STATISTICAL MAPS OF FIELD-ALIGNED CURRENTS INFERRED FROM SWARM: DEPENDENCE ON SEASON AND INTERPLANETARY MAGNETIC FIELD
Abstract and keywords
Abstract (English):
We report the initial results of the statistical analysis of field-aligned currents FACs observed above the ionosphere by the~low-Earth polar-orbiting Swarm satellite. FACs are the main electrodynamic agent of the solar wind-magnetosphere-ionosphere coupling. FACs flow along the high-conducting geomagnetic field lines between the magnetospheric boundary layers and the auroral ionosphere. A series of the~Swarm-based statistical maps of large-scale FACs~are constructed, resolving the seasonal dependences of the FAC distribution under conditions of the northward and southward interplanetary magnetic field IMF, low solar activity and the total IMF strength of 1-2~nT on average. The conventional R0/R1/R2 system is the dominant feature in the dark and sunlit polar ionosphere. The upward/downward current densities are well balanced within a given hemisphere, demonstrating a reasonable rate of elevation, going from winter to summer and from positive to negative IMF. The FAC intensities are larger by a factor of 1.6 in the summer hemisphere in comparison to the winter hemisphere.

Keywords:
solar wind-magnetosphere-ionosphere interaction, field-aligned currents, statistical maps, Swarm satellites
Text
Publication text (PDF): Read Download
References

1. Anderson, B. J., Takahashi, K., Toth, B. A. Sensing global Birkeland currents with Iridium engineering magnetometer data, // Geophysical Research Letters, 2000. - v. 27 - no. 24 - p. 4045.

2. Anderson, B. J., Korth, H., Waters, C. L., et al. Statistical Birkeland current distributions from magnetic field observations by the Iridium constellation, // Annales Geophysique, 2008. - no. 26 - p. 671.

3. Birkeland, K. The Norwegian Aurora Polaris Expedition 1902#x2013;1903 - Christiania, Norway: H. Aschelhoug ampersand Co.., 1908. - 994 pp.

4. Bythrow, P. F., Potemra, T. A., Erlandson, R. E., et al. Birkeland currents and charged particles in the high-latitude prenoon region: A new interpretation, // Journal of Geophysical Research, 1988. - v. 93 - no. A9 - p. 9791.

5. Christiansen, F., Papitashvili, V. O., Neubert, T. Seasonal variations of high-latitude field-aligned currents inferred from \Orsted and Magsat observations, // Journal of Geophysical Research, 2002. - v. 107 - no. A2 - p. SMP 5-1.

6. Edwards, T. R., Weimer, D. R., Tobiska, W. K., et al. Field-aligned current response to solar indices, // Journal of Geophysical Research: Space Physics, 2017. - v. 122 - no. 5 - p. 5798.

7. Farthing, W. H., Sugiura, M., Ledley, B. G., et al. Magnetic field observations on DE-A and -B, // Space Science Instrumentation, 1981. - v. 5 - p. 551.

8. Fujii, R., Iijima, T., Potemra, T.A., Sugiura, M. Seasonal dependence of large-scale Birkeland currents, // Geophysical Research Letters, 1981. - v. 8 - no. 10 - p. 1103.

9. Fukushima, N. Generalized theorem for no ground magnetic effect of vertical currents connected with Pedersen currents in the uniform-conductivity ionosphere, // Report of Ionosphere and Space Research in Japan, 1976. - v. 30 - no. 1#x2013;2 - p. 35.

10. Gvishiani, A. D., Lukianova, R. Yu. Geoinformatics and Observations of the Earth's Magnetic Field: The Russian Segment, // Izvestiya: Physics of the Solid Earth, 2015. - v. 51 - no. 2 - p. 157.

11. Haraguchi, K., Kawano, H., Yumoto, K., Ohtani, S., Higuchi, T., Ueno, G. Ionospheric conductivity dependence of dayside region-0, 1, and 2 field-aligned current systems: statistical study with DMSP-F7, // Annales Geophysicae, 2004. - no. 22 - p. 2775.

12. He, M., Vogt, J., L#xFC;hr, H., Sorbalo, E., Blagau, A., Le, G., Lu, G. A high-resolution model of field-aligned currents through empirical orthogonal functions analysis MFACE, // Geophysical Research Letters, 2012. - v. 39 - no. 18 - p. L18105 1.

13. Iijima, T., Potemra, T. A. The amplitude distribution of field-aligned currents of northern high latitudes observed by Triad, // Journal of Geophysical Research, 1976. - v. 81 - no. 13 - p. 2165.

