Oscillations of type-1 comet tails

Ershkovich, A. I.; Nusinov, A. A.; Chernikov, A. A.

doi:10.1016/0032-0633(72)90011-6

Cited by 30 publications

(7 citation statements)

References 12 publications

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“…Bull, 1984 , coronal streamers moving through the solar wind, the bound-Ž aries between adjacent sectors in the solar wind Parker, 1963;Sturrock . and Hartle, 1966;Jokipii and Davis, 1969 , the structure of the tails Ž of comets Dobrowolny and D'Angelo, 1972;Ershkovich et al, 1972;. Ershkovich and Chernikov, 1973;Brandt and Mendis, 1979 , and the boundaries of the jets propagating from the nuclei of extragalactic double Ž radio sources into their lobes Turland and Scheuer, 1976;Blandford and .…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Evolution of the Kelvin–Helmholtz Instability of Supersonic Tangential Velocity Discontinuities

Choudhury

1997

Journal of Mathematical Analysis and Applications

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A nonlinear stability analysis using a multiple-scales perturbation procedure is performed for the instability of two layers of immiscible, inviscid, arbitrarily compressible fluids in relative motion. Such configurations are of relevance in a variety of astrophysical and space configurations. For modes of all wavenumbers on, or in the stable neighborhood of, the linear neutral curve, the nonlinear evolution of the amplitude of the linear fields on the slow first-order scales is shown to be governed by a complicated nonlinear Klein᎐Gordon equation. Both the spatially dependent and space-independent versions of this equation are considered to obtain the regimes of physical parameter space where the linearly unstable solutions either evolve to final permanent envelope wave patterns resembling the ensembles of interacting vortices observed empirically, or are disrupted via nonlinear modulation instability.ᮊ 1997 Academic Press

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Section: Introductionmentioning

confidence: 99%

Nonlinear Evolution of the Kelvin–Helmholtz Instability of Supersonic Tangential Velocity Discontinuities

Choudhury

1997

Journal of Mathematical Analysis and Applications

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“…The Kelvin-Helmholtz instability caused by tangential velocity shear in homogeneous plasmas is of interest in investigating a variety of space, astrophysical, and geophysical situations involving sheared plasma flows. Configurations, where relevant, include the interface between the solar wind and the magnetosphere (Sen, 1965;Southwood, 1968;Southwood, 1974;Bridge et al, 1979;Ness et al, 1981;Pu and Kivelson, 1983), coronal streamers moving through the solar wind, the boundaries between adjacent sectors in the solar wind (Parker, 1963;Sturrock and Hartle, 1966;Jokipii and Davis, 1969), the structure of the tails of comets (Dobrowolny and D'Angelo, 1972; Ershkovich et al, 1972;Ershkovich and Chernikov, 1973;Brandt and Mendis, 1979), and the boundaries of the jets propagating from the nuclei of extragalactic double radio sources into their lobes (Turland and Scheuer, 1976;Blandford and Pringle, 1976; Begelman et al, 1984).…”

Section: Introductionmentioning

confidence: 99%

Quasiperiodicity and chaos in the nonlinear evolution of the Kelvin-Helmholtz instability of supersonic anisotropic tangential velocity discontinuities

Choudhury¹,

Brown²

2003

Quart. Appl. Math.

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Abstract.A nonlinear stability analysis using a multiple-scales perturbation procedure is performed for the instability of two layers of immiscible, strongly anisotropic, magnetized, inviscid, arbitrarily compressible fluids in relative motion. Such configurations are of relevance in a variety of astrophysical and space configurations.For modes near the critical point of the linear neutral curve, the nonlinear evolution of the amplitude of the linear fields on the slow first-order scales is shown to be governed by a complicated nonlinear Klein-Gordon equation.The nonlinear coefficient turns out to be complex, which is, to the best of our knowledge, unlike previously considered cases and leads to completely different dynamics from that reported earlier. Both the spatially dependent and space-independent versions of this equation are considered to obtain the regimes of physical parameter space where the linearly unstable solutions either evolve to final permanent envelope wave patterns resembling the ensembles of interacting vortices observed empirically, or are disrupted via nonlinear modulation instability. In particular, the complex nonlinearity allows the existence of quasiperiodic and chaotic wave envelopes, unlike in earlier physical models governed by nonlinear Klein-Gordon equations. In addition, numerical diagnostics reveal the onset of chaos as a consequence of modulation of the external magnetic field.

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“…A detailed understanding of the structure and dynamics of magnetopause regions, such as the presence of the magnetospheric boundary layer and of rapid boundary motions, has been obtained from the recent satellite observations of particles and fields. Many investigators have treated the instability of the interface between the solar wind and the magnetosphere [1]- [5], coronal streamers moving through the solar wind, the boundaries between the adjacent sectors in the solar wind, the structure of the tails of comets [6], [7], and the boundaries of the jets propagating from the nuclei of extragalactic double radio sources into their lobes [8]- [9]. The linear K-H instability of non-magnetized shear layer has been studied for flows with a subsonic velocity change by Chandrasekhar, Syrovatskii, and Northrop [10], and with an abrupt jump in vz of arbitrary magnitude by Gerwin [11].…”

Section: Introductionmentioning

confidence: 99%

An analytical study of the Kelvin-Helmholtz instabilities of compressible, magnetized tangential velocity discontinuities with generalized polytrope laws

Brown¹,

Choudhury²

2002

Quart. Appl. Math.

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Abstract.The linear Kelvin-Helmholtz instability of tangential velocity discontinuities in high velocity magnetized plasmas with isotropic or anisotropic pressure is investigated.A new analytical technique applied to the magnetohydrodynamic equations with generalized polytrope laws (for the pressure parallel and perpendicular to the magnetic field) yields the complete structure of the unstable, standing waves in the (inverse plasma beta, Mach number) plane for modes at arbitrary angles to the flow and the magnetic field. The stable regions in the (inverse plasma beta, propagation angle) plane are mapped out via a level curve analysis, thus clarifying the stabilizing effects of both the magnetic field and the compressibility. For polytrope indices corresponding to the double adiabatic and magnetohydrodynamic equations, the results reduce to those obtained earlier using these models. Detailed numerical results are presented for other cases not considered earlier, including the cases of isothermal and mixed waves. Also, for modes propagating along or opposite to the magnetic field direction and at general angles to the flow, a criterion is derived for the absence of standing wave instability-in the isotropic MHD case, this condition corresponds to (plasma beta) < 1.

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Oscillations of type-1 comet tails

Cited by 30 publications

References 12 publications

Nonlinear Evolution of the Kelvin–Helmholtz Instability of Supersonic Tangential Velocity Discontinuities

Nonlinear Evolution of the Kelvin–Helmholtz Instability of Supersonic Tangential Velocity Discontinuities

Quasiperiodicity and chaos in the nonlinear evolution of the Kelvin-Helmholtz instability of supersonic anisotropic tangential velocity discontinuities

An analytical study of the Kelvin-Helmholtz instabilities of compressible, magnetized tangential velocity discontinuities with generalized polytrope laws

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