Advertisement

Two-Dimensional Mapping of Dayside Convection

  • J. C. Foster
  • H.-C. Yeh
  • J. M. Holt
  • D. S. Evans
Part of the NATO ASI Series book series (ASIC, volume 278)

Abstract

Millstone Hill radar azimuth scans have been used to map the large-scale features of the ionospheric convection pattern in the vicinity of the cusp and cleft. Each scan covers 5 hours of MLT and 20° of invariant latitude, Λ, with 30 minute temporal resolution Individual “snapshots” of the convection pattern for disturbed conditions on 31 January 1982 span the entire region of convection convergence near noon and compare favorably with average model representations of the dayside region. The characteristic features of ion and electron precipitation observed during satellite overflights of the radar field of view are used to identify the cusp and cleft and to relate the location of these magnetospheric features to the pattern of ionospheric convection electric field. Cusp precipitation is seen at 70°Λ and 09 MLT at the sunward/anti-sunward convection reversal immediately after a sudden turning of interplanetary magnetic field (IMF) By from -5 nT to +5 nT while IMF Bz was-10 nT.

Keywords

Interplanetary Magnetic Field Convection Pattern Electron Precipitation Plasma Convection Ionospheric Convection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. de la Beaujardiere , et al., MITHRAS: a brief description, Radio Science, 19,665,1984.ADSCrossRefGoogle Scholar
  2. Eastman, T. E., E. W. Hones, Jr., S. J. Bame, and J. R. Asbridge, The magnetospheric boundary layer: site of plasma, momentum and energy transfer from the magnetosheath to the magnetosphere, Geophys. Res. Lett., 6,685,1976.ADSCrossRefGoogle Scholar
  3. Foster, J. C., Ionospheric signatures of magnetospheric convection, J. Geophys. Res., 89,855,1984.ADSCrossRefGoogle Scholar
  4. Foster, J. C. and J. R. Doupnik, Plasma convection in the vicinity of the dayside cleft, J. Geophys. Res., 89, 9107,1984.ADSCrossRefGoogle Scholar
  5. Foster, J. C., J. M. Holt, J. D. Kelly, and V. B. Wickwar, High resolution observations of electric fields and F-region plasma parameters in the cleft ionosphere. The Polar Cusp, J. A. Holt et and A. Egeland (eds.), D. Reidel Pub., Dordrecht, 349,1985.Google Scholar
  6. Foster, J. C., T. Turunen, P. Polari, H. Kohl, and V. B. Wickwar, Multi-radar mapping of the auroral ionosphere, Adv. Space Res., in press, 1989a.Google Scholar
  7. Foster, J. C. , Plasma transport through the dayside cleft: a source of ionization patches in the polar cap, in Electromagnetic Coupling in the Polar Clefts and Cap, A. Egeland and P. E. Sandholt (eds.), this volume, 1989b.Google Scholar
  8. Fullcr-Rowell, T. J., and D. S. Evans, Height-integrated Pedersen and Hall conductivity patterns inferred from the TIROS-NOAA satellite data, J. Geophys. Res., 92, 7606,1987.ADSCrossRefGoogle Scholar
  9. Hcelis, R. A., The effects of interplanetary magnetic field orientation on dayside high-latitude ionospheric convcction, J. Geophys. Res., 89, 2873,1984.ADSCrossRefGoogle Scholar
  10. Heelis, R. A., J. D. Winningham, W. B. Hanson, and J. L. Burch, The relationships between high- latitude convection reversals and the energetic particle morphology observed by Atmospheric Explorer, J. Geophys. Res., 85,3315,1980.ADSCrossRefGoogle Scholar
  11. Heikkila, W. J. , Definition of the cusp, The Polar Cusp, J. A. Holtet and A. Egeland (eds.), D. Reidel Pub., Dordrecht, 387,1985.Google Scholar
  12. Holt, J. M., R. H. Wand, and J. V. Evans, Millstone Hill measurements on 26 February 1979 during the solar eclipse and formation of a midday F region trough, J. Atmos. Terr. Phys., 46, 251, 1984.ADSCrossRefGoogle Scholar
  13. Holt, J. M., R. H. Wand, J. V. Evans, and W. L. Oliver, Empirical models for the plasma convection at high latitudes from Millstone Hill observations, J. Geophys. Res., 92, 203,1987.ADSCrossRefGoogle Scholar
  14. McDiarrnid, I. B., J. R. Burrows, and M. D. Wilson, Comparison of magnetic field perturbations at high latitudes with charged particle and IMF measurements, J. Geophys. Res., 83,681,1978.ADSCrossRefGoogle Scholar
  15. Newell, P. T., and C.-I. Meng, The cusp and the dcft/LLBL: low altitude identification and statistical local time variation, J. Geophys. Res., 94, in press, 1989.Google Scholar
  16. Reiff, P. H., T. W. Hill, and J. L. Burch, Solar wind plasma injection at the dayside magnetospheric cusp, J. Geophys. Res., 82, 479, 1977.ADSCrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • J. C. Foster
    • 1
  • H.-C. Yeh
    • 1
  • J. M. Holt
    • 1
  • D. S. Evans
    • 2
  1. 1.M.I.T. Haystack ObservatoryWestfordUSA
  2. 2.NOAA/SELBoulderUSA

Personalised recommendations