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Auroral substorm dynamics and field line resonances


Magnetospheric substorms frequently have oscillating auroral phenomena associated with them, and which may be related to field line resonances. In this paper we present an analysis of photometer data which displays such oscillations in luminosity. We use data from the Gillam station in the CANOPUS array for April 1, 2000. Clear pulsations in magnetometer and photometer data are observed at 2.2 mHz. The latitudinal distribution of the photometer pulsations indicates that the auroral luminosity variations, caused by precipitating electrons and protons, are modulated by large scale global compressional modes (field line resonances). The proton and electron auroras were found to oscillate essentially out of phase. As well, the variation of phase across the peak in the luminosity resonance follows the pattern expected for the coupling of resonant Alfve’n modes by normal compressional modes in the magnetotail.


  • Berger, S., Giant pulsations in the magnetic field and pulsating aurora, Planet. Space Sci., 11, 867, 1963.

    Article  Google Scholar 

  • Block, L. P. and C. G. Fälthammer, The role of magnetic field-aligned electric fields in auroral acceleration, J. Geophys. Res., 95, 5877, 1990.

    Article  Google Scholar 

  • Chen, L. and A. Hasegawa, A theory of long-period magnetic pulsations, 1, Steady excitation of field line resonances, J. Geophys. Res., 79, 1024, 1974.

    Article  Google Scholar 

  • Davidson, G. T., Pitch-angle diffusion and the origin of temporal and spatial structures in morningside aurorae, Space Sci. Rev., 53, 45, 1990.

    Article  Google Scholar 

  • Fenrich, F. R., et al., ULF high and low-m field line resonances observed with SuperDARN, J. Geophys. Res., 100, 21535, 1995.

    Article  Google Scholar 

  • Goertz, C. K. and R. W. Boswell, Magnetosphere-ionosphere coupling, J. Geophys. Res., 84, 7239, 1979.

    Article  Google Scholar 

  • Hasegawa, A., Particle acceleration by MHD surface wave and formation of aurora, J. Geophys. Res., 81, 5083, 1976.

    Article  Google Scholar 

  • Hughes, W. J., Hydromagnetic waves in the magnetosphere, in Solar-Terrestrial Physics: Principles and Foundations, edited by R. L. Carovillano and J. M. Forbes, D. Reidel, Norwell, Mass., 1983.

    Google Scholar 

  • Jacobs, J. A., et al, Classification of geomagnetic micropulsations, J. Geophys. Res., 69, 180, 1964.

    Article  Google Scholar 

  • Keiling, A., et al, Large Alfvén wave power in the plasma sheet boundary layer during the expansion phase of substorms, Geophys. Res. Lett, 27, 3169, 2000.

    Article  Google Scholar 

  • Liu, W. W., et al, Theory and observation of auroral substorms: a magnetohydrodynamic approach, J. Geophys. Res., 100, 79, 1995.

    Article  Google Scholar 

  • Lyatsky, W., et al, Field line resonance interference model for multiple auroral arc generation, J. Geophys. Res., 104, 263, 1999.

    Article  Google Scholar 

  • McDiarmid, D. R., et al, Simultaneous observation of a traveling vortex structure in the morning sector and a field line resonance in the postnoon sector, J. Geophys. Res., 99, 8891, 1994.

    Article  Google Scholar 

  • Milan, S. E., et al, Auroral forms and the field-aligned current structure associated with field line resonances, J. Geophys. Res., 106, 25825, 2001.

    Article  Google Scholar 

  • Rankin, R., et al, Shear flow vortices in magnetospheric plasmas, Phys. Plasmas, 4, 829, 1997.

    Article  Google Scholar 

  • Rostoker, G., et al, CANOPUS—a ground-based instrument array for remote sensing the high latitude ionosphere during the ISTP/GGS program, Space Sci. Rev., 71, 743–760, 1995.

    Article  Google Scholar 

  • Samson, J. C., et al, Substorm intensifications and field line resonances in the nightside magnetosphere, J. Geophys. Res., 97, 8495, 1992.

    Article  Google Scholar 

  • Samson, J. C., etal, Observations of field line resonances, auroral arcs, and auroral vortex structure, J. Geophys. Res., 101, 17373–17383, 1996.

    Article  Google Scholar 

  • Southwood, D. J., Some features of field line resonances in the magnetosphere, Planet. Space Sci., 22, 483, 1974.

    Article  Google Scholar 

  • Voronkov, I., et al, Dynamics of the substorm growth phase as observed using CANOPUS and SuperDARN instruments, J. Geophys. Res., 104, 28491–28505, 1999.

    Article  Google Scholar 

  • Walker, A. D. M., et al., STARE auroral radar observations of Pc 5 geomagnetic pulsations, J. Geophys. Res., 84, 3373, 1979.

    Article  Google Scholar 

  • Wanliss, J. A., et al., On the use of photometer data to map dynamics of the magnetotail current sheet during substorm growth phase, J. Geophys. Res., 105, 27673–27684, 2000.

    Article  Google Scholar 

  • Wanliss, J. A., et al., Field line resonances in a stretched magnetotail: CANOPUS optical and magnetometer observations, J. Geophys. Res., 2002 (in press).

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Correspondence to James A. Wanliss.

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Wanliss, J.A., Rankin, R. Auroral substorm dynamics and field line resonances. Earth Planet Sp 54, 927–932 (2002).

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  • Line Resonance
  • Photometer Data
  • Compressional Mode
  • Plasma Sheet Boundary Layer
  • Field Line Resonance