Basil Copeland and Anthony Watts
Image from NASA GSFC
Many WUWT readers will remember that last year we presented evidence of what we thought was a “solar imprint” in globally averaged temperature trends. Not surprisingly, given the strong interest and passion in the subject of climate change and global warming, our results were greeted with both praise and scorn. Some problems were pointed out in our original assessment, and other possible interpretations of the data were suggested. Some WUWT readers have wondered whether we would ever follow up on this.
We have been quietly working on this, and having learned much since our initial effort, are as persuaded as ever that the basic premise of our original presentation remains valid. We have tried out some new techniques, and have posted some preliminary trials on WUWT in the past few months, here, and here.
However, questions remain. Since a lot of bright and capable people read WUWT, rather than wait until we thought we had all the answers, we have decided to present an update and let readers weigh in on where we are at with all of this. We have, in fact, drafted a paper that we might at some point submit for peer review, when we are more comfortable with some of the more speculative aspects of the matter. What follows is taken from that draft, with some modification for presentation here.
For those that prefer to read this in printed form, a PDF of this essay is available for download here
Introduction
Evidence of decadal and bidecadal variations in climate are common in nature. Classic examples of the latter include the 20 year oscillation in January temperature in the Eastern United States and Canada reported by Mock and Hibler [1], and the bidecadal rhythm of drought in the Western High Plains, Mitchell, Stockton, and Meko [2], and Cook, Meko, and Stockton [3]. Other examples include a bidecadal (and pentadecadal) oscillation in the Aleutian Low, Minobe [4]; rainfall and the levels of Lake Victoria, East Africa, Stager et al. [5]; and evidence from tree rings along the Russian Arctic, Raspopov, Dergachev, Kolstrom [6], and the Chilean coast, Rigozo et al. [7].
Evidence of decadal or bidecadal oscillations in temperature data, however, especially upon a global scale, has proven to be more elusive and controversial. Folland [8] found a spectral peak at 23 years in a 335 year record of central England temperatures, and Newell et al. [9] found a 21.8 year peak in marine air temperature. Brunetti, Mageuri, Nanni [10] have reported evidence of a bidecadal signal in Central European mean alpine temperatures. But the first to report bidecadal oscillations – of 21 and 16 years – in globally averaged temperature were Ghil and Vautard [11]. Their results were challenged by Eisner and Tsonis [12], but were later taken up and extended by Keeling and Whorf [13, 14].
No less unsettled is the issue of attribution. Currie [15], examining U.S. temperature records, reported spectral peaks of 10.4 and 18.8 years, attributing the first to the solar cycle, and the latter to the lunar nodal cycle. In the debate over the bidecadal drought cycle of the Western High Plains, Mitchell, Stockton, and Meko [2] concluded that the bidecadal signal was a solar phenomenon, not a lunar one. Bell [16, 17] and Stockton, Mitchell, Meko [18] attributed the bidecadal drought cycle to a combined solar and lunar influence, as did Cook, Meko, and Stockton [3]. Keeling and Whorf [13], working with globally averaged temperature data, reported strong spectral peaks at 9.3, 15.2, and 21.7 years. Eschewing a simpler combination of solar and lunar influences, they proposed a complex mechanism of lunar tidal influences to explain the evidence [14].
The past decade has seen only sporadic interest in the question of whether decadal and bidecadal variations in climate have a solar or lunar attribution, or some combination of the two. Cerveny and Shaffer [19] and Treloar [20] report evidence of tidal influences on the southern oscillation and sea surface temperatures; Yndestad [21, 22] and McKinnell and Crawford [23] attribute climate oscillations in the Arctic and North Pacific to the 18.6 year lunar nodal cycle. But interest in discerning an anthropogenic influence on climate has largely eclipsed the study of natural climate variability, at least on a global scale. There continue to be numerous reports of decadal or bidecadal oscillations in a variety of climate metrics on local and regional scales, variously attributed to solar and or lunar periods [3-7, 10, 19-27], but little has been done to advance the state of knowledge of lunar or solar periodic cycles on globally averaged temperature trends since the final decade of the 20th Century.
Besides the shift in interest to discerning an anthropogenic influence on global climate, the lack of agreement on any kind of basic physical mechanism for a solar role in climate oscillations, combined with the apparent lack of consistency in the relation between solar cycles and terrestrial temperature trends perhaps has made this an uninviting area of research. The difficulty of attributing temperature change to solar influence has been thoroughly surveyed by Hoyt and Schatten [28]. In particular, there are numerous reports of sign reversals in the relationship between temperature and solar activity in the early 20th century, particularly after 1920 [28, pp 115-117]. More recently, Georgieva, Kirov, and Bianchi [29] surveyed comprehensively the evidence for sign reversal in the relationship between solar and terrestrial temperatures, and suggested that these sign reversals are related to a long term secular solar cycle with solar hemispheric asymmetry driving the sign reversals. Specifically, they argue that there is a double Gleissberg cycle in which during one half of the cycle the Southern solar hemisphere is more active, while during the other half of the cycle the Northern solar hemisphere is more active. They argue that this solar hemispheric asymmetry is correlated with long term terrestrial climate variations in atmospheric circulation patterns, with zonal circulation patterns dominating in the 19th and early 20th century, and meridional circulation patterns dominating thereafter (see also [30] and [31]).
In our research, we pick up where Keeling and Whorf [13, 14] leave off, insofar as documenting decadal and bidecadal oscillations in globally averaged temperature trends is concerned, but revert to the explanation proposed by Bell [16] and others [3, 18], that these are likely the result of a combined lunisolar influence, and not simply the result of lunar nodal and tidal influences. We show that decadal and bidecadal oscillations in globally averaged temperature show patterns of alternating weak and strong warming rates, and that these underwent a phase change around 1920. Prior to that time, the lunar influence dominates, while after that time the solar influence dominates. While these show signs of being correlated with the broad secular variation in atmospheric circulation patterns over time, the persistent influence of the lunar nodal cycle, even when the solar cycle dominates the warming rate cycles, implicates oceanic influences on secular trends in terrestrial climate. Moreover, while analyzing the behavior of the secular solar cycle over the limited time frame for which we have reasonably reliable instrumental data for measuring globally averaged temperature should proceed with caution, if the patterns documented here persist, we may be on the cusp of a downward trend in the secular solar cycle in which solar activity will be lower than what has been experienced during the last four double sunspot cycles. These findings could influence our expectations for the future regarding climate change and the issue of anthropogenic versus natural variability in attributing climate change.
In our original presentation, we utilized Hodrick-Prescott smoothing to reveal decadal and bidecadal temperature oscillations in globally averaged temperature trends. While originally developed in the field of economics to separate business cycles from long term secular trends in economic growth, the technique is applicable to the time series analysis of temperature data in reverse, by filtering out short term climate oscillations, isolating longer term variations in temperature.
For the mathematically inclined, here is what the HP filter equation looks like, courtesy of the Mathworks
The Hodrick-Prescott filter separates a time series yt into a trend component Tt and a cyclical component Ct such that yt = Tt + Ct. It is equivalent to a cubic spline smoother, with the smoothed portion in Tt.
The objective function for the filter has the form
where m is the number of samples and λ is the smoothing parameter. The programming problem is to minimize the objective over all T1, …, Tm. The first sum minimizes the difference between the time series and its trend component (which is its cyclical component). The second sum minimizes the second-order difference of the trend component (which is analogous to minimization of the second derivative of the trend component).
For those with an electrical engineering background, you could think of it much like a bandpass filter, which also has uses in meteorology:
Outside of electronics and signal processing, one example of the use of band-pass filters is in the atmospheric sciences. It is common to band-pass filter recent meteorological data with a period range of, for example, 3 to 10 days, so that only cyclones remain as fluctuations in the data fields.
(Note: For those that wish to try out the HP filter on data themselves, a freeware Excel plugin exists for it which you can download here)
When applied to globally averaged temperature, the HP filter works to extract the longer term trend from variations in temperature that are of short term duration. It is somewhat like a filter that filters out “noise,” but in this case the short term cyclical variations in the data are not noise, but are themselves oscillations of a shorter term that may have a basis in physical processes.
This approach reveals alternating cycles of weak and strong warming rates with decadal and bidecadal frequency. We confirm the validity of the technique using a continuous wavelet transform. Then, using MTM spectrum analysis, we analyze further the frequency of these oscillations in global temperature data. Using sinusoidal model analysis we show that the frequencies obtained using HP smoothing are equivalent to what are obtained using MTM spectrum analysis. In other words, the HP smoothing technique is simply another way of extracting the same spectral density information obtained using more conventional spectrum analysis, while leaving it in the time domain. This allows us to compare the secular pattern of temperature cycles with solar and lunar maxima, yielding results that are not obvious from spectral analysis alone.
