Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Longitudinal Spread of pc 1 Micropulsations in the Magnetosphere

Abstract

ONE of the important problems in the field of pc 1 micropulsation (pearl) research is to determine what portion of the magnetosphere is involved in the propagation of an individual structured pc 1 event. It is generally recognized1 that these micropulsations propagate back and forth in a dispersive medium2,3 between conjugate hemispheres guided by the Earth's magnetic field, but it is not known whether the waves are constrained to propagate along a single field line or whether they can spread out along an appreciable portion of a magnetic shell. Because energy is transferred back and forth between trapped particles and ultra-low frequency (ULF) waves in the cyclotron resonance interaction4, and because trapped particles undergo longitudinal drift, it is reasonable to assume that a structured pc 1 micropulsation may spread out along a magnetic shell even if it started on a particular field line. Dispersion measurements5–8 which have been used to locate the latitude where the field lines or shells intercept the surface of the Earth cannot be used to determine longitude, and hence one must resort to interstation comparison of data.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Tepley, L. R., J. Geomag. Geoelect., 18, 227 (1966).

    Article  ADS  Google Scholar 

  2. Jacobs, J. A., and Watanabe, T., J. Atmos. Terr. Phys., 26, 825 (1964).

    Article  ADS  Google Scholar 

  3. Obayashi, T., J. Geophys. Res., 70, 1069 (1965).

    Article  ADS  Google Scholar 

  4. Liemohn, H. B., J. Geophys. Res., 72, 39 (1967).

    Article  ADS  Google Scholar 

  5. Dowden, R. L., and Emery, M. W., Planet. Space Sci., 13, 773 (1965).

    Article  ADS  Google Scholar 

  6. Wentworth, R. C., J. Geomag. Geoelec., 18, 257 (1966).

    Article  ADS  Google Scholar 

  7. Watanabe, T., J. Geophys. Res., 70, 5839 (1965).

    Article  ADS  Google Scholar 

  8. Liemohn, H. B., Kenney, J. F., and Knaflich, H. B., Earth Plan. Sci. Lett., 2, 360 (1967).

    Article  ADS  Google Scholar 

  9. Tepley, L. R., and Landshoff, R. K., J. Geophys. Res., 71, 1499 (1966).

    Article  ADS  Google Scholar 

  10. Manchester, R. N., J. Geophys. Res., 71, 3749 (1966).

    Article  ADS  Google Scholar 

  11. Heacock, R. R., and Hessler, V. P., J. Geophys. Res., 67, 3985 (1962).

    Article  ADS  Google Scholar 

  12. Knaflich, H. B., and Kenney, J. F., Earth Planet. Sci. Lett., 2, 453 (1967).

    Article  ADS  Google Scholar 

  13. Troitskaya, V. A., J. Geophys. Res., 66, 5 (1961).

    Article  ADS  Google Scholar 

  14. Gendrin, R., Gokhberg, M., Lacourly, S., and Troitskaya, V., CR Acad. Sci., 262, 845 (1966).

    Google Scholar 

  15. Heacock, R. R., J. Geophys. Res., 72, 399 (1967).

    Article  ADS  Google Scholar 

  16. Hessler, V. P., editor, High Lat. Geophys. Data, 39–46 (Geophysical Institute, College, Alaska, 1965–66).

  17. Kenney, J. F., and Knaflich, H. B., J. Geophys. Res., 72, 2859 (1967).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

KNAFLICH, H., KENNEY, J. & HESSLER, V. Longitudinal Spread of pc 1 Micropulsations in the Magnetosphere. Nature 217, 1134–1136 (1968). https://doi.org/10.1038/2171134a0

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1038/2171134a0

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing