Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-19T22:51:36.020Z Has data issue: false hasContentIssue false

Parametric instabilities of circularly polarized large-amplitude dispersive Alfvén waves: excitation of parallel-propagating electromagnetic daughter waves

Published online by Cambridge University Press:  13 March 2009

Adolfo F. Viñas
Affiliation:
Laboratory for Extraterrestrial Physics, Code 692, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771, U.S.A.
Melvyn L. Goldstein
Affiliation:
Laboratory for Extraterrestrial Physics, Code 692, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771, U.S.A.

Abstract

We investigate the parametric decay and modulational instabilities of a large-amplitude circularly polarized dispersive Alfvén wave. Our treatment is more general than that of previous derivations based on the two-fluid equations in that we allow for propagation of the unstable daughter waves at arbitrary angles to the background magnetic field, although our main concern in this paper is the exploration of new aspects of propagation parallel to the DC magnetic field. In addition to the well-known coupling of pump waves to electrostatic daughter waves, we find a new parametric channel where the pump wave couples directly to electromagnetic daughter waves. Excitation of the electromagnetic instability occurs only for modulation (k/k0 ≤ 1) and not for decay (k/k0 < 1). In contrast with the modulational instability excited by the electrostatic coupling, the electromagnetic modulational instability exists for both left-hand (K > 0) and right-hand (K < 0) polarization. For large k/k0, the electromagnetic channel dominates, while at lower values the electrostatic channel has a larger growth rate for modest values of dispersion, pump-wave amplitude and plasma β. Unlike the electrostatic modulational instability, the growth rate of the electromagnetic instability increases monotonically with increasing pump wave amplitude. This analysis confirms that, for decay, the dominant process is coupling to electrostatic daughter waves, at least for parallel propagation. For modulation, the coupling to electromagnetic daughter waves usually dominates, suggesting that the parametric modulational instability is really an electromagnetic phenomenon.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1991

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

Abraham-Shrauner, B. & Feldman, W. C. 1977 J. Geophys. Res. 82, 618.CrossRefGoogle Scholar
Armstrong, J. W., Cordes, J. M. & Rickett, B. J. 1981 Nature, 291, 561.CrossRefGoogle Scholar
Boyd, T. J. M. & Sanderson, J. J. 1969 Plasma Dynamics. Barnes and Noble.Google Scholar
Bragtnskii, S. I. 1957 Soviet Phys. Dokl. 2, 345.Google Scholar
Cohen, R. 1975 J. Geophys. Res. 80, 3678.CrossRefGoogle Scholar
Cohen, R. H. & Dewar, R. L. 1974 J. Geophys. Res. 79, 4174.CrossRefGoogle Scholar
Derby, N. F. 1978 Astrophys. J. 224, 1013.CrossRefGoogle Scholar
Ferraro, V. C. A. 1955 Proc. R. Soc. Lond. A 223, 310.Google Scholar
Flå, T., Mjølhus, E. & Wyller, J. 1989 Physica Scripta, 40, 219.CrossRefGoogle Scholar
Formisano, V. & Kennel, C. F. 1969 J. Plasma Phys. 3, 55.CrossRefGoogle Scholar
Galeev, A. A. & Oraevskii, V. N. 1963 Soviet Phys. Dokl. 7, 988.Google Scholar
Goldstein, M. L. 1978 Astrophys. J. 219, 700.CrossRefGoogle Scholar
Goldstein, M. L., Klimas, A. J. & Barish, F. D. 1974 Solar Wind Three (ed. Russell, C. T.), p. 385. University of California Press.Google Scholar
Goldstein, M. L., Wong, H. K., Viñas, A. F. & Smith, C. W. 1985 J. Geophys. Res. 90, 302.CrossRefGoogle Scholar
Hoshino, M. & Goldstein, M. L. 1989 Phys. Fluids B 1, 1405.CrossRefGoogle Scholar
Inhester, B. 1990 J. Geophys. Res. 95, 10525.CrossRefGoogle Scholar
Ionson, J. A. & Ong, R. S. B. 1976 Plasma Phys. 18, 809.CrossRefGoogle Scholar
Kruer, W. L. 1988 The Physics of Laser Plasma Interactions. Addison-Wesley.Google Scholar
Lashmore-Davies, C. N. 1976 Phys. Fluids, 19, 587.CrossRefGoogle Scholar
Longtin, M. & Sonnerup, B. U. Ö 1986 J. Geophys. Res. 91, 6816.CrossRefGoogle Scholar
Mjølhus, E. 1976 J. Plasma Phys. 16, 321.CrossRefGoogle Scholar
Mjølhus, E. & Wyller, J. 1986 Physica Scripta, 33, 442.CrossRefGoogle Scholar
Mjølhus, E. & Wyller, J. 1988 J. Plasma Phys. 40, 299.CrossRefGoogle Scholar
Ovenden, C. R., Shah, H. A. & Schwartz, S. J. 1983 J. Geophys. Res. 88, 6095.CrossRefGoogle Scholar
Roberts, A. D. & Goldstein, M. L. 1991 In Contributions in Solar Planetary Relationships, U.S. National Report 1987–1990 (ed. Shea, M. A.), p. 932. American Geophysical Union.Google Scholar
Robinson, D. C. & Rusbridge, M. G. 1971 Phys. Fluids, 14, 2499.CrossRefGoogle Scholar
Sagdeev, R. Z. & Galeev, A. A. 1969 Nonlinear Plasma Theory (ed. O'Neil, T. & Book, D.). Benjamin.Google Scholar
Sakai, J.-I. & Sonnerup, B. U. Ö. 1983 J. Geophys. Res. 88, 9069.CrossRefGoogle Scholar
Spangler, S. R. 1985 Astrophys. J. 299, 122.CrossRefGoogle Scholar
Spangler, S. R. & Sheerin, J. P. 1982 J. Plasma Phys. 27, 193.CrossRefGoogle Scholar
Stringer, T. E. 1963 Plasma Phys. 5, 89.Google Scholar
Terasawa, T., Hoshino, M., Sakai, J.-I. & Hada, T. 1986 J. Geophys. Res. 91, 4171.CrossRefGoogle Scholar
Viñas, A. F. & Goldstein, M. L. 1991 J. Plasma Phys. 46, 129.CrossRefGoogle Scholar
Viñas, A. F., Goldstein, M. L. & Acuña, M. H. 1984 J. Geophys. Res. 89, 6813.CrossRefGoogle Scholar
Wong, H. K. & Goldstein, M. L. 1986 J. Geophys. Res. 91, 5617.CrossRefGoogle Scholar