Solar cycle 4

Last updated

Solar cycle 4
Sunspot data
Start dateSeptember 1784
End dateApril 1798
Duration (years)13.6
Max count235.3
Max count monthFebruary 1788
Min count15.9
Cycle chronology
Previous cycle Solar cycle 3 (1775–1784)
Next cycle Solar cycle 5 (1798–1810)

Solar cycle 4 was the fourth solar cycle since 1755, when extensive recording of solar sunspot activity began. [1] [2] The solar cycle lasted 13.6 years, beginning in September 1784 and ending in April 1798 (thus overlapping the Dalton Minimum). The maximum smoothed sunspot number observed during the solar cycle was 235.3 (in February 1788), and the starting minimum was 15.9. [3]

There are some recent speculations that cycle 4, the longest solar cycle since 1755, was actually two cycles, based on the appearance of new sunspots at high solar latitudes in 1793–1796 and a reconstruction of the sunspot butterfly diagram for cycles 3 and 4, [4] [5] although total sunspot numbers only show a single-peaked distribution. [3]

See also

Related Research Articles

Solar cycle Periodic change in the Suns activity

The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surface. Over the period of a solar cycle, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation from a period of minimum activity to a period of a maximum activity back to a period of minimum activity.

Solar cycle 2 Solar activity from June 1766 to June 1775

Solar cycle 2 was the second solar cycle since 1755, when extensive recording of sunspot activity began. The solar cycle lasted 9 years, beginning in June 1766 and ending in June 1775. The maximum smoothed sunspot number observed during the solar cycle was 193.0, and the starting minimum was 18.6.

Solar cycle 1 Solar activity from February 1755 to June 1766

Solar cycle 1 was the first solar cycle since extensive recording of solar sunspot activity began. The solar cycle lasted 11.3 years, beginning in February 1755 and ending in June 1766. The maximum smoothed sunspot number observed during the solar cycle was 144.1, and the starting minimum was 14.0.

Solar cycle 3 Solar activity from June 1775 to September 1784

Solar cycle 3 was the third solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 9.3 years, beginning in June 1775 and ending in September 1784. The maximum smoothed sunspot number observed during the solar cycle was 264.3, and the starting minimum was 12.0.

Solar cycle 5 Solar activity from April 1798 to August 1810

Solar cycle 5 was the fifth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 12.3 years, beginning in April 1798 and ending in August 1810. The maximum smoothed sunspot number observed during the solar cycle was 82.0, in February 1805, and the starting minimum was 5.3.

Solar cycle 6 Solar activity from August 1810 to May 1823

Solar cycle 6 was the sixth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 12.8 years, beginning in August 1810 and ending in May 1823. The maximum smoothed sunspot number observed during the solar cycle was 81.2, in May 1816, and the starting minimum was 0.0.

Solar cycle 7 Solar activity from May 1823 to November 1833

Solar cycle 7 was the seventh solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 10.5 years, beginning in May 1823 and ending in November 1833. The maximum smoothed sunspot number observed during the solar cycle was 119.2, and the starting minimum was 0.2.

Solar cycle 8 was the eighth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 9.7 years, beginning in November 1833 and ending in July 1843. The maximum smoothed sunspot number observed during the solar cycle was 244.9, and the starting minimum was 12.2.

Solar cycle 9 Solar activity from July 1843 to December 1855

Solar cycle 9 was the ninth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 12.4 years, beginning in July 1843 and ending in December 1855. The maximum smoothed sunspot number observed during the solar cycle was 219.9, and the starting minimum was 17.6. During the solar cycle minimum transit from solar cycle 9 to solar cycle 10, there were a total of 655 days with no sunspots.

Solar cycle 10 Solar activity from December 1855 to March 1867

Solar cycle 10 was the tenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.3 years, beginning in December 1855 and ending in March 1867. The maximum smoothed sunspot number observed during the solar cycle was 186.2, and the starting minimum was 6.0. During the transit from solar cycle 10 to 11, there were a total of 406 days with no sunspots.

