𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Regularities of variation of the heliospheric current sheet orientation during the solar activity cycle

✍ Scribed by R. A. Gulyaev; N. Ya. Vanyarkha


Publisher
Springer
Year
1992
Tongue
English
Weight
561 KB
Volume
140
Category
Article
ISSN
0038-0938

No coin nor oath required. For personal study only.

✦ Synopsis


Evolution of spatial orientation of the heliospheric current sheet (HCS) has been studied in detail using synoptic maps of the HCS configuration over the period [1971][1972][1973][1974][1975][1976][1977][1978][1979][1980][1981][1982][1983][1984][1985][1986][1987][1988][1989]. Analysis involves all phases of the sunspot cycle except for two years of maximum solar activity. The helmet-like coronal streamers are confirmed to be structural elements of the HCS. The r.m.s, deviation of a real HCS configuration from a plane does not exceed about 10 ~ during most of the sunspot cycle length. Hence, minimum-type corona should be observed every time the HCS is oriented parallel to the line-of-sight, independent of the cycle phase. Such occasions have been observed apart from the sunspot minimum epochs at the solar eclipses of 31 August, 1932 and 11 July, 1991. Regularities of variation of the two following parameters of the HCS orientation have been revealed: obliquity to the solar equator plane ('heel' or tilt) and longitudinal orientation ('yawing'). Behaviour of the above parameters is repeated in different cycles. However, heeling and yawing occur probably not synchronous but rather independent of one another.


πŸ“œ SIMILAR VOLUMES


On the short term variations of solar ac
✍ Tamer AtaΓ§ πŸ“‚ Article πŸ“… 1989 πŸ› Springer Netherlands 🌐 English βš– 323 KB

Short-term variations ot the last solar activity cycle were studied by the flare and coronal indices using Gleissberg method. Systematic short-term variations are found from their course during the 21st solar activity cycle. Comparison of their autocorrelograms constructed by the new set of data obt