Using the Hodrick-Prescott Filter to Reveal Oscillations in Globally Averaged Temperature
We use the open source econometric regression software gretl (GNU Regression, Econometrics, and Time Series) [34] to derive an HP filtered time series for the HadCRUT3 Monthly Global Temperature Anomaly, 1850:01 through 2008:11 [35].
Figure 1 is representative output in gretl for a series filtered with HP smoothing (λ of 129,000). In the top panel is the original series (in gray), with the resulting smoothed trend (in red). In the bottom panel is the cyclical component. In econometric analysis, attention usually focuses on the cyclical component. Our focus, though, is on the trend component in the upper panel, and in particular the first differences of the trend component. The first differences of a trend indicate rate of change.
By taking the first differences of the smoothed trend in Figure 1, we obtain the series (in blue) shown in Figure 2, plotted against the background of the original data (gray), and the smoothed trend (red).
What does this reveal? At first glance, we see an alternating pattern of decadal and bidecadal oscillations in the rate of warming, with a curious exception circa 1920-1930. We will return to this later. Concentrating for now on the general pattern, these oscillations in the rate of warming are representations, in the time domain, of spectral frequencies in the temperature data, with high frequency oscillations filtered out by the HP smoothing.
As evidence of this, Figure 3 presents the result of two Morelet continuous wavelet transforms, the first (in the upper panel) of the unfiltered HadCRUT3 monthly time series, and the second (in the lower panel) of results obtained with HP smoothing.
The wavelet transforms below a frequency of ~7 years (26.4 ≈ 84 months) are visually identical; the HP filter is simply acting as a low pass filter, filtering out oscillations with frequencies above ~7 years, while preserving the decadal and bidecadal oscillations of interest here. In the next section, we investigate these oscillations in further detail, supplementing our results from HP filtering with MTM spectrum analysis, and a sinusoidal model fit.
Frequency Analysis
Figure 4 is an MTM spectrum analysis of the unfiltered HadCRUT3 monthly global temperature analysis.
A feature of MTM spectrum analysis is that it distinguishes signals that are described as “harmonic” from those that are merely “quasi-oscillatory.” In MTM spectrum analysis a harmonic is a more clearly repeatable signal that passes a stronger statistical test of its repeatability. Quasi-oscillatory signals are statistically significant, in the sense of rising above the background noise level, but are not as consistently repeating as the harmonic signals.
The distinction between harmonic and quasi-oscillatory signals is well illustrated in Figure 4 by the two cycles that interest us the most – a “quasi-oscillatory” cycle with a peak at 8.98 years, and a “harmonic” signal centered at 21.33 years. Also shown are a harmonic, and a quasi-oscillatory cycle, of shorter frequencies, possibly ENSO related. The harmonic at 21.33 years in Figure 4 encompasses a range from 18.96 to 24.38 years, and the quasi-oscillatory signal that peaks at 8.93 years has sidebands above the 99% significance level that range from 8.53 to 10.04 years. These signals are consistent with spectra identified by Keeling and Whorf [13,14].
Figure 5 is an MTM spectrum analysis of the HP smoothed first differences.
The basic shape of the spectrum is unchanged, but it is now well above the background noise level because of the HP filtering. Attention is drawn in Figure 5 to four oscillatory modes or cycles because they correspond to the four strongest cycles derived from using the PAST (PAleontological STatistics) software [36] to fit a sinusoidal model to the HP smoothed first differences.
Shown in Figure 6, the sinusoidal fit results in periods of 20.68, 9.22, 15.07 and 54.56 years, in that order of significance. These periodicities fall within the ranges of the spectra obtained using MTM spectrum analysis, and yield a sinusoidal model with an R2 of 0.60.
Discussion
The first differences of the HP smoothed temperature series, shown in Figure 2 and Figure 6, show a pattern of alternating decadal and bidecadal oscillations in globally averaged temperature. From the sinusoidal model fit, these cycles have average frequencies of 20.68 and 9.22 years, results that are consistent with the MTM spectrum analysis, and with spectra in the results published by Keeling and Whorf [13, 14]. But to what can we attribute these persistent periodicities?
A bidecadal frequency of 20.68 years is too short to be attributed solely to the double sunspot cycle, and too long to be attributed solely to the 18.6 year lunar nodal cycle. There is indeed evidence of a spectral peak at ~15 years, which Keeling and Whorf combined with their evidence of a 21.7 year cycle to argue for attributing the oscillations entirely to the 18.6 year lunar nodal cycle.
But our evidence indicates that the ~15 year spectrum is much weaker, is not harmonic, and probably derives from the anomalous behavior of the spectra circa 1920-1930, something Keeling and Whorf could not appreciate with evidence only from the frequency domain. Especially in light of the evidence presented below, and because the bidecadal signal is harmonic, and readily discernible in the time domain representation of Figure 2 and Figure 6, we believe that a better attribution is the beat cycle explanation proposed by Bell [16], i.e. a cycle representing the combined influence of the 22 year double sunspot cycle and the 18.6 year lunar nodal cycle.
As for the decadal signal of 9.22 years, this is too short to be likely attributable to the 11 year solar cycle, but is very close to half the 18.6 year lunar nodal cycle, and thus may well be attributable to the lunar nodal cycle. Together, the pattern of alternating weak and strong warming cycles shown in Figure 2 and Figure 6 suggest a complex pattern of interaction between the double sunspot cycle and the lunar nodal cycle.
This complex pattern of interaction between the double sunspot cycle and lunar nodal maxima in relation to the alternating pattern of decadal and bidecadal warming rates is demonstrated further in Figure 6 with indicia plotted to indicate solar and lunar maxima. Since circa 1920, the strong warming rate cycles have tended to correlate with solar maxima associated with odd numbered solar cycles, and the weak warming rate cycles with lunar maxima.
Prior to 1920, the strong warming rate cycles tend to correlate with the lunar nodal cycle, with the weak warming rate cycles associated with even numbered solar cycles. The sinusoidal model fit begins to break down prior to 1870. Whether this is a reflection of the poorer quality of data prior to 1880, or indications of an earlier phase shift, we cannot say, though the timing would be roughly correct for the latter. But the anomalous pattern circa 1920, when viewed against the shift from strong warming rate cycles dominated by the lunar nodal cycle, to strong warming rate cycles dominated by the double sunspot cycle, has the appearance of a disturbance associated with what clearly seems to be a phase shift
These results agree with the evidence mustered by Hoyt and Schatten [28] and Georgieva, Kirov, and Bianchi [29] for a phase shift circa 1920 in the relationship between solar activity and terrestrial temperatures. However, we can suggest, here, that the supposed negative correlation between solar activity and terrestrial temperatures prior to 1920 rests on a misconstrued understanding of the data. As can be seen in Figure 6, the relationship between the change in the warming rate and solar activity is still positive, i.e. the warming rate is peaking near the peaks of solar cycles 10, 12, and 14, but at a much reduced level, indicative of the lower level of solar activity during the period. Indeed, for much of solar cycle 12, and all of solar cycle 14, the “warming” rate is negative, but the change in the warming rate is still following the level of solar activity, becoming less negative as solar activity increases, and more negative as solar activity decreases. Still, there is a strong suggestion in Figure 6 of a phase shift circa 1920 in which the relationship between solar activity and terrestrial temperatures changes dramatically before and after the shift. Before the shift, the lunar period dominates, and the solar period is much weaker. After the shift, the solar period dominates, and the lunar period becomes subordinate.
Speculating
To this point, we believe that we are on relatively solid ground in describing what the data show, and the likelihood of a lunisolar influence on global temperatures on decadal and bidecadal timescales. What follows now is more speculative. To what can we attribute the apparent phase shift circa 1920, evident not just in our findings, but as reported by Hoyt and Schatten [28] and Georgieva, Kirov, and Bianchi [29]? While the period of data is too short to do more than speculate, the periods before and after the phase shift appear to be roughly equivalent in length to the Gleissberg cycle.
