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No El Nino Until November 2015 Predict Physicists

10.01.2015
10.01.2015 02:58 Age: 2 yrs

Potentially significant research that provides a physical explanation for El Nino cycles by linking them to the sun also has major implications for our understanding of the importance of the role of the sun in the climate system more widely and for the implied reliability of climate models

Click to enlarge. From Part 1 paper. Plot associated with HadSST3. Plot of HadSST3(black, with data points) and aHadSST3(red). The 24-month and 36-month phase-locked segments are indicated by green shaded rectangles. Courtesy: authors and Physics Letters A.

Click to enlarge. From Part 1 paper. Plot associated with HadSST3. Plot of high-frequency component hHadSST3(lower curve) and its amplitude A(hHadSST3). Courtesy: authors and Physics Letters A.

Click to enlarge. From Part 1 paper. Plot associated with HadSST3. Autocorrelation of hHadSST3indicating a periodicity of 12 months. Courtesy: authors and Physics Letters A.

Click to enlarge. From Part 1 paper. Plot associated with HadSST3. Autocorrelation of segment of aHAdSST3from February 2002 to March 2008 (in red) and of segment of aSST3.4from 2008 to the end of available data (2013), indicating, respectively, periodicities of 24 and 36 months. Courtesy: authors and Physics Letters A.

Click to enlarge. David Douglass: "modest prediction". Courtesy: University of Rochester.

 

by Leon Clifford

There will be no El Nino Pacific Ocean warming event until November 2015 predict two US physicists who have developed a theory for how the sun drives warming and cooling cycles in the world's oceans.

Orbital eccentricity and the sun combine to make the ultimate “pacemaker” driving ocean warming and cooling cycles, the researchers say in two papers published in the journal Physics Letters A. And, crucially, their research provides a physical rationale for the observed pattern of El Nino events that are documented to appear between every two and seven years.

“We were trying to find a scientific explanation for El Nino and these papers are the beginning of that explanation,” reportingclimatescience.com was told by professor David Douglass of the University of Rochester in the US, co-author of the studies.

This research is based on a detailed mathematical analysis of sea surface temperature data for a part of the Pacific Ocean over a period from 1990 to 2013 which provided evidence that the sun is acting as a kind of pacemaker for driving the global climate.

Orbital eccentricity brings the Earth closer to the sun in January each year than it is in July which results in an annual cycle of slight warming and cooling as the planet circles the sun. But the researchers have discovered that this annual orbital cycle is mixed in with another signal which is also linked to the sun and which has a period of either two or three years.

Phase locking

Douglass explained that the Earth may become what he called “phase locked” with either a two year or a three year cycle and that there are also times when the Earth is not phase locked at all. In physics, phase-locking is the name given to the process where an output signal from a system – such as, the frequency of El Nino events - is somehow driven by the behaviour of various input signals going into the system – in this case various cycles related to the sun.

The combination of two and three year phase locked cycles together with gaps when there is no phase locking gives rise to the observed pattern of El Nino events occurring every two to seven years, Douglass explained to reportingclimatescience.com.

In a study published in 2011, which analysed the pattern of equatorial Pacific Ocean temperatures over the period from 1870 to 2008, Douglass identified ten such phase locked segments. This new study of more recent data finds three more segments in the period from 1990 to 2013.

Douglass and co author Robert Knox, also of the University of Rochester, believe that the Earth is currently phase locked into a three year cycle and that provided this remains the case then there will be no new maximum in the El Nino cycle until November 2015. “This is our modest prediction,” Dougass said, although he cautioned that these phase locked periods can start and end abruptly.

Implications

This discovery has significant implications for climate science more generally. “You can't get phase locking like this unless there is some non-linearity in the system somewhere,” stated Douglass. The appearance of such non-linear and chaotic processes at work in driving the climate system explains the abrupt changes between periods of phase locking. It also means that attempts to model climate phenomena such as El Nino events with conventional climate models that take past data and incrementally project it into the future are flawed.

More controversially, Douglass -  who is seen as being somewhat sceptical on the subject of climate change - believes that this has implications for other computer models used in climate science: “The models won't work,” he stated bluntly

The research also provides more evidence to those who argue that the sun plays a larger role in changes in the climate system than has previously been acknowledged.

The research is published in two papers. The first provides a detailed analysis of Pacific Ocean temperature data to identify the segments of phase locking in the period between 1990 and 2013.

The second extends this study to the global ocean, from surface to a depth of 700m and to 2000m. The same phase locking phenomena are found, according to the paper and the researchers show that the effects of El Nino warming and La Nina cooling events in the Pacific diffuse into the rest of the world oceans with a delay of about two months.

The Two Papers

The Sun is the climate pacemaker I

Highlights

Physics Letters A identifies the highlights of this paper as follows:

Central Pacific region temperature dataset SST3.4 from 1990 to 2014 is studied.

SST3.4 contains a sustained signal at 1.0 cycle/yr implying solar forcing.

SST3.4 also contains a signal (<1 cycle/yr) showing El Niño/La Niña effects.

This signal contains segments of period 2 or 3 years, phase locked to the annual.

A 12-month moving average improves on a “climatology” filter in removing annual effects.

Abstract

Equatorial Pacific Ocean temperature time series data contain segments showing both a phase-locked annual signal and a phase-locked signal of period two years or three years, both locked to the annual solar cycle. Three such segments are observed between 1990 and 2014. It is asserted that these are caused by a solar forcing at a frequency of 1.0 cycle/yr. These periodic features are also found in global climate data (following paper). The analysis makes use of a twelve-month filter that cleanly separates seasonal effects from data. This is found to be significant for understanding the El Niño/La Niña phenomenon.

Citation

The Sun is the climate pacemaker I. Equatorial Pacific Ocean temperatures  by David H. Douglass and Robert S. Knox published in Physics Letters A doi:10.1016/j.physleta.2014.10.057

Read the abstract and get the paper here.

The Sun is the climate pacemaker II

Highlights

Physics Letters A identifies the highlights of this paper as follows:

Global ocean temperatures at depths 0–700 m and 0–2000 m from 1990 to 2014 are studied.

The same phase-locked phenomena reported in Paper I are observed.

El Niño/La Niña effects diffuse to the global oceans with a two month delay.

Ocean heat content trends during phase-locked time segments are consistent with zero.

Abstract

In part I, equatorial Pacific Ocean temperature index SST3.4 was found to have segments during 1990–2014 showing a phase-locked annual signal and phase-locked signals of 2- or 3-year periods. Phase locking is to an inferred solar forcing of 1.0 cycle/yr. Here the study extends to the global ocean, from surface to 700 and 2000 m. The same phase-locking phenomena are found. The El Niño/La Niña effect diffuses into the world oceans with a delay of about two months.

Citation

The Sun is the climate pacemaker II. Global ocean temperatures by David H. Douglass and Robert S. Knox published in Physics Letters A doi:10.1016/j.physleta.2014.10.058

Read the abstract and get the paper here.

 

Note: This story replaces a previous report posted shortly before that contained three typographical errors.