The question of whether a conjunction of planets could create internal stresses which could affect sun spot activity is not one upon which I am presently qualified to speculate. My apologies if I suggested a verdict on your results. It was not my intention to venture beyond the narrow point I wished to make.

The point is that it is unlikely in the extreme that sunspot activity is correlated with motion about the barycenter. Since we appear to agree on that, there is no reason to discuss the issue further.

The correlations exist, it is the mechanism that is still in doubt. Click on my name if you would like to learn more.

RTG’s are “radioisotope thermal generators”. These are standard equipment on probes to the outer planets. It is hardly suprising that thermal radiation induced forces from these would dominate solar pressure induced forces at Saturn, particularly when the spacecraft has no solar arrays with large area impacted by photons from the Sun. Earlier in the mission, solar pressure would have been far more significant, since solar pressure falls off as 1/R^2.

Let it go. You don’t have to become an instant expert on everything imaginable to make your point. The point is that it is unlikely in the extreme that sunspot activity is correlated with motion about the barycenter. Since we appear to agree on that, there is no reason to discuss the issue further.

I am another physicist but do not have the patience to engage in this thankless task of elucidating physics. I pipe in so that you are not left with the impression that Leif is a lone ranger.

I add my two cents of the euro by saying that even if a correlation exists between planetary conjunctions and sunspot cycles, if the physical mechanism is not found it means nothing more than that two clocks always are correlated by construction: one clock the planetary motions, the other the internal clock of the sun “climate”. It says nothing about cause and effect.

Geoff Sharp (22:49:12) :
All disturbances lining up precisely with the recorded downturns. If that’s not at least a good correlation I must be missing something.
What you are missing is to quantify the correlation and show it is significant.

What about the potential for cloud impacts? The NASA article states that, “these surges heat Earth’s upper atmosphere, puffing it up”.

The article linked below states that, “Evaporation of water droplets and the sublimation of ice crystals (conversion from ice directly to vapor) are ways that clouds can dissipate. These dissipation dynamics are caused by two mechanisms, decreasing the moisture and increasing the air temperature.”
http://www.srh.noaa.gov/ohx/educate/Chapter_5.html

alphajuno (18:58:27) :
the correlation of the number of sunspots with barycenter movement is interesting (and seemingly odd). But that’s it.
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And the correlation is not even good, and does nothing to explain the polarity changes of the magnetic fields [Hale's laws].

So we have the current situation, then before that SC20, before that the Dalton, then the Maunder, then the Sporer and before that the Wolf, and if we go back through the Holocene records we see the same pattern . All disturbances lining up precisely with the recorded downturns. If that’s not at least a good correlation I must be missing something. Maybe a case of denial going on here?

The old “hale cycle” chestnut is irrelevant. A theory does not have to be all encompassing, other mechanisms can be interwoven.

Actually, http://www.mediatec-dif.com/issfd/OrbitdI/IESS.pdf concludes differently:
“The analysis of two years of radio-metric data from the Cassini mission using state noise compensation and deterministic multi-arc model has provided consistent results in the estimate of the radial component of the spacecraft non-gravitational acceleration. This acceleration is attributed almost entirely to anisotropic thermal emission from the three on-board RTGs, with much smaller contributions from the solar radiation pressure and anisotropic thermal emission from the spacecraft bus.”

In any event, the effects are small and not “very significant” because the errors are themselves small. And also irrelevant for the planetary influence on the Sun.

NASA press release about the pending launch of a sensor named “EVE,” short for EUV Variability Experiment, onboard the Solar Dynamics Observatory as early as this winter.
http://science.nasa.gov/headlines/y2009/27oct_eve.htm

“When the sun is active, intense solar EUV emissions can rise and fall by factors of thousands in just a matter of minutes. These surges heat Earth’s upper atmosphere, puffing it up and increasing the drag on satellites. EUV photons also break apart atoms and molecules, creating a layer of ions in the upper atmosphere that can severely disturb radio signals.”

“Measurements by a variety of spacecraft indicate a 12-year lessening of the sun’s “irradiance” by about 0.02% at visible wavelengths and 6% at EUV wavelengths.”

What are your thoughts about EUVs and their potential impacts on Earth’s climate system?

“And radiation pressure is not a very significant effect and is normally not taken into account in calculation of interplanetary spacecraft orbits, mainly because the the uneven distribution of surfaces extending in different directions. The effect can be incorporated later by empirical calibration, but is very small. The thermal emission from the spacecraft itself is generally larger than solar radiation pressure.”
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Actually, all interplanetary spacecraft orbit calculations take solar radiation pressure into account with reflectivity and absorption models for the solar panels, bus, and high-gain antenna. Solar radiation pressure can be one of the largest orbit error sources, even with the best models.

What is your explanation of why the corona is so hot?
There are several mechanisms, none of which involves radiation pressure. We are not quite sure which of these is the dominant, or if there is a dominant cause. Among the mechanisms are breaking of acoustic waves into shocks, dissipation of Alfven waves, or nanoflares caused by magnetic reconnection. The last one being a favorite.

“The radiation pressure comes from the hot gas emitting radiation, and it does that in all directions, inward and outwards, because the temperatures above and below an area normal to the radius of the Sun are very closely the same. The temperature falls by a few degrees per kilometer, so at a certain location might be 8,445,736 degrees and one kilometer further out be 8,445,730 degrees.”
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Actually, the temperature of the Sun’s chromosphere, the solar atmospheric layer just above the photosphere, rises as distance from the photosphere increases. The corona is much hotter yet, about 2 million degrees Kelvin, and is expanded outwards to great distances by the solar wind. What is your explanation of why the corona is so hot?