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Solar cycle 23

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This is an old revision of this page, as edited by Irpsit (talk | contribs) at 10:35, 29 October 2010 (Corrected the entry about the largest geomagnetic storms in cycle 23). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

The Sun with some sunspots visible.

Solar cycle 23 is the 23rd solar cycle since 1755, when recording of solar sunspot activity began.[1][2] The solar cycle lasted 12.6 years, beginning in May 1996 and ending in December 2008. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve month period) observed during the solar cycle was 120.8, and the minimum was 1.7.[3] There were a total of 805 days with no sunspots during this cycle.[4][5][6]

One of the first major aurora displays of solar cycle 23 occured in April 6, 2000, with bright red auroras visible as far south as Florida and South Europe.[7] On July 15, 2000, a strong G5 geomagnetic storm (the Bastille day storm) caused damage to GPS systems and in some power companies. Auroras were visible as far south as Texas.[8] Another major aurora display was observed in April 1, 2001, due to a coronal mass ejection hitting the Earth's magnetosphere. Auroras were observed as far south as Mexico and South Europe. The following day, a very large solar flare occured in April 2, 2001 (X20) but the blast was directed away from Earth. In late October 2003, a series of large solar flares occured. A X17 flare in October 28, 2003 (X17) resulted in autoras visible as far south as Florida and Texas.[9] A few days later, the largest solar flare ever measured with instruments occured in November 4, 2003 (initially measured at X28 and later upgraded to X45).[10][11] This flare was not Earth-oriented and thus only resulted in high-latitude auroras. Another large solar flare occured in September 7, 2005 (X17) with auroras visible in mid-latitudes. A complete list of the larger solar flares of this cycle is available at http://www.spaceweather.com/solarflares/topflares.html


See also

References

  1. ^ Kane, R.P. (2002). "Some Implications Using the Group Sunspot Number Reconstruction". Solar Physics 205(2), 383-401.
  2. ^ "The Sun: Did You Say the Sun Has Spots?". Space Today Online. Retrieved 12 August 2010.
  3. ^ SIDC Monthly Smoothed Sunspot Number. "[1]"
  4. ^ Spotless Days. "[2]"
  5. ^ What's Wrong with the Sun? (Nothing) more information: Spotless Days. "[3]"
  6. ^ Solaemon's Spotless Days Page. "[4]"
  7. ^ http://science.nasa.gov/science-news/science-at-nasa/2000/ast25apr_1m/
  8. ^ http://science.nasa.gov/science-news/science-at-nasa/2000/ast14jul_2m/
  9. ^ http://sohowww.nascom.nasa.gov/hotshots/2003_10_28/
  10. ^ http://sohowww.nascom.nasa.gov/hotshots/2003_11_04/
  11. ^ http://www.spaceref.com/news/viewpr.html?pid=13844


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