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sunspot cycle
sunspot cycle The variation in the number of sunspots and other forms of solar activity with an average period of about 11 years. In each successive cycle the north and south magnetic polarities of the Sun are reversed, so that there is a 22-year magnetic cycle. The monthly averages of relative sunspot numbers are around 6 in years of sunspot minimum and 116 at sunspot maximum. Not only sunspot number varies, but also the numbers of active regions and flares, and the level of ultraviolet, radio, and other emission associated with such regions. The 11-year periodicity is thought to arise through the action of the solar dynamo. The sunspot cycle may not always have operated in its present observed form, as suggested by the existence of the Maunder minimum.
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"sunspot cycle." A Dictionary of Astronomy. 1997. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "sunspot cycle." A Dictionary of Astronomy. 1997. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O80-sunspotcycle.html "sunspot cycle." A Dictionary of Astronomy. 1997. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-sunspotcycle.html |
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solar cycle
solar cycle See sunspot cycle.
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Cite this article
"solar cycle." A Dictionary of Astronomy. 1997. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "solar cycle." A Dictionary of Astronomy. 1997. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O80-solarcycle.html "solar cycle." A Dictionary of Astronomy. 1997. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-solarcycle.html |
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