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Title: Correlation of electron path lengths observed in the highly wound outer region of magnetic clouds with the slab fraction of magnetic turbulence in the dissipation range

Three magnetic cloud events, in which solar impulsive electron events occurred in their outer region, are employed to investigate the difference of path lengths L {sub 0eIII} traveled by non-relativistic electrons from their release site near the Sun to the observer at 1 AU, where L {sub 0eIII} = v {sub l} × (t {sub l} – t {sub III}), v {sub l} and t {sub l} being the velocity and arrival time of electrons in the lowest energy channel (∼27 keV) of the Wind/3DP/SST sensor, respectively, and t {sub III} being the onset time of type III radio bursts. The deduced L {sub 0eIII} value ranges from 1.3 to 3.3 AU. Since a negligible interplanetary scattering level can be seen in both L {sub 0eIII} > 3 AU and ∼1.2 AU events, the difference in L {sub 0eIII} could be linked to the turbulence geometry (slab or two-dimensional) in the solar wind. By using the Wind/MFI magnetic field data with a time resolution of 92 ms, we examine the turbulence geometry in the dissipation range. In our examination, ∼6 minutes of sampled subintervals are used in order to improve time resolution. We have found that, in the transverse turbulence,more » the observed slab fraction is increased with an increasing L {sub 0eIII} value, reaching ∼100% in the L {sub 0eIII} > 3 AU event. Our observation implies that when only the slab spectral component exists, magnetic flux tubes (magnetic surfaces) are closed and regular for a very long distance along the transport route of particles.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4]
  1. Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
  2. Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)
  3. College of Science, George Mason University, Fairfax, VA 22030 (United States)
  4. Department of Geophysics, Peking University, Beijing 100871 (China)
Publication Date:
OSTI Identifier:
22356932
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRELATIONS; DATA; DISTANCE; ELECTRONS; EMISSION; KEV RANGE; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETIC SURFACES; MASS; RELATIVISTIC RANGE; SCATTERING; SLABS; SOLAR WIND; SUN; TIME RESOLUTION; TURBULENCE; TWO-DIMENSIONAL CALCULATIONS; VELOCITY