Solar cycle 9
| Solar cycle 9 | |
|---|---|
| Sunspot data | |
| Start date | July 1843 |
| End date | December 1855 |
| Duration (years) | 12.4 |
| Max count | 131.9 |
| Max count month | February 1848 |
| Min count | 3.2 |
| Spotless days | 654 |
| Cycle chronology | |
| Previous cycle | Solar cycle 8 (1833-1843) |
| Next cycle | Solar cycle 10 (1855-1867) |
Solar cycle 9 was the ninth solar cycle since 1755, when extensive recording of solar sunspot activity began.[1][2] The solar cycle lasted 12.4 years, beginning in July 1843 and ending in December 1855. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve-month period) observed during the solar cycle was 131.9 (February 1848), and the minimum was 3.2.[3] There were a total of approximately 654 days with no sunspots during this cycle.[4][5][6]
Solar cycle 9 began in 1843, the year that Heinrich Schwabe discovered the sunspot cycle.[7] During this cycle, Edward Sabine, Rudolf Wolf, and other scientists recognized that solar disturbances affected the Earth's magnetic environment, so that solar cycles are identical to the Earth's geomagnetic cycles. Wolf also introduced the Wolf number during this period.
The phenomenon now known as geomagnetically induced current was seen for the first time during this cycle – it became apparent on the emerging electric telegraph network. Francis Ronalds, Honorary Director of the Kew Observatory and Sabine’s colleague, received data from telegraph operators on the movements of their magnetic needles for comparison with his own photo-recordings of atmospheric electricity and geomagnetic intensity variations but had insufficient resources to study the causes of the unexpected currents in detail.[8][9]
Geomagnetic activity during solar cycle 9 followed a double-peaked distribution, with more magnetic storms during the rising (1847–48) and falling (1851–54) parts of the cycle.[10]
See also
References
- ^ Kane, R.P. (2002). "Some Implications Using the Group Sunspot Number Reconstruction". Solar Physics 205(2), 383-401.
- ^ "The Sun: Did You Say the Sun Has Spots?". Space Today Online. Retrieved 12 August 2010.
- ^ SIDC Monthly Smoothed Sunspot Number. "[1]"
- ^ Spotless Days. "[2]"
- ^ What's Wrong with the Sun? (Nothing) more information: Spotless Days. "[3]"
- ^ Solaemon's Spotless Days Page. "[4]"
- ^ Claudio Vita-Finzi. Solar History: An Introduction, p. 4, Springer, 2012 ISBN 9400742959.
- ^ Ronalds, B.F. (2016). Sir Francis Ronalds: Father of the Electric Telegraph. London: Imperial College Press. ISBN 978-1-78326-917-4.
- ^ Ronalds, B.F. (2016). "Sir Francis Ronalds and the Electric Telegraph". Int. J. for the History of Engineering & Technology. doi:10.1080/17581206.2015.1119481.
- ^ Nevanlinna, H.; Ketola, A.; Häkkinen, L.; Viljanen, A.; Ivory, K. (23 April 1993). "Geomagnetic activity during solar cycle 9 (1844–1856)". Geophysical Research Letters. 20 (8): 743–746. Bibcode:1993GeoRL..20..743N. doi:10.1029/93GL00836.
| 18th century |
|  | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 19th century |
| ||||||||||
| 20th century |
| ||||||||||
| 21st century |
| ||||||||||
 | This article related to the Sun is a stub. You can help Wikipedia by expanding it. |