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Title: Coherent structures and turbulent spectrum in solar wind plasmas

The present paper investigates the localization of a uniform plane kinetic Alfvén wave (KAW) due to the coupling with the density/magnetic field fluctuations associated with a magnetosonic wave propagating in the transverse direction, i.e., perpendicular to the background magnetic field. To gain the physical insight into this evolution, a simplified analytical model based on the Mathieu equation has also been studied. Numerical method has also been used to analyse the evolution of KAW. The magnetic fluctuation spectrum follows Kolmogorovian scaling above the proton gyroradius scalelength, which is regarded as the inertial range. Below this scale, a steepened spectrum has been obtained in the dispersive range with power law index ∼−2.5, which continues up to the dissipation range. Our results reveal that the proposed mechanism may be an interesting physical mechanism for transferring the energy from larger lengthscales to smaller lengthscales in the solar wind plasmas. Relevance of the present study with Cluster spacecraft observations has also been discussed.
Authors:
; ;  [1]
  1. Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi-110016 (India)
Publication Date:
OSTI Identifier:
22227895
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 8; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALFVEN WAVES; ASTROPHYSICS; FLUCTUATIONS; GAIN; MAGNETIC FIELDS; MAGNETOACOUSTIC WAVES; MATHIEU EQUATION; NUMERICAL ANALYSIS; PLASMA DENSITY; PROTONS; SOLAR WIND; TURBULENCE; WAVE PROPAGATION