Atlantic’s ‘conveyor belt’ shows no sign of declining, new study shows

Posted: February 26, 2021 by oldbrew in Natural Variation, Ocean dynamics, research

A portion of the Atlantic meridional overturning circulation [image credit: R. Curry, Woods Hole Oceanographic Institution @ Wikipedia]

This follows on quite well from our post yesterday about the Beaufort Gyre. Another attempted climate alarm fades away.
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A 30-year reconstruction of the Atlantic meridional overturning circulation shows no decline, reports The Global Warming Policy Forum.

Abstract A decline in Atlantic meridional overturning circulation (AMOC) strength has been observed between 2004 and 2012 by the RAPID-MOCHA-WBTS (RAPID – Meridional Overturning Circulation and Heatflux Array – Western Boundary Time Series, hereafter RAPID array) with this weakened state of the AMOC persisting until 2017.

Climate model and paleo-oceanographic research suggests that the AMOC may have been declining for decades or even centuries before this; however direct observations are sparse prior to 2004, giving only “snapshots” of the overturning circulation. [Talkshop note: continues here].

Conclusions [Talkshop note: extract only]

Our model, applied to historical hydrographic data, has increased the resolution of the observed AMOC between 1981 and 2004 from approximately decadal to approximately annual, and in doing so we have shown decadal and 4-yearly variability of the AMOC and its associated layer transports.

The result is the creation of an AMOC time series extending over 3 decades, including for the first time deep density anomalies in an AMOC reconstruction.

Our model has not revealed an AMOC decline indicative of anthropogenic climate change (Stocker et al., 2013) nor the long-term decline reported in sea-surface-temperature-based reconstructions of the AMOC (Caesar et al., 2018).

It has accurately reproduced the variability observed in the RAPID data, showing that the downturn between 2008 and 2012 (McCarthy et al., 2012) marked not only the weakest AMOC of the RAPID era but the weakest AMOC since the mid-1980s.

Since this minimum, the strength of the AMOC has recovered in line with observations from the RAPID array (Moat et al., 2020). In fact, according to our model, southward flowing LNADW has regained a vigour not seen since the 1980s.

Recent cold and fresh anomalies in the surface of the North Atlantic subpolar gyre seemed to indicate a return to a cool Atlantic phase associated with a weak AMOC (Frajka-Williams et al., 2017).

However, a weakened AMOC was not the primary cause of these anomalies (Josey et al., 2018; Holliday et al., 2020).

Full report here.

Research article:
A 30-year reconstruction of the Atlantic meridional overturning circulation shows no decline (Feb. 2021)
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Talkshop comment: new research from the pro-alarmist PIK takes a different view…
Gulf Stream System at its weakest in over a millennium (Feb. 2021)

Never before in over 1000 years the Atlantic Meridional Overturning Circulation (AMOC), also known as Gulf Stream System, has been as weak as in the last decades. Researchers compiled proxy data, reaching back hundreds of years to reconstruct the AMOC flow history. They found consistent evidence that its slowdown in the 20th century is unprecedented in the past millennium.

  1. pochas94 says:

    My home grown theory is that a meltwater pulse that took place during a rapid warmup after the last ice age (Younger Dryas) actually did shut down the AMOC for a period of 1,000 years. That would definitely have affected climate.

  2. […] Atlantic’s ‘conveyor belt’ shows no sign of declining, new study shows […]

  3. oldbrew says:

    The Daily Telegraph weighs in…

    Ross Clark: Why is there always a round of climate scaremongering after the weather changes?
    Date: 27/02/21 Ross Clark, The Daily Telegraph

    Whether it’s floods or a drought, snowfall or no snow ever again, there’s always a prediction about the impending doom of climate change

    Had we not had a cold spell a couple of weeks ago I doubt many people would have got to hear about a paper in the journal Nature Geoscience claiming that something called the Atlantic Meridional Overturning Circulation (AMOC) could, thanks to human-induced climate change, reach a tipping point by the end of the century bringing Europe much colder winters.

    Yet, thanks to us all shivering for a few days, the paper, by the Potsdam Institute for Climate Impact Research, has fuelled claims that this month’s big freeze is a mere harbinger of even greater terror to come.
    – – –
    Weather offers endless possibilities for miserablists intent on ‘fuelling claims’ of doom ahead🥱
    Make enough claims and one might come true, then hope the rest are forgotten.

  4. oldbrew says: Gaslights Readers on Failed Ocean Predictions – Now Claims Opposite
    By James Taylor – March 2, 2021

    Just one year after climate activists and their media allies spread fear with claims that global warming is causing the world’s ocean currents to speed up, is now claiming the opposite – and claiming scientists predicted a slowing of ocean currents all along. CNN’s attempt at “Gaslighting” (a term derived from the 1944 movie Gaslight, in which a man attempts to convince his wife that she cannot believe her own memory) reveals the lack of honesty and lack of scientific basis for alarmist climate claims.
    – – –
    And they wonder why they’re accused of ‘fake news’?

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