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A Simple Solution: The 100-Kyr Tidal Cycle?

  1. Dec 30, 2008 #1
    I was slightly exasperated with this The 100,000-Year Ice-Age Cycle Identified and Found to Lag Temperature, Carbon Dioxide, and Orbital Eccentricity report:

    "It is difficult to explain this predominant cycle in terms of orbital eccentricity because the 100,000-year radiation cycle (arising from eccentricity variations) is much too small in amplitude and too late in phase to produce the corresponding climatic cycle by direct forcing"

    Why isn't the tidal cycle due to eccentricity variations given due consideration? The http://pangea.stanford.edu/research/Oceans/GES205/1800yrTidalCycleForcingAbruptClimateChange.pdf [Broken] give the tidal explanation much credibility. I further propose that the tidal variation could be amplified due to the effect of gravitational entropy (this is a subtle proposal which links the Earth science mysteries with those of modern physics). All of the major components of the system discussed are affected by tidal forces i.e. deep-sea temperature, the CO2 cycle, and the Dole effect. So why it is so blantantly ignored?
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Dec 30, 2008 #2
    That report talks of tidal variations at a period of 1,800 yrs which differs from the 100,000 yr cycle that you originally referred to. Granted, you might expect tidal cycles to match up with eccentricity cycles, in which case you would need to explain the amplitude and the phase that these cycles would theoretically have on climate (I guess you would need to understand how the oceans interacted at these scales)- do they match?
  4. Dec 30, 2008 #3
    The end of the report touches on the application of the idea to explain the 100-kyr orbital cycle:

    "We tentatively conclude that, although varying eccentricity strongly affects tidal forcing, and could possibly contribute to the 100-kyr cycle of glaciation.."

    The depth of the report suggests that there is a good match with the millennial cycle. I'm not an expert, but I can see that this is a distinct possibility of an explanation made by recognised scientists in the field. I just don't know why the tidal cycle is not more widely discussed.
  5. Dec 30, 2008 #4


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    The Keeling paper makes the following statement on the first page:

    Interpretations of sediment-cores by Bond et el indicate, however, that a 1- to 2-kyr periodicity persisted almost to the present, characterized by distinct cooling events, including the Little Ice Age that climaxed near A.D. 1600.

    The problem with this is that it is well established that the Huaynaputina stratovolcano in Peru exploded in the year 1600. Sulfuric acid levels (aerosal cooling) in the Greenland ice sheets were extremely high. Numerous records of famines, tree rings and ice conditions show that 1601 was one of the coldest in history and not surprisingly it took years for the climate to recover.
    Last edited: Dec 30, 2008
  6. Dec 31, 2008 #5
    I don't understand how you interpret the Huaynaputina eruption as a problem. The millennial cycle is shown to persist into the Holocene. This doesn't exclude the notion of climatic events being caused by the occassional volcanic eruption as well. The 1,800-yr tidal cycle of the Moon to explain the millennial cycle is a convincing one in my mind.
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