Cooling Outlook

The RAPID moorings being deployed in North Atlantic. Credit: National Oceanography Centre

In the comments on a previous post (here) ren points to the declining NAO, with the implication that a cooling phase is underway in the North Atlantic SSTs.  The cold blob in the North Atlantic was subject of a post here and elsewhere, and Paul Homewood posts today (here) on the increasing cold water, not only surface but coming from below.

Dr. Gerard McCarthy is a lead researcher on the RAPID array project measuring the AMO heat transport and provides a good context on their observations and the implications for the climate cooling in coming decades.

Our results show that ocean circulation responds to the first mode of Atlantic atmospheric forcing, the North Atlantic Oscillation, through circulation changes between the subtropical and subpolar gyres – the intergyre region. This a major influence on the wind patterns and the heat transferred between the atmosphere and ocean.

The observations that we do have of the Atlantic overturning circulation over the past ten years show that it is declining. As a result, we expect the AMO is moving to a negative (colder surface waters) phase. This is consistent with observations of temperature in the North Atlantic.

Summary:

The Atlantic Ocean’s surface temperature swings between warm and cold phases every few decades. Like its higher-frequency Pacific relative El Nino, this so-called “Atlantic Multidecadal Oscillation” can alter weather patterns throughout the world. The warmer spell we’ve seen since the late 1990s has generally meant warmer conditions in Ireland and Britain, more North Atlantic hurricanes, and worse droughts in the US Midwest.

However a colder phase in the Atlantic could bring drought and consequent famine to the developing countries of Africa’s Sahel region. In the UK it would offer a brief respite from the rise of global temperatures, while less rainfall would mean more frequent summer barbeques. A cold Atlantic also means fewer hurricanes hitting the southern US.

https://www.weforum.org/agenda/2015/06/how-the-atlantics-cool-phase-will-change-the-worlds-weather/

Implications for Arctic Ice

A 2016 article for EOS is entitled Atlantic Sea Ice Could Grow in the Next Decade

Changing ocean circulation in the North Atlantic could lead to winter sea ice coverage remaining steady and even growing in select regions.

The researchers analyzed simulations from the Community Earth System Model, modeling both atmosphere and ocean circulation. They found that decadal-scale trends in Arctic winter sea ice extent are largely explained by changes in ocean circulation rather than by large-scale external factors like anthropogenic warming.

From the Abstract of Yeager et al.

We present evidence that the extreme negative trends in Arctic winter sea-ice extent in the late 1990s were a predictable consequence of the preceding decade of persistent positive winter North Atlantic Oscillation (NAO) conditions and associated spin-up of the thermohaline circulation (THC). Initialized forecasts made with the Community Earth System Model decadal prediction system indicate that relatively low rates of North Atlantic Deep Water formation in recent years will result in a continuation of a THC spin-down that began more than a decade ago. Consequently, projected 10-year trends in winter Arctic winter sea-ice extent seem likely to be much more positive than has recently been observed, with the possibility of actual decadal growth in Atlantic sea-ice in the near future.

 

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7 comments

  1. Climatism · June 13, 2016

    Reblogged this on Climatism and commented:
    Radidly decling NAO has “implications for the climate cooling in coming decades.”

    Liked by 1 person

  2. ren · June 13, 2016

    AMO from 1980. Visible maximum in 2010..
    http://woodfortrees.org/plot/esrl-amo/from:1980

    Like

    • ren · June 13, 2016

      At the current a small increase had the impact of El Niño.

      Like

  3. Pingback: Science On The Verge Of A Nervous Breakdown | Atlas Monitor
  4. David A · June 21, 2016

    If decadal patterns in surface T move negative then it will be interesting to see how atmospheric accumulation of CO2 changes along with GMT.

    I found this interesting…
    ================
    “However a colder phase in the Atlantic could bring drought and consequent famine to the developing countries of Africa’s Sahel region”
    ================
    … as WUWT just had an CAGW scare article on future Africa droughts. https://wattsupwiththat.com/2016/06/20/claim-crop-breeding-is-not-keeping-pace-with-climate-change/
    This appears to me to be a miniature version of the entre CAGW science agenda, which profited from known multi-decadal ocean changes being correlated to human CO2 emissions. The CO2 emissions are the magicians distracting words and hand motion, while ocean mechanics are the hidden mechanism. If this article is correct, then it will be curious to see how the magicians hide this decline.

    Like

    • Ron Clutz · June 21, 2016

      Thanks for commenting David. Based on past behavior of CO2 magicians, they are likely to just blame the droughts in Sahel on “climate change”, without acknowledging any cooling that would undermine the narrative.

      Like

  5. Hifast · July 10, 2016

    Reblogged this on Climate Collections.

    Like

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