Auroras may become more intense this March due to the “vernal equinox effect”

This month could be the best time to see the aurora borealis in nearly a decade, as the combination of the equinox effect and excessive solar activity makes them more likely to occur. However, exactly when and where they will appear is still unknown.

At 10:46 a.m. UTC on Friday, March 20th, the sun will cross the celestial equator, marking the spring equinox in the northern hemisphere and the autumnal equinox in the southern hemisphere.

When this happens, the Earth’s axis will be horizontal to the sun. This means that the nights in the Northern Hemisphere will be shorter until the summer solstice in June, but it also means that auroras are more likely to occur in the weeks before and after the vernal equinox.

you may like

vernal equinox effect

This “equinox effect,” in which the likelihood of auroral activity doubles around the spring and fall equinoxes, was first described by scientists Christopher Russell and Robert McFarlon in a paper published in the Journal of Geophysical Research in 1973.

They argued that auroras are more likely to occur in March and September because the solar wind’s southward magnetic field cancels Earth’s northward magnetic field, making it easier for the solar wind to flow along magnetic field lines. Effectively, the door opens and allows more charged particles to enter, colliding with oxygen and nitrogen atoms in the upper atmosphere and causing auroras.

The March equinox comes as Solar Maximum (the peak of the Sun’s 11-year solar cycle) comes to a close. During solar maximum, the sun’s magnetism is at full power. NASA, the National Oceanic and Atmospheric Administration (NOAA), and the International Solar Cycle Prediction Panel reported that the sun is likely to reach its solar maximum in October 2024, but added that it would take months or years to confirm.

The Sun’s magnetic strength is calculated by counting sunspots (cooler areas of the Sun caused by concentration of magnetic field lines) on its surface. The number of sunspots is currently on the decline, with the Met Office announcing in January that activity appears to be decreasing. That means fewer solar flares and, crucially, fewer coronal mass ejections, which are clouds of charged particles that can travel toward Earth to produce auroras.

According to NOAA’s Space Weather Prediction Center, Solar Cycle 26 is expected to begin between January 2029 and December 2032, during which solar activity is likely to remain low.

Will there be a noticeable impact on the vernal equinox this March? These conditions could produce the best aurora borealis until the mid-2030s, but that doesn’t mean you can expect to see them in the more southern latitudes of the Northern Hemisphere.

After all, everything depends on solar activity, which is difficult to predict in advance. Early February saw one of the most active sunspots of the current solar cycle, producing aurora borealis at much lower latitudes than usual, but this monster sunspot has since disappeared. Unfortunately, there is no way to know if new ones will appear in time for the spring equinox.