Additional Remarks

2 April 1999

• The Nobeyama Radioheliograph data show that in the microwave range, besides large-scale trans-equatorial chains (see, e.g., the May 11-15, 1993 and November 1-4, 1993 events), there are also many examples displaying large and strongly evolving "longitudinal" or "internal" chains connecting remote active regions inside an active zone in one (northern or southern) hemisphere (the August 20-September 3, 1998 event).
  
  
• A consideration of the Nobeyama Radioheliograph data from June 1992 to March 1999 bring one to the following preliminary conclusion about the long-living microwave chains at the different stage of the solar activity cycle: at the decreasing phase of the 22nd cycle many trans-equatorial chains were observed (the May 11-15, 1993 and November 1-4, 1993 events), while at the present increasing phase of the 23rd cycle the "longitudinal" or "internal" chains are mainly characteristic (the August 20-September 3, 1998 event). This feature appears to be due to the corresponding low-latitude and high-latitude locations of the active zones.
  
  
• Simultaneous observations in the EUV range with the SOHO/EIT and TRACE, available now, allow to compare the images received with these two space observatories at the same wavelengths. Such a comparison shows that the quite identical chains and threads are present on the corresponding modified SOHO/EIT and TRACE images (the October 13, 1998 and March 30, 1999 events). It is the most direct proof of the reality of this novel phenomenon of the large-scale solar activity.
  
  
• The large-scale chains and threads observed in different ranges provide additional evidences that various remote active regions and other structures are closely related between themselves and form an unified, complex and global solar magnetosphere like to that as several neighboring sunspots form the active region magnetosphere.
  
  
• It is highly probable that the large-scale chains, particularly in the EUV range, light separators and quasi-separatrix layers forming on the boundaries of different interacting large-scale magnetic flux systems in the global solar magnetosphere.
  
  
• The fact that large-scale chains appear to reveal a close association with CMEs is a consequence that both these phenomena results from the evolution of the global solar magnetosphere and some its structures and that the evolving large-scale chains and threads appear to be an indicator of the development of the corresponding structures of the global solar magnetosphere (see, e.g., the March 28-April 02, 1999 event).
  
  
• A spectacular evolution of the chains and threads appears to occur not only after a CME (the August 22-23, 1996 event) at the stage of the prolonged post-CME energy release, but also before that (the June 1-2, 1998 event), when large-scale magnetic structures approach to their unstable state.

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Last update: 2 April 1999