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Initial observations of auroras by the multi-spectral auroral camera on board the Reimei satellite


The small Japanese scientific satellite Reimei was launched successfully from Baikonur Space Center into a sun-synchronous (noon-midnight meridian) polar orbit at an altitude of 630 km on August 23, 2005. Auroral fine structure observations have been performed by the multi-spectral auroral camera (MAC) and electron/ion spectrum analyzers (ESA/ISA) on board Reimei. The MAC is a three channel camera system used to simultaneously observe the temporal dynamics of the auroral fine structure at the wavelengths of 428 nm (N2+ 1NG), 558 nm (O), and 670 nm (N2 1PG). Since its successful launch, Reimei has been operated continuously and produced lots of unique data on the auroral fine structures with the MAC and ESA/ISA. The initial observation data from MAC has shown the temporal dynamics of auroral fine structure, such as the vortex street, appearing in the poleward edge of the auroral oval. The significant differences in the auroral shapes between the MAC channels suggest the existence of different emission processes. Further, the height profiles of the aurora and airglow are clearly seen in the image data in the limb direction. It is expected that the various mechanisms and dynamics of auroral fine structures can be investigated by analyzing the Reimei observation data.


  • Asamura, K., D. Tsujita, H. Tanaka, Y. Saito, T. Mukai, and M. Hirahara, Auroral particle instrument onboard the INDEX satellite, Adv. Space Res., 32, 375–378, 2003.

    Article  Google Scholar 

  • Borovsky, J. E., Auroral Arc Thicknesses as Predicted by Various Theories, J. Geophys. Res., 98, 6101–6138, 1993.

    Article  Google Scholar 

  • Carlson, C. W., R. F. Praff, and J. G. Watzin, The fast auroral snapshot (FAST) mission, Geophys. Res. Lett., 25(12), 2013–2016, 1998.

    Article  Google Scholar 

  • Cattell, C., S3-3 Satellite instrumentation and data, in The IMS Source Book, edited by C. Russell and D. Southwood, p. 91, AGU, Washington, D.C., 1982.

    Google Scholar 

  • Frey, H. U., G. Haerendel, J. H. Clemmons, M. H. Bochm, J. Vogt, O. H. Bauer, D. D. Wallis, L. Blomberg, and H. Lühr, Freja and ground-based analysis of inverted-V events, J. Geophys. Res., 103, 4303–4314, 1998.

    Article  Google Scholar 

  • Hoffman, R. A. and E. R. Schmerling, Dynamic Explorer program: An overview, Space Sci. Instrum., 5, 345–348, 1981.

    Google Scholar 

  • Lundin, R., G. Haerendel, and S. Grahn, The Freja project, Geophys. Res. Lett., 21(17), 1823, 1994.

    Article  Google Scholar 

  • Maggs, J. E. and T. N. Davis, Measurements of the thicknesses of auroral structures, Planet. Space Sci., 16, 205, 1968.

    Article  Google Scholar 

  • McFadden, J. P., C. W. Carlson, and R. E. Ergun, Microstructure of the auroral acceleration region as observed by FAST, J. Geophys. Res., 104, 14453–14480, 1999.

    Article  Google Scholar 

  • Oya, H. and K. Tsuruda, Introduction to the Akebono (EXOS-D) satellite observations, J. Geomag. Geoelectr., 42, 367–370, 1990.

    Article  Google Scholar 

  • Saito, H., T. Mizuno, K. Tanaka, Y. Sone, S. Fukuda, S. Sakai, N. Okuizumi, M. Mita, Y. Fukushima, M. Hirahara, K. Asamura, T. Sakanoi, A. Miura, T. Ikenaga, and Y. Masumoto, AN-OVERVIEW AND INITIAL IN-ORBIT STATUS OF “INDEX” SATELLITE, 56th International Astronautical Confernce, IAC-05-B5.6.B.05, 2005.

    Google Scholar 

  • Sakanoi, T., H. Fukunishi, and T. Mukai, Relationship between field-aligned currents and inverted-V parallel potential drops observed at midaltitudes, J. Geophys. Res., 100, 19343–19360, 1995.

    Article  Google Scholar 

  • Sakanoi, T., S. Okano, Y. Obuchi, T. Kobayashi, M. Ejiri, K. Asamura, and M. Hirahara, Development of the multi-spectral auroral camera onboard the INDEX satellite, Adv. Space Res., 32, 379–384, 2003.

    Article  Google Scholar 

  • Schriver, D., M. Ashour-Abdalla, R. J. Strangeway, R. L. Richard, C. Klezting, Y. Dotan, and J. Wygant, FAST/Polar conjunction study of field-aligned auroral acceleration and corresponding magnetotail drivers, J. Geophys. Res., 108, COA21–1, 2003.

    Google Scholar 

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Correspondence to Yasuyuki Obuchi.

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Obuchi, Y., Sakanoi, T., Yamazaki, A. et al. Initial observations of auroras by the multi-spectral auroral camera on board the Reimei satellite. Earth Planet Sp 60, 827–835 (2008).

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