The Sun’s Rotation Rate as Inferred from Magnetic Field Data
The pattern of solar magnetic fields has been used as a tracer to determine how the sun’s rotation rate varies with latitude and time. Two distinctly different rotation laws emerge from such an analysis, one agreeing with the surface Doppler rotation rate, the other corresponding to much more rigid rotation with a small polar spin-up. Detailed analysis shows that this second law cannot be explained in terms of flux redistribution on the solar surface, but that it represents the rotation properties of the sources of magnetic flux, which are likely to be located at the bottom of the convection zone.
The rotational phase velocity of the source pattern is found to be constant with time, which suggests that the depth at which the magnetic flux is stored and amplified inside the sun does not vary with the solar cycle, and that the phaae velocity also represents the plasma velocity.
KeywordsMagnetic Flux Solar Cycle Rotation Rate Rotation Period Convection Zone
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- DeLuca, E.E. (1987) ‘Dynamo theory for the interface between the convection zone and the radiative interior of a star’, NCAR Cooperative Thesis No. 104, Boulder, Colorado.Google Scholar
- Martin, S.F. (1989) ‘Evolution of small-scale magnetic fields’, in these proceedings.Google Scholar
- Rüdiger, G. and Tuominen, I. (1989) ‘Generators of solar differential rotation and implications of lielioseismology’, in these proceedings.Google Scholar