Active longitudes and north-south asymmetry of the activity the Sun as manifestations of its relic magnetic field |
| |
| Authors: | A V Mordvinov L L Kitchatinov |
| |
| Institution: | (1) Institute for Solar-Terrestrial Physics, Siberian Division, Russian Academy of Sciences, P.O. Box 4026, Irkutsk, 664033, Russia |
| |
| Abstract: | The distributions of dominant magnetic polarities in synoptic maps of photospheric magnetic fields and their extrapolations to the corona based on Stanford Observatory data are studied. Both dipolar and quadrupolar magnetic patterns are detected in the distributions of dominant polarities in the near-equatorial region of the photosphere for activity cycles 21, 22, and 23. The field in these patterns often has opposite signs on opposite sides of the equator, with this sign changing from cycle to cycle. A longitude-time analysis of variations of the mean solar magnetic field shows that the contribution of the large-scale magnetic patterns to the total field does not exceed 20 µT. The most stable magnetic structures at a quasi-source surface in the solar corona are separated by approximately 180° in heliographic longitude and are close to dipolar. The nature and behavior of these large-scale magnetic patterns are interpreted as a superposition of cyclic dynamo modes and the nonaxially symmetric relic field of the Sun. The contribution of the relic field to the mean solar magnetic field appears as a weak but stable rotational modulation whose amplitude does not exceed 8 µT. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
