Britannica
Sources used in this answer
How does the 11-year solar cycle affect the number of solar storms?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
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.
The 11-year solar cycle significantly influences the frequency and intensity of solar storms, which are primary drivers of space weather.1
The relationship between the cycle and solar storms is characterized by the following patterns:
- Solar Maximum: During this period of peak solar activity, solar storms such as solar flares and coronal mass ejections (CMEs) are most numerous and intense. These events are driven by the explosive rearrangement of solar magnetic fields through magnetic reconnection.12
- Solar Minimum: During the several-year period between maxima, solar activity can be extremely low. However, this phase is often associated with recurrent geomagnetic storms caused by coronal holes, which generate high-speed solar wind streams that repeat on a 27-day solar rotation period.123
- Declining Phase: Corotating interaction regions—disturbances where fast solar wind from coronal holes catches up with slower wind—are most commonly observed during the years following the solar maximum as the cycle transitions toward the solar minimum.2
Ultimately, while CMEs and flares are most frequent during the solar maximum, the Sun continues to influence Earth's space environment throughout the entire 11-year cycle.12