Since 1920, we’ve had four double sunspot cycles with strong warming rates ending in odd numbered cycles. Prior to 1920, while the results are less certain at the beginning of the data period, there is a reasonable interpretation of the data in which we see four bidecadal periods dominated by the influence of the lunar cycle. These differences may be attributable to the broad swings in atmospheric “circulation epochs” discussed by Georgeiva, et al. [30], characterized either predominantly by zonal circulation, or meridional circulation. With respect to the period of time shown in Figure 6, zonal circulation prevailed prior to 1920, and since then meridional circulation has dominated. These “circulation epochs” may have persistent influence on the relative roles of solar and lunar influence in warming rate cycles.
While the role of variation in solar irradiation over the length of a solar cycle on the broad secular rise in global temperature is disputed, we are presenting here evidence primarily of a more subtle repeated oscillation in the rate of change in temperature, not its absolute level. As shown in Figure 2 and Figure 6, the rate of change oscillates between bounded positive and negative values (with the exception circa 1920 duly noted). Variations in solar irradiance over the course of the solar cycle are a reasonable candidate for the source of this variation in warming rate cycle. As WUWT’s “resident solar physicist”, Leif Svalgaard, has pointed out, variations in TSI over a normal solar cycle can only account for about 0.07°C of total variation over the course of a solar cycle. The range of change in warming rates shown in Figure 2 and Figure 6 are at most only about one-tenth of this, or about ~0.006°C to ~0.008°C. If anything, we should be curious why the variation is so small. We attribute this to the averaging of regional and hemispheric variations in the globally averaged data. On a regional basis, analysis [not presented here] shows much larger variation, but still within the range of 0.07°C that might plausibly be attributed to the variation in TSI over the course of a solar cycle.
So variations in solar irradiance over the course of the solar cycle are a reasonable candidate for the source of this variation in warming rate cycle. At the same time, the lunar nodal cycle may be further modulating this natural cycle in the rate of change in global temperatures. As to the degree of modulation, that may be influenced by atmospheric circulation patterns. With zonal circulation, the solar influence is moderated and the lunar influence dominates the modulation of the warming rate cycles. With meridional circulation, the solar influence is stronger, and the warming rate cycles are dominated by the solar influence.
At this writing, we are in the transition from solar cycle 23 to 24, a transition that has taken longer than expected, and longer than the transitions typical of solar cycles 16 through 23. Indeed, the transition is more typical of the transitions of solar cycles 10 through 15. If the patterns observed in Figure 6 are not happenstance, we may be seeing an end to the strong solar activity of solar cycles 16-23, and a reversion to the weaker levels of activity associated with solar cycles 10-15. If that occurs, then we should see a breakdown in the correlation between warming rate cycles and solar cycles at bidecadal frequencies, and a reversion to a dominant correlation between temperature oscillations and the lunar nodal cycle.
Interestingly, there was a lunar nodal maximum in 2006 not closely associated with the timing of decadal or bidecadal oscillations in globally averaged temperature. This could be an indication of a breakdown in the pattern similar to what we see in the 1920’s, i.e. the noise associated with a phase shift in the weaker warming rate cycles will occur at times of the solar maximum, and the stronger warming rate cycles will occur at times of lunar nodal maximum.
Repeating, there appear to be parallels between our findings and the argument of Georgieva et al. [29] of a relationship between terrestrial climate and solar hemispheric asymmetry on the scale of a double Gleissberg cycle. Solar cycles 16-23, associated as we have seen with increased solar activity, and strong correlations with the strong terrestrial warming rate cycles of bidecadal frequency, represent 8 solar cycles, a period of time associated with a Gleissberg cycle.
While the existence of Gleissberg length cycles is hardly challenged, their exact length and timing is subject to a debate we will not entertain here at any length. Javariah [37] on the basis of the disputed 179 year cycle of Jose [38] believes that a descending phase of a Gleissberg cycle is already underway, and will end with the end of a double Hale cycle comprising solar cycles 22-25.
While it is true that solar activity, as measured by SSN, is already on the decline, we would include the double Hale cycle 20-23 in the recent peak of solar activity, and not necessarily expect to see the bottom of the current decline in solar activity that quickly.
The issue here can perhaps be framed with respect to Figure 7 below:
Assuming we are on the cusp of a downward trend in solar activity that began circa 1990 according to Javariah, and will decline, say, to a level comparable to the trough seen in the early 1900’s, will it be a sharp decline, like that seen at the beginning of the 19th Century, or a more moderate decline like that seen at the beginning of the 20th Century? A naïve extrapolation might be to replicate the more gradual decline seen during the latter half of the 19th Century, suggesting a gradual decline in solar activity through solar cycle 31, i.e. for most of the 21st Century. And based on the prospect of a phase shift in the pattern of decadal and bidecadal warming rate cycles, the bidecadal cycle would come to be dominated by the influence of the lunar nodal cycle, and the influence of the solar cycle would be diminished, leading at least to a reduction in the rate of global warming, if not an era of global cooling.
This is a prospect worthy of more investigation.
Finally, while we readily concede that multidecadal projections are at best little more than gross speculation, in Figure 6 we have carried the sinusoidal model fit out to 2030, and in Figure 8 we use the sinusoidal model of rate changes to project temperature
anomalies through 2030. Assuming a simple projection of the sinusoidal model of rate changes persists through 2030, there would be little or no significant change in global temperature anomalies for the next two decades.
Looking carefully at the sinusoidal model, what we are seeing projected for 2010-2020 are a return to conditions similar to what the model shows for circa 1850-1860, with the period 1853-2020 representing a complete composite cycle of the four combined periods of oscillation. That is, 1853 is the first point at which the sinusoidal model is crossing the x-axis, and at 2020 the model again crossing the x-axis and beginning to repeat a ~167 year cycle. In terms of solar cycle history, that corresponds to a return to conditions similar to solar cycles 10-15, with another phase shift reversing the phase shift of ~1920. If these broad, long term secular swings in solar activity and global atmospheric conditions and temperature anomalies are not random, but reflect solar-terrestrial dynamics that play out over multidecadal and even centennial time-scales, then the early 21st Century may yield a respite from the global warming of the late 20th Century.
Conclusion
There is substantial and statistically significant evidence for decadal and bidecadal oscillations in globally averaged temperature trends. Sinusoidal model analysis of the first differences of the HP smoothed HadCRUT3 time series reveals strong periodicities at 248.2 and 110.7 months, periodicities confirmed as well with MTM spectrum analysis.
Analyzing these periodicities in the time domain with the first differences of the HP smoothed HadCRUT3 time series reveals a pattern of correlation between strong warming rate cycles and the double sunspot cycle for the past four double sunspot cycles. Prior to that, with a phase shift circa 1920, the strong warming rate cycles were dominated by the timing of the lunar nodal cycle.
We suggest that this reversal may be related to a weaker epoch of solar activity prior to 1920, and that we may on the cusp of another phase shift associated with a resumption of such weakened solar activity.
If so, this may result in a reduction in the rate of global warming, and possibly a period of global cooling, further complicating the effort to attribute recent global warming to anthropogenic sources.
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[36] Hammer, Ø. Harper, D. Ryan, P. PAST: Paleontological Statistics Software Package for Education and Data Analysis. Palaeontologia Electronica. 2001; 4(1): 9pp. http://palaeo-electronica.org/2001_1/past/issue1_01.htm
[37] Javariah, J. Sun’s retrograde motion and violation of even-odd cycle rule in sunspot activity. 2005; 362(4): 1311-1318.
[38] Jose, P. Sun’s motion and sunspots. Astronics Journal. 1965; 70: 193-200.
gary gulrud (10:19:16) :
“You must be looking at something else.”
The SORCE site.
Link, please. You must be confused between the TIM and SIM instruments.
I can believe they accurately measure radiation pressure not energy.
They measure the heating [temperature] of the detector by the solar radiation, that is the energy absorbed. Then convert to power using known aperture size and sampling cadence.
The description of function is not rigorous.
I don’t think you know what you are talking about. The LASP description is very rigorous. I have just repeated [copy-paste at times] what they state.
Here are some notes about the lunar nodal cycle. I’ve extracted them from my paper, “The Sun’s role in regulating the Earth’s climate” published recently in the Journal of Energy and Environment paper (VOLUME 20 No. 1 2009).
By way of introduction, here is the Abstract of my paper:
This paper introduces this thesis:
The Sun-Earth system is electromagnetically, magneto-hydrodynamically and gravitationally coupled, dominated by significant non-linear, non-stationary interactions, which vary over time and throughout the three-dimensional structure of the Earth, its atmosphere and oceans. The essential elements of the Sun-Earth system are the solar dynamo, the heliosphere, the lunisolar tides, the Earth’s inner and outer cores, mantle, crust, magnetosphere, oceans and atmosphere. The Sun-Earth system is non-ergodic (i.e. characterised by continuous change, complexity, disorder, improbability, spontaneity, connectivity and the unexpected). Climate dynamics, therefore, are non-ergodic, with highly variable climatological features at any one time.
