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Thread: or is it the sun?

  1. #1 or is it the sun? 
    Forum Sophomore andre's Avatar
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    Although it is prohibited to think that the sun has any influence on the climate, there is a yet an increasing number of illegal underground partisans, finding different results.

    As far as the Holocene goes, it seems a fair substantiation, beyond that, the number of actors increase, most notably the oceans, and for certain, blurring the overall view.

    http://www.springerlink.com/content/f226g6036453m385/

    Abstract Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversial—perhaps because the observations had largely involved correlations between climate and the sunspot cycle that had persisted for only a few decades. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic ray variations recorded in cosmogenic isotope archives, providing persuasive evidence for solar or cosmic ray forcing of the climate. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Although this remains a mystery, observations suggest that cloud cover may be influenced by cosmic rays, which are modulated by the solar wind and, on longer time scales, by the geomagnetic field and by the galactic environment of Earth.

    Two different classes of microphysical mechanisms have been proposed to connect cosmic rays with clouds: firstly, an influence of cosmic rays on the production of cloud condensation nuclei and, secondly, an influence of cosmic rays on the global electrical circuit in the atmosphere and, in turn, on ice nucleation and other cloud microphysical processes. Considerable progress on understanding ion–aerosol–cloud processes has been made in recent years, and the results are suggestive of a physically-plausible link between cosmic rays, clouds and climate. However, a concerted effort is now required to carry out definitive laboratory measurements of the fundamental physical and chemical processes involved, and to evaluate their climatic significance with dedicated field observations and modelling studies.
    The Arxiv version is here:

    http://arxiv.org/PS_cache/arxiv/pdf/...804.1938v1.pdf

    featuring another very interesting debunking of the hockeystick


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  3. #2 Re: or is it the sun? 
    Universal Mind John Galt's Avatar
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    Quote Originally Posted by andre
    Although it is prohibited to think that the sun has any influence on the climate,
    Andre, please don't troll. You are perfectly aware that practically every climatologist on the planet acknowledges the critical role of the sun in determing our climate. You are erecting a strawman. Frankly I think such tactics are beneath you and am disappointed to see you indulging in them.
    Regards - in semi-moderator role- Ophiolite


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  4. #3  
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    Although it is prohibited to think that the sun has any influence on the climate, there is a yet an increasing number of illegal underground partisans, finding different results.
    Simply false, I doubt you could find a single climatologist who'd deny some solar role in climate change. The disagreement wouldn't center on if solar radiance plays a role, but how much--and most including the references you site, would say there's weak theoretical or observation evidence to think comes anywhere close to the magnitude of green house gas forcing. "illegal partisans".... LOL. Why the appeal to emotion?

    Ok getting back to science,

    From your souse:
    "The idea of a comic rays connection to clouds have been around for a few years now but lack both a physical mechanism and observational support."

    In one of the very few actual comparisons to observations there was no connection between cloud cover and sun spot cycle.

    "5 Conclusions
    The dip in amplitude of 1.28% in the low altitude cloud cover noted in references [1, 2] in solar cycle 22 (peaking in 1990) has also been seen in this analysis. This dip anti-correlates in shape with the observed mean daily sun spot number i.e. correlates with the change in cosmic ray intensity due to solar modulation. The dip is less evident in the following solar cycle 23 although it is possibly present in the tropical regions of the Earth. If the correlation noted in [1, 2] and its hypothesised causal connection between low cloud cover and ionization are real, it is shown that the magnitude of the effect implies that a large fraction of the low cloud cover is formed by ionization. However, no evidence could be found of changes in the cloud cover from known changes in the cosmic ray ionization rate.

    In conclusion, no corroboration of the claim of a causal connection between the changes in ionization and cloud cover, made in [1, 2], could be found in this investigation. From the distribution of the depth of the dip in solar cycle 22 with geomagnetic latitude (the VRCO) we find that, averaged over the whole Earth, less than 23% of the dip comes from the solar modulation of the cosmic ray intensity, at the 95% confidence level. This implies that, if the dip represents a real correlation, more than 77% of it is caused by a source other than ionization and this source must be correlated with solar activity."
    http://arxiv.org/PS_cache/arxiv/pdf/...803.2298v1.pdf

    I think the reason there doesn't seem to be a connection is because there isn't a lack of cloud condensation nuclei in the lower troposphere.
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  5. #4 Re: or is it the sun? 
    Forum Sophomore andre's Avatar
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    Quote Originally Posted by Ophiolite
    Quote Originally Posted by andre
    Although it is prohibited to think that the sun has any influence on the climate,
    Andre, please don't troll. You are perfectly aware that practically every climatologist on the planet acknowledges the critical role of the sun in determing our climate. You are erecting a strawman. Frankly I think such tactics are beneath you and am disappointed to see you indulging in them.
    Regards - in semi-moderator role- Ophiolite
    You guys don't appreciate a bit tongue in cheek and pay back time is arriving. I have not forgotten any of the insinuations like here or here or here. It's useless to try and talk objective science as long as the groupthink frenzy continues.

    Anyway this is the comment that I sent around in a groupsmail:

    In my opinion, the hypothesis is well substantiated up until the Holocene. As of the late Pleistocene things get more complicated. As usual even a comprehesive work like this fails to take all elements into consideration. For instance, the certain impact on climate of unusual oceanic activity during glacial transitions, of which is abundant evidence, remains untouched.

    A few things to note, are another implicite falsification of the hockeystick, and the correct observation that oxygen isotopes of calcite of a speleothem is representing precipitation rate rather than temperature. Yet, most paleo-climatologic research automatically assume isotopes to be temperature indeed.

    Also, the rather substantial temperature variation during the Holocene appears to be in the same order of magnitude as the temperature variations during the last glacial transition as seen by other proxies than 'water' isotopes, However the isotopes have a much smaller variation in the Holocene compared to the Pleistocene. How big is the step then to accept that the Greenland ice core isotopes may very well be recording predominantly rate of precipitation as well, rather than temperatures.

    That would shake up paleoclimatology in its fundamentals
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