Skip to main content
  • Article
  • Published:

Auroral electrojet oval

Abstract

The auroral electrojet is enhanced in the polar ionosphere associated with charged particle precipitation and field-aligned currents during substorms. In this paper the geometry of the elctrojet is determined by using the ionospheric equivalent current systems for every 5 minutes during March 18 and 19, 1978. The latitudinal and local time shifts of the oval are examined. Possible relationship of the electrojet oval with expansion of the auroral oval and the field-aligned current belts during substorms are discussed. The electrojet oval in the polar region consists of westward and eastward electrojets, varying with AE index. As the magnetic activity increases, the westward electrojet has distinct latitudinal shifts in different local time sectors: it shifts poleward around the midnight (23:00-03:00 MLT), while moves equatorward in the morning sector (03:00-10:00 MLT) and afternoon sector (20:00-23:00 MLT. The eastward electrojet includes two insulated parts: a higher-latitude part around 80° latitude in the nighttime sector (21:00-03:00 MLT) and a lower-latitude part between 60°–70° latitudes in other local time sectors. As AE index increases, the higher-latitude part of the eastward electrojet expands eastward from 03:00 to 08:00 MLT, while the lower-latitude part shows a equatorward shift in the afternoon sector, which is more or less similar to the westward electrojet.

References

  • Akasofu, S.-I., Magnetospheric substorms: A model, in Solar-Terrestrial Physics, Part 3, edited by E. R. Dyer, 131 pp., D. Reidel, Norwell, Mass., 1972.

    Google Scholar 

  • Akasofu, S.-I., B. H. Ahn, Y. Kamide, and J. H. Allen, A note on the accuracy of the auroral electrojet indices, J. Geophys. Res., 88, 5769–5772, 1983.

    Article  Google Scholar 

  • Atkinson, G. J., An approximate flow equation for geomagnetic flux tubes and its application to polar substorms, J. Geophys. Res., 72, 5373–5382, 1967.

    Article  Google Scholar 

  • Feldstein, Y. I., A. Grafe, L. I. Gromova, and V. A. Popov, Auroral electrojets during geomagnetic storms, J. Geophys. Res., 102, 14223–14235, 1997.

    Article  Google Scholar 

  • Greenwald, R. A., K. B. Baker, J. R. Dudeney, M. Pinnock, T. B. Jones, E. C. Thomas, J.-P. Villain, J.-C. Cerisier, C. Senior, C. Hanuise, R. D. Hunsucker, G. Sofko, J. Koehler, E. Nielsen, R. Pellinen, A. D. M. Walker, N. Sato, and H. Yamagishi, DARN/SuperDARN, Space Sci. Rev., 71(1-4), 761–791, 1995.

    Article  Google Scholar 

  • Iijima, T. and T. A. Potemra, The amplitude distribution of field-aligned currents at northern high latitudes observed by Triad, J. Geophys. Res., 81, 2165–2174, 1976a.

    Article  Google Scholar 

  • Iijima, T. and T. A. Potemra, Field-aligned currents in the dayside cusp observed by Triad, J. Geophys. Res., 81, 5971–5979, 1976b.

    Article  Google Scholar 

  • Iijima, T. and T. A. Potemra, Large-scale characteristics of field-aligned currents associated with substorms, J. Geophys. Res., 83, 599–615, 1978.

    Article  Google Scholar 

  • Kamide, Y., Electrodynamic processes, in The Earth’s Ionosphere and Magnetosphere, Kyoto Sangyo University Press, Kyoto, Japan, pp. 156–189, 1988.

    Google Scholar 

  • Kamide, Y. and S.-I. Akasofu, Latitudinal cross section of the auroral electrojet and its relation to the interplanetary magnetic field polarity, J. Geo-phys. Res., 79, 3755–3771, 1974.

    Article  Google Scholar 

  • Kamide, Y. and S.-I. Akasofu, Notes on the auroral electrojet indices, Rev. Geophys., 21, 1647–1665, 1983.

    Article  Google Scholar 

  • Kamide, Y. and S. Matsushita, Simulation studies of ionospheric electric fields and currents in relation to field-aligned currents, 1. Quiet periods, J. Geophys. Res., 84, 4083–4098, 1979a.

    Article  Google Scholar 

  • Kamide, Y. and S. Matsushita, Simulation studies of ionospheric electric fields and currents in relation to field-aligned currents, 2. Substorms, J. Geophys. Res., 84, 4099–4115, 1979b.

    Article  Google Scholar 

  • Kamide, Y., et al., Global distribution of ionospheric and field-aligned currents during substorm as determined from six IMS meridian chains of magnetometers: initial results, J. Geophys. Res., 87, 8228–8240, 1982a.

    Article  Google Scholar 

  • Kamide, Y., et al., Changes in the global electric fields and currents for March 17–19, 1978 from six IMS meridian chains of magnetometers, Rep. UAG-87, World Data Center A, Boulder, Colo., 1982b.

  • Lu, G., et al., Interhemispheric asymmetry of the high-latitude ionospheric convection pattern, J. Geophys. Res., 99, 6491–6510, 1994.

    Article  Google Scholar 

  • Lui, A. T. Y., Current controversies in magnetospheric physics, Rev. Geophys., 39, 535–563, 2001.

    Article  Google Scholar 

  • Matsushita, S. and W.-Y. Xu, Equivalent ionospheric current systems representing solar daily variations of the polar geomagnetic field, J. Geophys. Res., 87, 8241–8254, 1982.

    Article  Google Scholar 

  • McPherron, R. L., C. T. Russell, and M. P. Aubry, Satellite studies of magnetospheric substorm on August 15, 1968, 9. Phenomenological model for substorm, J. Geophys. Res., 78, 3131–3149, 1973.

    Article  Google Scholar 

  • Newell, P. T., The role of the ionosphere in aurora and space weather, Rev. Geophys., 39, 137–149, 2001.

    Article  Google Scholar 

  • Richmond, A. D., Assimilative mapping of ionospheric electrodynamics, Adv. Space Res., 12, 59–68, 1992.

    Article  Google Scholar 

  • Sun, W., W.-Y. Xu, and S.-I. Akasofu, Mathematical separation of directly driven and unloading components in the ionospheric equivalent currents during substorms, J. Geophys. Res., 103, 11695–11700, 1998.

    Article  Google Scholar 

  • Sun, W., W.-Y. Xu, and S.-I. Akasofu, An improved method to deduce the unloading component for magnetospheric substorms, J. Geophys. Res., 105, 13131–13140, 2000.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Geng-Xiong Chen.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chen, GX., Xu, WY., Wei, ZG. et al. Auroral electrojet oval. Earth Planet Sp 55, 255–261 (2003). https://doi.org/10.1186/BF03351757

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03351757

Key words