Solar Maximum and the sunspot cycle
Sunspots are regions of the Sun that are cooler than surrounding areas (about 2000 degrees) and are easily identified as dark areas on the surface of the Sun. Scientists have noticed that sunspot activity tends to follow a regular cycle that peaks every 11 years. This peak is known as Solar Maximum. The next peak is expected to occur in 2013.
Sunspots form when the Sun’s internal magnetic field becomes “twisted.” The Sun’s equator rotates more quickly than its poles, which creates bubble-shaped magnetic “knots” that trap enormous amounts of electrically charged gas inside. These bubbles eventually explode, sending fiery jets of hot plasma into space and increasing the amount of solar wind that can impact Earth.