The Solar Dynamo: Plasma Flows
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- Visualizations by:
- Tom Bridgman
- View full credits
In this visualization, we illustrate the fluid flows in the Sun which drive the solar magnetic dynamo. The flows can be considered as a combination of two components, a toroidal component and a meridional component.
The toroidal flow corresponds to the rotational motion of the Sun. In the cut-away view, this motion is represented by the streaking flow vectors. The color code of the cross-section on the right-hand side illustrates the rotational period of this flow. Here we see that flow near the equator (in violet) takes about 24.5 days to make it all the way around the Sun. As we move to higher latitudes, we see that the flow gets steadily slower, increasing the time it takes to go around the Sun to as much as 34 days (in red) near the poles. A non-uniform fluid flow such as this is known as differential rotation. This motion in the interior can be measured at the solar surface through techniques of helioseismology.
Deeper into the Sun, we see the different colors of the outer layers transition to a solid color (olive green). This transition point is called the tachocline. It is the boundary between the outer zone of the Sun where thermal energy is transferred by convection (the convective zone), and the inner region of the Sun where thermal energy is transferred by radiation (the radiative zone). The radiative zone is believed to rotate as a solid body with a period of about 28 days in this model.
The yellow and white center in this model represents the solar radiative zone.
In the cross-section on the left-side, we represent the other component of the flow, called the meridional flow, which moves plasma between the equator and the polar regions.
These flows of solar plasma are used as input data for dynamo modeling (see The Solar Dynamo: Toroidal and Poloidal Fields and The Solar Dynamo: Toroidal and Radial Fields.)
Credits
Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio
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Animator
- Tom Bridgman (Global Science and Technology, Inc.) [Lead]
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Scientists
- Andres Munoz-Jaramillo (Montana State University)
- Dibyendu Nandi (Indian Institute of Science Education and Research, Kolkata)
- Petrus C. H. Martens (Harvard Smithsonian Center for Astrophysics)
- William D. Pesnell (NASA/GSFC)
Missions
This visualization is related to the following missions:Series
This visualization can be found in the following series:Papers used in this visualization
Datasets used in this visualization
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SOHO Continuum
ID: 619This dataset can be found at: http://sohowww.nascom.nasa.gov
See all pages that use this dataset
Note: While we identify the data sets used in these visualizations, we do not store any further details, nor the data sets themselves on our site.
Related Pages
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ID: 3521 Visualization
The Solar Dynamo: Toroidal and Poloidal Magnetic Fields
Read moreUsing the solar plasma flows as input (see The Solar Dynamo: Plasma Flows), the equations of magnetohydrodynamics, and 'seeding' the calculations with an initial small magnetic field, one can compute how a magnetic field can grow and be maintained. This is the dynamo process, the net result being that part of the Sun's outflowing thermal convective energy from nuclear processes is used to create the magnetic field.In this view of the solar dynamo mechanism, we examine the evolution of the toroidal magnetic field, the field intensity represented by colors on the right-hand cross-section, and the poloidal magnetic potential field, represented by colors on the left-hand cross-section. The poloidal magnetic potential is a scalar quantity that contains information about the radial and latitudinal magnetic field vectors. To see the radial magnetic field, see The Solar Dynamo: Toroidal and Radial Magnetic Fields.In this visualization, the magnetic field lines (represented by the 'copper wire' structures) are 'snapshots' of the field structure constructed at each time step of the model. These field lines should not be considered as 'moving' or 'stretching' as the model evolves in time. Even this simplified model reproduces a number of characteristics observed in the actual solar magnetic field. Cyclic behavior with oscillations in the magnetic field amplitude.Magnetic regions at the surface migrate from high latitudes towards the equator as the solar cycle progresses. This reproduces the "Butterfly Diagram" pattern.Surface magnetic polarities reverse with each cycleBecause this model is axisymmetric, it cannot simulate non-axisymmetric features such as active longitudes. ||
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ID: 3583 Visualization
The Solar Dynamo: Toroidal and Radial Magnetic Fields
Read moreUsing the solar plasma flows as input (see The Solar Dynamo: Plasma Flows), the equations of magnetohydrodynamics, and 'seeding' the calculations with an initial small magnetic field, one can compute how a magnetic field can grow and be maintained. This is the dynamo process, the net result being that part of the Sun's outflowing thermal convective energy from nuclear processes is used to create the magnetic field.In this view of the solar dynamo mechanism, we examine the evolution of the toroidal magnetic field, intensities represented by color on the right-hand cross-section, and the radial magnetic field, represented on the left-hand cross-section. To see the poloidal magnetic vector potential, see The Solar Dynamo: Toroidal and Poloidal Magnetic Fields.In this visualization, the magnetic field lines (represented by the 'copper wire' structures) are 'snapshots' of the field structure constructed at each time step of the model. These field lines should not be considered as 'moving' or 'stretching' as the model evolves in time.Even this simplified model reproduces a number of characteristics observed in the actual solar magnetic field.Cyclic behavior with oscillations in the magnetic field amplitude.Magnetic regions at the surface migrate from high latitudes towards the equator. This reproduces the "Butterfly Diagram" pattern.Surface magnetic polarities reverse with each cycleBecause this model is axisymmetric, it cannot simulate non-axisymmetric features such as active longitudes. ||
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