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

Author(s)

Tan, Lun C. ^{[1, 2]} ; Reames, Donald V. ^[3] ; Ng, Chee K. ^[4] ; Shao, Xi ^{[1, 2]} ; Wang, Linghua ^[5]

Affiliation

^[1] Univ Maryland, Dept Astron, College Pk, MD 20742 - USA

^[2] Univ Maryland Baltimore Cty, Goddard Planetary Heliophys Inst, Baltimore, MD 21228 - USA

^[3] Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 - USA

^[4] George Mason Univ, Coll Sci, Fairfax, VA 22030 - USA

^[5] Peking Univ, Dept Geophys, Beijing 100871 - Peoples R China

• Document type: Journal article
• Source: ASTROPHYSICAL JOURNAL; v. 786, n. 2 MAY 10 2014.
• Web of Science Citations: 5

Abstract

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-0eIII traveled by non-relativistic electrons from their release site near the Sun to the observer at 1 AU, where L-0eIII = v(1) x (t(1) - t(III)), v(1) and t(1) being the velocity and arrival time of electrons in the lowest energy channel (similar to 27 keV) of the Wind/3DP/SST sensor, respectively, and t(III) being the onset time of type III radio bursts. The deduced L0eIII value ranges from 1.3 to 3.3 AU. Since a negligible interplanetary scattering level can be seen in both L-0eIII > 3 AU and similar to 1.2 AU events, the difference in L-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, similar to 6 minutes of sampled subintervals are used in order to improve time resolution. We have found that, in the transverse turbulence, the observed slab fraction is increased with an increasing L-0eIII value, reaching similar to 100% in the L-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. (AU)

• FAPESP's process: 10/19029-0 - 3D radiative transfer models: bridging theory and observations
• Grantee: Alex Cavaliéri Carciofi
• Support type: Regular Research Grants
• FAPESP's process: 09/07477-1 - Probing atmospheres and circumstellar environments of Be stars and evolved low mass stars with interferometry and polarimetry
• Grantee: Xavier Marie Alain Haubois
• Support type: Scholarships in Brazil - Post-Doctorate