Re; Helioseismic evidence that the solar dynamo originates near the tachocline

A new paper titled “ Helioseismic evidence that the solar dynamo originates near the tachocline” K. mandal 2026 indicates that sunspots originate far deeper into the solar interior than previously assumed: 

“Our analysis reveals that the gradient of rotation displays ‘butterfly’–like behavior near the tachocline, which is similar to the magnetic butterfly diagram at the surface. This result supports the idea that the solar dynamo has a deep-seated origin, likely operating either near the tachocline or throughout the convection zone, thereby disfavoring the rcent scenario of a shallow, near-surface dynamo”. “https://www.nature.com/articles/s41598-025-34336-1

“The team's analysis revealed that these migrating rotation bands in the deep solar interior form a butterfly-shaped flow pattern, mirroring the sunspot migration that later emerges at the surface.”

https://phys.org/news/2026-03-physicists-sun-magnetic-kilometers-surface.html

In other words this latest research published in Nature suggests that rather then being generated close to the suns surface the sunspot and their rotations in fact, start much deeper within the solar interior and nearer to the inner core than previously assumed.

So it looks like this latest research goes, at least part way, to confirming my Variable speed solar Dynamo model which predicts that sunspots and their rotations come from a physical mechanism deep within the suns core. A model that also explains the 22 year solar cycle more successfully than the traditional established “toroidial and polodial magnetic field” models driven by thermal convection of the solar plasma.

Sunspot Mechanism

In the variable speed model the overall solar dipole field is driven instead by a variable speed dynamo mechanism deep inside the sun. Proposed in this model is that the solar core rotates slower, and then faster than the outer solar plasma, as seen at the sun’s photosphere, over a 22 year repeating dynamo cycle. This creates an overall solar dipole field that reverses the suns overall magnetic dipole polarity every 11 years for a full 22 year cycle. The variable speed gradient between the rotation velocity of the inner core and rotational velocity of the outer parts of the solar plasma at the photosphere also creates physical eddies or vortices in the more liquid convection radiative zone plasma between the core and the photosphere. Vortices which in turn are observed as sunspots.

Very much in the same way as the speed gradient of a liquid, like water, flowing over a static river bottom will physically generate vortices or eddies in the water due to the speed gradient differential between the river bottom and the moving water surface. This means that sunspots,in the same way as the water eddies, are eddies or vortices that have their roots deep within the sun near its core and stretch upwards all the way to the surface at the photosphere. As this recently published research in Nature seems to have realised.

In the sun these individual vortices in the plasma are generated by differential rotation between the suns core and the surface in addition to the differential rotational speeds of the plasma due to the Coriolis effect between sun equator and poles, create the observed local swirling dynamo effects called sunspots in the solar plasma. The rotating plasma of each sunspot vortex is the dynamo that drives the localised sunspots magnetic field. Not the other way around as current models assume where established theory erroneously assumes magnetic fields generated by thermal convection twist the plasma into rotating dipoles of sunspots.

It is not a coincidence that the sunspots rotation direction is observed to be seen as having either negative or positive magnetic fields directions depending on the clockwise or counter clockwise rotation direction of the spot. Nor is it a coincidence that as the solar core rotates faster or slower relative to the photosphere, the coreolis effect and vortices rotation directions reverse for the sunspots in each hemisphere. And this reverse in rotation direction thus reverses the sunspots polarity. As observed.

Summary

In summary is important to point out here that contrary to traditional and current thermal convection theories of the solar dynamo which has magnetic fields generating sunspot rotation directions and motions, the variable speed model outlined here is the reverse. The physical rotations of the solar plasma between core and surface creates a dynamo that generates the overall solar dipole field and the rotational motions and rotations in the plasma as vortice eddies, in turn generate the dipole magnetic fields of sunspots.

A magnetic avalanche as the central engine powering a solar flare

 Introduction

“Magnetic field lines reconnecting”. At least that’s what the theorists in “A magnetic avalanche as the central engine powering a solar flare” by L. P. Chitta have latched onto to describe what is happening. Unfortunately these assumptions are based on a misunderstanding of the true mechanisms driving the solar Dynamo. This misunderstanding of the true mechanism of the solar dynamo is like saying a car moves on its own on the road as if by magical force, which in turn rotates its wheels on the road! What actually happens is the differential rotation of the solar plasma due to the suns rotation creates eddy vortices in the liquid plasma and what’s called the dynamo effect in these local vortices. These vortices are also synonymous with the sunspots and their observed polarity. The vortices of rotating plasma create the magnetic field by rotating the individual plasma atoms and in turn rotating their magnetic fields inducing overall positive or negative polarities in the vortices eddy depending on the relative rotation direction.  Usually sunspot pairs have opposing rotations, thus opposing polarities in their induced magnetic fields. It is these opposing polarities which join up to contain or ‘create’ the plasma filaments in the ejected solar material. (Simple geometry tells us: For the arc to rotate in one direction the vortices or sunspots at the two ends of the arc must rotate in opposing directions) As both ends of the arced filaments rotate at different rates the filament becomes twisted and the “braiding” effect is observed. Either the braiding increases due to increase difference in rotation rates and breaks or two separate filaments cross over, interfere and break. Releasing the filament plasma to be ejected away from the sun by the pressure of the overall solar wind. Notice this is confirmed by observations as CME’s tend to either speed up or slowdown to match the solar wind speed. So essentially it is not magnetic field lines breaking and connecting, it is the physical rotation of the sunspots plasma due to differential rotation which in turn physically rotates the ejected plasma into focussed filaments which in turn induce the observed magnetic fields. When these rotating filaments cross or braid, they break and the constant intense solar wind pressure pushes the broken filament outwards. 

Solar Dynamo mechanism

As the solar Dynamo model outlined in this paper cited here suggests, the magnetic fields, sunspots and solar flares are in fact created by the physical motion of the solar plasma due to differential rotation of the sun at and below the photosphere. This differential rotation creates vortices in the plasma. Rotations that when great enough become observable as sunspots. The direction of rotation defines the magnetic field of the dynamo mechanism within the sunspot vortex. And in turn this rotation is passed on to the filaments of plasma being ejected by the suns surface. Notice connecting filaments observed always connect opposing rotating vortices in the plasma. In other words a filament is always observed to connect between a positive and negative rotating vortices on the solar surface. They both rotate together. Two same direction rotations cannot connect physically as when they connect in an arch above the surface, they will rotating in opposite directions and not connect. It’s also noted in the Nature paper that the filaments rotate and become “braided”. This is because the rotations between two connecting vortices are unequal in rotation rates. One end of the filament arch is being rotated at a slightly different speed by its vortex source. The two rates mismatch and create braided structures in the filament.

As the sunspots become more tightly packed due to differential rotation near the height of the 11 year solar cycle, the rotating filaments also increase in number size and complexity. They increasingly overlap, braid, and cross over with others, interfere and and then break. 

The magnetic fields observed don’t drive the motions and flares. It’s the other way round. The rotation of the plasma in the vortices drive the motions and rotation directions of the filaments of ejected plasma.

Sunspot magnetic field modelled with a variable speed inner core solar dynamo

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.