Variations in the period of the sunspot cycle

Ochadlick, A.R.; Kritikos, H. N.; Giegengack, Robert

doi:10.1029/93gl01593

Cited by 39 publications

(24 citation statements)

References 9 publications

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“…The structure of this mode is consistent with modern variability in the period of the sunspot cycle observed in historical records [17]. The solar cycle could plausibly a¡ect sedi mentary layering indirectly by modulating climate parameters such as temperature [18,19] and rain fall [20] at interannual time scales.…”

Section: Spectral Interpretationsupporting

confidence: 82%

Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada

Hughes¹,

Giegengack²,

Kritikos³

2003

Earth and Planetary Science Letters

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Rhythmically deposited argillites of the Gowganda Formation (ca. 2.0^2.5 Ga) probably formed in a glacial setting. Drop stones and layered sedimentary couplets in the rock presumably indicate formation in a lacustrine environment with repeating freeze^thaw cycles. It is plausible that temporal variations in the thickness of sedimentary layers are related to interannual climatic variability, e.g. average seasonal temperature could have influenced melting and the amount of sediment source material carried to the lake. A sequence of layer couplet thickness measurements was made from high-resolution digitized photographs taken at an outcrop in southern Ontario, Canada. The frequency spectrum of thickness measurements displays patterns that resemble some aspects of modern climate. Coherent periodic modes in the thickness spectrum appear at 9.9^10.7 layer couplets and at 14.3 layer couplets. It is unlikely that these coherent modes result from random processes. Modern instrument records of regional temperature and rainfall display similar spectral patterns, with some datasets showing significant modes near 14 yr in both parameters. Rainfall and temperature could have affected sedimentary layering in the Gowganda argillite sequence, and climate modulation of couplet thickness emerges as the most likely explanation of the observed layering pattern. If this interpretation is correct, the layer couplets represent predominantly annual accumulations of sediment (i.e. they are varves), and the thickness spectrum provides a glimpse of Early Proterozoic climatic variability. The presence of interannual climate patterns is not unanticipated, but field evidence presented here may be of some value in developing a climate theory for the Early Proterozoic.

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Section: Spectral Interpretationsupporting

confidence: 82%

Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada

Hughes¹,

Giegengack²,

Kritikos³

2003

Earth and Planetary Science Letters

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“…This technique has been applied to this and related data sets by Vigouroux & Delache (1993, 1994; Ochadlick et al (1993) and Fligge et al (1999) with the aim of determining the solar cycle length. The length and amplitude records of the solar cycle are derived from the position (frequency) and the amplitude of the main power ridge in the wavelet transform.…”

Section: Method Data and Resultsmentioning

confidence: 99%

Search for a relationship between solar cycle amplitude and length

Solanki¹,

Krivova

Schüßler³

et al. 2002

A&A

110

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Abstract.The cross-correlation between time series of solar cycle length and amplitude suggests that the length precedes the amplitude. The relationship between the two is found to be more complex than a simple lag or phase shift, however. A simple empirical model is constructed which allows the amplitude of a given cycle to be predicted with relatively high accuracy from the lengths of earlier cycles. This result not only adds to the means at our disposal for predicting the amplitudes of future cycles, but also implies that the solar dynamo carries a memory of the length of one cycle over into the next. It may also have a bearing on why solar cycle length correlates better with the Earth's temperature record than cycle amplitude (Friis-Christensen & Lassen 1991). Thoughts on possible physical causes are presented.

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“…In the context of the solar cycles and stellar activity, WT has been used by some authors (Ochadlick et al 1993;Lawrence et al 1995;Oliver et al 1998;Sello 2000Sello , 2003Lara et al 2008;Choudhary et al 2014). A wavelet (wavelet mother) is a function with zero mean, which is defined in both the frequency, and time spaces (Grinsted et al 2004).…”

Section: The Continuous Wavelet Transformmentioning

confidence: 99%

“…In the context of solar cycles and stellar activity, several investigations have been carried out (Ochadlick et al 1993;Lawrence et al 1995;Oliver et al 1998;Sello 2000Sello , 2003Lou et al 2003;Lara et al 2008;Choudhary et al 2014). Recently, the relationship between CMEs, solar flares, and flux emergence using just the wavelet power spectrum analysis has been studied by Choudhary et al (2014).…”

Section: Introductionmentioning

confidence: 99%

Wavelet analysis of CME, X-ray flare, and sunspot series

Guedes

Pereira

Cecatto

2014

A&A

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Context. Coronal mass ejections (CMEs) and solar flares are the most energetic transient phenomena taking place at the Sun. Together they are principally responsible for disturbances in outer geospace. Coronal mass ejections and solar flares are believed to be correlated with the solar cycle, which is mainly characterized by sunspot numbers. Aims. Here, we search for pattern identification in CMEs, X-ray solar flares, and sunspot number time series using a new data mining process and a quantitative procedure to correlate these series. Methods. This new process consists of the combination of a decomposition method with the wavelet transform technique applied to the series ranging from 2000 until 2012. A simple moving average is used for the time-series decomposition as a high-pass filter. A continuous wavelet transform is applied to the series in sequence, which permits us to uncover signals previously masked by the original time series. We made use of the wavelet coherence to find some correlation between the data. Results. The results have shown the existence of periodic and intermittent signals in the CMEs, flares, and sunspot time series. For the CME and flare series, few and relatively short time intervals without any signal were observed. Signals with an intermittent character take place during some epochs of the maximum and descending phases of the solar cycle 23 and rising phase of solar cycle 24. A comparison among X-ray flares, sunspots, and CME time series shows a stronger relation between flare and CMEs, although during some short intervals (four-eight months) and in a relatively narrow band. Yet, in contrast we have obtained a fainter or even absent relation between the X-ray flares and sunspot number series as well as between the CMEs and sunspot number series.

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Variations in the period of the sunspot cycle

Cited by 39 publications

References 9 publications

Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada

Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada

Search for a relationship between solar cycle amplitude and length

Wavelet analysis of CME, X-ray flare, and sunspot series

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