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Title: Generation of kinetic Alfven waves in the high-latitude near-Earth magnetotail: A global hybrid simulation

In this paper, effects of a fast flow in the tail plasma sheet on the generation of kinetic Alfven waves (KAWs) in the high-latitude of the near-Earth magnetotail are investigated by performing a two-dimensional (2-D) global-scale hybrid simulation, where the plasma flow is initialized by the E×B drift near the equatorial plane due to the existence of the dawn-dusk convection electric field. It is found that firstly, the plasma sheet becomes thinned and the dipolarization of magnetic field appears around (x,z)=(−10.5R{sub E},0.3R{sub E}), where R{sub E} is the radius of the Earth. Then, shear Alfven waves are excited in the plasma sheet, and the strong earthward flow is braked by the dipole-like magnetic field. These waves propagate along the magnetic field lines toward the polar regions later. Subsequently, KAWs with k{sub ⊥}≫k{sub ∥} are generated in the high-latitude magnetotail due to the existence of the non-uniformity of the magnetic field and density in the polar regions. The ratio of the electric field to the magnetic field in these waves is found to obey the relation (δE{sub z})/(δB{sub y} )∼ω/k{sub ∥} of KAWs. Our simulation provides a mechanism for the generation of the observed low-frequency shear Alfven waves in the plasma sheetmore » and kinetic Alfven waves in the high-latitude near-Earth magnetotail, whose source is suggested to be the flow braking in the low-latitude plasma sheet.« less
Authors:
 [1] ;  [2] ;  [2] ; ;  [1] ;  [2] ; ;  [3] ;  [4] ; ;  [3] ;  [2]
  1. Key Laboratory of Ionospheric Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)
  2. (China)
  3. CAS Key Lab of Geoscience Environment, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei 230026 (China)
  4. (United States)
Publication Date:
OSTI Identifier:
22408070
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 2; 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; ALFVEN WAVES; CONVECTION; DIPOLES; ELECTRIC FIELDS; MAGNETIC FIELDS; MAGNETOTAIL; PLASMA SHEET; POLAR REGIONS; SHEAR; SIMULATION; TWO-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL SYSTEMS