Excitation of Banded Whistler Waves in the Magnetosphere
Abstract
Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.
- Authors:
-
- Los Alamos National Laboratory
- Publication Date:
- Research Org.:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Org.:
- USDOD
- OSTI Identifier:
- 1046514
- Report Number(s):
- LA-UR-12-22995
TRN: US1203782
- DOE Contract Number:
- AC52-06NA25396
- Resource Type:
- Conference
- Resource Relation:
- Conference: DTRA Review ; 2012-07-19 - 2012-07-19 ; Los Alamos, New Mexico, United States
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANISOTROPY; ELECTRIC FIELDS; ELECTRONS; EXCITATION; GEOMAGNETIC EQUATOR; INSTABILITY; LANDAU DAMPING; MAGNETIC FIELDS; SATURATION; WHISTLERS
Citation Formats
Gary, S Peter, Liu, Kaijun, and Winske, Dan. Excitation of Banded Whistler Waves in the Magnetosphere. United States: N. p., 2012.
Web.
Gary, S Peter, Liu, Kaijun, & Winske, Dan. Excitation of Banded Whistler Waves in the Magnetosphere. United States.
Gary, S Peter, Liu, Kaijun, and Winske, Dan. 2012.
"Excitation of Banded Whistler Waves in the Magnetosphere". United States. https://www.osti.gov/servlets/purl/1046514.
@article{osti_1046514,
title = {Excitation of Banded Whistler Waves in the Magnetosphere},
author = {Gary, S Peter and Liu, Kaijun and Winske, Dan},
abstractNote = {Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.},
doi = {},
url = {https://www.osti.gov/biblio/1046514},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jul 13 00:00:00 EDT 2012},
month = {Fri Jul 13 00:00:00 EDT 2012}
}