Monday, September 02, 2019

The Climate Change Alarmists are missing solar forcing

Here is a link to a blog entry by Judith Curry, a renowned expert on climate.

She provides more evidence that the Climate Change Alarmists and much of the climate change scientific community are missing the importance of solar forcing on climate.

Here are some excerpts.
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El Niño Southern Oscillation (ENSO) is the main source of interannual tropical climate variability with an important effect on global temperature and precipitation. Paleoclimatic evidence supports a relationship between ENSO and solar forcing. Moy et al. (2002) attribute the long-term increasing trend in ENSO frequency to orbitally induced changes in insolation (figure 1). The ENSO proxy record described by Moy et al. (2002) displays a millennial-scale oscillation that in the middle Holocene shifts its variance from a 1000-1500-yr period to a 2000-2500-yr period (Moy et al. 2002, their figure 1c). Both frequencies correspond to known solar periodicities, the Eddy and Bray solar cycles. As it has been shown previously (see “Centennial to millennial solar cycles“) the 1000-yr Eddy solar cycle became weaker at the Mid-Holocene Transition regaining strength in the last 2000 years. This 14C-deduced solar behavior corresponds to the ENSO behavior described by Moy et al. (2002).

In 2000 Theodore Landscheidt published an article in the proceedings from a meeting presenting his hypothesis of a solar forcing of El Niño and La Niña. He was not the first to defend such hypothesis, as 10 years earlier Roger Anderson (1990) had published some evidence for a solar cycle modulation of ENSO as a possible source of climatic change. Landscheidt’s (2000) article contains two observations and two predictions. The first observation is that most extreme ENSO events correlate with the ascending or descending phase of the solar cycle. He predicted the following El Niño based on the sun’s orbital angular momentum for 2002.9 (± 0.4). It was a 2-year ahead accurate prediction, as the next El Niño started in 2002.67. The second observation was the alternating preponderance of El Niño and La Niña following the 22-year Hale magnetic solar cycle. The 1954-76 Hale cycle showed Niña preponderance, and was followed by the 1976-96 that presented Niño dominance. While this is based only on two complete Hale cycles for which there is instrumental ENSO data it is interesting to read Landscheidt other prediction:

“If the pattern holds a preponderance of La Niña is to be expected during the Hale cycle that began in 1996.”
The Hale cycle-ENSO association is unclear to me due to insufficient data but it is undeniable that both of Landscheidt predictions were correct. Anderson’s and Landscheidt’s articles were completely ignored by the scientific community and they are rarely cited even by authors studying the same subject.

In 2008 van Loon & Meehl showed that the Pacific Ocean displayed a response to peak solar activity years similar to La Niña event years in the Southern Oscillation, but with a different stratospheric response. Haam & Tung (2012), however, failed to find an association between solar peak and La Niña years and warned that two autocorrelated time series might present a spurious correlation by chance. As I will show the problem is in the assumption that ENSO must display a linear response to solar activity with ENSO extremes at maximal and minimal solar activity. This assumption turns out to be false and the analysis of Haam & Tung (2012) using peak-solar years is misleading.

ENSO is usually described as a 2-7-year oscillation, while the Schwabe solar cycle is an 11 ± 2-year oscillation, so no linear relationship is obvious. White & Liu (2008) defend that most El Niño and La Niña episodes from 1900–2005 are grouped into non-commuting pairs that repeat every ~ 11 years, aligned with rising and falling transition phases of the solar cycle as Landscheidt (2000) described (they don’t cite him). These alignments arise from non-linear phase locking between an 11-year solar forced first harmonic and the 3rd and 5th 3.6 and 2.2-year harmonics in ENSO. These solar-forced 3rd and 5th harmonics explain ~ 52% of inter-annual variance in the Nino-3 temperature index. White & Liu (2008) propose “a new paradigm for ENSO, with El Niño and La Niña driven by the solar-forced quasi-decadal oscillation via non-linear processes in the tropical Pacific delayed action/recharge oscillator.”

Despite the evidence for a solar forcing of ENSO the accepted paradigm from model studies is that ENSO is self-excited or driven by internal variability random noise.

More recently two solar physicists, Leamon & McIntosh (2017), reported on the coincidence of the termination of the solar magnetic activity bands at the solar equator every ~ 11 years since the 1960s with a shift from El Niño to La Niña conditions in the Pacific. Their report prompted me to examine the issue, observing a pattern repetition since 1956 (figure 2). The solar minimum is preceded by Niña conditions, followed by Niño conditions, and afterwards Niña conditions accompany the rapid increase in solar activity.
If we assign 50% probability for seasonal positive or negative ONI (Oceanic Niño Index) values, the probability that the solar minimum will be preceded by Niña conditions, and followed by Niño conditions for six consecutive solar minima by chance is of only 0.024% (1 in 4000). The probability of the entire pattern (Niña-Niño-Niña) repeating six times at a specific time is even lower, indicating that the association between solar activity and ENSO is not due to chance. Solar control of ENSO has led to the prediction of El Niño conditions in 2018-19 by me, and to La Niña conditions in 2020-21 by Leamon & McIntosh (2017). The 2018-19 Niño prediction has been correct.
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Of course ENSO is not exclusively under solar control as it is a very complex phenomenon, and thus we shouldn’t expect that the patterns are always reproduced. However it is clear from paleoclimatic data (Moy et al., 2002), solar physics (Leamon & McIntosh 2017), Modeling and reanalysis (van Loon & Meehl 2008), frequency analysis (White & Liu 2008), and the present analysis, that solar activity has a clear strong effect on ENSO, probably being its main forcing. The reported 2-7-year ENSO periodicity appears to be an 11-year periodicity with several occurrences. The present (mid-2019) position in the solar cycle is at the transition between phases III-IV, close to the solar minimum. With some uncertainty due to the irregularity of the 11-yr solar cycle, a La Niña can be projected for phase V, by mid-2020 (Leamon & McIntosh 2017). The failed El Niño projection from February 2017 by ENSO models (figure 6) took place at the transition between phases II and III in figure 5, a time when the solar cycle favors La Niña conditions that finally developed a few months later. This is an instance when ENSO prediction from solar activity would have been superior to models.

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