A SOLAR CYCLE LOST IN 1793-1800: EARLY SUNSPOT OBSERVATIONS RESOLVE THE OLD MYSTERY
@article{Usoskin2009ASC, title={A SOLAR CYCLE LOST IN 1793-1800: EARLY SUNSPOT OBSERVATIONS RESOLVE THE OLD MYSTERY}, author={I. Usoskin and K. Mursula and R. Arlt and G. Kovaltsov}, journal={The Astrophysical Journal}, year={2009}, volume={700} }
Because of the lack of reliable sunspot observations, the quality of the sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784-1799) before the Dalton minimum. Using the newly recovered solar drawings by the 18-19th century observers Staudacher and Hamilton, we construct the solar butterfly diagram, i.e., the latitudinal distribution of sunspots in the 1790s. The sudden, systematic occurrence of sunspots at high solar latitudes in 1793-1796… CONTINUE READING
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References
SHOWING 1-10 OF 36 REFERENCES
Lost sunspot cycle in the beginning of Dalton minimum: New evidence and consequences
- Physics, Geology
- 2002
- 38
- PDF
Persistent 22-year cycle in sunspot activity: Evidence for a relic solar magnetic field
- Physics
- 2001
- 76
- PDF
Unusual activity of the Sun during recent decades compared to the previous 11,000 years
- Medicine
- Nature
- 2004
- 738
- PDF
The one hundredth year of Rudolf Wolf's death: Do we have the correct reconstruction of solar activity?
- Mathematics
- 1994
- 98
- PDF