Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.490 IF 1.490
  • IF 5-year value: 1.445 IF 5-year
    1.445
  • CiteScore value: 2.9 CiteScore
    2.9
  • SNIP value: 0.789 SNIP 0.789
  • IPP value: 1.48 IPP 1.48
  • SJR value: 0.74 SJR 0.74
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 88 Scimago H
    index 88
  • h5-index value: 21 h5-index 21
Volume 26, issue 10
Ann. Geophys., 26, 2975–2982, 2008
https://doi.org/10.5194/angeo-26-2975-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: SOHO 20 – Transient events on the Sun and in the...

Ann. Geophys., 26, 2975–2982, 2008
https://doi.org/10.5194/angeo-26-2975-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

  15 Oct 2008

15 Oct 2008

Non-thermal particle effects on the Hα and Hβ line profiles in the 18 August 2002 solar flare

L. K. Kashapova1, P. Kotrč2, and Yu. A. Kupryakov2,3 L. K. Kashapova et al.
  • 1Institute of Solar-Terrestrial Physics, Irkutsk, Russia
  • 2Astronomical Institute, Ondřejov, Czech Republic
  • 3GAISH, MGU, Moscow, Russia

Abstract. We present results of the 18 August 2002 flare analysis as an example for developing a diagnostic tool for thermal and non-thermal processes in chromospheric lines. Taking into account the hard X-ray (HXR) emission, we attempted to derive the Hα and Hβ line properties which were caused by the non-thermal electron contribution and could be useful for diagnostic purposes. The flare itself was a sequence of harder and softer bursts in HXR and we investigated three flare kernels associated with them. Two of the kernels appeared simultaneously. This phase of the flare could be observed in a broad band of wavelengths (HXR, UV, optical and microwaves). Kernel 1 did not clearly coincide with any HXR source but its intensity increased with the HXR flux rise. The flare kernel~3 did not show any significant response in microwaves, however, the related HXR flux was comparable with the flux of the previous kernels. We carried out an analysis of the difference between the Hα/Hβ profile rate in the line center at the distance of 0.5 Å from the line center. Only kernel 2 showed parameter fluctuations that were related to HXR flux evolution. The supposition of the non-thermal electron effect on the Hα/Hβ profile ratio was confirmed only at the kernel connected with the 25–50 keV HXR source. We found further confirmation that the Hα/Hβ line intensity ratio could be used as a diagnostic tool for non-thermal electron presence.

Publications Copernicus
Download
Citation