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In the present study we address the issue of discerning between deterministic and stochastic paradigms in order to understand the behavior of the solar cycle. To this end we show the degree of correlation between the instantaneous amplitude and frequency in the sunspot number time series by the use of the Gabor analytic signal. We compare this correlation with those arising from two theoretical models: (a) the Barnes model of widespread use in the literature and (b) a spatial truncation of the MHD equations. We show that comparisons between the correlation observed in the sunspot time series with those arising from theoretical models can be used to refute one of the models. 相似文献
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Simple Model of a Stochastically Excited Solar Dynamo 总被引:2,自引:0,他引:2
The aim of this paper is to investigate the dynamical nature of the complexity observed in the time evolution of the sunspot
number. We report a detailed analysis of the sunspot number time series, and use the daily records to build the phase space
of the underlying dynamical system. The observed features of the phase space prompted us to describe the global behavior of
the solar cycle in terms of a noise-driven relaxation oscillator. We find the equations whose solutions best fit the observed
series, which adequately describe the shape of the peaks and the oscillations of the system. The system of equations obtained
from this fitting procedure is shown to be equivalent to a truncation of the dynamo equations. A linear transformation maps
the phase space of these equations into the phase space reconstructed from the observations. The irregularities of the solar
cycle were modeled through the introduction of a stochastic parameter in the equations to simulate the randomness arising
in the process of eruption of magnetic flow to the solar surface. The mean values and deviations obtained for the periods,
rise times and peak values, are in good agreement with the values obtained from the sunspot time series. 相似文献
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