Implications of a Non-modal Linear Theory for the Marginal Stability State and the Dissipation of Fluctuations in the Solar Wind

A magnetized plasma with anisotropic particle distributions may be unstable to a number of different kinetic instabilities. The solar wind is often observed in a state which is close to that implying instability, i.e., in a marginal stability state. Normal-mode linear theory predicts that fluctuatio...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2010-05, Vol.715 (1), p.260-270
Main Authors: Camporeale, Enrico, Passot, Thierry, Burgess, David
Format: Article
Language:English
Subjects:
ANISOTROPY
Astronomy
ASTROPHYSICS, COSMOLOGY AND ASTRONOMY
CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
Earth, ocean, space
Exact sciences and technology
NORMAL-MODE ANALYSIS
PLASMA
SOLAR ACTIVITY
SOLAR WIND
STELLAR ACTIVITY
STELLAR WINDS
TURBULENCE
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A magnetized plasma with anisotropic particle distributions may be unstable to a number of different kinetic instabilities. The solar wind is often observed in a state which is close to that implying instability, i.e., in a marginal stability state. Normal-mode linear theory predicts that fluctuations in a stable plasma damp exponentially. The non-modal approach for a linearized system differs from a normal-mode analysis by following the temporal evolution of some perturbed equilibria, and therefore includes transient effects. We employ a non-modal approach for studying the stability of a bi-Maxwellian magnetized plasma using the Landau fluid model, which we briefly describe. We show that bi-Maxwellian stable equilibria can support transient growth of some physical quantities, and we study how these transients behave when an equilibrium approaches its marginally stable condition. The results obtained with a non-modal approach are relevant to a re-examination of the concept of linear marginal stability. Moreover, we highlight some aspects of the dissipation of turbulent fluctuations, which suggest that the non-modal approach should be included in future studies.
ISSN:0004-637X
1538-4357
DOI:10.1088/0004-637X/715/1/260