The Periodicity of High-Latitude Solar Activity

Li, K. J.; Li, Q. X.; Su, T. W.; Gao, P. X.

doi:10.1007/s11207-006-0008-6

Cited by 15 publications

(19 citation statements)

References 32 publications

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“…We found a good agreement between the frequencies of a quasi-biennial cycle detected by different indicators, observed only in some solar cycles (see e.g. Cadavid et al 2005;Li et al 2006;Knaack et al 2004Knaack et al , 2005, and the calculated lengths in the short-term periods investigated here. All these considerations indicate that this component of the solar activity, commonly considered as a sequence of multiple oscillations with different frequencies, could be simply the manifestation of the temporal modulation of a unique quasi-biennial activity cycle.…”

Section: Discussionsupporting

confidence: 79%

“…The quasi-biennial component of the solar cycle, although weaker than the main one, is very robust since it has been recorded by many indicators (see e.g. Kane 2005;Penza et al 2006;Li et al 2006;Cadavid et al 2005). The peak in P j (T ) corresponding to the short-term contribution, although significant, is underestimated compared to the main cycle peak.…”

Section: Time Evolution Of Pod Coefficients: Wavelet Analysis and Permentioning

confidence: 99%

“…Kane 2005). Many authors (Krivova & Solanki 2002;Knaack et al 2004Knaack et al , 2005Cadavid et al 2005;Li et al 2006), using different techniques of analysis and different activity indicators, have shown that the observed high frequency periodicities are not recognized as a typical feature of every solar cycle but seem to appear only from time to time. A corresponding quasi-biennial periodicity has also been found in contexts related to solar variability.…”

Section: Introductionmentioning

confidence: 99%

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Spatio-temporal analysis of solar activity: main periodicities and period length variations

Vecchio

Carbone

2009

A&A

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Aims. The spatio-temporal dynamics of solar activity has been investigated by studying the main oscillations and the time evolution of the basic periods. Methods. The spatio-temporal behavior of the green coronal emission line at 530.3 nm, recorded from 1939 to 2005, has been analyzed by using proper orthogonal decomposition, to extract the main components of the system, and the wavelet analysis to further investigate their time behaviour.Results. In addition to the main 11-year periodicity, a high-frequency component has been recorded mainly on the polar regions of the Sun, thus indicating a different origin from the emergence of active regions. Evidence for variations in the period lengths of this component has been found for the first time. The calculated period length varies between 1.5 years and 4 years, in good agreement with frequencies attributed to the quasi-biennial cycle extracted by different solar activity indicators. Our analysis shows that, unlike the main periodicity, the high-frequency component does not show the typical properties of a true mode of oscillation but seems to originate, in a narrow band of frequencies, from a stochastic superposition of different oscillators. Conclusions. The observed solar cycle frequencies in the range 1.5−4 years, commonly considered as independent modes of oscillation, could be the manifestation of the temporal modulation of a unique quasi-biennial periodicity. Our findings can provide more constraints on dynamo models introduced to describe the different components of the solar cycle. The calculated period length variations could also be helpful to improve our knowledge of the relationship between solar activity, neutrino flux variations and cosmic ray modulation.

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Section: Discussionsupporting

confidence: 79%

Section: Time Evolution Of Pod Coefficients: Wavelet Analysis and Permentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Spatio-temporal analysis of solar activity: main periodicities and period length variations

Vecchio

Carbone

2009

A&A

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“…This two-year cycle has been observed in radio flux (RF) on 10.7 cm (Belmont et al 1996), total solar irradiance (Penza et al 2006), flares and sunspots (Akioka 1987;Mursula et al 2003;Valdés-Galicia & Velasco 2008), and a green coronal emission line (Vecchio & Carbone 2008;Vecchio et al 2009). In these activity proxies the QBP appears only time to time and tends to be stronger over periods coinciding with solar maxima, and they are not recognized as typical feature of every cycle (Krivova & Solanki 2002;Knaack et al 2004;Cadavid et al 2005;Li et al 2006). This suggests that the mechanism behind the QBP might be closely linked to the strength of the global dynamo.…”

