Spring Equinox Brings Increased Northern Lights Activity—Here’s Why

As the spring equinox on March 20 approaches, the alignment of Earth’s magnetic field with solar winds increases the chances of witnessing the northern lights. This phenomenon, known as the Russell-McPherron effect, creates openings in Earth’s magnetic shield, allowing charged solar particles to intensify auroral activity. The ongoing solar maximum, expected to peak in 2025, further enhances these displays by increasing sunspots, solar flares, and coronal mass ejections. The equinox effect, which boosts geomagnetic disturbances, makes auroras more likely during spring and fall. Skywatchers in northern latitudes should stay alert for potential geomagnetic storms and vibrant auroras in the coming weeks.

Spring Equinox Brings Increased Northern Lights Activity—Here’s Why

As the spring equinox, or vernal equinox, approaches on March 20, skywatchers may have a greater chance of witnessing the northern lights, also known as the aurora borealis. This is due to the alignment of Earth’s magnetic field with solar winds, increasing the likelihood of vibrant aurora displays in the upper atmosphere.

Shannon Schmoll, director of the Abrams Planetarium, recently told CNET that the chances of seeing the aurora are lower in winter and summer since Earth’s tilt causes one hemisphere to be angled away from the Sun. However, during the March and September equinoxes, Earth’s axis is parallel to the Sun. This alignment, known as the Russell-McPherron effect, causes Earth’s magnetic field and solar winds to synchronize, creating “cracks” that allow charged particles to enter, intensifying auroral activity.

The Sun’s Activity and Its Effect on the Northern Lights

During periods of high solar activity, the Sun generates more sunspots, along with solar flares and coronal mass ejections, which trigger geomagnetic storms. These storms lead to enhanced northern light displays on Earth. According to Allison Jaynes, an associate professor of physics and astronomy at the University of Iowa, the current solar maximum—expected to peak in 2025—will likely be much stronger than the previous one in 2014, which was relatively weak.

How the Northern Lights Form

Earth’s magnetic field serves as a protective barrier against the charged particles from the Sun’s solar winds. However, when solar wind activity intensifies, it interacts with gases in Earth’s magnetic field, creating stunning auroras. These lights are produced when charged electrons from the Sun collide with air molecules, exciting them. As these molecules return to their normal state, they emit light—oxygen produces green and red hues, while nitrogen creates blue and purple shades.

For those interested in tracking the northern lights, resources such as the Space Weather Prediction Center offer an aurora dashboard, while Aurorasaurus provides a live map with notification alerts.

Powerful ‘Equinox Auroras’ May Be on the Way: How Seasonal Changes Enhance Northern Lights

As the Sun moves into the Northern Hemisphere, skywatchers may soon witness breathtaking auroras in the night sky.

At exactly 9:01 UTC (5:01 a.m. EDT) on March 20, the Sun will cross the celestial equator, marking the vernal (spring) equinox. This astronomical event signals the start of longer daylight hours in the Northern Hemisphere, lasting until June’s solstice.

While the equinox marks the transition to spring, it also signals the end of prime aurora-hunting season in the Arctic. Around 66 degrees north, sunrises and sunsets will shift, reducing nighttime darkness. However, before that happens, the aurora borealis may put on a spectacular display, thanks to the unique celestial alignment that occurs during the equinox.

How the ‘Equinox Effect’ Boosts Auroral Activity

During the equinoxes, Earth’s axis is perpendicular to the Sun, leading to nearly equal daylight and darkness worldwide. This alignment enhances auroral activity due to an increased interaction between Earth’s magnetic field and the solar wind.

The northern lights form when charged particles from the Sun—known as the solar wind—collide with Earth’s magnetic field. According to Tom Kerss, author of The Northern Lights: The Definitive Guide to Auroras, Earth’s magnetic poles align more favorably with the Sun’s magnetic field during the equinoxes. This alignment allows for more efficient energy transfer, creating temporary “holes” in Earth’s magnetic shield and allowing solar wind to enter the geospace environment.

Higher Chance of Geomagnetic Disturbances

NASA solar physicist David Hathaway notes that geomagnetic disturbances are nearly twice as likely in spring and fall compared to winter and summer. While increased auroral activity is influenced by this seasonal alignment, the most powerful displays depend on solar activity, which is currently reaching its peak during the ongoing solar maximum.

Although it’s uncertain whether this aurora season will conclude with an intense display, the “equinox effect” can last for weeks. Those in northern latitudes should stay alert for potential geomagnetic storms and vibrant northern lights in the nights ahead.