Solar cycle 11 Solar activity from March 1867 to December 1878

Solar cycle 11 was the eleventh solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.8 years, beginning in March 1867 and ending in December 1878. The maximum smoothed sunspot number observed during the solar cycle was 234.0, and the starting minimum was 9.9. During the minimum transit from solar cycle 11 to 12, there were a total of 1028 days with no sunspots.

Solar cycle 12 Solar activity from December 1878 to March 1890

Solar cycle 12 was the twelfth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.3 years, beginning in December 1878 and ending in March 1890. The maximum smoothed sunspot number observed during the solar cycle was 124.4, and the starting minimum was 3.7. During the minimum transit from solar cycle 12 to 13, there were a total of 736 days with no sunspots.

Solar cycle 13 Solar activity from March 1890 to January 1902

Solar cycle 13 was the thirteenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.8 years, beginning in March 1890 and ending in January 1902. The maximum smoothed sunspot number observed during the solar cycle was 146.5, and the starting minimum was 8.3. During the minimum transit from solar cycle 13 to 14, there were a total of 934 days with no sunspots.

Solar cycle 14 Solar activity from January 1902 to July 1913

Solar cycle 14 was the fourteenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.5 years, beginning in January 1902 and ending in July 1913. The maximum smoothed sunspot number observed during the solar cycle was 107.1, in February 1906, and the starting minimum was 4.5. During the minimum transit from solar cycle 14 to 15, there were a total of 1023 days with no sunspots.

Solar cycle 16 Solar activity from August 1923 to September 1933

Solar cycle 16 was the sixteenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 10.1 years, beginning in August 1923 and ending in September 1933. The maximum smoothed sunspot number observed during the solar cycle was 130.2, and the starting minimum was 9.4. During the minimum transit from solar cycle 16 to 17, there were a total of 568 days with no sunspots.

Solar cycle 17 was the seventeenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 10.4 years, beginning in September 1933 and ending in February 1944. The maximum smoothed sunspot number observed during the solar cycle was 198.6, and the starting minimum was 5.8. During the minimum transit from solar cycle 17 to 18, there were a total of 269 days with no sunspots.

Solar cycle 18 was the eighteenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 10.2 years, beginning in February 1944 and ending in April 1954. The maximum smoothed sunspot number observed during the solar cycle was 218.7, and the starting minimum was 12.9. During the minimum transit from solar cycle 18 to 19, there were a total of 446 days with no sunspots.

Solar cycle 20 Solar activity from October 1964 to March 1976

Solar cycle 20 was the twentieth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.4 years, beginning in October 1964 and ending in March 1976. The maximum smoothed sunspot number observed during the solar cycle was 156.6, and the starting minimum was 14.3. During the minimum transit from solar cycle 20 to 21, there were a total of 272 days with no sunspots.

Solar cycle 21 Solar activity from March 1976 to September 1986

Solar cycle 21 was the 21st solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 10.5 years, beginning in March 1976 and ending in September 1986. The maximum smoothed sunspot number observed during the solar cycle was 232.9, in December 1979, and the starting minimum was 17.8. During the minimum transit from solar cycle 21 to 22, there were a total of 273 days with no sunspots. The largest solar flare of this cycle (X15) occurred on July 11, 1978.

References

  1. Kane, R.P. (2002). "Some Implications Using the Group Sunspot Number Reconstruction". Solar Physics205(2), 383–401.
  2. "The Sun: Did You Say the Sun Has Spots?". Space Today Online. Retrieved 12 August 2010.
  3. 1 2 SIDC Monthly Smoothed Sunspot Number. ""
  4. Usoskin, I. G.; Mursula, K.; Arlt, R.; Kovaltsov, G. A. (2009). "A Solar Cycle Lost in 1793–1800: Early Sunspot Observations Resolve the Old Mystery". The Astrophysical Journal. 700 (2): L154. arXiv: 0907.0063 . Bibcode:2009ApJ...700L.154U. doi:10.1088/0004-637X/700/2/L154.
  5. "Centuries-old sketches solve sunspot mystery", New Scientist, 1 August 2009, p. 10.