Annales Geophysicae (Dec 2010)

First measurements of electron vorticity in the foreshock and solar wind

  • C. Gurgiolo,
  • M. L. Goldstein,
  • A. F. Viñas,
  • A. N. Fazakerley

DOI
https://doi.org/10.5194/angeo-28-2187-2010
Journal volume & issue
Vol. 28
pp. 2187 – 2200

Abstract

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We describe the methodology used to set up and compute spatial derivatives of the electron moments using data acquired by the Plasma Electron And Current Experiment (PEACE) from the four Cluster spacecraft. The results are used to investigate electron vorticity in the foreshock. We find that much of the measured vorticity, under nominal conditions, appears to be caused by changes in the flow direction of the return (either reflected or leakage from the magnetosheath) and strahl electron populations as they couple to changes in the magnetic field orientation. This in turn results in deflections in the total bulk velocity producing the measured vorticity.