Papers on solar cycle length

This is a list of papers on the solar cycle length, and especially on its effect to the climate. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative. Thanks to John Cook for notifying me about this subject, and doing lot of preliminary paper searching as shown here.

Transition of solar cycle length in association with the occurrence of grand solar minima indicated by radiocarbon content in tree-rings – Miyahara et al. (2008) “In this paper, we review the variation of the 11-year solar cycle since the 15th century revealed by the measurement of radiocarbon content in single-year tree-rings of Japanese cedar trees. … As a result, slight stretching of the “11-year” and the “22-year” solar cycles was found during these two grand solar activity minima; continuously during the Maunder Minimum and only intermittently during the Spoerer Minimum. On the contrary, normal or slightly shortened 11-year cycles were detected during the interval period of these two minima.”

A Note on Solar Cycle Length Estimates – Vaquero et al. (2006) “In this short contribution, we show estimates of the solar cycle length using the RFC-method and the Group Sunspot Number (R_G) instead the R_Z. Several authors have showed the advantages of RG for the analysis of sunspot activity before 1850. The use of R_G solves some doubtful solar cycle length estimates obtained around 1800 using R_Z.”

A review of the solar cycle length estimates – Benestad (2005) “New estimates of the solar cycle length are calculated from an up-to-date monthly sunspot record using a novel but mathematically rigorous method involving multiple regression, Fourier approximation, and analytical expressions for the first derivative based on calculus techniques. … There have been speculations about an association between the solar cycle length and Earth’s climate, however, the solar cycle length analysis does not follow Earth’s global mean surface temperature. A further comparison with the monthly sunspot number, cosmic galactic rays and 10.7 cm absolute radio flux since 1950 gives no indication of a systematic trend in the level of solar activity that can explain the most recent global warming.”

Pattern of Strange Errors Plagues Solar Activity and Terrestrial Climate Data – Damon & Laut (2004) “The last decade has seen a revival of various hypotheses claiming a strong correlation between solar activity and a number of terrestrial climate parameters. Links have been made between cosmic rays and cloud cover, first total cloud cover and then only low clouds, and between solar cycle lengths and northern hemisphere land temperatures. These hypotheses play an important role in the scientific debate as well as in the public debate about the possibility or reality of a man-made global climate change. Analysis of a number of published graphs that have played a major role in these debates and that have been claimed to support solar hypotheses shows that the apparent strong correlations displayed on these graphs have been obtained by incorrect handling of the physical data.” [Full text]

Solar activity and terrestrial climate: an analysis of some purported correlations – Laut (2003) “I have analyzed a number of published graphs which have played a major role in these debates and which have been claimed to support solar hypotheses. My analyses show that the apparent strong correlations displayed on these graphs have been obtained by an incorrect handling of the physical data. … In 1991 Friis-Christensen and Lassen published an article claiming a ‘strikingly goodagreement ’ between solar cycle lengths (SCLs) and Northern Hemisphere land air temperatures. … The apparent agreement with the recent global warming is obtained artificially by combining the 20 points of the smoothed curve with the most recent of several ‘upward swings’ of the oscillating non-filtered data, i.e., by combining two incongruous sets of physical data.” [Full text]

Persistence of the Gleissberg 88-year solar cycle over the last ∼12,000years: Evidence from cosmogenic isotopes – Peristykh & Damon (2003) “For that perspective,we examined the longest detailed cosmogenic isotope record—INTCAL98 calibration record of atmospheric ¹⁴C abundance. The most detailed precisely dated part of the record extends back to ∼11,854 years B.P. During this whole period, the Gleissberg cycle in ¹⁴C concentration has a period of 87.8 years and an average amplitude of ∼1‰(in Δ¹⁴C units). Spectral analysis indicates in frequency domain by sidebands of the combination tones at periods of ≈91.5 ±0.1 and ≈84.6 ± 0.1 years that the amplitude of the Gleissberg cycle appears to be modulated by other long-term quasiperiodic process of timescale∼2000 years. … Attempts have been made to explain 20th century global warming exclusively by the component of irradiance variation associated with the Gleissberg cycle. These attempts fail, because they require unacceptably great solar forcing and are incompatible with the paleoclimatic records.” [Full text]

