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

Journal metrics

Journal metrics

  • IF value: 1.621 IF 1.621
  • IF 5-year value: 1.614 IF 5-year
  • CiteScore value: 1.61 CiteScore
  • SNIP value: 0.900 SNIP 0.900
  • SJR value: 0.910 SJR 0.910
  • IPP value: 1.58 IPP 1.58
  • h5-index value: 24 h5-index 24
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 80 Scimago H
    index 80
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 26 Mar 2019

Regular paper | 26 Mar 2019

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

Swarm field-aligned currents during a severe magnetic storm of September 2017

Renata Lukianova1,2 Renata Lukianova
  • 1Space Research Institute, 117997 Moscow, Russia
  • 2Institute of Earth Science, Saint Petersburg State University, 199034 Saint Petersburg, Russia

Abstract. Swarm satellites observations are used to characterize the extreme behavior of large- and small-scale field-aligned currents (FACs) during the severe magnetic storm of September 2017. Evolution of the current intensities and the equatorward displacement of FACs are analyzed while the satellites cross the pre-midnight, pre-noon, dusk and dawn sectors in both hemispheres. The equatorward boundaries of FACs mainly follow the dynamics of ring current (as monitored in terms of the SYM-H index). The minimum latitude of the FAC boundaries is limited to 50° MLat, below which saturation occurs. The FAC densities are very variable and may increase dramatically, especially in the nightside ionosphere during the storm-time substorms. At the peak of substorm, the average FAC densities reach 3 μA/m2, while the quite level is below 0.1 μA/m2. The dawn–dusk asymmetry is manifested in the enhanced dusk-side R2 FACs in both hemispheres. Filamentary high-density structures are always observed confirming that a substantial fraction of R1/R2 FACs is composed of many small-scale currents. In the pre-noon sector, the bipolar structures (7.5 km width FACs of opposite polarities adjacent to each other) dominate, while in the post-midnight sector the upward and downward FACs tend to form more latitudinally extended structures of a certain polarity. The most intense small-scale FACs (up to ~80 μA/m2) is observed just in the post-midnight sector. Simultaneous magnetic and plasma perturbations indicate that this structure is likely a current system of a mesoscale auroral arc.

Renata Lukianova
Interactive discussion
Status: open (until 07 May 2019)
Status: open (until 07 May 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Renata Lukianova
Renata Lukianova
Total article views: 145 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
111 33 1 145 2 1
  • HTML: 111
  • PDF: 33
  • XML: 1
  • Total: 145
  • BibTeX: 2
  • EndNote: 1
Views and downloads (calculated since 26 Mar 2019)
Cumulative views and downloads (calculated since 26 Mar 2019)
Viewed (geographical distribution)  
Total article views: 102 (including HTML, PDF, and XML) Thereof 102 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 21 Apr 2019
Publications Copernicus
Short summary
During the most intense storm of the solar cycle 24, the magnetosphere-ionosphere interaction, which is primarily associated with field-aligned currents (FAC) and particle precipitation, was much stronger than usual. Measurements onboard the polar-orbiting satellite show that the equatorial boundaries of FAC are shifted equatorward as low as 50° MLat. The intensities of FAC increase dramatically the peaks of the storm-time substorm. The extreme instantaneous FACs is up to ~80 μA/m2.
During the most intense storm of the solar cycle 24, the magnetosphere-ionosphere interaction,...