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An improved prediction of sunspot maximum by Vondrak smoothing method
Author(s) -
Yin Z. Q.,
Han Y. B.
Publication year - 2018
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.201713373
Subject(s) - sunspot , smoothing , mathematics , value (mathematics) , solar minimum , epoch (astronomy) , solar maximum , sunspot number , solar cycle 24 , amplitude , statistics , solar cycle , meteorology , physics , astrophysics , optics , solar wind , quantum mechanics , magnetic field , stars
Studies of solar activity characteristics and prediction are gaining more attention. Using the 13‐month smoothed value of monthly sunspot numbers, we studied correlations between the rising rate of sunspot numbers of the first 24 months of the solar cycle (SC) and the coming cycle maximum; published forecasting results demonstrated that the maximum value was 139.2 ± 18.8 for the 23rd SC, while the observed value was 120.8 and the error was about 15.2%. The present paper introduces our improved forecasting methods. The Vondrak smoothing method is used to deal with the monthly sunspot numbers. The relationships between the rise rate of earlier months of sunspot numbers of Vondrak smoothed sequence and the coming maximum value in each SC are studied. The results show that the rising rate of sunspot numbers are highly related with the coming maximum values, and simulated prediction of maximum for 22 ∼ 24 cycles show that, using the 24‐month rise rate of three SCs, the maximum forecasting error is about 8.6%. The differences between prediction and observation of ascending time are within ±10%. The new prediction method can shift at least 6 months ahead in comparison with the common method using the 13‐month smoothed value, that is, the amplitude and epoch of solar maximum in the SC can be predicted about 2 years after the solar minimum.