Large-scale transport of magnetic flux in solar convection zone.
Abstract
Horizontal displacements of the photospheric magnetic flux in zonal and meridian directions are interpreted as a partial consequence of horizontal large-scale velocity field, driven in deeper layers by giant convection. Determination of horizontal streamlines of solar plasma for different phases of the 11 year solar activity cycle was made according to the inferred large-scale velocity fields. The flow systems are horizontally limited, creating the cellular-like patterns with up-flow in the center and the down-flow on the boundaries. The flow patterns indicate the giant convection cells, many of them were detected during a period of more than four Carrington rotations (about 120 days). The characteristic distribution of the large-scale horizontal eddies (with characteristic scale lengths from 350 to 490 Mm) was found in the broad equatorial zone, limited between about 50 - 60 degrees of latitude in both hemispheres. The typical dimension of the observed velocity patterns varies with the spatial averaging of the velocity signal. The zonal mean of the zonal component of the flow relates with the differential rotation law, but the latitude dependence of the rotation rate is lower than the usually accepted surface data. The possible influence of radial dependence on the derived rotation rate is considered.
- Publication:
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JOSO Annu. Rep., 1998
- Pub Date:
- 1999
- Bibcode:
- 1999joso.proc...91A
- Keywords:
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- Solar Convective Zone: Magnetic Flux Tubes