On the length of the solar cycle and the Earth’s climate – Kristjánsson (2001) Reviews the situation briefly. [Full text]

Solar forcing of the Northern hemisphere land air temperature: New data – Thejll & Lassen (2000) “Adding new temperature data for the 1990s and expected values for the next sunspot extrema we test whether the solar cycle length model is still adequate. We find that the residuals are now inconsistent with the pure solar model. We conclude that since around 1990 the type of Solar forcing that is described by the solar cycle length model no longer dominates the long-term variation of the Northern hemisphere land air temperature.” [Full text]

Is There a Correlation between Solar Cycle Lengths and Terrestrial Temperatures? Old Claims and New Results – Laut & Gundermann (2000) Analyses the work of Friis-Christensen & Lassen (1991) “Our present work demonstrates that an alternative analysis of the underlying physical data leads to figures which do not support the claims mentioned above.” [Full text]

Solar cycle lengths and climate: A reference revisited – Laut & Gundermann (2000) “An article published by Friis-Christensen and Lassen [1991] appeared to indicate an association between solar cycle lengths (SCLs) and climate. … We here present an updated analysis using a recent temperature reconstruction with the time period of comparison considerably expanded. The correlation is found to be weak. In the light of this new result we analyze the question how the article by Friis-Christensen and Lassen was able to create the impression of a ‘strikingly good agreement’, as the authors described it. We show that the main reason is an unacceptable mixing of filtered and nonfiltered data in the graphical representation. Hereby, an artificial agreement of the solar data with the global warming since 1970 was established. The article by Friis-Christensen and Lassen has created and still creates confusion both in scientific and public discussions on climate change.”

Solar cycle length and 20th Century northern hemisphere warming: Revisited – Damon & Peristykh (1999) “It has been suggested that the length of the solar cycle (SCL) is related to solar forcing of global climate change [Friis‐Christensen and Lassen, 1991]. Although no physical mechanism had been proposed, the relation seemed to be supported by interesting correlations with several paleoclimate records and, separately, with the 20th century Northern Hemisphere instrumental record. Actually, what has been correlated is the quasi‐sinusoidal Gleissberg cycle which is slightly greater in the 18th century than in the 20th century. Using the pre‐industrial record as a boundary condition, the SCL‐temperature correlation corresponds to an estimated 25% of global warming to 1980 and 15% to 1997.”

Determination of solar cycle length variations using the continuous wavelet transform -Fligge et al. (1999) “The length of the sunspot cycle determined by Friis-Christensen & Lassen (1991) correlates well with indicators of terrestrial climate, but has been criticized as being subjective. In the present paper we present a more objective and general cycle-length determination. Objectivity is achieved by using the continuous wavelet transform based on Morlet wavelets and carrying out a careful error analysis. … All activity indicators give cycle length records which agree with each other within the error bars, whereby the signal due to the solar cycle is weaker within (10) Be than in the other indicators. In addition, all records exhibit cycle length variations which are, within the error bars, in accordance with the record originally proposed by Friis-Christensen & Lassen (1991).” [Full text]

Solar cycle length hypothesis appears to support the ipcc on global warming – Laut & Gundermann (1998) “We analyse the period 1579–1987 and find that the solar hypothesis—instead of contradicting—appears to support the assumption of a significant warming due to human activities. We have tentatively corrected the historical northern hemisphere land air temperature anomalies by removing the assumed effects of human activities. … It turns out that the agreement of the filtered solar cycle lengths with the corrected temperature anomalies is substantially better than with the historical anomalies, with the mean square deviation reduced by 36% for a climate sensitivity of 2.5°C, the central value of the IPCC assessment, and by 43% for the best-fit value of 1.7°C. Therefore our findings support a total reversal of the common assumption that a verification of the solar hypothesis would challenge the IPCC assessment of man-made global warming.”

