Skip to main content
SpringerLink
Log in

The solar Ca II K index and the Mg II core-to-wing ratio

  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

The 1 Å index of the solar Ca II K line is compared with the core-to-wing ratio of satellite measurements of the Mg II h and k lines. The correlation coefficient r = 0.976 for the Nimbus-7 Mg II ratio during solar cycle 21 andr = 0.99 for the NOAA9 Mg II ratio in cycle 22. Linear regression analysis for the full dynamic range of both data sets is used to combine the Nimbus-7 and NOAA9 Mg II data. These relations permit the ground-based Ca K index to estimate the solar UV flux.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Allen, M. S., McAllister, H. C., and Jefferies, J. T.: 1978, High Resolution Atlas of the Solar Spectrum 2678–2931 A, Inst. Astron., U. Hawaii, Honolulu, Hawaii, 58 pp.

    Google Scholar 

  • Avrett, E. H.: 1992, in R. F. Donnelly (ed.), Proc. of the Workshop on the Solar Electromagnetic Radiation Study for Solar Cycle 22, Space Environment Lab., NOAA ERL, Boulder, Colo., 20.

    Google Scholar 

  • Donnelly, R. F.: 1991, J. Geomagnet. Geoelectr. 43, Suppl., 835.

    Google Scholar 

  • Fredga, K.: 1971, Solar Phys. 21, 60.

    Google Scholar 

  • Hall, L. A., and Anderson, G. P.: 1988, Ann. Geophys. 6, 531.

    Google Scholar 

  • Heath, D. F. and Schlesinger, B. M.: 1986, J. Geophys. Res. 91, 8672.

    Google Scholar 

  • Lemaire, P.: 1984, Adv. Space Res. 4, (8)29.

    Google Scholar 

  • White, O. R. and Livingston, W. C.: 1981, Astrophys. J. 249, 798.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Space Environment Lab., NOAA ERL, 80303, Boulder, CO, USA

    R. F. Donnelly

  2. High Altitude Observatory, NCAR, 80307, Boulder, CO, USA

    O. R. White

  3. National Solar Observatory, NOAO, 85726, Tucson, AZ, USA

    W. C. Livingston

Authors
  1. R. F. Donnelly
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. O. R. White
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. W. C. Livingston
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Donnelly, R.F., White, O.R. & Livingston, W.C. The solar Ca II K index and the Mg II core-to-wing ratio. Sol Phys 152, 69–76 (1994). https://doi.org/10.1007/BF01473185

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01473185

Keywords

Search

Navigation