skip to main content

SciTech ConnectSciTech Connect

Title: FULL PARTICLE ELECTROMAGNETIC SIMULATIONS OF ENTROPY GENERATION ACROSS A COLLISIONLESS SHOCK

Experimental data from Cluster have shown that entropy density can be generated across Earth's bow shock. These new observations are a starting point for a more sophisticated analysis that includes computer modeling of a collisionless shock using observed shock parameters as input. In this Letter, we present the first comparison between observations and particle-in-cell simulations of such entropy generation across a collisionless shock. The ion heating at the shock is dominated by the phase mixing of reflected and directly transmitted ions, which are separated from the incident ions. The electron heating is a nearly thermal process due to the conservation of their angular momentum. For both species, we calculate the entropy density across the shock, and obtain good consistency between observations and simulations on entropy generation across the shock. We also find that the entropy generation rate is reduced as the shock Mach number decreases.
Authors:
; ; ;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China)
  2. Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
  3. Department of Physics and Astronomy, University of Delaware, Newark, DE (United States)
  4. CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei (China)
  5. Memorial University of Newfoundland, St. John's (Canada)
Publication Date:
OSTI Identifier:
22365001
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 793; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANGULAR MOMENTUM; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DENSITY; ELECTRONS; ENTROPY; IONS; MACH NUMBER; PLASMA; SHOCK WAVES; SOLAR WIND