• Relatively weak extended emitting chains with a characteristic length comparable with the solar disk diameter were detected on the modified heliograms in the microwave (Nobeyama Radioheliograph), soft X-ray (Yohkoh/SXT), EUV (SOHO/EIT, TRACE), and other ranges (Chertok, 1997…2000, Chertok and Shibasaki, 1999, 2000).

 
• The chains appear to light up separators or quasi-separatrix layers between different interacting large-scale magnetic flux systems in the global solar magnetosphere and, in particular, to outline large-scale coronal structures involved in the CME process.

 

 

(For active regions: e.g., Somov, 1992; D\'emoulin et al., 1996; Priest, 1996; Sakurai and Wang, 1999; Titov, 1999).

    Present report:

• Some features of the chains and their relations to CMEs are illustrated for a number of halo CME-associated events.

 
• 23 events of 1997-2000

    Data:

• SOHO/EIT (DelaboudiniХre et al., 1995) images and movies at 171 and 195 ;
• Yohkoh/SXT (Tsuneta et al., 1991) images and movies;
• H-alpha heliograms of BBSO and Meudon;
• SOHO/LASCO (Brueckner et al., 1995) images and movies

        SOHO/EIT,  Yohkoh/SXT -- negative (inverted) images;
        H-alpha,  SOHO/LASCO -- positive (normal) images.

        --   Javaskript movies from modified SOHO/EIT images at 195 A
 
 

      Halo-CME-associated events of November 1997

      November 3, 1997 :  09-10 UT,  S20 W15, 1B/M4.2 flare preceding the proton events

      November 4, 1997 :  05:58 UT, S14 W33, 2B/X2.1 flare; ISTP event; J(E>10 MeV)~72 pfu;
                                       FD~3%; Dst~-110 nT

      *November 6, 1997 :  11:55 UT,  S18 W63, 2B/X9.4 flare; ISTP event; J(E>10 MeV)~490 pfu;
                                       GLE~12 %

       Conclusion

• The analysis confirms the previous assumptions and conclusions concerning the evolution of the chains in the global solar magnetosphere and their relations to CMEs.

 
• It is obvious that the chains connect all remote active regions and centers, including ones  located in different solar hemispheres on the both sides from the helioequator. It means that the global solar magnetosphere exists really.

 
• The features of the chain appear to support the assumption that the chains can particularly  light up separators and  quasi-separatrix  layers, forming on the  boundaries of different interacting and reconnecting large-scale magnetic flux systems. Therefore the chains can be considered as an indicator of the evolution of the global solar magnetosphere.

 
• The chains demonstrate clearly that the flares and/or filament eruptions, which are considered usually as sources of the corresponding CMEs, indeed are only a part of a much more large-scale (or even global) activity covering often the whole solar disk.

 
• The significant chain evolution takes place usually during many hours both before and after a CME eruption.

 
• The chains preceding CMEs appear to display energy release resulting from evolving large-scale magnetic structures at the stage when the development of these structures approach to a CME eruption.

 
• The chains following CMEs can result from the post-eruption energy release when magnetic fields in an extended region of the corona, strongly disturbed by a CME eruption, relaxes to its initial state via magnetic reconnection in large-scale coronal current sheets.

 
• Generally, the chains appear to outline the large-scale coronal structures involved in the processes of the CME eruption and post-eruption energy release.

 

More information and data on the solar large-scale chains are presented at the web page: