Posted on 09/29/2014 11:20:07 AM PDT by Ernest_at_the_Beach
Both observational and proxy records of climate change often show quasi periodic variations similar to solar activity cycles over a wide range of time scales. However, the detailed mechanism and the extent of the influence of solar activity on climate change have not been clearly understood. Although the exact role of each of solar parameters on climate change has not been quantitatively clarified, several possible mechanisms are proposed; such as the forcing through total (e.g. Lean et al., 1995) and spectral irradiance (e.g. Haigh 1996; Kodera and Kuroda, 2005), solar wind (e.g. Tinsley, 1996) and the galactic cosmic rays (Friis-Christensen and Svensmark, 1997; Svensmark, 2007). Among these parameters related to solar activity, galactic cosmic rays possess characteristic variations depending on the polarity of solar dipole magnetic filed as shown in Figure 1.
The polarity of solar dipole magnetic field reverses at every maxima of 11-year sunspot activity cycle, and so the polarity reversals of solar magnetic field possess 22-year cycle. The cosmic rays are modulated by solar wind and the interplanetary magnetic field and hence the flux of cosmic rays at the earth varies with the 11-year solar activity cycle, while, the polarity of solar dipole magnetic field determines the trajectory of cosmic rays in the heliosphere and thus the flux of cosmic rays at the earth varies depending also on the polarity of solar dipole magnetic field (Kota and Jokipii 2001). As is shown in
Figure 1, the patterns of cosmic ray flux over solar cycles slightly differ depending on the polarity of solar dipole magnetic field, resulting in the component of 22-year cycle in cosmic-ray variation. This feature is very helpful in distinguishing the effect of cosmic rays on climate change from the other effects caused by e.g. irradiative outputs of the Sun.
Extension of the record of cosmic rays back in time enable us to examine if the connection between cosmic rays and climate change suggested by Friis-Christensen and Svensmark (1997) and Svensmark (2007) for the recent two decades had also existed in the past. We had investigated the history of Schwabe and Hale solar and cosmic ray cycles based on the carbon-14 content in tree rings with annual time resolution, originally for understanding the mechanism of multi-decadal to multi-centennial variation of solar activity level. Such record is however also applicable to investigating the Sun-climate relationship at decadal time scale. Carbon-14 is produced by cosmic rays, and circulates in the form of carbon dioxide to be absorbed in trees by photo synthesis. Since the age determination of each annual data is assured in the case of using tree rings, it is possible to determine the history of solar cycles with accurate timing. The beryllium-10 in ice cores from polar region can be also used for the reconstruction of solar cycles in the past.
In the case of using ice cores, it is often difficult to obtain the record with absolute age, while, it is possible to derive much clear signal than carbon-14 due to the difference in the circulation process. The combination of these two nuclides provides clear image of cosmic ray variation with reliable age.
…
The mechanism of the influence of cosmic rays on the cloud formation is not fully understood, however, our proxy based analyses of cosmic rays and climate change during the Maunder Minimum exhibit the importance of cosmic rays as a medium of solar forcing of climate change at decadal to multi-decadal time scales. The complex features of solar magnetic and cosmic ray cycles, such as the variable length of the “11-year” cycle, the subsequent lengthening/shortening of the “22-year” Hale cycle, the amplification of the 22-year cycle in cosmic rays at grand solar minima, may be able to explain some of the complex features of climate change at this time scale.
Influence of solar cycles on climate change during the Maunder Minimum
Hiroko Miyahara et al., Solar and Stellar Variability: Impact on Earth and Planets
Abstract. We have examined the variation of carbon-14 content in annual tree rings, and investigated the transitions of the characteristics of the Schwabe/Hale (11-year/22-year) solar and cosmic-ray cycles during the last 1200 years, focusing mainly on the Maunder and Spoerer minima and the early Medieval Maximum Period. It has been revealed that the mean length of the Schwabe/Hale cycles changes associated with the centennial-scale variation of solar activity level. The mean length of Schwabe cycle had been ∼14 years during the Maunder Minimum, while it was ∼9 years during the early Medieval Maximum Period. We have also found that climate proxy record shows cyclic variations similar to stretching/shortening Schwabe/Hale solar cycles in time, suggesting that both Schwabe and Hale solar cycles are playing important role in climate change. In this paper, we review the nature of Schwabe and Hale cycles of solar activity and cosmic-ray flux during the Maunder Minimum and their possible influence on climate change. We suggest that the Hale cycle of cosmic rays are amplified during the grand solar minima and thus the influence of cosmic rays on climate change is prominently recognizable during such periods.
Full paper (PDF)
Thank you. Nicely done!
Well, there’s no way to avoid it now. The Sun is officially a “denier.”
DUH! What gave them the first clue? The information has been available for a long time.
This is such BS....Big Oil Oligarchs obviously bought and paid for this kind of pseudo-science.
One of the reasons is that the data is based on tree rings. Tree rings only show when a ‘change’ occurs, not the temperature.
Reader's Digest would put their own slant on it.
However, the 'condensed version' can be found in post #6.
Which is probably what the FARMER’S ALMANAC bases their predictions on . Sunspot Activity.
Yep...that is what I understand,
OMG...the SUN causes global warming and cooling? Who would have ever guessed?
Even in the 'arts'.
LOL!
Bookmark.
I agree with the Global Warmists that the ice will melt and the sea levels will rise, devastating coastal communities around the world. Except that catastrophe already happened 12,000 years ago. We’re not going to get much warmer. The seas won’t rise much more, although coastal land may sink as it always does. So, as usual, they’re trying so solve the last deca-millenium’s problems.
Those two warmer than the millennial average temperature periods, by the way, were golden ages for expanding human populations. That little fact may explain much about why people who hate and despise their fellow humans (and no doubt themselves, although they haven't the honesty or guts to do something about it) believe a warmer global climate is somehow bad. Cold, on the other hand, would potentially kill billions.
Thank you - I feel so smart today!
Exactly
Mucho garcias, cap’n. That was beautiful.
Al Gore is a manipulative genius. People who listen to him and give him $$ are the idiots. Gore does NOT believe anything he espouses.
Thanks Ernest.
“Al Gore is an idiot.....”
“DUh,,,, What’s tha bright light in the sky?”
“That’s out Sun, Al!”
“What’s it doing on in the daytime? Turn it off!”
“Splonk” He’s out guys! Come on! Let’s klick him!”
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