Using Dynamo Theory to predict the sunspot number during Solar Cycle 21

Schatten, Kenneth H.; Scherrer, P. H.; Svalgaard, Leif; Wilcox, John M.

doi:10.1029/gl005i005p00411

Cited by 304 publications

(244 citation statements)

References 14 publications

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“…9 and 10 we therefore conclude that the polar field strength at solar sunspot minimum is a precursor of the subsequent sunspot maximum; cf. also Schatten et al (1978) and Svalgaard et al (2005).…”

Section: Polar Variability In the Framework Of The Total Solar Variationmentioning

confidence: 99%

A Remarkable Recent Transition in the Solar Dynamo

et al. 2016

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We summarize the major aspects of the remarkable, fairly long lasting period (∼ 2005 to ∼ 2010) of low solar activity, that we will call the Transition. It is the transitional stage between the Grand Maximum of the 20th century and a forthcoming (most probably Regular) episode of solar activity. The various kinds of activity in the functioning of the equatorial components of the solar dynamo before and during the Transition are summarized. While the behavior of unipolar magnetic regions and their rest-latitudes already gave very early indications -mid 20th century -of the forthcoming Transition, more such indications became available around 1995 and the main part of it occurred between 2005 and 2010. Some of the inferences are discussed. We submit the hypothesis that the solar tachocline undergoes pulsations and we present some helioseismic evidences. In that scenario we find that its equatorial part has moved downward over a fairly small semi-amplitude (∼ 0.03 solar radii) during the time of the Transition. There are several indications, apart from this 'pulsation', that the tachocline may even be pulsating with still smaller amplitudes in more modes. We speculate about the physical mechanism(s).

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Section: Polar Variability In the Framework Of The Total Solar Variationmentioning

confidence: 99%

A Remarkable Recent Transition in the Solar Dynamo

et al. 2016

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“…Here I will focus on the work by Cliver and Ling (2010) which also suggested a novel source for such a ground state -the omnipresent slow solar wind. The chain of reasoning that led to this suggestion began with the paper on sunspot cycle prediction by Schatten et al (1978). Schatten et al (1978) argued that because (in the dynamo model for solar activity) poloidal fields at solar minimum provide the "seed" for the toroidal fields of the subsequent maximum, the peak sunspot number of a cycle should be related to the strength of the solar polar fields at the preceding minimum.…”

Section: Introductionmentioning

confidence: 99%

“…The chain of reasoning that led to this suggestion began with the paper on sunspot cycle prediction by Schatten et al (1978). Schatten et al (1978) argued that because (in the dynamo model for solar activity) poloidal fields at solar minimum provide the "seed" for the toroidal fields of the subsequent maximum, the peak sunspot number of a cycle should be related to the strength of the solar polar fields at the preceding minimum. It was difficult to test this idea directly at the time however, because reliable measurements of the solar polar fields had 180 E. W. Cliver been made at only one solar minimum up to that point.…”

Section: Introductionmentioning

confidence: 99%

The floor in the solar wind: status report

Cliver

2011

Proc. IAU

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Abstract. Cliver & Ling (2010) recently suggested that the solar wind had a floor or groundstate magnetic field strength at Earth of ∼2.8 nT and that the source of the field was the slow solar wind. This picture has recently been given impetus by the evidence presented by Schrijver et al. (2011) that the Sun has a minimal magnetic state that was approached globally in 2009, a year in which Earth was imbedded in slow solar wind ∼70% of the time. A precursor relation between the solar dipole field strength at solar minimum and the peak sunspot number (SSN M A X ) of the subsequent 11-yr cycle suggests that during Maunder-type minima (when SSNM A X was ∼0), the solar polar field strength approaches zero -indicating weak or absent polar coronal holes and an increase to nearly ∼100% in the time that Earth spends in slow solar wind.

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“…Although the correlation between the polar field maximum and the subsequent cycle strength was proposed by Schatten et al (1978) based on the BL-type FT dynamo, here we would like to stress that not all BL-type FT dynamo can give the correlation. In the BL-type dynamo, poloidal field is generated at surface layer due to the decay of the tilt sunspot groups.…”

Section: Possible Reasons Responsible For the Polar Field Precursormentioning

confidence: 99%

“…Solar polar field was first proposed to be solar cycle precursor by Schatten et al(1978), who suggested the correlation between the polar field near the solar minimum and the subsequent cycle strength. WSO has the continuous solar polar field observations since 1976 shown in Figure 5 (red curve) overplotted with the sunspot number †.…”

Section: Solar Polar Field Precursormentioning

confidence: 99%

Solar-cycle precursors and predictions

Jiang

2012

Proc. IAU

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Abstract. The sunspot number data during the past 400 years indicates that both the profile and the amplitude of the solar cycle have large variations. Some precursors of the solar cycle were identified aiming to predict the solar cycle. The polar field and the geomagnetic index are two precursors which are received the most attention. The geomagnetic variations during the solar minima are potentially caused by the solar polar field by the connection of the solar open flux. The robust prediction skill of the polar field indicates that the memory of the dynamo process is less than 11 yrs based on the frame of the Babcock-Leighton flux transport dynamo. One possible reason to get the short magnetic memory is the high magnetic diffusivity in the convective zone. Our recent studies show that the radial downward pumping is another possible reason. Based upon the mechanism, we well simulate the cycle irregularities during RGO time period. This opens the possibility to set up a standard dynamo based model to predict the solar cycle. In the end, the no correlation between the polar field and the preceding cycle strength due to two nonlinearities involved in the sunspot emergence will be stressed.

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Using Dynamo Theory to predict the sunspot number during Solar Cycle 21

Cited by 304 publications

References 14 publications

A Remarkable Recent Transition in the Solar Dynamo

A Remarkable Recent Transition in the Solar Dynamo

The floor in the solar wind: status report

Solar-cycle precursors and predictions

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