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Synchronization of Sunspot Numbers and Sunspot Areas
Solar Physics, 2009Sunspot activity is usually described by either sunspot numbers or sunspot areas. The smoothed monthly mean sunspot numbers (SNs) and the smoothed monthly mean areas (SAs) in the time interval from November 1874 to September 2007 are used to analyze their phase synchronization.
K. J. Li, P. X. Gao, L. S. Zhan
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Investigation of Sunspot Area Varying with Sunspot Number
Solar Physics, 2016The statistical relationship between sunspot area (SA) and sunspot number (SN) is investigated through analysis of their daily observation records from May 1874 to April 2015. For a total of 1607 days, representing $3~\%$
K. J. Li, F. Y. Li, J. Zhang, W. Feng
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Group Sunspot Numbers: Sunspot Cycle Characteristics
Solar Physics, 2002We examine the "Group" sunspot numbers constructed by Hoyt and Schatten to determine their utility in characterizing the solar activity cycle. We compare smoothed monthly Group Sunspot Numbers to Zurich (International) Sunspot Numbers, 10.7-cm radio flux, and total sunspot area.
David H. Hathaway +2 more
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Relationship between sunspot numbers during years of sunspot maximum and sunspot minimum
Solar Physics, 1980A correlation analysis shows that the sunspot numbers at the peaks of the last eight solar cycles are well-correlated with the sunspot numbers in heliolatitudes 20°–40° (specially in the southern hemisphere) occurring in the solar minimum years immediately preceding the solar maximum years.
R. P. Kane, N. B. Trivedi
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The Schwabe and Gleissberg Periods in the Wolf Sunspot Numbers and the Group Sunspot Numbers
Solar Physics, 2005Three wavelet functions: the Morlet wavelet, the Paul wavelet, and the DOG wavelet have been respectively performed on both the monthly Wolf sunspot numbers (R-z) from January 1749 to May 2004 and the monthly group sunspot numbers (R-g) from June 1795 to December 1995 to study the evolution of the Gleissberg and Schwabe periods of solar activity.
K. J. Li, P. X. Gao, T. W. Su
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The sunspot areas and the relative sunspot numbers
Geofisica pura e applicata, 1960Within each sunspot cycle the yearly means (A) of the daily sunspot areas increase faster than the corresponding sunspot numbers (R) from the minimum to the maximum of solar activity and then decrease also faster than these numbers till the next minimum.
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Eos, Transactions American Geophysical Union, 1949
A formula for predicting smoothed annual sunspot numbers is developed. A first approximation to the prediction of a future value in a cycle is the mean of all past values for that part of the cycle. This estimate can be improved by adding to the mean a correction proportional to the departure of earlier values of the cycle from the mean cycle.
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A formula for predicting smoothed annual sunspot numbers is developed. A first approximation to the prediction of a future value in a cycle is the mean of all past values for that part of the cycle. This estimate can be improved by adding to the mean a correction proportional to the departure of earlier values of the cycle from the mean cycle.
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Nature, 1953
SUNSPOT numbers form a quasi-periodic series (see Fig. 1, upper curve) going back for eighteen cycles to 1750. Very numerous attempts have been made to analyse the series, with little success. It does not appear to contain a truly periodic term, as do tides and weather records.
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SUNSPOT numbers form a quasi-periodic series (see Fig. 1, upper curve) going back for eighteen cycles to 1750. Very numerous attempts have been made to analyse the series, with little success. It does not appear to contain a truly periodic term, as do tides and weather records.
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On the average rate of growth in sunspot number and the size of the sunspot cycle
Solar Physics, 1990The average rate of growth in sunspot number over selected time intervals and the maximum average value as they both relate to the size of the cycle are examined, in order to predict the size of cycle 22. The predictions are compared with those of Wilson (1990) to determine whether a consensus is apparent.
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Wavelet analysis of sunspot numbers
Chinese Astronomy and Astrophysics, 1998Abstract The principle of detecting singularities in the signal using wavelet transform is discussed. The yearly mean sunspot numbers during 1700–1993 are analyzed by this technique and the individual periods of sunspot activity are determined, as dinstinct from the tranditional method.
Bo Feng, Xi-zheng Ke, Hua-ling Ding
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