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Origin of two-band chorus in the radiation belt of Earth
Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two dist...
Autores principales: | , , , , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6791895/ https://www.ncbi.nlm.nih.gov/pubmed/31611553 http://dx.doi.org/10.1038/s41467-019-12561-3 |
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author | Li, Jinxing Bortnik, Jacob An, Xin Li, Wen Angelopoulos, Vassilis Thorne, Richard M. Russell, Christopher T. Ni, Binbin Shen, Xiaochen Kurth, William S. Hospodarsky, George B. Hartley, David P. Funsten, Herbert O. Spence, Harlan E. Baker, Daniel N. |
author_facet | Li, Jinxing Bortnik, Jacob An, Xin Li, Wen Angelopoulos, Vassilis Thorne, Richard M. Russell, Christopher T. Ni, Binbin Shen, Xiaochen Kurth, William S. Hospodarsky, George B. Hartley, David P. Funsten, Herbert O. Spence, Harlan E. Baker, Daniel N. |
author_sort | Li, Jinxing |
collection | PubMed |
description | Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two distinct frequency bands separated by a gap. The origin of this two-band structure remains a 50-year old question. Here we report, using NASA’s Van Allen Probe measurements, that banded chorus waves are commonly accompanied by two separate anisotropic electron components. Using numerical simulations, we show that the initially excited single-band chorus waves alter the electron distribution immediately via Landau resonance, and suppress the electron anisotropy at medium energies. This naturally divides the electron anisotropy into a low and a high energy components which excite the upper-band and lower-band chorus waves, respectively. This mechanism may also apply to the generation of chorus waves in other magnetized planetary magnetospheres. |
format | Online Article Text |
id | pubmed-6791895 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-67918952019-10-17 Origin of two-band chorus in the radiation belt of Earth Li, Jinxing Bortnik, Jacob An, Xin Li, Wen Angelopoulos, Vassilis Thorne, Richard M. Russell, Christopher T. Ni, Binbin Shen, Xiaochen Kurth, William S. Hospodarsky, George B. Hartley, David P. Funsten, Herbert O. Spence, Harlan E. Baker, Daniel N. Nat Commun Article Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two distinct frequency bands separated by a gap. The origin of this two-band structure remains a 50-year old question. Here we report, using NASA’s Van Allen Probe measurements, that banded chorus waves are commonly accompanied by two separate anisotropic electron components. Using numerical simulations, we show that the initially excited single-band chorus waves alter the electron distribution immediately via Landau resonance, and suppress the electron anisotropy at medium energies. This naturally divides the electron anisotropy into a low and a high energy components which excite the upper-band and lower-band chorus waves, respectively. This mechanism may also apply to the generation of chorus waves in other magnetized planetary magnetospheres. Nature Publishing Group UK 2019-10-14 /pmc/articles/PMC6791895/ /pubmed/31611553 http://dx.doi.org/10.1038/s41467-019-12561-3 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Li, Jinxing Bortnik, Jacob An, Xin Li, Wen Angelopoulos, Vassilis Thorne, Richard M. Russell, Christopher T. Ni, Binbin Shen, Xiaochen Kurth, William S. Hospodarsky, George B. Hartley, David P. Funsten, Herbert O. Spence, Harlan E. Baker, Daniel N. Origin of two-band chorus in the radiation belt of Earth |
title | Origin of two-band chorus in the radiation belt of Earth |
title_full | Origin of two-band chorus in the radiation belt of Earth |
title_fullStr | Origin of two-band chorus in the radiation belt of Earth |
title_full_unstemmed | Origin of two-band chorus in the radiation belt of Earth |
title_short | Origin of two-band chorus in the radiation belt of Earth |
title_sort | origin of two-band chorus in the radiation belt of earth |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6791895/ https://www.ncbi.nlm.nih.gov/pubmed/31611553 http://dx.doi.org/10.1038/s41467-019-12561-3 |
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