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Bumba, V.; Klvana, M.

doi:10.1023/a:1004932004407

Cited by 2 publications

(9 citation statements)

References 2 publications

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“…The only significant flare in this area was the 3B/M7.3 flare on Sept. 29, at 15:13 UT, but it was located between NOAAs 6853 and 6850 (see Fig. 4 in Bumba et al 1995a), and was probably the result of interaction between the evolving NOAA 6853 and the emerging magnetic flux in the middle of NOAA 6850. The occurrence of a large flare inbetween the spotgroups is another argument for grouping together these groups in a complex of activity.…”

Section: Long Term Evolution Of the Complex At (L =  • ) From Julymentioning

confidence: 95%

“…1847 has been studied in (Bumba et al 1995a). Active region NOAA 6850 remained stable during this transit (Sept. 24 -Oct. 8), of class FKC and with a delta magnetic configuration throughout, its area around 1500 m. s. h.. A significant change occurred around Sept. 29-30, when a new group began to develop in its middle part, inbetween the multi-umbra delta spot and an old f-polarity spot.…”

Section: Long Term Evolution Of the Complex At (L =  • ) From Julymentioning

confidence: 99%

“…The most interesting of them was NOAA 6850, magnetically an inactive deltaconfiguration (Bumba et al 1995a), and NOAA 6891, a very active complex group (Kálmán 1995). We noticed that we photoelectrically had measured the same region of the solar surface one rotation prior to the formation of NOAA 6850 (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…1847 (see Fig. 7 in Bumba et al 1995a) prompted us to investigate these forms subsequently for all disk passages, i.e. during all stages of development of the complex.…”

Section: Introductionmentioning

confidence: 99%

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The 1991 southern hemisphere complex of activity

Bumba

Klvaňa

Kalman

et al. 1996

Astron. Astrophys. Suppl. Ser.

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Abstract. -We have investigated the development of a complex of activity which took place in the southern hemisphere of the Sun between July 1991 and April 1992. The whole process culminated with the successive formation of two large active regions with sunspot groups NOAA 6850 (September/October) and NOAA 6891 (October/November 1991), both having complicated magnetic fields, but the former without heavy flare activity. We observed the appearance of the individual active regions as the consequence of the development stage of large-scale magnetic fields in the given area of the solar surface, in connection with their longitudinal and latitudinal distribution. We have studied the dynamics of this development on magnetic synoptic charts, as well as on spectroheliograms taken in the K-line of ionized calcium. Our new observations confirm the regularities found earlier and connection of global and local developments with convection. We think that they could become a tool for solar activity prediction and that they could be used for comparative studies of stellar complexes of activity.

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Section: Long Term Evolution Of the Complex At (L =  • ) From Julymentioning

confidence: 95%

Section: Long Term Evolution Of the Complex At (L =  • ) From Julymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…1847 (see Fig. 7 in Bumba et al 1995a) prompted us to investigate these forms subsequently for all disk passages, i.e. during all stages of development of the complex.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The 1991 southern hemisphere complex of activity

Bumba

Klvaňa

Kalman

et al. 1996

Astron. Astrophys. Suppl. Ser.

Self Cite

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“…AR NOAA 6850 (Sep. 26-Oct. 7, 1991) appeared in this complex of activity; it was large, magnetically complex and evolving, but was not flare-active, although large motions were observed in it (Bumba et al 1995). Another active complex, containing regions NOAA 7220/22 and NOAA 7428/51 (July 6-18 and Aug. 02-13 1992) was also selected; in these spotgroups quick growth and large sunspot proper motions also occurred.…”

Section: Introductionmentioning

confidence: 95%

Submergence of magnetic flux in interaction of sunspot groups

Kalman

2001

A&A

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Abstract.Submergence of magnetic flux is demonstrated in the process of evolution of sunspot groups NOAA 6850 (26 Sep.-07 Oct. 1991) and 7220/22 (06-17 July 1992). In both cases new magnetic flux emerges immediately behind an existing spotgroup. The new flux does not interact with the old one, as can be seen in YOHKOH X-ray images, so no significant flare activity occurs, although umbrae of different magnetic polarity collide. In both cases the quickly forward moving p-spots of the new flux force the submergence of the f-spots of the older region, these being squeezed from two sides between the old and new p-spots. This leads to the disappearance of about 16 10 21 Mx of f-polarity in AR 6850. In the case of this region the submerged flux interacts with newly emerging magnetic fields and in the next rotation continues its life as the complex and eruptive AR 6891. In AR 7220/22, spots of both polarities submerge in the intermediate part of the complex between the old leader of AR 7220 and the quickly growing AR 7222, leaving in the next rotation a bipolar-looking group (AR 7248), consisting of two p-polarity spots. So, submergence of magnetic flux due to interaction of old and new activity may play an important role in the decay of sunspot groups.

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Cited by 2 publications

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The 1991 southern hemisphere complex of activity

The 1991 southern hemisphere complex of activity

Submergence of magnetic flux in interaction of sunspot groups

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