Sun  ID: 3496

The Solar Dynamo: Plasma Flows

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.)

Visualization Credits

Tom Bridgman (GST): Lead Animator
Andres Munoz-Jaramillo (Montana State University): Scientist
Dibyendu Nandi (Indian Institute of Science Education and Research, Kolkata): Scientist
William D. Pesnell (NASA/GSFC): Scientist
Petrus C. H. Martens (Harvard Smithsonian Center for Astrophysics): Scientist
Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio

Science Paper:
Helioseismic Data Inclusion in Solar Dynamo Models

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Data Used:
SOHO/Michelson Doppler Interferometer (MDI)/Continuum May 1996 to February 2009

This item is part of these series:
SDO Pre-launch
Solar Dynamo
SDO - Visualizations

SVS >> Magnetic Fields
SVS >> Solar Cycle
SVS >> Solar Rotation
SVS >> Sun
GCMD >> Location >> Solar Interior
SVS >> Hyperwall
SVS >> Solar Differential Rotation
SVS >> For Educators
SVS >> Sunspot Cycle
NASA Science >> Sun

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version