14. Korth, H., Anderson, B. J., Waters, C. L. Statistical analysis of the dependence of large-scale Birkeland currents on solar wind parameters, // Annales Geophysicae, 2010. - v. 28 - no. 2 - p. 515.

15. Langel, R. A., Estes, R. H. The near-earth magnetic field at 1980 determined from Magsat data, // Journal of Geophysical Research: Solid Earth, 1985. - v. 90 - no. B3 - p. 2495.

16. Lui, A. T. Y. Current disruption in the Earth's magnetosphere: Observations and models, // Journal of Geophysical Research: Space Physics, 1996. - v. 101 - no. A6 - p. 13067.

17. Lukianova, R., Hanuise, C., Christiansen, F. Asymmetric distribution of the ionospheric electric potential in the opposite hemispheres as inferred from the SuperDARN observations and FAC-based convection model, // Journal Atmospheric and Solar-Terrestrial Physics, 2008. - no. 70 - p. 2324.

18. Lukianova, R. Yu., Kozlovsky, A., Christiansen, F. Asymmetric structures of field-aligned currents and convection of ionospheric plasma controlled by the IMF azimuthal component and season of year, // Geomagnetism and Aeronomy, 2010. - v. 50 - no. 5 - p. 667.

19. Lukianova, R., Kozlovsky, A. IMF $B_y$ effects in the plasma flow at the polar cap boundary, // Annales Geophysicae, 2011. - v. 29 - no. 7 - p. 1305.

20. McGranaghan, R. M., Mannucci, A. J., Forsyth, C. A comprehensive analysis of multiscale field-aligned currents: Characteristics, controlling parameters, and relationships, // Journal of Geophysical Research: Space Physics, 2017. - v. 122 - no. 12 - p. 11,931.

21. Neubert, T., Mandea, M., Hulot, G., von Frese, R., Primdahl, F. , et al., \Orsted satellite captures high-precision geomagnetic field data, // Eos Trans. AGU, 2001. - v. 82 - no. 7 - p. 81.

22. Olsen, N., Friis-Christensen, E., Floberghagen, R., et al., The SWARM satellite constellation application and research facility SCARF and SWARM data products, // Earth, Planets and Space, 2013. - no. 65 - p. 1189.

23. Papitashvili, V. O., Christiansen, F., Neubert, T. A new model of field-aligned currents derived from high-precision satellite magnetic field data, // Geophysical Research Letters, 2002. - v. 29 - no. 12 - p. 28-1.

24. Reigber, C., L#xFC;hr, H., Schwintzer, P., Wickert, J. Earth Observation with CHAMP. Results from Three Years in Orbit - Berlin, Germany: Springer-Verlag., 2004. - 629 pp.

25. Ritter, P., L#xFC;hr, H., Rauberg, J. Determining field-aligned currents with the Swarm constellation mission, // Earth, Planets and Space, 2013. - no. 65 - p. 1285.

26. Robinson, R. M., Vondrak, R. R. Measurements of $E$ region ionization and conductivity produced by solar illumination at high latitudes, // Journal of Geophysical Research: Space Physics, 1984. - v. 89 - no. A6 - p. 3951.

27. Ruohoniemi, J. M., Greenwald, R. A. Dependencies of high-latitude plasma convection: Consideration of IMF, seasonal, and UT factors in statistical patterns, // Journal of Geophysical Research, 2005. - v. 110 - no. A9 - p. A09204 1.

28. Siscoe, G., Maynard, N. Distributed two-dimensional region 1 and Region 2 currents: Model results and data comparisons, // Journal of Geophysical Research: Space Physics, 1991. - v. 96 - no. A12 - p. 21071.

29. Swarm Level 2 Processing System Consortium., Detailed Processing Model DPM FAC - Potsdam, Germany: GFZ., 2012.

30. Weimer, D. R. Maps of ionospheric field-aligned currents as a function of the interplanetary magnetic field derived from Dynamics Explorer 2 data, // Journal of Geophysical Research: Space Physics, 2001. - v. 106 - no. A7 - p. 12889.

31. Xiong, C., L#xFC;hr, H., Wang, H., Johnsen, M. G. Determining the boundaries of the auroral oval from CHAMP field-aligned current signatures~#x2013;~Part 1, // Annales Geophysicae, 2014. - v. 32 - no. 6 - p. 609.

32. Zanetti, L.J., Potemra, T.A., Iijima, T., et al. Ionospheric and Birkeland current distributions for northward interplanetary magnetic field - inferred polar convection, // Journal of Geophysical Research: Space Physics, 1984. - v. 89 - no. A9 - p. 7453.

Login or Create
* Forgot password?