Advertisement

Observed Low Frequency Fluctuations in Space

  • Norman F. Ness
Conference paper
Part of the Astrophysics and Space Science Library book series (ASSL, volume 14)

Abstract

Measurements in the magnetosphere of low frequency magnetic fluctuations less than 1 KHz have been obtained recently with the OGO, ATS and IMP series of satellites. The OGO results indicate the existence of magnetically noisy regions of limited spatial extent within the magnetosphere. Fluctuations between 1Hz-1 kHz show two distinct classes of occurrence, steady and burst occurrences. The general character of the steady noise properties is in agreement with lower altitude ELF hiss measurements. The burst events may be associated with whistler loss cone instabilities. Transverse low frequency fluctuations with periods between 1 to 6 min have been observed on the ATS-1 satellite. Monochromatic oscillations of peak amplitude 2–20 gammas appear to represent the second harmonic of a standing Alfvén wave on a field line. Longer period oscillations of 6 or 8 min have also been observed and may represent an eigenmode oscillation of the magnetopause boundary. Compressional oscillations of the geomagnetic tail with periods of ~ 20 min have been observed by Explorer-33 and probably represent the eigenmodes of the geomagnetic tail. A review of observations and theoretical studies of magnetic fluctuations below 1 kc is given in this paper.

Short Bibliography on Observed Low Frequency Fluctuations in Space

  1. Anderson, K. A., Bincsak, J. H., and Fairfield, D. H.: 1968, ‘Evidence for Hydromagnetic Waves of 3 to 5 min Period on the Magnetopause and Their Relation to Bow Shock Spikes’, J. Geophys. Res. 73, 2371.ADSCrossRefGoogle Scholar
  2. Burlaga, L. F.: 1968, ‘Micro-Scale Structures in the Interplanetary Medium’, Solar Phys. 4, 67–92.ADSCrossRefGoogle Scholar
  3. Cummings, W. D., O’Sullivan, R. J., and Coleman, Jr., P. J.: 1968, ‘Standing Alfvén Waves in the Magnetosphere’, UCLA-IGPP Preprint No. 697.Google Scholar
  4. Field, E. C. and Greifinger, C.: 1965, ‘Transmission of Geomagnetic Micropulsations through the Ionosphere and Lower Exosphere’, J. Geophys. Res. 70, 4885–4889.ADSCrossRefGoogle Scholar
  5. Greifinger, C. and Greifinger, P.: 1965, ‘Transmission of Micropulsations through the Lower Ionosphere’, J. Geophys. Res. 70, 2217–2231.ADSCrossRefMathSciNetGoogle Scholar
  6. Holzer, R. E., McLeod, M. G., and Smith, E. J.: 1966, ‘Preliminary Results from the OGO-1 Seareh Coil Magnetometer: Boundary Positions and Magnetic Noise Spectra’, J. Geophys. Res. 71, 1481–1486.ADSCrossRefGoogle Scholar
  7. Holzer, R. E., McLeod, M. G., Olson, J. V., and Russell, C. T.: 1968, ‘The Magnetic Component of Plasma Waves associated with the Interaction of the Magnetosphere and Solar Wind’, presented at International Meeting on Physics of the Magnetosphere, Washington, D.C.Google Scholar
  8. Judge, D. L. and Coleman, P. J.: 1962, ‘Observations of Low Frequency Hydromagnetic Waves in the Distant Geomagnetic Field: Explorer-6’, J. Geophys. Res. 67, 5071–5090.ADSCrossRefGoogle Scholar
  9. Lerche, L: 1966, ‘Validity of the Hydromagnetic Approach in discussing Instability of the Magnetosphere Boundary’, J. Geophys. Res. 71, 2365.ADSCrossRefGoogle Scholar
  10. McClay, J. F. and Radoski, H. R.: 1967, ‘Hydromagnetic Propagation in a Theta Model Geomagnetic Tail’, J. Geophys. Res. 72, 4525–4528.ADSCrossRefGoogle Scholar
  11. McDonald, G. J. F.: 1961, ‘Spectrum of Hydromagnetic Waves in the Exosphere’, J. Geophys. Res. 66, 3639–3671.ADSCrossRefMathSciNetGoogle Scholar
  12. Ness, N. F.: 1968, ‘The Geomagnetic Tail’, 1969, Rev. Geophys. 7, 97–127.ADSCrossRefGoogle Scholar
  13. Patel, V. L.: 1968, ‘Magnetosphere Tail as a Hydromagnetic Waveguide’, Phys. Letters 26A, 596–597.ADSCrossRefGoogle Scholar
  14. Russell, C. T., Holzer, R. E., and Smith, C. J.: 1968, ‘OGO-3 Observations of ELF Noise in the Magnetosphere: Part 1. Spatial Extent and Frequency of Occurrence’, UCLA-IGPP Preprint No. 696Google Scholar
  15. Sari, J. M. and Ness, N. F.: 1968, ‘Power Spectra of the Interplanetary Magnetic Field’, NASA-GSFC Preprint X-616–68–318.Google Scholar
  16. Siscoe, G. L., Davis, Jr., L., Smith, E. J., Coleman, Jr., P. J., and Jones, D. E.: 1967, ‘Magnetic Fluctuations in the Magnetosheath, Mariner-4’, J. Geophys. Res. 72, 1–17.ADSCrossRefGoogle Scholar
  17. Smith, E. J., Holzer, R. E., McLeod, M. C., and Russell, C. T.: 1967, ‘Magnetic Noise in the Magnetosheath in the Frequency Range 3–300 Hz’, J. Geophys. Res. 72, 4803–4813.ADSCrossRefGoogle Scholar
  18. Zmuda, A. J., Martin, J. H., and Heuring, F. T.: 1966, ‘Transverse Magnetic Disturbances at 1100 km in the Auroral Region’, J. Geophys. Res. 71, 5033–5045.ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1969

Authors and Affiliations

  • Norman F. Ness
    • 1
  1. 1.Extraterrestrial Physics Branch, Laboratory for Space SciencesNASA-Goddard Space Flight CenterGreenbeltUSA

Personalised recommendations