Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: 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.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
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
_version_ 1783459045781274624
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
work_keys_str_mv AT lijinxing originoftwobandchorusintheradiationbeltofearth
AT bortnikjacob originoftwobandchorusintheradiationbeltofearth
AT anxin originoftwobandchorusintheradiationbeltofearth
AT liwen originoftwobandchorusintheradiationbeltofearth
AT angelopoulosvassilis originoftwobandchorusintheradiationbeltofearth
AT thornerichardm originoftwobandchorusintheradiationbeltofearth
AT russellchristophert originoftwobandchorusintheradiationbeltofearth
AT nibinbin originoftwobandchorusintheradiationbeltofearth
AT shenxiaochen originoftwobandchorusintheradiationbeltofearth
AT kurthwilliams originoftwobandchorusintheradiationbeltofearth
AT hospodarskygeorgeb originoftwobandchorusintheradiationbeltofearth
AT hartleydavidp originoftwobandchorusintheradiationbeltofearth
AT funstenherberto originoftwobandchorusintheradiationbeltofearth
AT spenceharlane originoftwobandchorusintheradiationbeltofearth
AT bakerdanieln originoftwobandchorusintheradiationbeltofearth