Solar cycle 18

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Solar cycle 18
Sunspot Data
Start date February 1944
End date April 1954
Duration (years) 10.2
Max count 151.8
Max count month May 1947
Min count 3.4
Spotless days 446
Cycle chronology
Previous cycle Solar cycle 17 (1933-1944)
Next cycle Solar cycle 19 (1954-1964)

Solar cycle 18 was the eighteenth solar cycle since 1755, when extensive recording of solar sunspot activity began.[1][2] The solar cycle lasted 10.2 years, beginning in February 1944 and ending in April 1954. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve-month period) observed during the solar cycle was 151.8 (May 1947), and the minimum was 3.4.[3] There were a total of 446 days with no sunspots during this cycle.[4][5][6]

Cycle 18 was characterised by "giant" sunspots.[7] The recording of the 10.7 cm (2800 MHz) solar radio flux began partway during this cycle,[8] and values of the solar flux during this cycle turned out to be particularly high.[7]

See also[edit]

References[edit]

  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. ^ a b Dodson, Helen W.; Hedeman, E. Ruth; Mohler, Orren C. (August 1974). "Comparison of activity in solar cycles 18, 19, and 20". Reviews of Geophysics 12 (3): 329–341. doi:10.1029/RG012i003p00329. 
  8. ^ Petersen, Edward (2012). Single Event Effects in Aerospace. Wiley. p. 20. ISBN 1118084306.