The sun has been very active lately. Since the solar cycle began last May, the number of sunspots and solar flares has increased steadily until it suddenly increased between December 2022 and January 2023. On April 21, the coronal mass ejection caused a pulse of plasma (superheated magnetized gas) toward Earth and triggered a geomagnetic storm with a level 4 on the 5 degree scale used by the US National Oceanic and Atmospheric Administration (NOAA). The storm brought observers a bright aurora that spread as far south as New Mexico in the US or France and Germany in Europe.

This peak in solar activity has led many to wonder if the current solar cycle is becoming more active than scientists had predicted.

The sun goes through cycles of magnetic activity, lasting an average of 11 years, in which its magnetic poles shift. The active phase near the middle of the cycle is marked by frequent sunspots, flares, and eruptions, followed by a quiet period when sunspots may disappear for days or weeks and flares are rare. The intensity of solar cycles also varies from one to the next. The last cycle, 24 since systematic monitoring of sunspots began, was one of the quietest in the history of observation.

To understand this variability and its causes, scientists estimate the exact length and intensity of each solar cycle using a variety of methods, from purely statistical models using observations of previous cycles to complex simulations of solar physics. The Solar Cycle Prediction Panel, an international group of experts, evaluates the value of individual predictions and tries to come up with a single prediction for the next cycle.

Lisa Upton (Space Systems Research Company), co-chairman of the Solar Cycle 25 Prediction Panel, says the activity we’re seeing is normal for a peaking cycle, and the panel still fits in with the panel’s prediction of an equally weak cycle. “Like humans, our memories tend to be short, and it’s been ten years since we reached the maximum of the solar cycle,” says Upton, “so people have forgotten what solar activity looks like.” like.” .