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Saturday, March 24, 2012

A Possible Reason for the 1.3 year Solar Oscillations near the Sun's Tachocline

Back in 2006, I was investigating the possibility that variations 
in planetary gravitational/tidal forces might be linked with the 
newly discovered 1.3 year oscillations seen near the Sun's
Tachocline boundary.

Howe et al. ScienceVol. 287 no. 5462 pp. 2456-2460  
Dynamic Variations at the Base of the Solar Convection Zone


We have detected changes in the rotation of the sun near the base 
of its convective envelope, including a prominent variation with a 
period of 1.3 years at low latitudes. Such helioseismic probing of
 the deep solar interior has been enabled by nearly continuous 
observation of its oscillation modes with two complementary 
experiments. Inversion of the global-mode frequency splittings 
reveals that the largest temporal changes in the angular velocity 
Ω are of the order of 6 nanohertz and occur above and below the
 tachocline that separates the sun's differentially rotating convection 
zone (outer 30% by radius) from the nearly uniformly rotating deeper 
radiative interior beneath. Such changes are most pronounced near 
the equator and at high latitudes and are a substantial fraction of the
 average 30-nanohertz difference in Ω with radius across the 
tachocline at the equator. The results indicate variations of rotation 
close to the presumed site of the solar dynamo, which may generate 
the 22-year cycles of magnetic activity.

The plot below shows a Fast Fourier Transform (FFT) Spectra 
of the Solar Motion about the Barycentre of the Solar System 
caused by the Terrestrial planets.

 The Solar Baycentric motion due to the Terrestrial planets is 
dominated by the Synodic periods of Venus/Earth (= 1.5593 yrs)
and Earth/Mars (=2.13 years). Also evident in this plot is the 
~ 6.4 year beat period between these two synodic periods
(i.e. Venus/Earth and Earth/Mars).

Now, I knew that Jovian planets act like a large washing 
machine, stirring the inner terrestrial planets with a 
gravitational force that varies with a frequency that is 
determined by the beat period between two main competing 
Jovian planetary alignments.

The first is that produced by the the retrograde tri-synodic 
period of Jupiter/Saturn ( = 59.577 yrs) and the second is 
the pro-grade synodic period of Uranus/Neptune (171.41 yrs):

(59.577 x 171.41) / (171.41 + 59.577) = 44.21 yrs

This driving period of the Jovian planets closley matched 
the synodic periods of the three largest Terrestrial planets 
with Jupiter

69 × SVJ = 44.770 yrs    SVJ = synodic period Venus/Jupiter
41 × SEJ = 44.774 yrs    SEJ = synodic period Earth/Jupiter
20 × SMJ = 44.704 yrs    SMJ = synodic period Mars/Jupiter

The 44. 7 year period for the three largest Terrestrial planets 
to realign with Jupiter appears to link Jupiter's orbital period 
directly into the time it takes for the three largest terrestrial 
planets to return to their same (relative) orbital configuration, 
which just happens to be 6.40 years:

4 x SVE = 6.3946 yrs  SVE = synodic period Venus/Earth
3 x SEM = 6.4059 yrs SEM = synodic period Earth/Mars
7 x SVM = 6.3995 yrs SVM = synodic period Venus/Mars
28 × SVE = 7 x (6.3946 yrs) = 44.763 yrs   

This lead me to propose that resonances in the relative 
motion of the Jovian planets had effectively molded and 
shaped the orbital periods of the three main terrestrial 
planets, producing the 6.4 year period for their orbital 

In addition, I proposed that the gravitational/tidal pumping 
action of the Jovian planets would lead to a 6.4 amplitude 
modulation of the dominant 1.6 year frequency of the Sun's 
Barycentric motion [See the graph above], producing two 
side-lobes, one at 1.28 years and the other at 2.13 years. 

I speculated that it was this ~ 1.3 year side lobe that was 
driving the fundamental solar oscillation that Howe et al. 
2000 had observed near the Tachocline boundary. 

This "discovery" lead me to think that the relative orbital
configurations of the Jovian planets were not directly 
responsible for modulating/driving the level of solar activity 
on the Sun. Instead, I began to realize that it was more likely 
that the motion of the Jovian planets had molded the orbital
periods of the terrestrial planets and it was the tidal effects
of the latter (i.e. mostly due to tidal alignments of Venus
and the Earth) that 
were directly responsible for 
driving/modulating the Sun's activity, especially when they 
were coupled with the effects of Jupiter's dominant 
gravitational force acting upon the convective layers of the

This revelation lead me to propose the tidal-torquing
(spin-orbit coupling) model that I have outlined at: 


  1. Hi Ian, I have had problems contacting you via email and via comment in your blog....if this works please join my website so we can discuss the Jose cycle etc.

    Geoff Sharp

  2. Thanks Geoff, I am looking forward to joining the discussion over at your site. I put in an application to join your site a few weeks ago and it is still pending. Do you want me to resubmit my application?

  3. Sorry Ian, it looks like my email notification for account applications has gone haywire. Your account is approved. I will also comment on your new article re Jose.