Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T18:50:56.034Z Has data issue: false hasContentIssue false

A parametric survey of the first critical Mach number for a fast MHD shock

Published online by Cambridge University Press:  13 March 2009

J. P. Edmiston
Affiliation:
Department of Physics and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024
C. F. Kennel
Affiliation:
Department of Physics and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024

Abstract

The first critical fast Mach number is rigorously defined to be the one at which the downstream flow speed in the shock frame equals the ordinary downstream sound speed. Above the first critical Mach number, resistivity alone is unable to provide all the dissipation needed for the required Rankine-Hugoniot shock jump. A survey of the dependence of the first critical Mach number upon upstream plasma parameters is needed to guide studies of the structure of collisionless shocks in space. We vary the upstream plasma beta, the upstream shock normal angle, and the ratio of specific heats for the plasma. The first critical Mach number depends sensitively upon upstream plasma parameters, and is between 1 and 2 for typical solar wind parameters, rather than the often quoted value of 2·7, which is valid for perpendicular shocks propagating into a cold plasma. We introduce the suggestion that the flux of superthermal and energetic ions upstream at quasi-parallel shocks might increase suddenly at the first critical Mach number. Our parametric survey indicates that this hypothesis might be most conveniently tested using interplanetary shocks.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1984

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Axford, W. I., Leer, E. & Skadron, G. 1977 Proceedings of International Cosmic Ray Conference, Plovdiv, p. 446.Google Scholar
Blandford, R. P. & Ostriker, J. P. 1978 Ap. J. 221, L 29.CrossRefGoogle Scholar
Coroniti, F. V. 1970 J. Plasma Phys. 4, 265.Google Scholar
Edmiston, J. P., Kennel, C. F. & Eichler, D. 1982 J. Geophys. Res. 9, 531.Google Scholar
Eselevich, V. G., Es'kov, A. G., Kurtmullaev, R. Kh. & Malyutin, A. I. 1971 Soviet Phys. JETP, 33, 1120.Google Scholar
Eselevich, V. G. 1981 Preprint 1981, Sibizmir.Google Scholar
Eselevich, V. G. 1983 Preprint 783, Sibizmir.Google Scholar
Formisano, V. 1977 J. de Physique, 12, C 6.Google Scholar
Forslund, D. W. & Freidberg, J. P. 1971 Phys. Rev. Lett. 27, 1189.CrossRefGoogle Scholar
Kantrowitz, A. R. & Petschek, H. E. 1966 Plasma Physics Theory and Application (ed. Kunkel, W. B.), p. 147. McGraw-Hill.Google Scholar
Kurtmullaev, R. Kh., Nesterikhin, Yu. E., Pil'skii, V. I. & Sagdeev, R. Z. 1965 Proceedings of 2nd International Conference on Plasma Physics and Controlled Fusion, Culham, p. 192.Google Scholar
Lee, M. A. 1982 J. Geophys. Res. 87, 5063.CrossRefGoogle Scholar
Lee, M. A. 1983 J. Geophys. Res. 88, 6109.CrossRefGoogle Scholar
Leroy, M. M., Goodrich, C. C., Winske, D., Wu, C. S. & Papadopoulos, K. 1981 Geophys. Res. Lett. 8, 1269.Google Scholar
Leroy, M. M., Winske, D., Goodrich, C. C., Wu, C. S. & Papadopoulos, K. 1982 J. Geophys. Res. 87, 5081.CrossRefGoogle Scholar
Leroy, M. M. & Winske, D. 1984 Annales Geophysicae. (To be published.)Google Scholar
Livesey, W. A., Kennel, C. F. & Russell, C. T. 1982 Geophys. Res. Lett. 9, 1037.Google Scholar
Livesey, W. A., Russell, C. T. & Kennel, C. F. 1984 J. Geophys. Res. 89, 6824.Google Scholar
Marshall, W. 1955 Proc. R. Soc. A 233, 367.Google Scholar
Paul, J. W. M., Holms, L. S., Parkinson, M. J. & Sheffield, J. 1965 Nature, 208, 133.CrossRefGoogle Scholar
Phillips, P. E. & Robson, A. E. 1972 Phys. Rev. Lett. 29, 154.CrossRefGoogle Scholar
Tanaka, M., Goodrich, C. C., Winske, D. & Papadopoulos, K. 1983 J. Geophys. Res. 88, 3046.CrossRefGoogle Scholar
Tidman, D. A. & Krall, N. A. 1971 Shock Waves in Collisionless Plasmas. Wiley.Google Scholar
Woods, L. C. 1968 J. Plasma Phys. 11, 25.CrossRefGoogle Scholar