Longitudinal Structure of Solar Magnetic Fields During the Transition from Cycle 22 to Cycle 23 Inferred from SOHO MDI Data
Abstract
We present the results of investigation the latitudinal and longitudinal structure of the solar magnetic field by using full disk SOHO MDI data. It was found that during the transition from cycle 22 to cycle 23 solar activity clustered in fixed longitudinal zones, and that the old magnetic fluxes were replaced by new magnetic fluxes in the same fixed longitudinal regions. The most interesting longitudinal zone was located from 240 deg to 280 deg. From the CR1911 until CR1918, there was a complex of activity of old magnetic fluxes. This complex of solar activity first emerged in the southern hemisphere and decayed to CR1916. Then, the next old magnetic flux appeared in the same longitudinal zone in the northern hemisphere and existed until CR1919. The same longitudinal zone became active again in CR1923 when a complex of solar activity of new magnetic flux emerged. This longitudinal zone of pronounced activity existed for more than 15 Carrington rotations. Apparently, this zone was the place of reversal of polarity of the toroidal magnetic field during the transition from one cycle to another. We discuss implications of these results for theories of solar cycle.
- Publication:
-
SOHO-9 Workshop on Helioseismic Diagnostics of Solar Convection and Activity
- Pub Date:
- 1999
- Bibcode:
- 1999soho....9E..41B