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Thread: Rapid Warming in North Atlantic

  1. #1 Rapid Warming in North Atlantic 
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    A study of marine sediments off Western Svalbard finds unprecedented recent warming compared to the past 2000 years.

    Svalbard is an interesting place. Though at nearly 80North latitude, it's at the Northern range of the Gulf current and almost some 18C degrees warmer than average for that latitude. This also makes its islands a center of marine life and bird breeding as well as open water that allows its settlement a few hundred years ago. Sixty percent of the Svalbard is glaciated, but other studies show rapid retreat. Though the sediment study can't address the dynamics in detail, the pronounced warming is almost surely a combination of arctic amplification as predicted by AGW and some current energy changes--the Earth is shuttling a lot of it's excess energy from AGW into the North Atlantic.

    http://www.sciencemag.org/content/331/6016/450.short



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    Any new Titanics sailing there should beware.


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    I'll bet it could easily be correlated to the change in the Earth's precession changes over time. That far North will be affected by precession as the earth travels through it's elliptical path.
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    Lynx Fox, the horizontal scale isn't visible and the full article requires payment. Can you clarify the time scale?

    Thanks in advance.
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    Quote Originally Posted by Bunbury
    Lynx Fox, the horizontal scale isn't visible and the full article requires payment. Can you clarify the time scale?

    Thanks in advance.
    Ya...I'll look for another figure.

    It's over 2300 years or so. Also the sediments used plankton remains so this is mostly a proxy for summer temps.
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    Quote Originally Posted by cobra
    I'll bet it could easily be correlated to the change in the Earth's precession changes over time
    A spike like that? In that direction during a cooling phase?

    I'll take your money: how much?
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    It's over 2300 years or so. Also the sediments used plankton remains so this is mostly a proxy for summer temps.
    It just rained again in central Minnesota, for the 14th or 15th consecutive January. (barely made it: rain on December 31, then a cold snap with much snow, then rain on the 29th of Jan IIRC).

    Until the current streak, rain fell in about one January every seven. This would be a reasonable, rule of thumb proxy for winter night temperatures over the center of the North American land mass.

    We also have seen the northward spread of possums, into and through the state. Another proxy for winter temps in the region.
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    I would like to point out the distance in years between data points. Higher temperatures could have been there, but not sampled.
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    Quote Originally Posted by Wild Cobra
    I would like to point out the distance in years between data points. Higher temperatures could have been there, but not sampled.
    The temporal resolution is 17-28 years (based on sedimentation rate from 1 cm slices). Anything like the recent warming would have been caught on at least 3-5 data points. The closest thing to it was the medievel warming period which is consistent with other European proxies. Though it last a few centuries, it's not nearly as strong as the current warming and that too is consistent with other European proxies.
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    Quote Originally Posted by Lynx_Fox
    Quote Originally Posted by Wild Cobra
    I would like to point out the distance in years between data points. Higher temperatures could have been there, but not sampled.
    The temporal resolution is 17-28 years (based on sedimentation rate from 1 cm slices). Anything like the recent warming would have been caught on at least 3-5 data points. The closest thing to it was the medievel warming period which is consistent with other European proxies. Though it last a few centuries, it's not nearly as strong as the current warming and that too is consistent with other European proxies.
    The AW temperature points are obviously spaced about 100 years apart.

    Then riddle me this...

    How do they reliable use Plankton as a proxy, when so many factors can affect it that probably are not be accounted for?
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    Quote Originally Posted by Wild Cobra
    Then riddle me this...

    How do they reliable use Plankton as a proxy, when so many factors can affect it that probably are not be accounted for?
    Such as? They use two methods in the study. The first is a comparison of micro fossils from two species.. They compare types of organisms (planktonic foraminiferal) and are finding predominantly species that only exist in warmer waters during recent times that aren't found prior to that time. It's pretty unlikely that these species have evolved to favor different water temperatures over such a short time.

    The second method is a oxygen isotopic ratios.

    Both are also consistent with other longer term studies which look at the somewhat grainier Ma/Ca ratios used for much longer reconstructions in the same region.

    While I'm not an expert in these sedimentation proxies, I do know when they are consistent with recent temperature calibrations, biological population simulations of the organisms involved, and with many other proxies it adds a great deal of confidence in their reliability.
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    Quote Originally Posted by Lynx_Fox
    Quote Originally Posted by Wild Cobra
    Then riddle me this...

    How do they reliable use Plankton as a proxy, when so many factors can affect it that probably are not be accounted for?
    Such as? They use two methods in the study. The first is a comparison of micro fossils from two species.. They compare types of organisms (planktonic foraminiferal) and are finding predominantly species that only exist in warmer waters during recent times that aren't found prior to that time. It's pretty unlikely that these species have evolved to favor different water temperatures over such a short time.

    The second method is a oxygen isotopic ratios.

    Both are also consistent with other longer term studies which look at the somewhat grainier Ma/Ca ratios used for much longer reconstructions in the same region.

    While I'm not an expert in these sedimentation proxies, I do know when they are consistent with recent temperature calibrations, biological population simulations of the organisms involved, and with many other proxies it adds a great deal of confidence in their reliability.
    In both cases, the change in water chemistry after the Maunder Minima could have skewed the proxy data.

    I'm just trying to be scientific about this. We cannot be certain of any particular theory until all else is ruled out.
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    Expressing "extraordinary and incredible, valid, well supported likelihood" expressing "certainty."
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