Solar Activity

  • Z. Mouradian
Conference paper
Part of the NATO Science Series book series (ASIC, volume 558)


In this lecture, we start with a short introduction and give a few references for future study. Then we introduce two criteria to distinguish the quiet from the active sun: these are respectively the permanence of the structures and the presence of an inversion line of magnetic field background. In the third part we describe a few structures of the quiet sun that vary as a function of the solar activity cycle. We then discuss the two typical active sun sites: prominences and active regions. These sites usually evolve quietly until some transient event triggers an acceleration. Such transient events are the sudden disappearance of a prominence and, for active regions, flares and associated phenomena. At the end of the lecture we explain the activity indices and activity mapping, the 11-, 22- and 100-year solar activity cycles, and their effect on the quiet sun, with solar variability. We finish with a few comments on the solar-stellar relation.


Solar Activity Solar Cycle Coronal Mass Ejection Solar Phys Sunspot Group 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Brants, J.J. and Steenbeek, J.C.M. (1985) Morphological evolution of an emerging flux region, Solar Phys. 96 229–252.ADSCrossRefGoogle Scholar
  2. 2.
    Cameron, A.Collier, and 17 co-authors (1999) Multisite observations of surface structures on AB Doradus in 1994 November, MNRAS 308 pp. 493–509.ADSCrossRefGoogle Scholar
  3. 3.
    Canfield, R.C., Reardon, K.P., Leka, K.D., Shibata, K., Yokpyama, T., Shimoto, M., (1996) Hα surges and X-ray Jets in AR 7260, Ap.J. 464 1016–1029.ADSCrossRefGoogle Scholar
  4. 4.
    Cox, A.N., Livingston, W.C., Matthews, M.S. (eds.), (1991) Solar Interior and Atmosphere, The Univ. of Arizona Press, Tucson.Google Scholar
  5. 5.
    Donea, A., Lindsey, C., Braun, D. (1999) Helioseismic holography - a technique for studying seismic signatures of solar flares, Poster publication of this lectures in Romanian Astro. J. 9 Suppl., (in press).Google Scholar
  6. 6.
    Fang, Ch., Mouradian, Z., Banos, G., Dumont, S., Pecker, J.C. (1984) Structure and physics of solar faculae: IV-Chromospheric granular structure, Solar Phys. 91 61–70.ADSCrossRefGoogle Scholar
  7. 7.
    Gaizauskas, V., Harvey, K.L., Harvey, J.W., Zwaan, C. (1983) Large-scale patterns formed by solar active regions during the ascending phase of cycle 21, Ap.J. 265 1056–1065.ADSCrossRefGoogle Scholar
  8. 8.
    Gosling, J.T., (1993) The solar flare myth, J. of Geophys . Res. 98, No. All 18937–18949.ADSCrossRefGoogle Scholar
  9. 9.
    Hénoux, J.-C. and Vogt, E. (1998) Application to astrophysics of collisional polarization spectroscopy, Physica Scripta T78 60–67.ADSCrossRefGoogle Scholar
  10. 10.
    Hudson, H.S. (1988) Modeling of total Solar irradiance variability: an overview, in G. A. Chapman (ed.), Solar and Middle Atmosphere Variability, Adv. Space Res. 8 Nb. 7 pp. 15–20.ADSGoogle Scholar
  11. 11.
    Jensen, E., and Wiik, J.,E. (1990) Plasma parameters in quiescent prominences, in V. Ruzdjak and E. Tandberg-Hanssen (eds.), Dynamics of Quiescent Prominences, IAU Coll. No 117, Lecture Notes in Physics. 363 Springer-Verlag, Berlin, pp.298–301.Google Scholar
  12. 12.
    Khan, J.I., Uchida, Y., McAlister, A.H., Mouradian, Z., Soru-Escaut, I., Hiei, E. (1998) A flare-associated filament eruption observed in soft X-rays by Yohkoh on 1992 May 7, A & A, 336 ‘753–768.ADSGoogle Scholar
  13. 13.
    Laclare, F., Dalmas, C., Coin, J.P., Irbah, A. (1996) Measurements and variations of the solar diameter, Solar Phys. 166 211–229.ADSCrossRefGoogle Scholar
  14. 14.
    Lindsey, C., and Braun, D.C. (1999) Helioseismic holography, Ap.J. 485 985–903.Google Scholar
  15. 15.
    Liu, Y., Akioka, M., Yan, Y. and Sato, J. (1998) A flare due to the interaction of a small loop and a large loop, Solar Phys. 180 377–392.ADSCrossRefGoogle Scholar
  16. 16.
    Livingston, W. (1993) Surrogates for total solar irradiance, in E. Nesme-Ribebs (ed.) The Solar Engine and Its Influence on Terrestrial Atmosphere and Climate, NATO ASI Series I 25 pp.145–162.Google Scholar
  17. 17.
    Machado, M.E., Avret, E.H., Vernazza, J.E.,Noyes, R.W. (1980) Semi-empirical models of chromospheric flare region, Ap.J. 242 336–351.ADSCrossRefGoogle Scholar
  18. 18.
