Dr. Roger Pielke Sr. writes about a new paper from Nicola Scafetta.:
A new paper has just appeared
Nicola Scafetta 2011: A shared frequency set between the historical mid-latitude aurora records and the global surface temperature. Journal of Atmospheric and Solar-Terrestrial Physics In Press doi:10.1016/j.jastp.2011.10.013
This paper is certainly going to enlarge the debate on the role of natural climate variability and long term change.
The abstract reads [highlight added]
Herein we show that the historical records of mid-latitude auroras from 1700 to 1966 present oscillations with periods of about 9, 10–11, 20–21, 30 and 60 years. The same frequencies are found in proxy and instrumental global surface temperature records since 1650 and 1850, respectively, and in several planetary and solar records. We argue that the aurora records reveal a physical link between climate change and astronomical oscillations. Likely in addition to a Soli-Lunar tidal effect, there exists a planetary modulation of the heliosphere, of the cosmic ray flux reaching the Earth and/or of the electric properties of the ionosphere. The latter, in turn, has the potentiality of modulating the global cloud cover that ultimately drives the climate oscillations through albedo oscillations. In particular, a quasi-60-year large cycle is quite evident since 1650 in all climate and astronomical records herein studied, which also include a historical record of meteorite fall in China from 619 to 1943. These findings support the thesis that climate oscillations have an astronomical origin. We show that a harmonic constituent model based on the major astronomical frequencies revealed in the aurora records and deduced from the natural gravitational oscillations of the solar system is able to forecast with a reasonable accuracy the decadal and multidecadal temperature oscillations from 1950 to 2010 using the temperature data before 1950, and vice versa. The existence of a natural 60-year cyclical modulation of the global surface temperature induced by astronomical mechanisms, by alone, would imply that at least 60–70% of the warming observed since 1970 has been naturally induced. Moreover, the climate may stay approximately stable during the next decades because the 60-year cycle has entered in its cooling phase.
The highlights listed in the announcement of the paper read
► The paper highlights that global climate and aurora records present a common set of frequencies. ► These frequencies can be used to reconstruct climate oscillations within the time scale of 9–100 years. ► An empirical model based on these cycles can reconstruct and forecast climate oscillations. ► Cyclical astronomical physical phenomena regulate climate change through the electrification of the upper atmosphere. ► Climate cycles have an astronomical origin and are regulated by cloud cover oscillations.
Dr. Scafetta writes in and attaches the full paper in email to me (Anthony) this week saying:
I can forecast climate with a good proximity. See figure 11. In this new paper the physical link between astronomical oscillations and climate is further confirmed.
What the paper does is to show that the mid-latitude aurora records present the same oscillations of the climate system and of well-identified astronomical cycles. Thus, the origin of the climatic oscillations is astronomical what ever the mechanisms might be.
In the paper I argue that the record of this kind of aurora can be considered a proxy for the electric properties of the atmosphere which then influence the cloud cover and the albedo and, consequently, causes similar cycles in the surface temperature.
Note that aurora may form at middle latitude or if the magnetosphere is weak, so it is not able to efficiently deviate the solar wind, or if the solar explosions (solar flare etc) are particularly energetic, so they break in by force.
During the solar cycle maxima the magnetosphere gets stronger so the aurora should be pushed toward the poles. However, during the solar maxima a lot of solar flares and highly energetic solar explosions occurs. As a consequence you see an increased number of mid-latitude auroras despite the fact that the magnetosphere is stronger and should push them toward the poles.
On the contrary, when the magnetosphere gets weaker on a multidecadal scale, the mid-latitude aurora forms more likely, and you may see some mid-latitude auroras even during the solar minima as Figure 2 shows.
In the paper I argue that what changes the climate is not the auroras per se but the strength of the magnetosphere that regulates the cosmic ray incoming flux which regulate the clouds.
The strength of the magnetosphere is regulated by the sun (whose activity changes in synchrony with the planets), but perhaps the strength of the Earth’s magnetosphere is also regulated directly by the gravitational/magnetic forces of Jupiter and Saturn and the other planets whose gravitational/magnetic tides may stretch or compress the Earth’s magnetosphere in some way making it easier or more difficult for the Earth’s magnetosphere to deviate the cosmic ray.
