Advertisement

Solar Physics

, Volume 4, Issue 4, pp 409–421 | Cite as

On the development of magnetic fields in active regions

  • M. K. V. Bappu
  • V. M. Grigorjev
  • V. E. Stepanov
Article

Abstract

Transverse and longitudinal magnetic field scans together with K232 spectroheliograms that cover the early phases of active region formation reveal the following:
  1. (a)

    The new active region forms near the periphery of an old magnetic region. There is evidence that the new region forms an interrelated system with the old magnetic structures on the sun.

     
  2. (b)

    Noticeable changes in the background magnetic field are seen nearly 3 days prior to the appearance of the sunspot. Magnetic hills of the longitudinal component appear along with bright localized K232 emission. Subsequently the K232 emission spreads along the boundary of one or two adjacent supergranules and at the time of sunspot formation occupies the whole supergranular cell.

     
  3. (c)

    Transverse fields with strengths of 100–150 gauss form closed regions in the area of the longitudinal component hills, in the very early phases of the region. These fields stretch and link up the two areas later, at which time the peak transverse fields with values near 250 gauss coincide with the zero line of the longitudinal field. When subsequently the spots appear in the new region, the transverse fields are located about the hills of the longitudinal field. The total field vectors just prior to sunspot formation are pressed to the surface. These are inclined about 45° to the surface after the spot appears. The findings indicate that the magnetic field of a new region emerges from the sub-photospheric layers. It is highly likely that the dynamics of a supergranule influences only the emergence of the magnetic field into the upper layers of the solar atmosphere.

     

Keywords

Magnetic Field Active Region Solar Atmosphere Longitudinal Component Zero Line 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aleksandrovich, I.I. and Stepanov, V.E.: 1968, Izv. Sib. IZMIR (in press).Google Scholar
  2. Bray, R.J. and Loughhead, R.E.: 1964, Sunspots, Vol. VII (International Astrophysics Series), Chapman and Hall, London, p. 67.Google Scholar
  3. Bruzek, A.: 1951, Z. Astrophys. 28, 277.Google Scholar
  4. Bruzek, A.: 1952, Z. Astrophys. 31, 99.Google Scholar
  5. Bumba, V.: 1967, Izv. Krym. astrofiz. Obs. 36, 56.Google Scholar
  6. Bumba, V. and Howard, R., 1965a: Astrophys. J. 141, 1502.Google Scholar
  7. Bumba, V. and Howard, R.: 1965b, Astrophys. J. 141, 1942.Google Scholar
  8. Butler, C.P.: 1922, Mon. Not. R. astr. Soc. 82, 334.Google Scholar
  9. Butler, C.P.: 1924, Mon. Not. R. astr. Soc. 84, 134.Google Scholar
  10. Gopasyuk, S.I.: 1966, Izv. Krym. astrofiz. Obs. 35, 139.Google Scholar
  11. Gopasyuk, S.I.: 1967, Izv. Krym. astrofiz. Obs. 36, 56.Google Scholar
  12. Kuklin, G.V. and Stepanov, V.E.: 1963, Soln. Dann. Bjull. N2, 43.Google Scholar
  13. Kuznetsov, D.A., Kuklin, G.V., and Stepanov, V.E.: 1966, Nauka 1, 133.Google Scholar
  14. Moreton, G.E. and Ramsay, H.E.: 1963, Publ. astr. Soc. Pacific 72, 357.Google Scholar
  15. Parker, E.N.: 1955, Astrophys. J. 121, 491.Google Scholar
  16. Richardson, R.S.: 1951, Astrophys. J. 114, 356.Google Scholar
  17. Simon, G.W. and Leighton, R.B.: 1964, Astrophys. J. 140, 1120.Google Scholar
  18. Smith, H.J. and Booton, W.D., 1962, Geophys. Res. Notes No. 58.Google Scholar
  19. Stepanov, V.E.: 1958, Izv. Krym. astrofiz. Obs. 20, 52.Google Scholar
  20. Vasiljeva, G.J.: 1961, Soln. Dann. Bjull. N12, 64.Google Scholar
  21. Vasiljeva, G.J.: 1968, Bull. Pulkovo Obs. (in press).Google Scholar
  22. Vitinskiji, U.I. and Izsanov, R.N.: 1964, Soln. Dann. Bjull. N10, 57.Google Scholar

Copyright information

© D. Reidel Publishing Company 1968

Authors and Affiliations

  • M. K. V. Bappu
    • 1
  • V. M. Grigorjev
    • 2
  • V. E. Stepanov
    • 2
  1. 1.Kodaikanal ObservatoryIndia
  2. 2.Sayan ObservatorySib. IZMIRU.S.S.R.

Personalised recommendations