A theoretical framework for considering the role of the Sun in relation to the Earth’s climate dynamics is outlined and ways in which the Sun affects climate reviewed. The forcing sources (independent variables) that influence climate processes (dependent variables) are analysed. This theoretical framework shows clearly the interaction effects between and amongst the two classes of variables. These seem to have the greatest effect on climate dynamics.
Climate processes are interconnected and oscillating, yielding variable periodicities. Solar processes, especially when interacting, amplify or dampen these periodicities producing distinctive climatic cycles. As solar and climate processes are non-linear, non-stationary and non-ergodic, appropriate analytic methodologies are necessary to reveal satisfactorily solar/climate relationships.
In this context, the Lunar Nodal Cycle is but one of the solar variables (arising from the Sun’s gravitational field) that has to be understood in order to understand fully the many ways by which the Sun regulates the climate of the Earth.
The lunar nodal cycle and climate.
The 18.6 year lunar nodal cycle (LNC) tidal periodicity has a pervasive role in climate change. It is the period of a full rotation of the Moon’s orbital plane around the ecliptic, the geometric plane of the Earth’s orbit around the Sun. It is the clearest tidal signal in the thousands of time series analysed.
The LNC encodes information about the Moon, Earth, Sun geometry that relates to tidal extremes, at least at high latitudes. It defines how the angle of the Moon’s orbit to the Earth’s equatorial plane combines with, or partially cancels out, the tilt in the Earth’s axis. From the perspective of an observer on the Earth, during the LNC the Moon moves along a northern latitude about ten degrees from a position about 18.5 degrees north of the equator to one that is 28.5 degrees, which it reaches after 18.6 years.
The regular sequence of eclipses is a result of the regular, highly predictable rotation of the plane of the Moon’s orbit round the Earth. It has been known since ancient times that eclipses occurred in regular predictable cycles of a little more than 18 years. This period is known as the Saros cycle.
Mazzarella and Palumba (1994) point out that bistable modes of oscillation with respect to time are well known in physical and engineering systems and have been extensively studied. This research from Physics and Engineering demonstrates that a sinusoidal force applied to any dynamic system induces sinusoidal periodicities in the system. Accordingly, the LNC induces bistable sinusoidal periodicities in the atmosphere (pressure, temperature and rainfall) and the ocean (temperature and sea level). The sinusoidal, highly stable 18.6 year LNC has a distinctive and significant effect on the Earth’s climate dynamics.
The elongated tidal bulge necessarily continues to be aligned with the Moon as Figure 2 shows. The bulge moves to the northern (and southern) latitudes as the Moon moves northwards because of the LNC, being the furthest north it can get to at the 18.6 yr point. This last happened on September 16, 2006. Even though the amplitude of the LNC is at most 5 cm, a small tide over a long period has great power. The ocean currents generated by the northward movement of the tidal bulge, in conjunction with the rotation of the Earth through the bulges in the normal manner creating our experience of the tides, brings warmish equatorial water to the Arctic accelerating the warming that had being going on there because of other forms of solar activity as discussed below.
The LNC has maximum effect at higher latitudes, resulting in higher sea levels at these latitudes. It creates tidal currents resulting in diapycnal mixing, bringing the warmer equatorial waters into the Arctic. The LNC is therefore a major determinant of Arctic climate dynamics, influencing long term fluctuations in Arctic ice. As a result, it is a key driver of European climate. Da Silva and Avissar (2005) showed that LNC is unambiguously correlated with the Arctic Oscillation since the 1960s. The authors explain how the LNC tidal forces contribute significantly to the regulation of the Arctic Oscillation, which is a major driver of climate variability in the Northern Hemisphere.
Complex interaction effects between the lunar nodal cycle other solar variables and climate.
The joint effects of the LNC and other solar variables illustrate that solar variables may interact to produce significant climate events, in this case the melting of the ice in the Arctic and higher sea surface temperatures at northern latitudes. In 2006 the LNC jointly with other solar activity during the preceding ten years provide an adequate explanation for the observed recent Arctic warming.
1. Camp and Tung (2007c) established for the first time as statistically significant that the warm ENSO (i.e. El Niño) warms the Arctic. Moderate to very strong El Niño events occurred in the following years since 1972: 1972/3; 1977/78; 1982/83; 1986/88; 1991/92; 1993/94; 1994/95; 1997/98; 2002/03; and 2004/05. The El Niño event which began in early 1997 and continued for about one year was one of the strongest ever recorded, both in terms of sea surface temperatures in the eastern tropical Pacific and atmospheric circulation anomalies reflected in the Southern Oscillation Index. The last El Niño event started in September 2006 and lasted until early 2007, occurring at precisely the same time as the peak of the LNC..
2. Camp and Tung (2007a and 2007b) also revealed the surface pattern of warming caused by the Sun. Amongst other things, polar amplification is shown clearly with the largest warming in the Arctic (treble that of the global mean), followed by that of the Antarctic (double). Surprisingly, the warming over the polar region occurs during late winter and spring.
3. Camp and Tung (2006) found that there is a significant relationship between polar warming and the sunspot cycle.
4. Soon (2005) showed a statistically significant relationship between solar radiance and Arctic-wide surface air temperatures. Solar Cycle 23 peaked during 2000/01, having been preceded by the unusually strong 1997/98 El Niño.
5. Shirochkov et al (2000) report that the extent of Arctic sea ice is largely a function of solar variability. The extent of Arctic sea ice varies directly with all measureable indices of variable solar activity. Specifically, solar wind plays a notable role in the variation of the extent of Arctic sea ice.
6. The ice-albedo (i.e. reflectance) effect will amplify the increased melting of the sea ice resulting from the interaction of El Niño, solar irradiance and the LNC on the Arctic. The increased expanse of ocean warms further as it absorbs more solar irradiance. This will lead to more warming and more sea ice will melt. So the process would continue unless something intervened. Recent observations show Da Silva and Avissar (2005) showed that the LNC accelerates this warming processes. These processes enable a larger volume of liquid water to respond to the tidal forces. In addition, the changes in ocean stratification that follow improve the mixing efficiency.
Since the Moon’s orbit is elliptical, there is a point when the Moon is closest to the Earth (the perigee) and a point where it is furthest (apogee). It is to be noted that the perigee (and therefore the apogee) is not constant. Both vary, largely because of the perturbing effect of the Sun. There is a 40 percent difference between the lunar tidal forces at the perigee and the apogee of the Moon’s orbit. The Moon moves faster at the perigee, and slower at the apogee. This means that tidal currents quicken as the Moon approaches the perigee of its orbit. They are slower at apogee. The Arctic Oscillation (AO) is regulated by the solar cycle in a non-linear manner. Heightened and weakened solar activity activates the large Rossby and Kelvin waves. The effects of these waves on atmospheric circulation are intensified by the creation of Ozone during times of increased solar activity. The AO is stronger with more zonal circulation over mid-latitudes, especially in the European-North Atlantic sector, and more variable during the peak of the solar cycle.
The AO is also regulated by the peak 9.3 year and 18.6 year LNC tidal oscillations. The processes by which the effect occurs are different from those of variable solar activity. The tidal oscillation impacts on atmospheric circulation and on the large Rossby and Kelvin waves. It also impacts on the churning of the oceans. Nevertheless, the two solar processes interact amplifying each other’s contribution. The AO has a key role in Northern Hemisphere climate variability and its behaviour is largely the result of the interaction of the solar cycle and the 9.3 and 18.6 year LNC tidal oscillations. Berger (2007) found that solar modulation of the NAO is amplified by tidal cycles. He found that there is non-linear resonance between solar cycles and tidal cycles, especially the LNC and the perigean tidal cycle the effect of which is to amplify solar modulation of the NAO.
References:
Berger, W. H., 2007. Solar modulation of the North Atlantic Oscillation: Assisted by the tides? Quaternary International, 188, 24-30; doi:10.1016/j.quaint.2007.06.028.
Camp, C. D., and Tung, Ka-Kit, 2006. The Influence of the Solar Cycle and QBO on the Late Winter Stratosphereic Polar Vortex. Journal of Atmospheric Sciences in press.
Camp, C. D., and Tung, Ka-Kit, 2007a. Surface warming by the solar cycle as revealed by the composite mean difference projection, Geophysical Research Letters Vol. 34, L14703, doi:10.1029/2007GL030207..