    Malherbe, J.M., Schmieder, B., Mein, P., Mein, N., van Driel-Gesztelyi, L. and von Uexküll, M. (1998) Arch filament systems associated with X-ray loops, Solar Phys. 180 313–329.ADSCrossRefGoogle Scholar
  19. 19.
    Martin, S.F. (1998) Filament chirality: A link between fine-scale and global patterns, in D. Webb, D. Rust and B. Schmieder, (eds.), New Perspectives on Solar Prominences, IAU Coll. 167, ASP Conf. Ser. 150 pp. 419–429.Google Scholar
  20. 20.
    Mouradian, Z., (1995) Spectral signatures of solar structures, Astrophysics, 38 508–518.CrossRefGoogle Scholar
  21. 21.
    Mouradian, Z., Martres, M.J., Soru-Escaut, I.(1987) The heating of filaments as a disappearance process in A.I. Poland (ed) Coronal and Prominence Plasmas, Proc. of Workshops in 1985 and 1986, NASA Conference Publication no. 2442, pp. 221–223.Google Scholar
  22. 22.
    Mouradian, Z., Martres, M.J., Soru-Escaut, I.,Gesztelyi, L. (1987) Local rigid rotation and the emergence of active centers, ACA, 183 129–134.Google Scholar
  23. 23.
    Mouradian, Z., Soru-Escaut, I. (1991) On the dynamics of the large-scale magnetic fields of the sun and the sunspot cycle, A&A 251 649–654.ADSGoogle Scholar
  24. 24.
    Mouradian, Z., Soru-Escaut,I.(1993) On solar activity and the solar cycle. A new analysis of the Butterfly Diagram of sunspots, MIA 280 661–665.Google Scholar
  25. 25.
    Mouradian, Z., Soru-Escaut, I. (1995) The flare productivity of the sun related to the 11 - and 80 - year activity cycles, Solar Phyis. 159 173–179.ADSCrossRefGoogle Scholar
  26. 26.
    Mouradian, Z., Soru-Escaut, I., Hiei, E., McAlister, A.H., Shibasaki, K., Ohyama, M., Khan, J.I., Uchida, Y.(1998) The filament disappearance of 1992, May 07 (the EBI), Solar Phys. 180 313–329.Google Scholar
  27. 27.
    Mouradian, Z., Soru-Escaut, I. Pojoga, S. (1994) On the two classes of filament-prominence disappearance and their relation to coronal mass ejections, Solar Phys. 158 269–281.ADSGoogle Scholar
  28. 28.
    Muller, R.(1989) The solar granulation, in G.A. Chapman (ed.) Solar and Middle Atmosphere Variability, Adv. Space Res. 8, No.7 pp 159–167.Google Scholar
  29. 29.
    Pojoga, S., Molowny-Horas, R. (1999) The transverse velocity field of EUV solar prominence, Solar Phys. 185 113–125.ADSCrossRefGoogle Scholar
  30. 30.
    Schmieder, B. Heinzel, P., Wiik, J.E., Leman, J., Anwar, B. Kotrec, P., Hiei, E. (1995) Relation between cool and hot post flare loops derived from optical observations and Yohkoh/STX, Solar Phys. 156 337–361.ADSCrossRefGoogle Scholar
  31. 31.
    Schrijver, C.J. and 16 co-authors (1999) A new view of the solar outer atmosphere by the transition region and coronal explorer, Solar Phys. 187 261–302.ADSCrossRefGoogle Scholar
  32. 32.
    Semel, M. (1989) Zeeman-Doppler imaging of active sun. I Basic principes, A & A 225 456–466.ADSGoogle Scholar
  33. 33.
    Semel, M., Mouradian, Z., Soru-Escaut, I., Maltby, P., Rees, D., Makita, M. (1991) Active regions, sunspots and their magnetic fields, in A.N., Cox, W.C., Livingston, M.S., Matthews, (eds.), Solar Interior and Atmosphere, The Univ. of Arizona Press, Tucson, pp. 844–859.Google Scholar
  34. 34.
    Solar Geophysical Data, World Data Center A for Solar-Terrestrial Physics, NOAA, Boulder.Google Scholar
  35. 35.
    Sonett, C.P., Giampapa, M.S., Matthews, M.S. (eds.) (1991) The Sun in Time, The Univ. of Arizona Press, Tucson.Google Scholar
  36. 36.
    Stix, M. (1989) The Sun, Springer Verlag, Berlin.CrossRefGoogle Scholar
  37. 37.
    Švestka, Z. (1989) Solar flares: the gradual phase, in B. M. Haisch and M. Rodono (eds.), Solar and Stellar Flares, Kluwer Acad. Pub. Dordrecht, pp. 399–417.CrossRefGoogle Scholar
  38. 38.
    Tandberg-Hanssen, E. (1995) The Nature of Solar Prominences, D. Reidel Publ. Co., Dordrecht.Google Scholar
  39. 39.
    Tandberg-Hanssen, E. and Emslie, A. G. (1988) The Physics of Solar Flares, Cambridge Univ. Press, Cambridge.Google Scholar
  40. 40.
    Uchida, Y. (2000) New findings about flares and active regions by Yohkoh. (this issues).Google Scholar
  41. 41.
    Wilson, P.R. (1994) Solar and Stellar Activity Cycles, Cambridge Univ. Press, Cambridge.CrossRefGoogle Scholar
  42. 42.
    Zirin, H. (1988) Astrophysics of the Sun, Cambridge Univ. Press, Cambridge.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2000

Authors and Affiliations

  • Z. Mouradian
    • 1
  1. 1.Observatoire de ParisMeudonFrance

Personalised recommendations