year cycle. Solar physicists expect continued eruptions and coronal mass ejections through 2026 and into 2027 before activity begins declining toward the next minimum.
The Bigger Picture
This moderate geomagnetic storm and aurora borealis display fits a pattern of increased solar activity. January alone has seen multiple CME eruptions, including several M-class flares and one X1.9 flare on January 18 from Active Region 4341.
While G2 storms occur several times per year during solar maximum, each event provides researchers with data on how our technological infrastructure handles space weather. The information helps engineers design more robust systems for satellites, power grids, and communication networks.
For millions who witnessed the January 10 aurora, the storm delivered a reminder that Earth sits inside the sun’s extended atmosphere. When our star throws a tantrum, the results illuminate our skies.