Camp, C. D., and Tung, Ka-Kit, 2007b. Solar Cycle Warming at the Earth’s Surface and an Observational Determination of Climate Sensitivity, submitted to the Journal of Geophysical Research, and published by the University of Washington on Ka Kit Tung’s departmental website,
http://www.amath.washington.edu/research/articles/Tung/journals/solar-jgr.pdf
Camp, C. D., and Tung, Ka-Kit, 2007c. Stratospheric polar warming by ENSO in winter: a statistical study, Geophysical Research Letters Vol. 34, L14809, doi:10.1029/2006GL03028521..
Da Silva, R. R., and Avissar, R., 2006. The impacts of the Luni-Solar Oscillation on the Artic Oscillation. Geophysical Research Letters 32, L22703, doi:10.1029/2005GL023418,2005.
Goldreich, Peter, 1972. Tides and the Earth-Moon System, Scientific American, 226, 4, pps 42-52.
McCully, J. G., 2006. BEYOND THE MOON A Conversational, Common Sense Guide to Understanding the Tides. World Scientific, Singapore.
Mazzarela, A. and Palumbo, A., 1994. The Lunar Nodal Induced-Signal in Climatic and Ocean Data over the Western Mediterranean Area and on its Bistable Phasing, Theoretical and Applied Climatology 50, 93-102.
Shirochkov, A. V., Makarova, L .N. and Volobuev, D. M., 2000. The arctic sea ice extent as a function of solar variability, presentation to the first conference of S-RAMP (Solar- Terrestrial Energy Program, 1990-1997 Results, Applications and Modeling Phase; A fiveyear (1998-2002) effort to optimize the analysis of data obtained during the Solar-Terrestrial Energy Program, 1990-1997). The conference was held at Sapporo, Japan, October 2-6, 2000. See http://www.kurasc.kyoto-u.ac.jp/s-ramp/abstract/s18.txt
Soon, W. W.-H., 2005. Variable solar irradiance as a plausible agent for multidecadal variations in the Arctic-wide surface air temperature for the past 130 years, Geophysical Research Letters, 32, L16712, doi:10.1029/2005GL023429.
NOTE: THE JPG IMAGES FOR FIGS 1 & 2 WON”T COPY
Figure 1 follows:
Figure 1. The Lunar Nodal Cycle
The diagram is adapted from Goldreich (1972), page 49
The Sun’s gravitational field makes the Moon’s Earthly orbit swivel around in a clockwise manner, over a cycle of 18.6 years, with respect to the plane of the Earth’s orbit, the ecliptic. The Moon moves with respect to the ecliptic up and down a northerly latitude throughout the LNC. This arises because the Earth is titled on it axis and inclined away from the Sun and because the Moon’s orbit is tilted a little relative to the ecliptic, It is as if the Sun strives to pull the plane of the Moon’s orbit into its own plane, the ecliptic. But there is an alternate motion at right angles to the applied force, resulting in a revolution of the pole of the Moon’s orbit around the pole of the ecliptic.
Figure 2. Alignment of the tidal bulge (greatly exaggerated) with the Moon during the LNC
The diagram is adapted from McCully (2006), Illustration 3-3, page 33 As the Moon moves in a northerly direction during the LNC, approaching a maximum of 28.5O, so does the tidal bulge.
Here is the Abstract of a relevant paper only just published. The paper is:
Yasuda, Ichiro (2009) “The 18.6-year period moon-tidal cycle in Pacific Decadal Oscillation reconstructed from tree-rings in western North America”, GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L05605, doi:10.1029/2008GL036880, 2009.
The Abstract reads:
Time-series of Pacific Decadal Oscillation (PDO) reconstructed from tree-rings in Western North America is found to have a statistically significant periodicity of 18.6- year period lunar nodal tidal cycle; negative (positive) PDO tends to occur in the period of strong (weak) diurnal tide. In the 3rd and 5th (10th, 11th and 13rd) year after the maximum diurnal tide, mean-PDO takes significant negative (positive) value, suggesting that the Aleutian Low is weak (strong), western-central North Pacific in 30 50_N is warm (cool) and equator-eastern rim of the Pacific is cool (warm). This contributes to climate predictability with a time-table from the astronomical tidal cycle.
Richard Mackey (19:23:31) :
Here are some notes about the lunar nodal cycle. I’ve extracted them from my paper, “The Sun’s role in regulating the Earth’s climate” published recently in the Journal of Energy and Environment paper (VOLUME 20 No. 1 2009).
What did the reviewers have to say about the paper? Did you have to clarify points or strengthen/soften the tone here and there?
Leif: that is a fair question and I can summarize the situation along these lines.
Reviewers made these major criticisms:
The draft tends to ‘gild the lily’ regarding the thesis that the Sun affects our climate. More specifically, my draft did not include:
• Any critical evaluation of the papers cited but seems to accept any reported finding as valid, often without reflecting the qualifications or hesitations of the original author(s). My draft appears to treat all the published papers cited as having equivalent and high validity.
• Any papers reporting disconfirming findings or arguments about Sun/climate relationships;
Additionally, my draft covered too broad a canvass and is therefore too thin at many critical points.
However, there was general acknowledgement that the thesis of the paper – that one has to consider the totality of the ways in which the Sun might potentially affect our climate and any interactions between them, – was a useful contribution and worth publishing, given the above shortcomings. The general view seemed to be that the paper makes a good case for this thesis on the basis of the science cited, the analysis outlined and the framework introduced.
Inclusion of the statement:
“The maturity and degree of corroboration of science reviewed in this paper is variable. This is indicated to some extent by reference to publications which corroborate and/or develop the specific area under consideration. However, this paper does not evaluate the overall quality and/or durability of findings drawn upon to present overall conclusions.”
went some way towards meeting the criticism that I treat all papers cited as if they are of equally high veracity.
There was also criticism of my labouring of the ideas of “ergodicity” and “nonergodicity”.
I had the privilege of discussing “ergodicity”, “nonergodicity”, and “randomness” with Demetris Koutsoyiannis at the EGU 2009 in Vienna in April.
I think the gist of his argument is that randomness, entropy and the principles of thermodynamics are enough to explain phenomena; we don’t need the ideas of “ergodicity” or “nonergodicity”, whatever these might be considered to mean in the real world in which we live. I feel he is probably right and that I went a bit overboard on the use of the idea of “non-ergodicity by Douglass North who most likely was using it figuratively or metaphorically, not in any technical way.
There was also criticism that I didn’t adequately deal with the very different nature of the all variables I talked about (whether independent or dependent).
This criticism was dealt with by inclusion of this paragraph:
“The variables are not of the same logical category. Some are one dimensional such as temperature, pressure, atmospheric angular momentum and measures of solar output whereas others are systems of equations or in more complex instances, best represented as mathematical models.”
[In case some one says systems of equations are mathematical models, I should say that I meant by ‘mathematical models’ something more than just systems of equations (which are, of course, mathematical models); something more elaborate, perhaps ensembles of systems of equations, including numerical simulations].
I suppose the general view was that on balance it was worth publishing as it does a reasonable job of bringing attention to the need to consider the totality of solar phenomena in relation to our climate, if one is to answer in a valid way, the question “Does the Sun affect climate?”
The totality of solar phenomena is:
• the variations in the quantity, intensity and distribution over the Earth of the solar output, including electromagnetic radiation, matter and the Sun’s electromagnetic field;
• the variable gravitational force the Sun exerts on the Earth, the Moon and the Moon and the Earth as a system; and
• interactions between these processes.
From my point of view, I am aware of the paper’s shortcomings, but I do think it has merit. In addition, putting all that together as a hobby on top of the demands of a fulltime job, family and everything else in my own time at my own cost, is a big challenge and there is a limit to what one can do in a reasonable time.
I hope others find my paper a useful stimulus to their forward thinking on this subject.
I hope the debate about climate and the Sun will shift from the preoccupation with one or another variable, e.g. UV, Infrared, galactic cosmic rays, solar wind, electromagnetism, gravitation, to the consideration of the totality of all solar variables in relation to the totality of all climate variables and to all the interaction effects and in relation to time lags. Then we can have sensible discussions about the reasons for our planet’s climate dynamics.
Richard
PS: Earlier drafts had mistakes I had to correct, exaggerated statements I had to deleted, missed some papers worth citing that I had to read and cite, muddled confusions I hope I’ve cleared away and instances of serious misunderstandings I had to overcome, amongst (many) other things.
