The Shape of Solar Cycle Described by a Modified Gaussian Function
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The shape of each sunspot cycle is found to be well described by a modified Gaussian function with four parameters: peak size A, peak timing t m, width B, and asymmetry α. The four-parameter function can be further reduced to a two-parameter function by assuming that B and α are quadratic functions of t m, computed from the starting time (T 0). It is found that the shape can be better fitted by the four-parameter function, while the remaining behavior of the cycle can be better predicted by the two-parameter function when using the data from a few (about two) months after the starting time defined by the smoothed monthly mean sunspot numbers. As a new solar cycle is ongoing, its remaining behavior can be constructed by the above four- or two-parameter function. A running test shows that the maximum amplitude of the cycle can be predicted to within 15% at about 25 months into the cycle based on the two-parameter function. A preliminary modeling to the first 24 months of data available for the current cycle indicates that the peak of cycle 24 may probably occur around June 2013±7 months with a size of 72±11. The above results are compared to those by quasi-Planck functions.
KeywordsModels Solar cycle Sunspots
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- Gnevyshev, M.N., Ohl, A.I.: 1948, Astron. Zh. 25, 18. Google Scholar
- Hathaway, D.H.: 2010, Living Rev. Solar Phys. 7(1). Google Scholar
- Petrovay, K.: 2010, Living Rev. Solar Phys. 7(6). Google Scholar
- Vitinskii, Yu.I.: 1965, Solar-Activity Forecasting, Israel Program for Scientific Translations Jerusalem, NASA-TT-F-289. Google Scholar
- Vitinskij, Yu.I., Kopetskij, M., Kuklin, G.V.: 1986, Statistics of Sunspot Activity, Nauka, Moscow, 296 (in Russian). Google Scholar
- Waldmeier, M.: 1935, Astron. Mitt. Zürich 14, 133. Google Scholar
- Wolf, R.: 1852, C. R. Acad. Sci. 35, 704. Google Scholar