A deep ocean current shift gives 400-year notice of massive climate change

Posted: March 29, 2019 by oldbrew in climate, Cycles, History, Natural Variation, Ocean dynamics, research, Temperature
Tags:

Credit: NASA – GISS


Showing once again that significant warming and cooling are normal features of the global climate over thousands of years and longer. We could speculate whether this particular research might be linked to the de Vries cycle.

The warm waters of the Gulf Stream flow up along the east coast of North America, moderating the climate of vast areas of northern and western Europe, says Phys.org.

Once the Gulf Stream gets far enough north, the warm waters cool.

As they cool, they sink and start flowing south, forming what scientists call the North Atlantic Deep Water.

Nick Balascio explained that the Gulf Stream/Deep Water system is known as the AMOC, or Atlantic Meridional Overturning Circulation.

Balascio, an assistant professor in William & Mary’s Department of Geology, is a member of a group of scientists that found evidence that changes in the strength of AMOC can serve as an precursor to massive future climate changes.

Their findings were published in the journal Nature Communications in a paper “Deep-water circulation changes lead North Atlantic climate during deglaciation.” Deglaciation, or the widespread melting of glaciers, have triggered massive shifts in climate.

Balascio explains that the team’s evidence shows that a strengthening in the AMOC flow was a precursor to a sudden warming trend about 11,000 years ago.

Conversely, a weakening AMOC was followed by what is known as the Younger Dryas stadial, a major cooling period about 13,000 years ago. Balascio pointed out that each shift in AMOC strength preceded the climactic shift by the same amount of time—around 400 years.

He also noted that the AMOC has been weakening once again for the past century or so. The paper indicates that once the Younger Dryas settled in, air temperatures in Greenland dropped by about six degrees.

“These results suggest that changes in ocean circulation precede major global climate events,” he said. “So we should therefore take seriously the evidence that suggests the AMOC has been slowing down over the past century or more.”

The team recorded the relative strength of the AMOC and the development of the Deep Water Formation through comparison of various coring samples of ice and sediment from various points across the North Atlantic, including sites from the land, ocean and lakes.

“Each record provides one piece of the puzzle,” Balascio said. “So each record provides information on a different aspect of the climate system such as past atmospheric temperatures and surface ocean conditions.”

Full report here.

Comments
  1. oldbrew says:

    Re the de Vries cycle (Jupiter-Saturn-Earth repeating synodic periods):

    one sixth of 2503 years is 417.1666 years which is 21 J-S, 382 J-E, 403 S-E and two de Vries cycles.

    https://tallbloke.wordpress.com/2015/04/17/why-phi-jupiter-saturn-and-the-de-vries-cycle/

    Is this the period ‘around 400 years’ referred to by the researchers?
    – – –
    Paleoclimate forcing by the solar De Vries/Suess cycle
    H.-J. Lüdecke,*, C. O. Weiss,*, and A. Hempelmann
    Published: 12 February 2015

    Evidences of the dominance of the De Vries/Suess cycle of solar activity on terrestrial climate are given in Seidenglanz et al. (2012); Leal-Silva and Herrera (2012); Costas et al. (2012), and Scafetta (2012) to mention just a few of a long list of papers showing the action of the solar De Vries/Suess cycle on the Earth climate

    https://www.clim-past-discuss.net/11/279/2015/cpd-11-279-2015.pdf
    – – –
    Possible solar forcing of 400-year wet–dry climate cycles in northwestern China [2009]

    This approximate 400-year periodicity of wet–dry climate oscillations appear to correlate with solar activity as shown by atmosphere 14C concentration and with paleo-moisture records in interior North America.

    https://link.springer.com/article/10.1007/s10584-009-9604-4

  2. ivan says:

    At long last real scientists are beginning to dismantle the UN Church of Climatology Socialist Cult. The problem will be that the Cult and its adherents will fight tooth and nail to keep their One World Order in place regardless of the truth. We can just hope that more of the common people of the world will wake up to the scam and fight back.

    Since the CAGW is a scam the following applies;
    Every scam depends on the mark wanting to believe the scam is true.
    Falling for a scam is painful. The first reaction is to deny being scammed, of course. The second is to blame skeptics for being correct in their scepticism.

