Nonlinear evolution of parametric instability of a large-amplitude nonmonochromatic Alfvén wave

Malara, F.; Primavera, Leonardo; Veltri, P.

doi:10.1063/1.874136

Cited by 69 publications

(65 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, Primavera et al (1999); Malara et al (2000Malara et al ( , 2001; Primavera et al (2003) investigated in detail how the parametric instability could be responsible for typical features observed in the radial evolution of the Alfvénic turbulence in the solar wind high speed streams. This instability develops in a compressible plasma and, in its simplest form, involves the decay of a large amplitude Alfvén wave (generally called a "pump wave", or "mother wave") in a magnetosonic fluctuation and a backscattered Alfvén wave.…”

Section: Results Of the Numerical Simulations Of Parametric Instabilitymentioning

confidence: 99%

On the probability distribution function of small-scale interplanetary magnetic field fluctuations

Bruno¹,

Carbone

Primavera

et al. 2004

Ann. Geophys.

Self Cite

View full text Add to dashboard Cite

Abstract. In spite of a large number of papers dedicated to the study of MHD turbulence in the solar wind there are still some simple questions which have never been sufficiently addressed, such as: a) Do we really know how the magnetic field vector orientation fluctuates in space? b) What are the statistics followed by the orientation of the vector itself? c) Do the statistics change as the wind expands into the interplanetary space?A better understanding of these points can help us to better characterize the nature of interplanetary fluctuations and can provide useful hints to investigators who try to numerically simulate MHD turbulence.This work follows a recent paper presented by some of the authors which shows that these fluctuations might resemble a sort of random walk governed by Truncated Lévy Flight statistics. However, the limited statistics used in that paper did not allow for final conclusions but only speculative hypotheses. In this work we aim to address the same problem using more robust statistics which, on the one hand, forces us not to consider velocity fluctuations but, on the other hand, allows us to establish the nature of the governing statistics of magnetic fluctuations with more confidence.In addition, we show how features similar to those found in the present statistical analysis for the fast speed streams of solar wind are qualitatively recovered in numerical simulations of the parametric instability. This might offer an alternative viewpoint for interpreting the questions raised above.

show abstract

Section: Results Of the Numerical Simulations Of Parametric Instabilitymentioning

confidence: 99%

On the probability distribution function of small-scale interplanetary magnetic field fluctuations

Bruno¹,

Carbone

Primavera

et al. 2004

Ann. Geophys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This could be either due to the slower development of turbulence in the fast wind, with respect to the slow wind, or to the presence of superposed uncorrelated Alfvénic fluctuations, which could hide the structures responsible for intermittency in the fast wind closer to the Sun. These uncorrelated Alfvénic fluctuations, ubiquitous in the fast wind, are indeed observed to decay with R, as suggested for example by a parametric instability model (Malara et al 2000(Malara et al , 2001Bruno et al 2003Bruno et al , 2004.…”

Section: Intermittencymentioning

confidence: 94%

Solar Wind Turbulence and the Role of Ion Instabilities

et al. 2013

View full text Add to dashboard Cite

Solar wind is probably the best laboratory to study turbulence in astrophysical plasmas. In addition to the presence of magnetic field, the differences with neutral fluid isotropic turbulence are: (i) weakness of collisional dissipation and (ii) presence of several characteristic space and time scales. In this paper we discuss observational properties of solar wind turbulence in a large range from the MHD to the electron scales. At MHD scales, within the inertial range, turbulence cascade of magnetic fluctuations develops mostly in the plane perpendicular to the mean field, with the Kolmogorov scaling k −5/3 ⊥ for the perpendicular cascade and k −2 for the parallel one. Solar wind turbulence is compressible in nature: density fluctuations at MHD scales have the Kolmogorov spectrum. Velocity fluctuations do not follow magnetic field ones: their spectrum is a power-law with a −3/2 spectral index. Probability distribution functions of different plasma parameters are not Gaussian, indicating presence of intermittency. At the moment there is no global model taking into account all these observed properties of the inertial range. At ion scales, turbulent spectra have a break, compressibility increases and the density fluctuation spectrum has a local flattening. Around ion scales, magnetic spectra are variable and ion instabilities occur as a function of the local plasma parameters. Between ion and electron scales, a small scale turbulent cascade seems to be established. It is characterized by a well defined power-law spectrum in magnetic and density fluctuations with a spectral index close to −2.8. Approaching electron scales, the fluctuations are no more self-similar: an exponential cut-off is usually observed (for time intervals without quasi-parallel whistlers) indicating an onset of dissipation. The small scale inertial range between ion and electron scales and the electron dissipation range can be together described by ∼ k −α ⊥ exp(−k ⊥ d ), with α 8/3 and the dissipation scale d close to the electron Larmor radius d ρ e . The nature of this small scale cascade and a possible dissipation mechanism are still under debate.

show abstract

“…[26], where the acceleration of charged particles by large amplitude MHD waves was studied. In contrast, if Alfvénic turbulence without any envelope modulation [27] is given, the "acceleration" may not be observed. These high energy particles in the outer ring may escape from the region of interaction with the Alfvén waves and can contribute to the fast particle population in astrophysical and space plasmas.…”

Section: Test Particle Simulations Of Pseudoheatingmentioning

confidence: 98%

Ion pseudoheating by low-frequency Alfvén waves revisited

Dong

Singh

2013

Physics of Plasmas

View full text Add to dashboard Cite

Pseudoheating of ions in the presence of Alfvén waves is studied. We show that this process can be explained by E × B drift. The analytic solution obtained in this paper are quantitatively in accordance with previous results. Our simulation results show that the Maxwellian distribution is broadened during the pseudoheating; however, the shape of the broadening distribution function depends on the number of wave modes (i.e., a wave spectrum or a monochromatic dispersionless wave) and the initial thermal speed of ions (v p ). It is of particular interests to find that the Maxwellian shape is more likely to maintain during the pseudoheating under a wave spectrum compared with a monochromatic wave. It significantly improves our understanding of heating processes in interplanetary space where Alfvénic turbulences exist pervasively. Compared with a monochromatic Alfvén wave, E × B drift produces more energetic particles in a broad spectrum of Alfvén waves, especially when the Alfvénic turbulence with phase coherent wave modes is given. Such particles may escape from the region of interaction with the Alfvén waves and can contribute to fast particle population in astrophysical and space plasmas.

show abstract

Nonlinear evolution of parametric instability of a large-amplitude nonmonochromatic Alfvén wave

Cited by 69 publications

References 17 publications

On the probability distribution function of small-scale interplanetary magnetic field fluctuations

On the probability distribution function of small-scale interplanetary magnetic field fluctuations

Solar Wind Turbulence and the Role of Ion Instabilities

Ion pseudoheating by low-frequency Alfvén waves revisited

Contact Info

Product

Resources

About