Richard Mackey (04:49:34) :
Reviewers made these major criticisms:
The draft tends to ‘gild the lily’ regarding the thesis that the Sun affects our climate.
I would add that you lean too much on Camp and Tung for the solar end. The lunar tides at least has the energy budget to have an influence, while the solar variation does not. My main criticism is that the whole field is too ‘disconnected’, having all kinds of different findings piled on top of on another. The usual method in a valid endeavor is the build on other’s results, but I see very little of that here [other than saying that others also find some relations]. Until that happens this field has not gotten off the ground.
Pitched at a nice, introductory level:
Benjamin F. Chao (2004). Earth rotational variations excited by geophysical fluids. International Very Long Base Line Interferometry (VLBI) Service (IVS) 2004 General Meeting Proceedings, p.38-46.
html:
http://ivs.nict.go.jp/mirror/publications/gm2004/chao/
http://ivscc.gsfc.nasa.gov/publications/gm2004/chao
pdf:
ftp://ivscc.gsfc.nasa.gov/pub/general-meeting/2004/pdf/chao.pdf
Note: The graphics are lousy on the html pages.
– –
Overview with a treasure chest of references:
R.S. Gross (2007). Earth Rotation Variations – Long Period. In: T. Herring & G. Schubert (eds.) Treatise on Geophysics, Volume 3, Geodesy, pp. 239-294.
ftp://euler.jpl.nasa.gov/outgoing/EarthRotation_TOGP2007.pdf
– –
Towards simplicity:
1.
Harald Schmitz-Hubsch & Harald Schuh (1999). Seasonal and short-period fluctuations of Earth rotation investigated by wavelet analysis. Technical Report 1999.6-2 Department of Geodesy & Geoinformatics, Stuttgart University, p.421-432.
http://www.uni-stuttgart.de/gi/research/schriftenreihe/quo_vadis/pdf/schmitzhuebsch.pdf
Brilliant wavelet images – very high quality.
Very nice writing – crystal-clear explanations.
Worthy of thorough, comprehensive consumption, top-to-bottom.
2.
Y.H. Zhou, D.W. Zheng, & X.H. Liao (2001). Wavelet analysis of interannual LOD, AAM, and ENSO: 1997-98 El Nino and 1998-99 La Nina signals. Journal of Geodesy 75, 164-168.
http://202.127.29.4/yhzhou/ZhouYH_2001JG_LOD_ENSO_wavelet.pdf
http://adsabs.harvard.edu//abs/2001JGeod..75..164Z
3.
D. Zheng, X. Ding, Y. Zhou, & Y. Chen (2003). Earth rotation and ENSO events: combined excitation of interannual LOD variations by multiscale atmospheric oscillations. Global and Planetary Change 36, 89-97.
(sorry – no free link found so far)
– –
Also noteworthy:
Zhou YH, Yan XH, Ding XL, Liao XH, Zheng DW, Liu WT, Pan JY, Fang MQ, & He MX (2004). Excitation of non-atmospheric polar motion by the migration of the Pacific Warm Pool. Journal of Geodesy 78, 109-113.
http://www.shao.ac.cn/yhzhou/ZhouYH_2004JG_PM_Warmpool.pdf
http://202.127.29.4/yhzhou/ZhouYH_2004JG_PM_Warmpool.pdf
– – –
Important – Note to barycentre (& solar) enthusiasts:
Beware the hazards of confounding.
“I don’t think you know what you are talking about.”
I have company. “absorptance” from their discription is Beer’s Law nomenclature, not Thermal Physics. The Law was developed at the end of the 18th century to aid astronomers in finding the absolute magnitude of stars from the apparent magnitude knowing the path through the atmosphere.
The law is naive, ‘absorptance’ includes reflectance and scattering, all causes for the diminution of the signal. What and how measurement takes place is not specified in your “cut and paste”. Most of the discussion is taken up by efforts to maintain a reference and working detector.
Your credulity regarding the understanding of other scientists is charming.
I would agree with you, Lief, that the field of research about relationships between the Sun’s behaviour and our climate is disconnected. I can’t say whether this disconnectedness is any more or less pronounced than other areas of scientific research.
I do know that research in many areas of scholarship (ie not only science and mathematics) is noticeably tunnel vision and hostile to outsiders.
A dynamic builds up largely through conditions of employment, promotion and funding for professionals to become better and better at less and less. Employees don’t have the luxury of spreading their wings. Publish as much as possible, get cited as much as possible, get on funding gravy trains and stay there as long as possible are the dynamics throughout most areas of scholarship, probably most professions. Professionals doing well in their area of specialization tend to close ranks against outsiders; multidiciplinarians are seen as jacks of all trades and masters of none, despised jackals coming to take away goodies from the hard working specialists. Worse still, specialist professionals will join ranks to gang up on their common enemy – the generalist who dares to challenge the specialists’ cherished paradigms and certainties. Once the outsider has been repelled the specialists resume their research programs within their narrow specialisms with the understanding that they won’t encroach on each other.
I note that Leif’s criticism that “the whole field is too ‘disconnected’, having all kinds of different findings piled on top of on another. The usual method in a valid endeavour is the build on other’s results, but I see very little of that here [other than saying that others also find some relations]” has been made before, most noticeably by one of the great minds of modern solar physics, John Wilcox, (see http://wso.stanford.edu/images/people/wilcox.html ) with whom Leif worked closely in his earlier years.
In 1973 John Wilcox wrote:
“An appreciable influence of solar activity on the weather is not widely accepted, and it is not in everyday use for forecasting purposes. The literature on the subject tends to be contradictory, and the work of the authors tends to be done in isolation. It is often difficult to compare the claims of one author against those of another. Many times an author starts from scratch, rather than building on the work of his predecessors in the classical pattern of science. A widely accepted physical mechanism has not yet emerged.”
I thought it would be helpful to our understanding of this situation and of interest to the millions who frequent WUWT to reflect just a little on some history of the field so as to better understand this enduring problem of disconnectedness.
The first major scientific effort to relate solar variability to climate was William Herschel’s two papers in 1801. At the time he was 63 and was acknowledged by all as Europe’s most distinguished Astronomer. He had held the appointment of the King’s Astronomer since 1782, was a Fellow of the Royal Society, which had awarded him the prestigious Copely Medal in 1781.
I have studied his papers and am writing a short paper about his work.
His two Sun/climate papers were careful, meticulous, full of qualifications and bubbling with excitement – as his papers to the Royal Society often were. They were first rate pieces of work. He had available Adam Smith’s huge tabulation of wheat prices. Adam Smith’s 1776 book, An Inquiry into the Nature and Causes of the Wealth of Nations, included details of English wheat prices over 562 years from 1202 to 1764 compiled in the most careful manner. In contrast to this data, Herschel had rather flimsy solar activity data and he knew this.
William Herschel’s language is wonderful!
He wrote:
“Since light and heat are so essential to our well-being, it must certainly be right for us to look into the source from whence they are derived, in order to see whether some material advantage may not be drawn from a thorough acquaintance with the causes from which they originate.”
His observations showed that sometimes the Sun had more spots than others, sometime it had no spots. He concluded that the Sun’s output of ‘light and heat’ increased with the number of sunspots. He went over observational records since 1610 and identified five periods longer than two years in which no spots had been recorded. He reasoned that with no spots the Earth would receive less ‘light and heat’ and therefore be cooler.
Herschel reasoned that if the climate cooled in response to diminished ‘light and heat’ from the spotless Sun, the wheat harvest would be reduced and accordingly, the price of wheat would rise. He further reasoned that the effect of variable solar output on vegetation would be similar to the tidal effect of the Sun and the Moon. That is, that in some parts of the world the tides are very high and very low and that the tidal phenomena vary around the world over time and in relation to latitude and longitude. He pointed out that even though there were these great variations, the tidal phenomena are universally the result of a single principle, the variable gravitation of the Sun and the Moon, as Newton had shown.
Herschel applied his test to the five lean periods by tabulating the price of wheat for these periods.
Herschel found, and reported to the Royal Society that, roughly speaking, the price of wheat in England was highest when sunspots were absent. He summed up his argument in this way:
“The result of this review of the foregoing five periods is, that, from the price of wheat, it seems probable that some temporary scarcity or defect of vegetation has generally taken place, when the Sun has been without those appearances which we surmise to be the symptoms of a copious emission of light and heat.”
Members of the Royal Society mocked him mercilessly. One member, Henry Brougham, then aged 25, who in October 1802 launched the Edinburgh Review, which was to become one of the most influential British magazines of the 19th century, made William Herschel the target of his mockery.
