Journal ArticleDOI
Measurement of the rugged invariants of magnetohydrodynamic turbulence in the solar wind
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In this paper, the authors measured the total energy, cross helicity, and magnetic helicity of the solar wind at 1, 2.8, and 5 AU, and found that the magnetic heliometry typically lies at scales larger than the magnetic correlation length, consistent with the expectations of the inverse cascade and selective decay hypotheses of three-dimensional MHD turbulence theory.Abstract:
Measurements of the total energy, cross helicity, and magnetic helicity of the solar wind at 1, 2.8, and 5 AU are presented. These quantities are the three rugged invariants of three-dimensional ideal incompressible MHD turbulence theory. The theoretical technique for measuring the magnetic helicity from the matrix of two-point correlations is shown. The length scales characterizing the magnetic helicity are found to be equal to or greater than those which characterize the magnetic energy. The magnetic helicity typically lies at scales larger than the magnetic correlation length, consistent with the expectations of the inverse cascade and selective decay hypotheses of three-dimensional MHD turbulence. At smaller scales, the magnetic helicity oscillates in sign. Measurements of the cross helicity are not fully consistent with the usual interpretation in terms of outward propagating Alfvenic functions. Especially during the interval at 5 AU the cross helicity is found to oscillate in sign indicating fluctuations propagating both outward and inward.read more
Citations
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Journal ArticleDOI
The Solar Wind as a Turbulence Laboratory
Roberto Bruno,Vincenzo Carbone +1 more
TL;DR: In this paper, the authors focus on a topic of fundamental importance for both plasma physics and astrophysics, namely the occurrence of large-amplitude low-frequency fluctuations of the fields that describe the plasma state.
Book ChapterDOI
The ace magnetic fields experiment
TL;DR: The magnetic field experiment on ACE provides continuous measurements of the local magnetic field in the interplanetary medium as discussed by the authors, which are essential in the interpretation of simultaneous ACE observations of energetic and thermal particles distributions.
Journal ArticleDOI
MHD structures, waves and turbulence in the solar wind : observations and theories
Chia-Ying Tu,Eckart Marsch +1 more
TL;DR: A comprehensive overview of recent observational and theoretical results on solar wind structures and fluctuations and magnetohydrodynamic waves and turbulence, with preference given to phenomena in the inner heliosphere, is presented in this paper.
Journal ArticleDOI
Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades in Magnetized Weakly Collisional Plasmas
Alexander Schekochihin,Alexander Schekochihin,Steven Cowley,Steven Cowley,William Dorland,Gregory W. Hammett,Gregory G. Howes,Eliot Quataert,Tomoya Tatsuno +8 more
TL;DR: In this paper, a theoretical framework for understanding plasma turbulence in astrophysical plasmas is presented, motivated by observations of electromagnetic and density fluctuations in the solar wind, interstellar medium and galaxy clusters, as well as by models of particle heating in accretion disks.
Journal ArticleDOI
Observational constraints on the dynamics of the interplanetary magnetic field dissipation range
TL;DR: In this paper, the authors examined wind observations of inertial and dissipation range spectra in an attempt to better understand the processes that form the dissipation ranges and how these processes depend on the ambient solar wind parameters (interplanetary magnetic field intensity, ambient proton density and temperature, etc.).
References
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Journal Article
The Local Structure of Turbulence in Incompressible Viscous Fluid for Very Large Reynolds' Numbers
TL;DR: In this article, the authors consider the problem of finding the components of the velocity at every point of a point with rectangular cartesian coordinates x 1, x 2, x 3, x 4, x 5, x 6, x 7, x 8.
Journal ArticleDOI
Inertial Ranges in Two‐Dimensional Turbulence
TL;DR: In this paper, it was shown that two-dimensional turbulence has both kinetic energy and mean square vorticity as inviscid constants of motion, and two formal inertial ranges, E(k)∼e2/3k−5/3/3, where e is the rate of cascade of kinetic energy per unit mass, η is the time taken to reach a cascade of mean square velocity, and k is the kinetic energy of the entire mass.
Journal ArticleDOI
The Spectrum of Turbulence
Journal ArticleDOI
Relaxation of toroidal plasma and generation of reverse magnetic fields
TL;DR: In this article, the spontaneous generation of reversed fields in toroidal plasmas is shown to be a consequence of relaxation under constraints, and the onset of the reversed field and other features of this model agree well with observations on ZETA.