A paper in “New Journal of Physics” titled “Secular variation of the Earth’s magnetic field: induced by the ocean flow?” (available at http://iopscience.iop.org/1367-2630/11/6/063015/pdf/1367-2630_11_6_063015.pdf ) suggests:
- Abstract. Secular variation of the Earth’s main magnetic field is believed
to originate in the Earth’s core. (The main field is operationally defined
as comprising spherical harmonics of degree l 6 10.) I propose a different
mechanism of secular variation: ocean water being a conductor of electricity,
the magnetic field induced by the ocean as it flows through the Earth’s main
field may depend on time and manifest itself globally as secular variation. This proposal is supported by calculation of secular variation using the induction equation of magnetohydrodynamics, the observed main field and the ocean flow field. The predicted secular variation is in rough agreement with that observed. Additional support is provided by the striking temporal correlation (hitherto unsuspected) between the intensity of the North Atlantic oceanic circulation and the rate of secular variation in Western Europe; this explains, in particular, the geomagnetic jerks, and the recently discovered correlation between secular variation and climate. Spatial correlation between ocean currents and secular variation is also strong.
This might be related to work by Rog Tallbloke in turn based on some of my work. I have suggested that the solar magnetic field is strongly influenced by a GR effect of the planets on the solar core. In effect the positions of the massive planets North or South of the Solar equator cause convection currents within the Sun which influence the Solar cycle. For my proposal to work it is necessary that the Sun have a natural resonance of close to 10.5 years. Evidence for the proposal is that all of the expected planetary frequencies (including pairs of planets) are found in the sunspot cycle spectrum, and the amplitudes are consistent with the proposed resonance.
What Rog further found is that these solar motions, which are in fact represented simply as the displacement of the Sun in the z direction from the Solar system baricentre, are highly correlated with the Earth’s rate of rotation changes and temperatures on Earth. The Earth’s rate of rotation changes have many cycles present, including the 11 year sunspot cycle. So we see that the pattern of correlations is extended.
I further proposed that the Earth’s magnetic field reversals might be calculated in a similar way. This is more difficult because the period between reversals is much longer and the plane of the earth’s equator is precessing rapidly compared to the reversals period. The earth reversals, contrary to often stated, does show periodicity, particularly a period of 1.11 million years (also perhaps 9 million years). That period does relate to outer planetary orbital dynamics (Jupiter-Neptune energy exchange) which supports the hypothesis.
At this stage a suitable calculation has not been performed. If successful, that calculation wold show that the major cause of magnetic fields in planets and stars lies in orbital dynamics, an idea that has not previously been entertained.
My proposal “Explaining Planetary Alignments Relationship to the Sunspot Cycle” http://www.bautforum.com/showthread.php/72665-Explaining-Planetary-Alignments-Relationship-to-the-Sunspot-Cycle
Tallbloke’s article “Planetary – solar – climate connection found” http://tallbloke.wordpress.com/2009/11/29/planetary-solar-climate-connection-found/