Abstract
We review the results of radar studies of the Sun made at El Campo, Texas 1961–69 with particular emphasis on the record of observed solar radar cross sections. Using ray traces which include the effects of refraction, absorption, and scattering in non-spherically symmetric models of the corona, we investigate the role of focusing by large-scale coronal geometries in enhancing the radar cross section. We find that certain coronal geometries (e.g. disk-center coronal holes) can, in principle, significantly increase the radar cross section. However the observations of large cross sections do not correspond very well with periods when such large-scale focusing geometries existed in the corona. We conclude that the present dataset does not support the hypothesis that radar observations of the Sun will be useful in determining the properties of large-scale coronal features.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Armstrong, J. W., Coles, W. A., and Rickett, B. J.: 1972, J. Geophys. Res. 77, 2739.
Bartels, J.: 1958, Abhandlung der Akademie der Wissenschaften zu Göttingen, Beitraege zum I.G.S., Heft 3.
Budden, K. G.: 1961, Radio Waves in the Ionosphere, Cambridge University Press, Cambridge, p. 271.
Chandrasekhar, S.: 1952, Monthly Notices Roy. Astron. Soc. 112, 475.
Coles, W. A., Rickett, B. J., and Rumsey, V. H.: 1974, in C. J. Russell (ed.), Solar Wind Three, Institute of Geophysics and Planetary Sciences, UCLA.
Erickson, W. C.: 1978, J. Geophys. Res. 83, 4153.
Eshleman, V. R., Barthle, R. C., and Gallagher, P. B.: 1960, Science 131, 329.
Evans, J. V. and Hagfors, T.: 1968, Radar Astronomy, McGraw-Hill, New York.
Gerasimova, N. N.: 1975, Soviet Astron. 18, 482.
Gordon, J. M.: 1973, Space Sci. Rev. 15, 157.
Grieg, D. D., Metzger, S., and Waer, R.: 1948, Proc. IRE 36, 652.
Groth, E. J.: 1974, Astrophys. J. Suppl. 29, 285.
Hansen, R. T., Garcia, S. F., Hansen, S. F., and Loomis, H. G.: 1969, Solar Phys. 7, 417.
Hansen, R. T., Hansen, S. F., and Sawyer, C.: 1975, Planetary Space Scri. 24, 381.
Hewish, A. and Symonds, M. D.: 1969, Planetary Space Sci. 17, 313.
Hollweg, J. V.: 1970, J. Geophys. Res. 75, 3715.
Hundhausen, A. J.: 1977, in J. B. Zirker (ed.), Coronal Holes and High Speed Wind Streams, Colorado Associated University Press, Boulder, Ch. 7.
James, J. C.: 1966, Astrophys. J. 146, 356.
James, J. C.: 1968, in J. V. Evans and T. Hagfors (eds.), Radar Astronomy, McGraw-Hill, New York, Ch. 7.
James, J. C.: 1970, Solar Phys. 12, 143.
Riddle, A. C: 1974, Solar Phys. 35, 153.
Saito, K.: 1970, Ann. Tokyo Astr. Obs. Ser. 2, 12, 53.
Scheuer, P. G.: 1960, Monthly Notices Roy. Astron. Soc. 120, 180.
Steinberg, J. L., Aubier-Giraud, M., Leblanc, Y., and Boischot, A.: 1971, Astron. Astrophys. 10, 362.
Author information
Authors and Affiliations
Additional information
The National Center for Atmospheric Research is sponsored by the National Science Foundation.
Rights and permissions
About this article
Cite this article
Owocki, S.P., Newkirk, G.A. & Sime, D.G. Radar studies of the non-spherically symmetric solar corona. Sol Phys 78, 317–331 (1982). https://doi.org/10.1007/BF00151611
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00151611