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Long time convergence of magnetohydrodynamic flows to alfvénic states

Published online by Cambridge University Press:  01 December 2007

MANUEL NÚÑEZ
MANUEL NÚÑEZ*
Affiliation:
Departamento de Análisis Matemático, Universidad de Valladolid, 47005 Valladolid, Spain ([email protected])
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Abstract

Alfvénic states of a plasma, where velocity and magnetic field coincide, form a particular simple class of ideal equilibria and are also found in certain astrophysical phenomena. While transient processes of alignment in turbulent plasmas are well known and due to preferential spectral transfer, the possible long-term evolution of a magnetohydrodynamic plasma towards an alfvénic state has been rarely studied. It is shown that this tendency does not exist: neither specific ideal alfvénic equilibria nor the whole set of such states attract trajectories in any functional sense. Another possibility is that the perturbations of a static equilibrium could tend to become alfvénic, such as the classical Alfvén waves. We find that if these equilibria are current free, when a perturbation approaches an alfvénic state it immediately bounces away from it.

Type
Papers
Information
Journal of Plasma Physics , Volume 73 , Issue 6 , December 2007 , pp. 947 - 955
Copyright
Copyright © Cambridge University Press 2007

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References

[1]Chandrasekhar, S. 1961 Hydrodynamic and Hydromagnetic Stability. Oxford: Oxford University Press (1981 New York: Dover).Google Scholar
[2]Biskamp, D. 2000 Nonlinear Magnetohydrodynamics. Cambridge: Cambridge University Press.Google Scholar
[3]Burlage, L. F. and Turner, J. M. 1976 Microscale Alfvén waves in the solar wind at 1 AU. J. Geophys. Res. 81, 73–77.CrossRefGoogle Scholar
[4]Grappin, R., Frisch, U., Léorat, J. and Pouquet, A. 1982 Alfvénic fluctuations as asymptotic states of MHD turbulence. Astron. Astrophys. 105, 6–14.Google Scholar
[5]Matthaeus, W. H., Goldstein, M. L. and Montgomery, D. C. 1983 Turbulent generation of outward-traveling interplanetary alfvénic fluctuations. Phys. Rev. Lett. 51, 1484–1487CrossRefGoogle Scholar
[6]Maron, J. and Goldreich, P. 2001 Simulations of incompressible magneto\-hydrodynamic turbulence. Astrophys. J. 554, 1175–1196CrossRefGoogle Scholar
[7]Cho, J. and Lazarian, A. 2002 Simulations of magnetohydrodynamic turbulence in a strong magnetized medium. Astrophys. J. 564, 291–301CrossRefGoogle Scholar
[8]Lithwick, Y. and Goldreich, P. 2003 Imbalanced weak magnetohydrodynamic turbulence. Astrophys. J. 582, 1220–1240CrossRefGoogle Scholar
[9]Ting, A. C., Matthaeus, W. H. and Montgomery, D. 1986 Turbulent relaxation processes in magnetohydrodynamics. Phys. Fluids 29 (10), 3261–3274.CrossRefGoogle Scholar
[10]Stribling, T. and Matthaeus, W. H. 1991 Relaxation process in a low-order three-dimensional magnetohydrodynamic model. Phys. Fluids B 3, 1848–1864CrossRefGoogle Scholar
[11]Biskamp, D. 2003 Magnetohydrodynamic Turbulence. Cambridge: Cambridge Univeristy Press.CrossRefGoogle Scholar
[12]Dobrowolny, M., Mangeney, A. and Veltri, P. 1980 Fully developed anisotropic hydromagnetic turbulence in interplanetary space. Phys. Rev. Lett. 45, 144–147CrossRefGoogle Scholar
[13]Diamond, P. H. 1990 On the Alfvén effect in MHD turbulence. Comments Plasma Phys. Control. Fusion 13, 287–297Google Scholar
[14]Goldreich, P. and Sridhar, S. 1995 Towards a theory of interstellar turbulence I: weal alfvénic turbulence. Astrophys. J. 432, 612–621; Towards a theory of interstellar turbulence II: strong alfvénic turbulence. Astrophys. J. 438, 763–775Google Scholar