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Why are solar flares and coronal mass ejections more common near solar maximum?

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Space weather Earth's full North Polar auroral oval, in an image taken in ultraviolet light by the U.S. Polar spacecraft over northern Canada, April 6, 1996. In the colour-coded image, which simultaneously shows dayside and nightside auroral activity, the most intense levels of activity are red, and the lowest levels are blue. Polar, launched in February 1996, was designed to further scientists' understanding of how plasma energy contained in the solar wind interacts with Earth's magnetosphere.

Solar flares and coronal mass ejections (CMEs) are more frequent near solar maximum because they are driven by the complex, intense magnetic fields associated with sunspots, which reach their peak abundance and activity during this phase of the 11-year solar cycle.21

These phenomena are manifestations of the explosive rearrangement of solar magnetic fields through a process known as magnetic reconnection. During solar maximum, the Sun’s surface features a high number of active regions—clusters of magnetic flux loops that emerge from below the surface. When these magnetic fields become twisted or sheared by material motion, they store significant amounts of energy in electrical currents. This energy is cataclysmically released when the magnetic field lines reconnect, resulting in the sudden, impulsive release of energy seen as a solar flare or the eruption of plasma known as a CME. Because these active regions are most numerous and complex during solar maximum, the frequency of these high-energy events increases accordingly.123