Li W., R. M. Thorne, J. Bortnik, Y. Y. Shprits, Y. Nishimura, V. Angelopoulos, C. Chaston, O. Le Contel, J. W. Bonnell, (2011), Typical properties of rising and falling tone chorus waves, Geophysical Research Letters, 38, doi:10.1029/2011GL047925

Abstract

Chorus waves, which have received intense attention recently due to their significant role in radiation belt electron dynamics, frequently exhibit rising and falling tones. Lower-band chorus waves, observed using THEMIS wave burst data, are analyzed to obtain the typical properties of either class of chorus emissions. Our results show that rising tones are more likely to be quasi field-aligned, whereas falling tones are typically very oblique, close to the resonance cone. Furthermore, rising tones occur significantly more often than falling tones, and magnetic amplitudes of rising tones are generally much larger than those of falling tones. We also show the preferential regions of rising and falling tones dependent on MLT and magnetic latitude. Our new findings suggest that two separate mechanisms may be responsible for the generation and nonlinear evolution of rising and falling tone chorus.

Authors (sorted by name)

Angelopoulos Bonnell Bortnik Chaston Le Contel Li Nishimura Shprits Thorne

Journal / Conference

Geophysical Research Letters

Acknowledgments

This research was funded in part by NASA grants NNX11AD75G, NNX08AI35G, and NAS5‐02099, and NSF grant AGS‐0840178. The authors acknowledge A. Roux for use of SCM data, F. S. Mozer for use of EFI data, and K. H. Glassmeier, U. Auster, and W. Baumjohann for the use of FGM data provided under the lead of the Technical University of Braunschweig and with financial support through the German Ministry for Economy and Technology and the German Center for Aviation and Space (DLR) under contract 50 OC 0302.

Grants

50 OC 0302 AGS‐0840178 NAS5‐02099 NNX08AI35G NNX11AD75G

Bibtex

@article{doi:10.1029/2011GL047925,
author = {Li, W. and Thorne, R. M. and Bortnik, J. and Shprits, Y. Y. and Nishimura, Y. and Angelopoulos, V. and Chaston, C. and Le Contel, O. and Bonnell, J. W.},
title = {Typical properties of rising and falling tone chorus waves},
journal = {Geophysical Research Letters},
year = {2011},
volume = {38},
number = {14},
pages = {},
keywords = {chorus, falling tone, rising tone, wave normal angle},
doi = {10.1029/2011GL047925},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011GL047925},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2011GL047925},
abstract = {Chorus waves, which have received intense attention recently due to their significant role in radiation belt electron dynamics, frequently exhibit rising and falling tones. Lower-band chorus waves, observed using THEMIS wave burst data, are analyzed to obtain the typical properties of either class of chorus emissions. Our results show that rising tones are more likely to be quasi field-aligned, whereas falling tones are typically very oblique, close to the resonance cone. Furthermore, rising tones occur significantly more often than falling tones, and magnetic amplitudes of rising tones are generally much larger than those of falling tones. We also show the preferential regions of rising and falling tones dependent on MLT and magnetic latitude. Our new findings suggest that two separate mechanisms may be responsible for the generation and nonlinear evolution of rising and falling tone chorus.}
}