Sunday, April 6, 2014

New paper finds natural ocean oscillations responsible for record cold US winter, not CO2

A new paper published in Environmental Research Letters finds the natural ocean oscillations the Atlantic Multidecadal Oscillation [AMO] and the North Atlantic Oscillation [NAO] may be responsible for the recent resurgence of record cold extreme temperatures in the Eastern US and Europe, and that extreme cold winters in these regions will persist as long as the AMO remains positive. The AMO shifted from negative to positive around the year 2000, along with the "pause" in global warming. A typical AMO cycle lasts ~60-70 years, and thus the current positive phase of the AMO and extreme cold US winters could occur for another ~18 or so years.

According to the authors, "Our statistical analyses suggest that the AMO signal precedes the NAO by 10–15 years with an interesting predictability window for decadal forecasting... As in observations, the positive phase of the AMO results in more frequent negative NAO—and blocking episodes in winter that promote the occurrence of cold extreme temperatures over the eastern United States and Europe. Thus, it is plausible that the AMO plays a role in the recent resurgence of severe winter weather in these regions and that wintertime cold extremes will be promoted as long as the AMO remains positive."


Warmists such as Jennifer Francis have made the silly claim that the record US cold winter was due to man-made global warming causing jet stream blocking, but this paper and many others prove natural cycles are responsible, not CO2. In addition, both the AMO and NAO, as well as other ocean & atmospheric oscillations, have been linked to solar activity. 


AMO index with a Fourier analysis showing a cycle length of ~60-70 years. The AMO shifted to the positive phase [above zero] around the beginning of the 21st century, so the positive phase has another ~18 or so years to go. 

Wavelet analysis shows predominant periodicity of AMO is ~64 years. How to read wavelet analyses.



Forcing of the wintertime atmospheric circulation by the multidecadal fluctuations of the North Atlantic ocean

OPEN ACCESS


Yannick Peings and Gudrun Magnusdottir

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The North Atlantic sea surface temperature exhibits fluctuations on the multidecadal time scale, a phenomenon known as the Atlantic Multidecadal Oscillation (AMO). This letter demonstrates that the multidecadal fluctuations of the wintertime North Atlantic Oscillation (NAO) are tied to the AMO, with an opposite-signed relationship between the polarities of the AMO and the NAO. Our statistical analyses suggest that the AMO signal precedes the NAO by 10–15 years with an interesting predictability window for decadal forecasting. The AMO footprint is also detected in the multidecadal variability of the intraseasonal weather regimes of the North Atlantic sector. This observational evidence is robust over the entire 20th century and it is supported by numerical experiments with an atmospheric global climate model. The simulations suggest that the AMO-related SST anomalies induce the atmospheric anomalies by shifting the atmospheric baroclinic zone over the North Atlantic basin. As in observations, the positive phase of the AMO results in more frequent negative NAO—and blocking episodes in winter that promote the occurrence of cold extreme temperatures over the eastern United States and Europe. Thus, it is plausible that the AMO plays a role in the recent resurgence of severe winter weather in these regions and that wintertime cold extremes will be promoted as long as the AMO remains positive.

7 comments:

  1. The cold phase of the NAO/MDO began in 2000 and is expected to last fror 35 years, to 2035, which would mean 20 years or so to go.

    This implies that the warm phase of these ocean oscillations started 35 years before 2000, around 1965.

    Has anybody explored the extent to which the warm phase of these ocean oscillations -- plus maybe the PDO -- caused warming from 1965 and have thus biased the estimates of AGW?

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  2. Dan Pangburn has published some info in a blog. He uses the multi-decadal ocean oscillation as a modifier of a function that integrates susnpot number to come up with a pretty good fit to the shape of the T curve for the last 160 years. (Actually the best I've ever seen)

    http://climatechange90.blogspot.com/2013/05/natural-climate-change-has-been.html

    It would be good for him to complete this study and publish it in a proper journal. Although I can understand he might be hesitant given the political climate about AGW.

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    Replies
    1. Yes, I've published with his permission several of his posts, including another today.

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  3. This is a known. How is this a discovery? Its been a known for decades. It forms the basis of forecast foundation for goodness sakes

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  4. we forecasted a nasty cold winter, but analogging SSTs with 1917-1918 and 1993-1994. Weatherbell.com had this from the fall. So how is this some earth shattering discovery.

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    Replies
    1. Mainstream climate science is just now discovering natural variability that weather forecasters have known about for a long time.

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  5. http://environmentalresearchweb.org/cws/article/news/56801

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