Section: Introductionmentioning

confidence: 99%

The quasi-biennial periodicity (QBP) in velocity and intensity helioseismic observations

Simoniello

Finsterle

Salabert

et al. 2012

A&A

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Aims. We looked for signatures of quasi-biennial periodicity (QBP) over different phases of solar cycle by means of acoustic modes of oscillation. Low-degree p-mode frequencies are shown to be sensitive to changes in magnetic activity due to the global dynamo. Recently there has been reported evidence of two-year variations in p-mode frequencies. Methods. Long high-quality helioseismic data are provided by BiSON (Birmingham Solar Oscillation Network), GONG (Global Oscillation Network Group), GOLF (Global Oscillation at Low Frequency) and VIRGO (Variability of Solar IRradiance and Gravity Oscillation) instruments. We determined the solar cycle changes in p-mode frequencies for spherical degree = 0, 1, 2 with their azimuthal components in the frequency range 2.5 mHz ≤ ν ≤ 3.5 mHz. Results. We found signatures of QBP at all levels of solar activity in the modes more sensitive to higher latitudes. The signal strength increases with latitude and the equatorial component also seems to be modulated by the 11-year envelope. Conclusions. The persistent nature of the seismic QBP is not observed in the surface activity indices, where mid-term variations are found only from time to time and mainly in periods of high activity. This feature, together with the latitudinal dependence, provides more evidence of a mechanism that is almost independent and different from the one that brings the active regions up to the surface. Therefore, these findings can be used to provide more constraints on dynamo models that consider a further cyclic component on top of the 11-year cycle.

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“…Le et al [17] used the wavelet analysis and achieved the cycles of 11, 53, 101 a. In the recent years, Li et al [18,19] made the wavelet analysis for the monthly-mean-values of SSN, of sunspot area and of sunspot element area, and deeply researched the edge effect of the wavelet analysis.…”

Section: Wavelet Spectrum Of Sunspot Numbermentioning

confidence: 99%

Possible effect of solar activity on variation of the tree-rings of a 500 a platycladus orientalis at the Mausoleum of Emperor Huang

Feng

Han

2009

Sci. China Ser. G-Phys. Mech. Astron.

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The variation of the tree-ring's index of a platycladus orientalis at the Mausoleum of Emperor Huang and of a long series of sunspots relative number during AD1470-1974 are analyzed by using the wavelet power spectrum method, and their variation characters are also discussed. It is determined that the tree-ring's variation has cycles of approximate 2-7, 11, 93 and 150 a. Two data series are used for analyzing sunspot relative number (SSN) variation. First, the analysis of the annual average SSN during AD1700-1974 proved that variation cycles are about 11, 50, and 93 a; then, the data during AD1465-1975 obtained from the decadal average SSN train over 7000 a reconstructed on the geomagnetic data is analyzed and its variation cycles are about 50, 90, and 160 a. Besides the tree-rings cycle of 2-7 a is commonly considered to be related to ENSO, while 11 a cycle is related to solar Schwabe cycle; in addition, it is possible that the cycles of 90 and150 a are likely to be related to solar Gleissberg cycle and Suess cycle. The correlations between them are possibly due to the effect of solar activity on the climate and additionally on the tree's growth.tree-ring, solar activity, climate change, wavelet spectrum

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The Periodicity of High-Latitude Solar Activity

Cited by 15 publications

References 32 publications

Spatio-temporal analysis of solar activity: main periodicities and period length variations

Spatio-temporal analysis of solar activity: main periodicities and period length variations

The quasi-biennial periodicity (QBP) in velocity and intensity helioseismic observations

Possible effect of solar activity on variation of the tree-rings of a 500 a platycladus orientalis at the Mausoleum of Emperor Huang

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