    Unfortunately politicians having no idea about the real world are the first to be scammed and will always push the population in the direction of the scam – we have an excellent before us with the Brexit fiasco, we should have just left and gone back to what we had before.

  3. oldbrew says:

    Why wouldn’t the Atlantic behave in a similar manner to this?

    The long memory of the Pacific Ocean
    Historical cooling periods are still playing out in the deep Pacific
    Date: January 4, 2019
    Source: Woods Hole Oceanographic Institution

    Summary:
    Cold waters that sank in polar regions hundreds of years ago during the Little Ice Age are still impacting deep Pacific Ocean temperature trends. While the deep Pacific temperature trends are small, they represent a large amount of energy in the Earth system.

    The ocean has a long memory.

    https://www.sciencedaily.com/releases/2019/01/190104121426.htm

  4. Gamecock says:

    “These results suggest that changes in ocean circulation precede major global climate events,” he said. “So we should therefore take seriously the evidence that suggests the AMOC has been slowing down over the past century or more.”

    Why take seriously? Climates could change a few hundred years from now? So what?

    Come and find the place where I am lying,
    And kneel and say an “Ave” there for me.
    And tell me how this worked out, as dead I well may be.

  5. The catastrophists would assert that, assuming this effect is real, it presages a cooling period about three hundred years from now. By that time, they assert, life on Earth would already have been utterly destroyed.

    ===|==============/ Keith DeHavelle (@DeHavelle)

  6. oldbrew says:

    As Svensson puts it: “As long as we do not understand the climate of the past, it is very difficult to constrain the climate models needed to make realistic future scenarios.”

    Enough said 😎

  7. hunterson7 says:

    The article is so interesting.
    The implications are clear:
    The so-called “missing heat is hidden in the deep oceans” Is just post hoc arm waving…

  8. Stephen Richards says:

    The gulf stream cannot change of it’s own accord. It is not the primary climate signal.

  9. oldmanK says:

    Gamecock says: March 29, 2019 at 6:20 pm quote: “Why take seriously? Climates could change a few hundred years from now? So what?” That perhaps is being optimistic.

    If climate changes every about 400 years (but perhaps more like 480; 1/2 Eddy), and the last change was around 1645CE,,,,,, Well, ,,,.

  10. phil salmon says:

    This AMOC perspective is very important.
    It was published by Andrew Weaver et al. in 2003:

    http://home.sandiego.edu/~sgray/MARS350/deglaciation.pdf

  11. phil salmon says:

    Steven Richards
    The gulf stream cannot change of it’s own accord. It is not the primary climate signal.

    The AMOC including the Norwegian Sea deep water formation is a system that is chaotically unstable over a timescale of centuries and millenia. Since it contains an intermittent positive feedback in the reinforcement of salinity transport and cold water downwelling, it is an “excitable medium” in the sense of nonlinear oscillatory systems.

    For this reason, “changing of its own accord” is not necessarily an entirely inaccurate way of describing it.

    Note however that chaotic nonlinear oscillators can be externally periodically forced, either strongly or weakly. Thus for instance solar forcing of the AMOC is possible, if there exist solar periodicities that are long enough.

  12. Gamecock says:

    How old are you, oldmanK? I suspect that you, like me, will be totally, completely, irrevocably dead when any of this happens.

    But wait . . . The Gulf Stream is going to do what it is going to do. Our ‘taking it seriously’ changes what?

  13. ivan says:

    He also noted that the AMOC has been weakening once again for the past century or so. Maybe that explains why my met station is recording night time temperatures of 6 to 8 degrees C when I have about 20 degree C. If it keeps up it will get colder before it gets any warmer and what will the warmists do then poor things?

  14. oldmanK says:

    @ Gamecock: Possibly a bit worse for wear. In my case definitely it is purely academic.

    Still; since I’m old enough to remember very different times, and what survival was like (no different than several centuries before ) I worry about my grand-kids who take much for granted. In my early years rural society taught us resilience. Today society teaches a way of life like ‘Victorian aristocracy’ but with deep debts rather than deep pockets – ‘highly leveraged’. I see where it all leads to in the faces of the ‘uninvited visitors’. A mild natural disruption to the base of the pyramid can have very dire effects.

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