Seip & Fuglestvedt (1998, Cicerone 6/1998) As described by Kristjánsson (2001): “Already in Cicerone 6/98, Seip and Fuglestvedt pointed out that updated temperature and solar-cycle data showed that the correlation between solar cycle length and global temperature did not apply beyond the period that Friis-Christensen and Lassen were looking at. … As Seip and Fuglestvedt (Cicerone 6/98) pointed out, however, there was no physical mechanism that could explain the alleged correlation.”

A new method to determine the solar cycle length – Mursula & Ulich (1998) “Here we propose a new method to define the solar cycle length as a difference between the median activity times of two successive sunspot cycles. The great advantage of this method is that the median times are almost independent of how the sunspot minima are determined. Therefore the method allows the solar cycle lengths to be calculated with a very small inaccuracy of a few days only. We show that the individual cycle lengths calculated from the conventional and the median method may differ by nearly a year. However, the long‐term trend of cycle lengths remains roughly the same during modern times.” [Full text]

Variability of the solar cycle length during the past five centuries and the apparent association with terrestrial climate – Lassen & Friis-Christensen (1995) “Therefore, a critical assessment of existing and proxy solar data prior to 1750 is reported and tables of epochs of sunspot minima as well as sunspot cycle lengths covering the interval 1500–1990 are presented. The tabulated cycle lengths are compared with reconstructed and instrumental temperature series through four centuries. The correlation between solar activity and northern hemisphere land surface temperature is confirmed.”

Solar cycle length, greenhouse forcing and global climate – Kelly & Wigley (1992) “Here we model the effects of a combination of greenhouse and solar-cycle-length forcing and compare the results with observed temperatures. We find that this forcing combination can explain many features of the temperature record, although the results must be interpreted cautiously; even with optimized solar forcing, most of the recent warming trend is explained by greenhouse forcing.”

Length of the Solar Cycle: An Indicator of Solar Activity Closely Associated with Climate – Friis-Christensen & Lassen (1991) “It has recently been suggested that the solar irradiance has varied in phase with the 80- to 90-year period represented by the envelope of the 11-year sunspot cycle and that this variation is causing a significant part of the changes in the global temperature. This interpretation has been criticized for statistical reasons and because there are no observations that indicate significant changes in the solar irradiance. A set of data that supports the suggestion of a direct influence of solar activity on global climate is the variation of the solar cycle length. This record closely matches the long-term variations of the Northern Hemisphere land air temperature during the past 130 years.” [Full text]

Secularly smoothed data on the minima and maxima of sunspot frequency – Gleissberg (1967) “When I introduced the method of secular smoothing into the study of the variations of sunspot frequency (GLEISSBERG, 1944) I published a table containing the secularly smoothed epochs and ordinates od sunspot minima and maxima which I had deduced from the data published by BRUNNER in 1939. … Now, the table ought to be enlarged for two reasons: on the one side, two 11-year cycles more have elapsed in the meantime and, on the other side, the ordinates of five minima and four maxima between 1698 and 1745 were deduced (GLEISSBERG, 1960) from the annual means of sunspot-relative numbers 1700-1748 as published by WOLF (1868) and corrected by CHERNOSKY and HAGAN (1958).”

A table of secular variations of the solar cycle – Gleissberg (1944) “In Table 1 the secular variations of the solar cycle show themselves by systematic fluctuations of the intervals between two minima (m-m), between two maxima (M-M), from minimum to maximum (3I-m) or from maximum to minimum (m-M), and of the quantities r and R which characterize the depths of secularly smoothed minima and the heights of secularly smoothed maxima. … It would be of interest to learn whether the secular variations of the solar cycle are reproduced also in terrestrial phenomena”