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Coronal Holes and Flare Index: A correlation study

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Abstract

The correlation between the presence of coronal holes and flare indices has been investigated for the period from 1976 to 1995. The analysis shows that in the cases of 227 Carrington rotations (CRs) backward time lags yield the highest correlation between the coronal holes and flare indices. The maximum correlations were found at time lags of 222 and 142 CRs for polar and equatorial coronal holes, respectively. The period of study covers the past two solar cycles (21 and 22). Correlation analysis of both solar cycles has also been studied individually. The correlation analysis reveals that there is in general a forward shift in the maximum correlation for polar coronal holes, but it cannot be recommended to use polar coronal hole numbers for forecasting the next solar cycle.

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References

  • Ataç, T. and Özgüç, A.: 1998, Solar Phys. 180, 397.

    Google Scholar 

  • Babcock, H. W.: 1961, Astrophys. J. 133, 572.

    Google Scholar 

  • Bravo, S.: 1992, Ann. Geophys. 10, 449.

    Google Scholar 

  • Bravo, S. and Otaola, J. A.: 1989, Solar Phys. 122, 335.

    Google Scholar 

  • Bravo, S. and Stewart, G. A.: 1994, Solar Phys. 154, 377.

    Google Scholar 

  • Bravo, S. and Stewart, G. A.: 1997, Solar Phys. 173, 193.

    Google Scholar 

  • Bravo, S., Mendoza, B., Pérez-Enriquez, R., and Valdés-Galica, J.: 1988, Ann. Geophys. 6, 377.

    Google Scholar 

  • Das, T. K., Chatterjee, T. N., and Sen, A. K.: 1993, Solar Phys. 148, 61.

    Google Scholar 

  • Dorotovič, I.: 1996, Solar Phys. 167, 419.

    Google Scholar 

  • Hoyng, P.: 1992, in J. T. Schmelz and J. C. Brown (eds.), The Sun: A Laboratory for Astrophysics, Kluwer Academic Publishers, Dordrecht, Holland, p. 99.

    Google Scholar 

  • Ibarra, A. S.: 1990, Solar Phys. 125, 125.

    Google Scholar 

  • Kleczek, J.: 1952, Publ. Centr. Inst. Astron. No. 22, Prague.

  • Krieger, A. S., Timothy, A. F., and Roeloff, E. C.: 1973, Solar Phys. 29, 505.

    Google Scholar 

  • Levine, R. H.: 1977, in J. B. Zirker (ed.), Coronal Holes and High-Speed Wind Streams, Colorado University Association Press Boulder, p. 103.

  • Parker, E. N.: 1977, Ann. Rev. Astron. Astrophys. 15, 45.

    Google Scholar 

  • Speich, D. M., Smith, J. R., Jr., Wilson, R. M., and McIntosh, P. S.: 1978, NASA TM-78166, Marshall Space Flight Center, Alabama, 25 pp.

    Google Scholar 

Download references

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Joshi, A. Coronal Holes and Flare Index: A correlation study. Solar Physics 198, 149–161 (2001). https://doi.org/10.1023/A:1005208028228

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  • DOI: https://doi.org/10.1023/A:1005208028228

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