Coronal Activity During the 22-Year Solar Magnetic Cycle |
| |
| Authors: | Storini Marisa Sýkora Július |
| |
| Institution: | (1) Cosmic Ray Section (PNRA/MURST Operative Unit) - IFSI/CNR c/o Department of Physics, La Sapienza University, I-00185 Rome, Italy;(2) Astronomical Institute, 05960 Tatranská Lomnica Slovak, Republic |
| |
| Abstract: | The existence of a 22-year heliomagnetic cycle was inferred long ago not only from direct measurements of the solar magnetic field but also from a cyclic variability of a number of the solar activity phenomena. In particular, it was stated (a rule derived after Gnevyshev and Ohl (1948) findings and referenced as the G–O rule in the following) that if sunspot number Rz cycles are organized in pairs of even–odd numbered cycles, then the height of the peak in the curve of the yearly-averaged sunspot numbers Rz-y is always lower for a given even cycle in comparison with the corresponding height of the following odd cycle. Exceptions to this rule are only cycles 4 and 8 which, at the same time, are the nearest even cycles to the limits of the so-called Dalton minimum of solar activity (i.e., the 1795–1823 time interval). In the present paper, we are looking for traces of the mentioned G–O rule in green corona brightness (measured in terms of the Fexiv 530.3 nm emission line intensity), using data covering almost five solar cycles (1943–1994). It was found that the G–O rule seems to work within the green-line corona brightness, namely, when coronal intensity measured in an extended solar middle-latitude zone is considered separately from the rest of the solar surface. On the other hand, the same G–O rule is valid at the photospheric level, as the heliographic latitudinal dependence of sunspot numbers (1947–1984) shows. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
