New Method of Time Series Analysis and Its Application to Wolf's Sunspot     Number Data. II: Periodicities of The Daily Sunspot Numbers

Terachi, Saburou; Ohtomo, Norio; Tanaka, Yukio; Tokiwano, Kazuo; Kaneko, Noboru

doi:10.1143/jjap.36.957

Cited by 9 publications

(6 citation statements)

References 23 publications

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“…39) The details of ''MemCalc'' are described elsewhere. [18][19][20][25][26][27][28][29][30][31][32]39) …”

Section: Discussionmentioning

confidence: 99%

“…The method has been widely used in various fields such as medical and biological sciences as well as physical science and engineering. [18][19][20][26][27][28][29][30][31][32] Therein, the exponential power spectral density (PSD) was universally observed for the time series generated from various nonlinear dynamical systems. 19,27,28,33) Furthermore, the underlying variation of the time series data determined by our method was successfully used for a prediction analysis.…”

Section: Introductionmentioning

confidence: 99%

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Spectral Study of Measles Epidemics: The Dependence of Spectral Gradient on the Population Size of the Community

Sumi¹,

Olsen

Ohtomo

et al. 2003

Jpn. J. Appl. Phys.

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We have carried out spectral analysis of measles notifications in several communities in Denmark, UK and USA. The results confirm that each power spectral density (PSD) shows exponential characteristics, which are universally observed in the PSD for time series generated from nonlinear dynamical system. The exponential gradient increases with the population size. For almost all communities, many spectral lines observed in each PSD can be fully assigned to linear combinations of several fundamental periods, suggesting that the measles data are substantially noise-free. The optimum least squares fitting curve calculated using these fundamental periods essentially reproduces an underlying variation of the measles data, and an extension of the curve can be used to predict measles epidemics. For the communities with large population sizes, some PSD patterns obtained from segment time series analysis show a close resemblance to the PSD patterns at the initial stages of a period-doubling bifurcation process for the so-called susceptible/exposed/infectious/recovered (SEIR) model with seasonal forcing. The meaning of the relationship between the exponential gradient and the population size is discussed.

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“…39) The details of ''MemCalc'' are described elsewhere. [18][19][20][25][26][27][28][29][30][31][32]39) …”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spectral Study of Measles Epidemics: The Dependence of Spectral Gradient on the Population Size of the Community

Sumi¹,

Olsen

Ohtomo

et al. 2003

Jpn. J. Appl. Phys.

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“…The short periodicities in sunspot numbers of 27, 30, 50, and 155 days have been identified by wavelet analysis (Torrence and Campo, 1998). Long-term periodicities have been identified by using the power spectral density (Terachi et al, 1997).…”

Section: Sunspot Statistics and Solar Activity Cyclesmentioning

confidence: 99%

“…Long-term periodicities have been identified by using the power spectral density (Terachi et al, 1997). The long-term variation of the solar activity cycles (50 -80, 90 -140, and 170 -260 periodicities) may have existed for 10 000 years (Ogurtsov et al, 2002).…”

Section: Sunspot Statistics and Solar Activity Cyclesmentioning

confidence: 99%

Analysis of Sunspot Activity Cycles

Greenkorn

2009

Sol Phys

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A nonlinear analysis of the daily sunspot number for each of cycles 10 to 23 is used to indicate whether the convective turbulence is stochastic or chaotic. There is a short review of recent papers considering sunspot statistics and solar activity cycles. The differences in the three possible regimes -deterministic laminar flow, chaotic flow, and stochastic flow -are discussed. The length of data sets necessary to analyze the regimes is investigated. Chaos is described and a chronology of recent results that utilize chaos and fractals to analyze sunspot numbers follows. The parameters necessary to describe chaostime lag, phase space, embedding dimension, local dimension, correlation dimension, and the Lyapunov exponents -are determined for the attractor for each cycle. Assuming the laminar regime is unlikely if chaos is not indicated in a cycle by the calculations, the regime must be stochastic. The sunspot numbers in each of cycles 10 to 19 indicate stochastic behavior. There is a transition from stochastic to chaotic behavior of the sunspot numbers in cycles 20, 21, 22, and 23. These changes in cycles 20 -23 may indicate a change in the scale of turbulence in the convection zone that could result in a change in the convective heat transfer and a change in the size of the convection region for these four cycles.

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“…As is well known, an 11-year periodic mode is clearly observed for time-series data of sunspot numbers, i.e. typical solar activity [8][9][10][11], and therefore the periodicity of cholera incidence is possibly related to solar activity.…”

Section: Introductionmentioning

confidence: 99%

Relationship of cholera incidence to El Niño and solar activity elucidated by time-series analysis

et al. 2009

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Using time-series analysis, we investigated the monthly cholera incidence in Dhaka, Bangladesh during an 18-year period for its relationship to the sea surface temperature (SST) linked to El Niño, and to the sunspot number. Dominant periodic modes identified for cholera incidence were 11.0, 4.8, 3.5, 2.9, 1.6, 1.0 and 0.5 years. The majority of these modes, e.g. the 11.0-, 4.8-, 3.5-, 1.6- and 1.0-year modes, were essentially consistent with those obtained for the SST data (dominant modes: 5.1, 3.7, 2.5, 2.1, 1.5, 1.0 years) and the sunspot number data (dominant modes: 22.1, 11.1, 7.3, 4.8, 3.1 years). We confirmed that the variations of cholera incidence were synchronous with SSTs, and were inversely correlated to the sunspot numbers. These results suggest that the cholera incidence in Bangladesh may have been influenced by the occurrence of El Niño and also by the periodic change of solar activity.

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New Method of Time Series Analysis and Its Application to Wolf's Sunspot Number Data. II: Periodicities of The Daily Sunspot Numbers

Cited by 9 publications

References 23 publications

Spectral Study of Measles Epidemics: The Dependence of Spectral Gradient on the Population Size of the Community

Spectral Study of Measles Epidemics: The Dependence of Spectral Gradient on the Population Size of the Community

Analysis of Sunspot Activity Cycles

Relationship of cholera incidence to El Niño and solar activity elucidated by time-series analysis

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