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Title: Inhomogeneities of plasma density and electric field as sources of electrostatic turbulence in the auroral region

Inhomogeneities of plasma density and non-uniform electric fields are compared as possible sources of a sort of electrostatic ion cyclotron waves that can be identified with broadband extremely low frequency electrostatic turbulence in the topside auroral ionosphere. Such waves are excited by inhomogeneous energy-density-driven instability. To gain a deeper insight in generation of these waves, computational modeling is performed with various plasma parameters. It is demonstrated that inhomogeneities of plasma density can give rise to this instability even in the absence of electric fields. By using both satellite-observed and model spatial distributions of plasma density and electric field in our modeling, we show that specific details of the spatial distributions are of minor importance for the wave generation. The solutions of the nonlocal inhomogeneous energy-density-driven dispersion relation are investigated for various ion-to-electron temperature ratios and directions of wave propagation. The relevance of the solutions to the observed spectra of broadband extremely low frequency emissions is shown.
Authors:
 [1] ;  [2] ; ;  [1] ; ;  [3]
  1. Space Research Institute of the Russian Academy of Science, Moscow 117997 (Russian Federation)
  2. (Russian Federation)
  3. Polar Geophysical Institute of the Russian Academy of Science, Apatity, Murmansk region 184209 (Russian Federation)
Publication Date:
OSTI Identifier:
22408228
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 3; Other Information: (c) 2015 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; AURORAL ZONES; COMPUTERIZED SIMULATION; DISPERSION RELATIONS; ELECTRIC FIELDS; ELECTRON TEMPERATURE; EMISSION; ENERGY DENSITY; ION PLASMA WAVES; ION TEMPERATURE; MATHEMATICAL SOLUTIONS; PLASMA DENSITY; PLASMA INSTABILITY; SPATIAL DISTRIBUTION; SPECTRA; TURBULENCE