Definitions for "Solar cycle"
Keywords:  sunspot, cme, julian, eleven, gregorian
The period of 22 years in which the Sun's magnetic field rotates a full 360 degrees, causing its poles to switch
Solar activity changes over a period of, on average, 11 years. At solar maximum, solar activity is high and so too the EUV radiation output which affects the ionosphere. At solar minimum, the opposite is true. A solar cycle commences at solar minimum.
Regular increase and decrease of sunspots and other solar activity, such as solar flares and CMEs, which are thought to be physically related. Sunspots go through one cycle of activity in approximately 11 years. The Sun's magnetic polarity reverses between every cycle.