Will the Sun’s Magnetic Field Reverse?
The disappointing strength of the latest sunspot cycle brings up this interesting question. As discussed in a number of previous posts, e.g. the Kreutz Sungrazers, the asteroids ejected from the great jet on Jupiter over the last 6,000 years are still impacting the Sun causing sunspots and the resulting CMEs. Just as their ‘brother’ main belt asteroids, these bodies contain a unique combination of elements, i.e. a small complement of all heavy elements, including iron and nickel, which mimic the elemental composition, but not the physical structure (Methane Gas Hydrate) of Jupiter itself. Because they coalesced from hot gas while still within the magnetic field of Jupiter they posses remnant magnetism, as has been observed of several main belt asteroids.
As they approach the Sun, their south poles become oriented toward its north magnetic pole. When they strike the surface of the Sun, this magnetism can be detected in the resulting sunspots by earth telescopes using spectroscopy and polarimetry. The impacts display a systematic N-S arrangement induced by the magnetic dipole field of the Sun. That is, their orientation opposes the existing dipole polarity of the Sun. At the peak of the impacts, the so-called ‘sunspot maximum’, so much opposing magnetic flux is usually delivered to the Sun, that its dipole field is overwhelmed and flips. See the following article:
This is beautifully illustrated in a magnetic butterfly diagram, originated by David Hathaway of NASA Marshall, shown in Figure 1. The magnetic fields at mid-latitudes represent the influx due to the impacting asteroids, which only impact at latitudes less than about 30 degrees, while the magnetic fields at the very top and bottom show the dipole field of the Sun. Note that the dipole field is overwhelmed at the maximum of asteroid input flux and becomes reversed at that time.
The weak sunspot maximum which characterizes the current cycle raises the question as to whether the Sun’s magnetic field will reverse. Or it may just be strong enough to cancel out the existing field. I maintain that this effect proves that the Suns magnetic field is superficial and not of great significance to the Earth. However the weakness of sunspot activity can effect Earth’s climate, since the so-called Coronal Mass Ejections heat the Earth, particularly at the poles and pump-up the Earth’s magnetic field, which originates in the superconducting solid core by Faraday and Lentz ‘laws’.