2)
Solar and Orbital Variations
William Herschel theoretical and observational work provided the foundation for modern binary star astronomy; he was the first to recognize the orbital relationship that may physically link together double stars (Poyet, 2017a-b) and not consider them to be just fortuitous alignments «I may therefore immediately go to the second, which treats of binary sidereal systems, or real double stars» (Herschel, 1803). He is also the discoverer in 1800 of infra-red radiations (IR), that characterize the absorption spectrum of trace gas that we have studied in this work, water vapor first, though it is unclear whether this discovery happened while testing solar filters to observe solar spots or rather pioneering the use of astronomical spectrophotometry, using prisms and temperature measuring equipment to record the wavelength distribution of stellar spectra. But the reason to mention Herschel’s work here, is that he ventured into the speculation that there would exist a link between solar irradiance and climate. This was based on an apparent correlation he had found between sunspot numbers and the price of wheat, and Herschel (1801) reported «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 symptoms of a copious emission of light and heat» p. 316. The hypothesis that there would exist such a relationship did not bring him fame, as this had already happened thanks to his discovery of Uranus on March 13, 1781 but rather mockery and elicited guffaws (from Lord Brougham among others). It took some time before this relationship would be further investigated and confirmed by two researchers in Israel who have found a statistical link between the activity of the Sun and the price of wheat in seventeenth-century England, confirming that “at the point in the solar cycle when sunspots were least likely, wheat prices tended to be high” (Pustilnik and Yom Din, 2004). This is well summed up by Pustilnik and Yom Din (2004) «The results of our study show: a) The coincidence between the statistical properties of the distributions of intervals between wheat price bursts in medieval England (1259-1702) and intervals between minimums of solar cycles (1700-2000); b) The existence of 100% sign correlation between high wheat prices and states of minimal solar activity established on the basis of 10Be data for Greenland ice measurements for the period 1600-1700. These results imply a causal connection between solar activity and wheat prices in medieval England. This conclusion is consistent with our conceptual model of the causal chain, consisting of “solar activity – cosmic ray intensity – terrestrial weather – wheat production – wheat price” that presented in this work ». They add that for all ten solar cycles between 1600 and 1700, high wheat prices coincided with low activity, and vice versa and that «the probability of this happening by chance is less than 1 in 500». Therefore, changes in solar activity alter the strength of the solar wind, i.e. the stream of charged particles that flows from the Sun throughout the solar system (Parker, 1958 173). When the solar wind is strong, it is more difficult for charged particles from deep space to penetrate Earth's atmosphere. Once in the atmosphere, these cosmic rays collide with molecules in the air to produce ions, which help cloud droplets to form. So in periods of high solar activity the skies are less cloudy. Over the past few years, satellite observations have confirmed this link as well as results from the Earthshine project which studies the modulation of the albedo (Pallé et al., 2004a). One should remember that a change of albedo of a tiny 3% (say from 31% down to 30%) is equivalent to the warming anticipated by a doubling of [CO2]. The tidal forcing of the planets on the solar surface and solar wind has been explored by Poulos (2016; 2020). In fact this line of reasoning has been explored probably first by Denton and Karlén (1973) using C 14 variations measured from tree rings “Short-term atmospheric C14 variations measured from tree rings correlate closely with Holocene glacier and tree-line fluctuations during the last 7000 yr. Such a correspondence, firstly, suggests that the record of short-term C14 variations may be an empirical indicator of paleoclimates and, secondly, points to a possible cause of Holocene climatic variations. The most prominent explanation of short-term C 14 variations involves modulation of the galactic cosmic-ray flux by varying solar corpuscular activity”, then Tinsley and Deen (1991) and later by Svensmark and FriisChristensen (1997) and Marsh and Svensmark (2000), Carslaw et al. (2002), Kirkby (2007) as reminded by Veizer (2005) “In this alternative, an increase in TSI results not only in an enhanced thermal energy flux, but also in more intense solar 173When Eugene Parker submitted a paper on his discovery of solar wind in 1957, two eminent reviewers rejected the paper. However, since Chandrasekhar was editor of the Astrophysical Journal and could not find any mathematical flaws in Parker's work, he went ahead and published the paper in 1958.
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