In January 1803 in the second issue of the Edinburgh Review Brougham made his most vindictive of all comment about Herschel’s theory of a relationship between variable solar activity and the price of wheat. Henry Brougham wrote:
“To the speculations of the Doctor on the nature of the Sun, contained in the last volume [of the Transactions of the Royal Society], we have many similar objections but they are eclipsed by the grand absurdity which he has committed in his hasty and erroneous theory concerning the influence of the solar spots on the price of grain.”
Sir Joseph Banks, the President of the Royal Society, implored William Herschel to ignore the ‘darts’ of Henry Brougham, assuring William that “….nothing can affect and overturn truths and discoveries founded on experience and observation.”
Henry Brougham would rise far in politics becoming Lord Chancellor and Baron Brougham in 1830, receiving a second peerage 30 years later.
Interestingly, Pustilnik and Yom Din 2004 reported their analysis of records of the price of wheat in England from 1259 to 1702 in relation to the established sunspot record. They found that Herschel was right: the price of wheat was high in medieval England during periods when there were hardly any sunspots, and low during solar maxima.
The following year Solar Physics published a second paper by the two authors extending their analysis to wheat prices in the US during the 20th century (Pustilnik and Yom Din 2005). The authors recorded their surprise, finding a relationship between numbers of sunspots and the price of wheat, just as Sir William hypothesised. The authors did not expect to see a sunspot connection due to modern technologies that make crops more robust in unfavourable weather, globalised markets, and the massive economic disruption that occurred during the two world wars. They reasoned that these factors should have cancelled out any variation in the data attributable to a sunspot effect. They surmise that the effect persists because 70% of US durum wheat grows in one part of North Dakota, where localised weather conditions could be expected to have a dramatic impact on total production.
Jumping to the 19th Century, the topic of the Sun causing climate change was fashionable and main stream. William Jevons, who became a famous Economist, Logician and Statistician, claimed that variable solar activity was responsible for almost everything that changed on the face of the Earth. He introduced the idea of business cycles into our economic language: he attributed them to the Sun’s activity cycles.
Towards the end of the 19th Century governments around the world were setting up national meteorological agencies. At that time, meteorologists were keen to understand weather and climate and devoted scarce resources to the search for explanations of the phenomena they were employed to predict. They embraced solar explanations.
In 1898, one of the world’s leading meteorologists of the day, Professor Bigelow, wrote:
“That there is a causal connection between the observed variations in the forces of the Sun, the terrestrial magnetic field, and the meteorological elements has been the conclusion of every research into this subject for the past 50 years.”
See here, for example: http://query.nytimes.com/mem/archive-free/pdf?_r=1&res=9E0DE4DB1631E733A2575BC2A9669D946797D6CF (aka http://tinyurl.com/odr8um )
In the 1920s and 30s when it was still respectable for Government agencies to examine Sun/climate relationships, Australia’s Bureau of Meteorology published two papers reporting that the Sun regulated our climate. One published in 1925 concluded that “The year 1914 was the culmination of what was in all probability the worst drought in Australian history” and attributed the drought to the weakness of Sunspot Cycle No. 14. In the other, published in 1938, the Bureau concluded:
“A rough generalisation from the winter rainfall over northern Victoria would suggest that when the new solar cycle begins with a rapid rise to a definite peak then the heaviest rains are in the early years, but when the solar activity begins more gradually and takes four or more years to reach a low or moderate maximum, then comparatively poor seasons may be expected in the early part.” (Details can be found in my paper, Mackey 2007, available here:
http://www.griffith.edu.au/conference/ics2007/pdf/ICS176.pdf )
The low amplitude forecast for Solar Cycle 24 is that it will be the same as Solar Cycle 14. On the basis of the BoM’s early research this suggests another Federation drought for Australia beginning in the next year or two and poor seasons in northern Victoria. I wonder if the BoM of today would take this hypothesis seriously enough to allocate scarce resources to it.
In 1972, the distinguished scientist, Edward Bowen (see http://www.science.org.au/academy/memoirs/bowen.htm ) reported that in relation to these two BoM reports (see Bowen, 1975): “Other workers (Deacon and Das, private communication) have since extended these data to the 1950s, that is, for another 30 yr, and the relationship stands up”.
Dr Bowen also reported that the march of the high and low pressure systems around the poles as a result of solar activity first identified by the BoM in the 1920s could be used to improve the accuracy of long term weather forecasting.
A couple of generations after the pioneering research of the 1920s, the government meteorological agencies seem to have been lobotomised: explanatory-type research was generally prohibited and those that dabbled ostracised. Weather bureaux concentrated on getting good measurements of meteorological variables and forecasting by statistical analyses of them. Even research into the major oceanic/atmospheric oscillations, which are usually the proximal cause of weather, was heavily discouraged by the mandarins who controlled the weather bureaux.
Neville Nicholls, an Australian scientist employed for most of his professional life in Australia’s BoM who pioneered the BoM’s study of ENSO, pointed out that the BoM’s management took many decades of convincing before acknowledging in the 1990s that ENSO was a worthwhile subject of study for meteorological purposes (see Nicholls 2005).
Interestingly, Nicholls also reports the following:
“Throughout the atmospheric sciences in the middle decades of the twentieth century, climatology was “neither respected nor valued” (quoting from P. J. Lamb, “The Climate Revolution: A Perspective”, Climate Change, Vol 54, 2002, pps 11 – 28). According to Kenneth Hare, “only the old, the halt, and the infirm could be appointed to the climatological branch; the able-bodied men were expected to be forecasters” (quoting from F. K. Hare, “Dynamic and Synoptic Climatology”, Annals of the Association of American Geographers, Vol 35, 1955, pps 152 – 162). Climatology was regarded as “mere book-keeping….. to be posted to the climatological branch of a national weather service was like being made an intelligence officer, or a lighthouse keeper; it was a terminal appointment” (quoting from F. K. Hare, “The Concept of Climate” Geography, Vol 51, 1966, pps 99 – 110)”.
As I read the history of national weather services, after WWII management had a very narrow focus of operational meteorology. Unlike the earlier period, there was no interest in trying to understand the phenomena, there was little interest in long term predictions and any attempt to think outside the square of management’s paradigm was to risk dismissal. Management was not strategic, but obsessed with operational agendas. The persistence of this ingrained thinking may help explain the refusal of national weather services in Australia, the UK, the USA, Canada and NZ to resume research about Sun/climate relationships. In contrast, the national weather services of Russia and Japan maintain active and highly effective research programs in this field.
In 1972 one of the world’s leading meteorologists, Andrei Monin, wrote:
“The greatest attention should be devoted to the question of whether there is a connection between the Earth’s weather and fluctuations in solar activity. [emphasis in original]. The presence of such a connection would be almost a tragedy for meteorology, since it would evidently mean that it would first be necessary to predict the solar activity in order to predict the weather; this would greatly postpone the development of scientific methods of weather prediction. Therefore, arguments concerning the presence of such a connection should be viewed most critically.”
By the time Jack Eddy published his papers in the mid 1970s about the role of the Sun, the field was no longer fashionable and Eddy’s thesis suffered a fate not unlike William Herschel’s.
Nevertheless science marches on! An increasing quantity and quality of papers continued to be published supporting the hypothesis that the Sun regulates our climate.
A NASA organised conference in 1973 (at which Leif Svalgaard presented a significant paper) surveyed the entire area of Sun/climate research. The conference proceedings (Bandeen and Maran, 1975) outlined a framework which could guide future research. It included solar radiation, solar plasma and the Sun’s electromagnetic field and the complex structures created by solar activity in the Heliosphere (itself one of those structures) which could have climate consequences.
In 1978 NASA published a comprehensive review of Sun, climate and weather relationships (Herman and Goldberg 1978). John Wilcox wrote the following in his foreword to the book:
“’A growing mass of evidence suggests that transient events on the Sun affect our weather and long-term variations of the Sun’s energy output affect out climate Solar terrestrial exploration can help establish the physical cause and effect relationships between solar stimuli and terrestrial responses. When these relationships are understood, science will have an essential tool for weather and climate prediction.’ This paragraph, written by Robert D. Chapman as part of a proposal for a fiver-year plan fro Solar Terrestrial Programs in NASA, is an indication of the present status of Sun-weather/climate investigations.”
It is to be noted that neither NASA publication addressed the role of the Sun’s gravitational field in the regulation of the Earth’s climate.
