Maunder Minimum

The Maunder Minimum shown in a 400-year history of sunspot numbers

The Maunder Minimum, also known as the "prolonged sunspot minimum", was a period around 1645 to 1715 during which sunspots became exceedingly rare. During the 28-year period 1672–1699 within the minimum, observations revealed fewer than 50 sunspots. This contrasts with the typical 40,000–50,000 sunspots seen in modern times over a similar timespan.[1]

The Maunder Minimum was first noted by Gustav Spörer in publications in 1887 and 1889, work that was relayed to the Royal Astronomical Society in London, and then expanded on, by solar astronomers Edward Walter Maunder (1851–1928), and his wife Annie Russell Maunder (1868–1947), who also studied how sunspot latitudes changed with time. Two papers were published in Edward Maunder's name in 1890[2] and 1894,[3] and he cited the two earlier papers written by Gustav Spörer.[4][5] Because Annie Maunder had not received a university degree, restrictions at the time caused her contribution not to be publicly recognized.[6] The term Maunder Minimum was popularised by John A. Eddy,[7] who published a landmark paper in Science in 1976.[8]

The Maunder Minimum occurred within the Little Ice Age, a long period (c. 1300 – c. 1850) of lower-than-average European temperatures.[9] The reduced solar activity may have contributed to the climatic cooling, although the cooling began before the solar minimum and its primary cause is believed to be volcanic activity.[10]

  1. ^ John E. Beckman & Terence J. Mahoney (1998). The Maunder Minimum and Climate Change: Have Historical Records Aided Current Research?. Library and Information Services in Astronomy III. ASP Conference Series. Vol. 153. Instituto de Astrofísica de Canarias, Tenerife: Astronomical Society of the Pacific.
  2. ^ Maunder, E. W. (1890). "Professor Spoerer's researches on sun-spots". Monthly Notices of the Royal Astronomical Society. 50: 251–252.
  3. ^ Maunder, E. W. (August 1, 1894). "A prolonged sunspot minimum". Knowledge. 17: 173–176.
  4. ^ Spörer, Gustav (1887). "Über die Periodicität der Sonnenflecken seit dem Jahre 1618, vornehmlich in Bezug auf die heliographische Breite derselben, und Hinweis auf eine erhebliche Störung dieser Periodicität während eines langen Zeitraumes" [On the periodicity of sunspots since the year 1618, especially with respect to the heliographic latitude of the same, and reference to a significant disturbance of this periodicity during a long period]. Vierteljahrsschrift der Astronomischen Gesellschaft. 22. Leipzig: 323–329.
  5. ^ Spoerer, G. (February 1889). "Sur les différences que présentent l'hémisphère nord et l'hémisphère sud du Soleil" [On the differences that the northern hemisphere and southern hemisphere of the Sun present]. Bulletin Astronomique. 6: 60–63. doi:10.3406/bastr.1889.10197. S2CID 222462846.
  6. ^ Brück, Mary T. (1994). "Alice Everett and Annie Russell Maunder, torch bearing women astronomers". Irish Astronomical Journal. 21: 280–291. Bibcode:1994IrAJ...21..281B.
  7. ^ Weber, Bruce (June 17, 2009). "John A. Eddy, Solar Detective, Dies at 78". The New York Times. Retrieved July 28, 2015.
  8. ^ Eddy, J. A. (June 1976). "The Maunder Minimum" (PDF). Science. 192 (4245): 1189–1202. Bibcode:1976Sci...192.1189E. doi:10.1126/science.192.4245.1189. PMID 17771739. S2CID 33896851. Archived from the original (PDF) on 2010-02-16.
  9. ^ Mörner, Nils-Axel (July 2010). "Solar Minima, Earth's rotation and Little Ice Ages in the past and in the future: The North Atlantic–European case". Global and Planetary Change. 72 (4): 282–293. Bibcode:2010GPC....72..282M. doi:10.1016/j.gloplacha.2010.01.004. Retrieved 2 February 2023.
  10. ^ Crowley, Thomas (2008). "Volcanism and the Little Ice Age". PAGES. 16 (2): 22–23. doi:10.22498/pages.16.2.22.