Articles | Volume 17, issue 12
Ann. Geophys., 17, 1503–1512, 1999

Special issue: Equator S

Ann. Geophys., 17, 1503–1512, 1999

  31 Dec 1999

31 Dec 1999

EDI convection measurements at 5-6 RE in the post-midnight region

J. M. Quinn1, G. Paschmann2, N. Sckopke2, V. K. Jordanova1, H. Vaith2, O. H. Bauer2, W. Baumjohann2, W. Fillius3, G. Haerendel2, S. S. Kerr3, C. A. Kletzing4, K. Lynch1, C. E. McIlwain3, R. B. Torbert1, and E. C. Whipple5 J. M. Quinn et al.
  • 1Space Science Center, Morse Hall, University of New Hampshire, Durham, NH, 03824, USA
  • 2Max-Planck-Institut f. extraterrestrische Physik, 85740 Garching, Germany
  • 3Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
  • 4Department of Physics and Astronomy, University of Iowa, Iowa City, IO, 52242, USA
  • 5Geophysics Program, University of Washington, Seattle, WA, 98195, USA

Abstract. We present the first triangulation measurements of electric fields with the electron drift instrument (EDI) on Equator-S. We show results from five high-data-rate passes of the satellite through the near-midnight equatorial region, at geocentric distances of approximately 5–6 RE, during geomagnetically quiet conditions. In a co-rotating frame of reference, the measured electric fields have magnitudes of a few tenths of mV/m, with the E × B drift generally directed sunward but with large variations. Temporal variations of the electric field on time scales of several seconds to minutes are large compared to the average magnitude. Comparisons of the "DC" baseline of the EDI-measured electric fields with the mapped Weimer ionospheric model and the Rowland and Wygant CRRES measurements yield reasonable agreement.

Key words. Magnetospheric physics (electric fields; plasma convection; instruments and techniques)

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