The developments in solar physics during the 1970s and 80s must have greatly aggravated the meteorologists’ nightmares so eloquently described by Andrei Monin.
Within a few years two prominent meteorologists, John Houghton (UK) and Bert Bolin (Sweden) joined the evil Maurice Strong to create the hideous, post-modern Golem of AGW/GHGs that is now on the cusp of destroying the world’s advanced democratic societies and sophisticated economies, as Maurice Strong originally and publicly intended.
For the meteorologists, the deal with Maurice Strong was that solar physics hypothesis would be buried so that meteorology would not become subservient to solar physics, but rather would be positioned to be indispensible to the governments of the world thus assuring meteorology a permanent place on the funding table of benevolent governments. In return, the meteorologists would give Strong’s environmental global domination agenda a veneer of scientific respectability with some plausibly sounding science and the elaborate climate computer-based models that meteorologists developed for their craft.
Returning to solar physics for the moment, the two NASA publications mentioned above provided a framework, which if followed, would end the disconnectedness in Sun/climate research reported by Lief and by John Wilcox more than 35 years before.
Inexplicably, the framework is ignored by some prominent solar physicists.
Thus the two distinguished solar physicists, Mike Lockwood and Claus Frohlich, ignore it totally in their mischievous papers published by the Royal Society in 2007/08.
These papers ignore the substantial findings about the role of the Sun’s plasma output and numerous heliospheric topology variables in generating the Earth’s climate dynamics (heliospheric variables include heliospheric structures (Heliospheric Current Sheet structure (inclination; homogeneity; thickness; current density); the Interplanetary Magnetic Field structure; open and closed fluxes; solar wind, Coronal Mass Ejections, Solar Proton Events; interplanetary counterparts of CMEs; Alfvenic waves; magnetic field directional turnings; pressure balanced structures; magnetic ropes and clouds (chilarity); and corotating interaction regions); solar polarity (dipole to multipole); solar hemispheric asymmetries; solar-terrestrial magnetic field orientation (parallel, antiparallel); solar-terrestrial orientation; Helioid; and Helioid-Geoid orientation. For an entrée into this world of science see the university website of Brian Tinsley, Professor of Physics at the University of Texas, Dallas:
http://www.utdallas.edu/nsm/physics/faculty/tinsley.html )
Lockwood and Frohlich ignore completely the established findings about the role of the gravitational fields of the Sun and the Moon in the regulation of the Earth’s climate. Because of this and other glaring errors in their papers, the Royal Society should not have published them. But not only did the Royal Society publish them, the Royal Society triumphantly editorialised that the papers prove that “the Earth’s surface air temperature does not respond to the solar cycle” and, as if Henry Brougham was still writing for the Royal Society, the blurb on the website of the Proceedings of the Royal Society states in relation to the Lockwood and Frohlich papers, the truth about global warming! The sun is not a factor in recent climate change!
Why would two of the world’s leading solar physicists author papers so blatantly incomplete? Why would a once esteemed scientific society make such a blatantly false announcement? As is usually the case, when lies are told it is inevitably the teller of the lies who is the most deceived. It is most unfortunate in the extreme that there is no one in the Royal Society (or in any leadership position in science in the UK, Australia or the USA) of the calibre and integrity of Sir Joseph Banks who was able to minimise the rabid nonsense of Henry Brougham.
More recently on May 7, 2008 as WUWT recently listed, NASA issued a press release quoting NASA’s Robert Cahalan, Head, Climate & Radiation Branch with news that “about 1,361 watts per square meter of solar energy reaches Earth’s outermost atmosphere during the sun’s quietest period. But when the sun is active, 1.3 watts per square meter (0.1 percent) more energy reaches Earth.” “This TSI measurement is very important to climate models that are trying to assess Earth-based forces on climate change,” Robert Cahalan said. There is no mention at all of established relationships between other solar variables and climate. It is as if NASA has dementia and all the work in the above mentioned NASA publications of 1978 and 1975, which has in the intervening 30 years advanced enormously, is lost to NASA’s corporate memory. Why is this?
It is customary in scientific research when trying to understand some phenomena to consider all relevant variables that might have a role and which a scientist can investigate. It is customary when doing so to use the notions of independent and dependent variables,
(see http://www.viswiki.com/en/Dependent_and_independent_variables )
Yet this way of thinking is totally absent in the science of climate dynamics; it is scarcely used in the study of solar-terrestrial relationships. Why is this?
If it was fully utilised in these two fields of inquiry the disconnectedness noted by Lief (and before him by John Wilcox) might finally vanish.
References:
BANDEEN, W. R. and MARAN, S. P., 1975. Symposium on Possible Relationships between Solar Activity and Meteorological Phenomena Proceedings of a Symposium held November 7 8, 1973 at the Goddard Space Flight Center Greenbelt Md.: NASA Goddard Space Flight Center, NASA SP 36.
Bigelow, F. H., 1898. “Solar and Terrestrial Magnetism in their relations to Meteorology”, U. S. Department of Agriculture, Weather Bureau, Bulletin No. 21. [quoted by Wilcox 1975].
Bowen, Edward G., 1975. “Kidson’s relation between sunspot number and the movement of high pressure systems in Australia” paper in Bandeen and Maran 1975 pps 43 – 45.
Brougham, Henry, 1803. “Art. XV. Observations on the two lately discovered Celestial Bodies By William Herschel, L.L.D. F.R.S. From Phil. Trans. RS 1802”. Edinburgh Review Vol 1 pps 426 – 431, January 1803.
Herman, John R., and Goldberg, Richard A., Sun, Weather, and Climate National Aeronautics and Space Administration 1978.
Herschel, W., 1801. “Observations tending to investigate the Nature of the Sun, in order to find the Causes or Symptoms of its variable Emission of Light and Heat; with Remarks on the Use that may possibly be drawn from Solar Observations”. Philosophical Transactions of the Royal Society, pps 265 to 301; Read April 16, 1801.
Herschel, W., 1801. “Additional Observations tending to investigate the Symptoms of the variable Emission of the Light and Heat of the Sun; with Trials to set aside darkening Glasses, by transmitting the Solar Rays through Liquids; and a few Remarks to remove Objections that might be made against some of the Arguments contained in the former Paper”. Philosophical Transactions of the Royal Society, pps 354 to 363; Read May 14, 1801.
KIDSON, E., 1925. Some Periods in Australian Weather. Research Bulletin No. 17 Bureau of Meteorology, Melbourne.
Lockwood, M. and Frohlich, C. 2007 “Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature” Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences June 2007.
See http://www.journals.royalsoc.ac.uk/content/h844264320314105/fulltext.pdf
Lockwood, M. and Fröhlich, C. 2008. Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature. II. Different reconstructions of the total solar irradiance variation and dependence on response time scale Proc. Roy. Soc. A, 464 (2094) , 1367-1385 , 2008.
Lockwood, M. 2008. Recent changes in solar outputs and the global mean surface temperature. III. Analysis of contributions to global mean air surface temperature rise Proc. Roy. Soc. A, 464 (2094), 1387-1404, 2008.
Mackey, R., 2007 Rhodes Fairbridge and the idea that the solar system regulates the Earth’s climate. Journal of Coastal Research, Special Issue 50 (Proceedings of the 9th International Coastal Symposium), 955 – 968. Gold Coast, Australia.
Monin, Andrei, 1972. Weather Forecasting as a Problem in Physics. MIT Press. [quoted by Wilcox 1975].
Nicholls, N. 2005. “Climatic Outlooks: from revolutionary science to orthodoxy” a chapter in Sherratt, T., Griffiths, T., and Robin, L. A Change in the Weather – Climate and Culture in Australia. National Museum of Australia Press 2005.
Pustilnik, L. and Yom Din, G., 2004. “Influence of solar activity on state of wheat market in medieval England”, Solar Physics, v. 223, Numbers 1-2, pps 335-356.
Pustilnik, L. and Yom Din, G., 2005. “Space Climate Manifestation in Earth Prices – from Medieval England up to Modern U.S.A.” Solar Physics v 224 Numbers 1-2, pps 473-481.
QUAYLE, E. T., 1925. Sunspots and Australian Rainfall. Proceedings of the Royal Society of Victoria New Series, 37 Part 2, 131 143.
QUAYLE, E. T., 1938. Australian Rainfall in Sunspot Cycles. Research Bulletin No. 22 Bureau of Meteorology Melbourne.
Wilcox, J. 1975. “Solar Activity and the Weather” paper in Bandeen and Maran 1975 pps 25 – 38.