Very Oblique Whistler Mode Propagation in the Radiation Belts: Effects of Hot Plasma and Landau Damping
Abstract
Satellite observations of a significant population of very oblique chorus waves in the outer radiation belt have fueled considerable interest in the effects of these waves on energetic electron scattering and acceleration. However, corresponding diffusion rates are extremely sensitive to the refractive index N, controlled by hot plasma effects including Landau damping and wave dispersion modifications by suprathermal (15–100 eV) electrons. A combined investigation of wave and electron distribution characteristics obtained from the Van Allen Probes shows that peculiarities of the measured electron distribution significantly reduce Landau damping, allowing wave propagation with high N ∼ 100–200. Further comparing measured refractive indexes with theoretical estimates incorporating hot plasma corrections to the wave dispersion, we provide the first experimental demonstration that suprathermal electrons indeed control the upper limit of the refractive index of highly oblique whistler mode waves. Such results further support the importance of incorporating very oblique waves into radiation belt models.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 26, 2017
- Source ID
- 10.1002/2017gl075892
Entities
People
- Anton V. Artemyev
- Craig Kletzing
- D. Mourenas
- Geoffrey D Reeves
- George G. Hospodarsky
- Harlan Spence
- John Wygant
- Qianli Ma
- Richard Thorne
- Wen Li
- William S. Kurth
Organizations
- Air Force Office of Scientific Research
- Boston University
- European Committee for Treatment and Research in Multiple Sclerosis
- Los Alamos National Laboratory
- National Aeronautics and Space Administration
- National Science Foundation
- University of Iowa
- University of Minnesota
- University of New Hampshire