Articles | Volume 43, issue 2
https://doi.org/10.5194/angeo-43-447-2025
https://doi.org/10.5194/angeo-43-447-2025
Regular paper
 | 
27 Aug 2025
Regular paper |  | 27 Aug 2025

Small-scale and mesoscale field-aligned auroral current structures: their spatial and temporal characteristics deduced by the Swarm constellation

Hermann Lühr and Yun-Liang Zhou

Related authors

Properties of large-amplitude kilometer-scale field-aligned currents at auroral latitudes, as derived from Swarm satellites
Yun-Liang Zhou and Hermann Lühr
Ann. Geophys., 43, 667–686, https://doi.org/10.5194/angeo-43-667-2025,https://doi.org/10.5194/angeo-43-667-2025, 2025
Short summary

Cited articles

Ala-Lahti, M., Pulkkinen, T. I., Pfau-Kempf, Y., Grandin, M., and Palmroth, M.: Energy flux through the magnetopause during flux transfer events in hybrid-Vlasov 2D simulations, Geophys. Res. Lett., 49, e2022GL100079, https://doi.org/10.1029/2022GL100079, 2022. 
Anderson, B. J., Korth, H., Waters, C. L., Green, D. L. Merkin, V. G., Barnes, R. J., and Dyrud, L. P.: Development of large-scale Birkeland currents determined from the active magnetosphere and planetary electrodynamics experiment, Geophys. Res. Lett., 41, 3017–3025, https://doi.org/10.1002/2014GL059941, 2014. 
Finlay, C. C., Kloss, C., Olsen, N., Hammer, M., Toeffner-Clausen, L., Grayver, A., and Kuvshinov, A.: The CHAOS-7 geomagnetic field model and observed changes in the South Atlantic Anomaly, Earth Planets Space, 72, 156, https://doi.org/10.1186/s40623-020-01252-9, 2020. 
Forsyth, C., Rae, I. J., Mann, I. R., and Pakhotin, I. P.: Identifying intervals of temporally invariant field-aligned currents from Swarm: Assessing the validity of single-spacecraft methods, J. Geophys. Res.-Space Phys., 122, 3411–3419, https://doi.org/10.1002/2016JA023708, 2017. 
Friis-Christensen, E., McHenry, M. A., Clauer, C. R., and Venneström, S.: Ionospheric traveling convection observed near the polar cleft: a triggered response to sudden changes in the solar wind, Geophys. Res. Lett., 15, 253–256, 1988. 
Short summary
The study makes use of magnetic field data from the closely spaced Swarm A and C spacecraft during the counter-rotating orbit phase. It allows investigating the spatial and temporal correlation lengths of small-scale and mesoscale FAC (field-aligned current) structures at auroral latitudes. Stationarity features of small-scale FACs (10–50 km scale size) are temporal length < 18 s and correlation length < 12 km. For mesoscale FACs (75–220 km scales) we obtain a stability of > 40 s and correlation length > 20 km.
Share