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

Journal metrics

Journal metrics

  • IF value: 1.585 IF 1.585
  • IF 5-year value: 1.698 IF 5-year
  • CiteScore value: 1.62 CiteScore
  • SNIP value: 0.820 SNIP 0.820
  • IPP value: 1.52 IPP 1.52
  • SJR value: 0.781 SJR 0.781
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 83 Scimago H
    index 83
  • h5-index value: 24 h5-index 24
Discussion papers
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Regular paper 17 Apr 2019

Regular paper | 17 Apr 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Annales Geophysicae (ANGEO).

Strong influence of solar X-ray flares on low-frequency electromagnetic signals in middle latitudes

Alexandr Rozhnoi1, Mariya Solovieva1, Viktor Fedun2, Peter Gallagher3, Joseph McCauley3, Mohammed Y. Boudjada4, Sergiy Shelyag5, and Hans U. Eichelberger4 Alexandr Rozhnoi et al.
  • 1Schmidt Institute of Physics of the Earth of RAS, 10-1 B. Gruzinskaya Str., 123242 Moscow, Russia
  • 2Plasma Dynamics Group, Department of Automatic Control and Systems Engineering, University of Sheffield, Mappin 6 Str., Sheffield, S1 3JD, UK
  • 3Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
  • 4Space Research Institute of AAS, Schmiedlstrase 6, 8042 Graz, Austria
  • 5School of Information Technology, Deakin University, Geelong, Australia

Abstract. In this paper we analysed Sudden Phase Anomalies (SPAs) of VLF/LF signals recorded at Graz (Austria), Birr (Ireland) and Moscow (Russia) stations during two strong solar flares in September 2017. The first X-class 9.3 flare occurred on 6 September at 12:02 UT and the second X-class 8.2 flare was observed on 10 September 2017 at 16:06 UT. Data from seven transmitters in a frequency range between 20–45 kHz are used for the analysis. The SPAs were observed in all middle-latitudes paths (differently orientated) with path lengths from 350 km to 7000 km. Solar X-ray burst data were taken from GOES satellite observations in the wavelength band of 0.05–0.4 nm. If was found that (i) the amplitude of SPAs in different paths varies from 10 to 282 degrees, and (ii) the correlation between the amplitudes of SPAs, the lengths of paths and the signal frequency is weak. The change in effective height of reflection due to lowering of the reflecting layer during the flares was found to be about 12 km for the first event and about 9 km for the second event. Spectral analysis of the X-ray and LF data, filtered in the range between 5 s and 16 min, showed that the LF signal spectra are very similar to X-ray spectra. Maxima of both X-ray and LF spectra are in 2–16 min interval.

Alexandr Rozhnoi et al.
Interactive discussion
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Topical Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Alexandr Rozhnoi et al.
Alexandr Rozhnoi et al.
Total article views: 174 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
126 46 2 174 2 1
  • HTML: 126
  • PDF: 46
  • XML: 2
  • Total: 174
  • BibTeX: 2
  • EndNote: 1
Views and downloads (calculated since 17 Apr 2019)
Cumulative views and downloads (calculated since 17 Apr 2019)
Viewed (geographical distribution)  
Total article views: 159 (including HTML, PDF, and XML) Thereof 156 with geography defined and 3 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 21 Jul 2019
Publications Copernicus