Solar cycle 15

Solar cycle 15 is the fifteenth solar cycle since 1755, when recording of solar sunspot activity began.[1][2] The solar cycle lasted 10 years, beginning in August 1913 and ending in August 1923. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve month period) observed during the solar cycle was 105.4, and the minimum was 5.6.[3] There were a total of 534 days with no sunspots during this cycle.[4][5][6] A major geomagnetic storm occurred on May 13, 1921 causing damage in communication systems and aurora displays at Zenith in California [7]

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. http://www.spacetoday.org/SolSys/Sun/Sunspots.html. 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://www.solarstorms.org/SS1921.html