So, when Jupiter and Saturn get closer to the Sun, they may do the following things: 1) may make the sun more active; 2) the more active sun makes the magnetosphere stronger; 3) Jupiter and Saturn contribute with their magnetic fiend to make stronger the magnetic field of the inner part of the solar system; 4) the Earth’ magnetosphere is made stronger and larger by both the increased solar activity and the gravitational and magnetic stretching of it caused by the Jupiter and Saturn. Consequently less cosmic ray arrive on the Earth and less cloud form and there is an heating of the climate.
However, explaining in details the above mechanisms is not the topic of the paper which is limited to prove that such kind of mechanisms exist because revealed by the auroras’s behavior.
The good news is that even if we do not know the physical nature of these mechanisms, climate may be in part forecast in the same way as the tides are currently forecast by using geometrical astronomical considerations as I show in Figure 11.
The above point is very important. When trying to predict the tides people were arguing that there was the need to solve the Newtonian Equation of the tides and the other physical equations of fluid-dynamics etc. Of course, nobody was able to do that because of the enormous numerical and theoretical difficulty. Today nobody dreams to use GCMs to predict accurately the tides. To overcome the issue Lord Kelvin argued that it is useless to use the Newtonian mechanics or whatever other physical law to solve the problem. What was important was only to know that a link in some way existed, even if not understood in details. On the basis of this, Lord Kelvin proposed an harmonic constituent model for tidal prediction based on astronomical cycles. And Kelvin method is currently the only method that works for predicting the tides. Look here:
Figure 11 is important because it shows for the first time that climate can be forecast based on astronomical harmonics with a good accuracy. I use a methodology similar to Kelvin’s one and calibrate the model from 1850 to 1950 and I show that the model predicts the climate oscillations from 1950 to 2010, and I show also that the vice-versa is possible.
Of course the proposed harmonic model may be greatly improved with additional harmonics. In comparison the ocean tides are predicted with 35-40 harmonics.
But this does not change the results of the paper that is: 1) a clearer evidence that a physical link between the oscillations of the solar system and the climate exists, as revealed by the auroras’ behavior; 2) this finding justifies the harmonic modeling and forecast of the climate based on astronomical cycles associated to the Sun, the Moon and the Planets.
So, it is also important to understand Kelvin’s argument to fully understand my paper.
This work is the natural continuation of my previous work on the topic.
Nicola Scafetta. Empirical evidence for a celestial origin of the climate
oscillations and its implications. Journal of Atmospheric and Solar-Terrestrial Physics Volume 72, Issue 13, August 2010, Pages 951-970
We investigate whether or not the decadal and multi-decadal climate
oscillations have an astronomical origin. Several global surface temperature
records since 1850 and records deduced from the orbits of the planets
present very similar power spectra. Eleven frequencies with period between 5
and 100 years closely correspond in the two records. Among them, large
climate oscillations with peak-to-trough amplitude of about 0.1 and 0.25°C,
and periods of about 20 and 60 years, respectively, are synchronized to the
orbital periods of Jupiter and Saturn. Schwabe and Hale solar cycles are
also visible in the temperature records. A 9.1-year cycle is synchronized to
the Moon’s orbital cycles. A phenomenological model based on these
astronomical cycles can be used to well reconstruct the temperature
oscillations since 1850 and to make partial forecasts for the 21st century.
It is found that at least 60% of the global warming observed since 1970 has
been induced by the combined effect of the above natural climate
oscillations. The partial forecast indicates that climate may stabilize or
cool until 2030–2040. Possible physical mechanisms are qualitatively
discussed with an emphasis on the phenomenon of collective synchronization
of coupled oscillators.
The claims here are pretty bold, and I’ll be frank and say I can’t tell the difference between this and some of the cycl0-mania calculation papers that have been sent to me over the last few years. OTOH, Basil Copeland and I looked at some of the effects of luni-solar on global temperature previously here at WUWT.
While the hindcast seems impressive, a real test would be a series of repeated and proven short-term future forecasts. Time will tell.