Current theory on solar magnetic fields posits that the overall solar and local sunspot magnetic fields are created by thermal convection heating in the convection zone. Which then creates the overall solar dipole magnetic field and also the observed Magnetic field loops at the photosphere which then drive the physical rotations of the plasma in sunspots.
The novel Variable speed core solar dynamo model described in this paper here proposes exactly the opposite. In that it is the differential rotation of the solar plasma in the convection zone due to the suns rotation, that is the mechanism that produces the dynamo that induces the observed solar magnetic field. A model where the suns dipole polarity reverses depending on whether the inner core rotates slower or faster than the plasma in the outer convection zone. A cycle of 11 year slower, then 11 year faster periods called the solar cycle. In each cycle this differential rotation also creates local eddy currents or vortices in the plasma. These vortices are observed at the photosphere as sunspots.
For sunspots, where the rotation axis of the plasma vortex of the sunspot is at right angles to the suns surface (pointing straight up from the suns surface), then the direction of the local induced dipole magnetic field of the sunspot predicted by the Variable speed core solar dynamo model will be parallel to the rotation axis of the plasma in the sunspot. The sunspot magnetic field in this model is thus predicted to be orthogonal to the suns surface. That is, it should point straight up from the suns surface. This is confirmed in Borrero et al 2014, where the authors found that there is also a further link between sunspot magnetic polarity and direction and the physical rotation of the plasma vortex that creates the sunspot. They observed that the polarity of the sunspot magnetic field is dictated by the direction of rotation of the sunspot vortex. Clockwise gives positive polarity, counter clockwise negative. This rotation direction/polarity relationship is also consistent with and predicted by the Variable speed core solar dynamo model.
Borrero et al also confirm that the sunspot magnetic field is at it strongest and points directly outwards-upwards from the surface of the photosphere at the center of the the rotating sunspot, the umbra, and declines in strength and to more tangental directions relative to the suns surface the farther out from the center of the rotating sunspot one looks. Confirming the Variable speed core solar dynamo model’s predictions. Which propose that the differing velocity gradient across the rotating plasma of the sunspot produces a N-S magnetic field parallel to the axis of the rotating plasma that is also strongest at the center of the axis of rotation.
We also know from various studies including Yan et al, 2008 that not only do sunspots vortices rotate, they also have opposite sunspot rotations and magnetic polarities between the hemispheres. In that if in any solar cycle there are more positive magnetic polarities in the northern hemisphere then will always be more negative polarities in the Southern Hemisphere. And vice versa for subsequent cycles. This further confirms predictions made by the Variable speed core solar dynamo model which posits that differential rotation of the plasma will induce, on average, opposite rotations of sunspots in opposite hemispheres. And in turn these rotational directions of the sunspot plasma will induce opposite polarities depending on whether the rotation is CW or CCW.
This relationship between rotational velocity of the sunspot plasma and its its induced magnetic field in the variable speed model is additionally confirmed in Li and Liu 2015 and Wang et al. 2016: “There is a direct relationship between rotations and the triggering of solar flares. Across all of the active regions examined, there are a number of commonalities observed in the rotational behaviour of sunspot groups. As expected, the higher-flaring regions show much higher average angular velocity values”.
Another study by Brown, Nightingale et al, found a connection between the increased activity of a coronal loop with a speeding up of the rotation of a sunspot. Further confirming that the physical rotational period of the dynamo of the rotating sunspot plasma dictates not only the direction of the induced field but its strength.
And in this following paper it is also found that sunspot rotations reverse rotational directions and polarities between solar cycles. Consistent with the variable speed model where it is predicted that the slowing down or speeding up of the inner core relative to the convection zone between 11 year solar cycles will reverse the direction of the differential rotation every 11 years. In other words clockwise rotation of the plasma induces an opposite polarity to counter clockwise rotation. Further confirming that the physical rotation of the convection zone plasma is the dynamo driver that induces the overall solar and local sunspot magnetic fields.
And in their 2016 paper Zheng et al also observed the following: “In the year of 2003, the α sunspot groups and the preceding sunspots tend to rotate counterclockwise and have positive magnetic polarity in the northern hemisphere. In the southern hemisphere, the magnetic polarity and rotational tendency of the α sunspot groups and the preceding sunspots are opposite to the northern hemisphere. From 2014 January to 2015 February, the α sunspot groups and the preceding sunspots tend to rotate clockwise and have negative magnetic polarity in the northern hemisphere. The patterns of rotation and magnetic polarity of the southern hemisphere are also opposite to those of the northern hemisphere.” Zheng et al, 2016.
These observations are also consistent with the Variable speed core solar dynamo model. In that not only are the polarities of sunspots dictated by the direction of sunspot rotation, but that the average overall direction of rotation of sunspots for each hemisphere reverses between each succesive solar cycle.
Summary
These various data cited above confirm predictions made by a Variable speed core solar dynamo model that the more solid solar inner core rotates faster and then slower than the outer part of the convection zone at the photosphere. Producing an equatorial east west reversal* in the rotation direction of the convection zone plasma every 11 years. And in turn inducing local eddy currents in the plasma and observe as sunspots at the photosphere
*A reversal in the direction of the rotation of the convection zone in an observer frame that rotates with the suns mass around its axis. (Imagine hovering above a sunspot on the sun as it rotates around the suns axis of rotation.)
This is not the same frame as the heliocentric frame where the sun rotates around its axis in the observer frame and the inner core is then said to be rotating faster then slower than the outer convection zone plasma.
