Very Oblique Whistler Mode Propagation in the Radiation Belts: Effects of Hot Plasma and Landau Damping

Q. Ma; A. V. Artemyev; D. Mourenas; W. Li; R. M. Thorne; C. A. Kletzing; W. S. Kurth; G. B. Hospodarsky; G. D. Reeves; H. E. Spence; J. Wygant

doi:10.1002/2017GL075892

Very Oblique Whistler Mode Propagation in the Radiation Belts: Effects of Hot Plasma and Landau Damping

Q. Ma, A. V. Artemyev, D. Mourenas, W. Li, R. M. Thorne, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky, G. D. Reeves, H. E. Spence, J. Wygant

Physics and Astronomy (Twin Cities)

Research output: Contribution to journal › Article › peer-review

28 Scopus citations

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.

Original language	English (US)
Pages (from-to)	12,057-12,066
Journal	Geophysical Research Letters
Volume	44
Issue number	24
DOIs	https://doi.org/10.1002/2017GL075892
State	Published - Dec 28 2017

Bibliographical note

Funding Information:
The work of Q. M. was supported by JHU/APL contracts 967399 and 921647 under NASA’s prime contract NAS5-01072 and by the EMFISIS subaward 1001057397:01 and ECT subaward 13-041. W. L. would like to acknowledge the NASA grants NNX17AD15G and NNX17AG07G, the NSF grant AGS-1723588, and the AFOSR grant FA9550-15-1-0158. The Van Allen Probes data from the EMFISIS instrument are available from http://emfisis.physics.uiowa.edu/ data/index/, data from the HOPE instrument are available from http://www.rbsp-ect.lanl.gov/data_pub/, and data from the EFW instrument are available from http://rbsp.space. umn.edu/data/rbsp/.

Funding Information:
The work of Q. M. was supported by JHU/APL contracts 967399 and 921647 under NASA's prime contract NAS5-01072 and by the EMFISIS subaward 1001057397:01 and ECT subaward 13-041. W. L. would like to acknowledge the NASA grants NNX17AD15G and NNX17AG07G, the NSF grant AGS-1723588, and the AFOSR grant FA9550-15-1-0158. The Van Allen Probes data from the EMFISIS instrument are available from http://emfisis.physics.uiowa.edu/data/index/, data from the HOPE instrument are available from http://www.rbsp-ect.lanl.gov/data_pub/, and data from the EFW instrument are available from http://rbsp.space.umn.edu/data/rbsp/.

Publisher Copyright:
©2017. American Geophysical Union. All Rights Reserved.

Keywords

Landau damping
Van Allen Probes observation
maximum refractive index
oblique chorus waves
thermal electron effects

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10.1002/2017GL075892

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@article{efede9636bf149cb96abf7539be276d3,

title = "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.",

keywords = "Landau damping, Van Allen Probes observation, maximum refractive index, oblique chorus waves, thermal electron effects",

author = "Q. Ma and Artemyev, {A. V.} and D. Mourenas and W. Li and Thorne, {R. M.} and Kletzing, {C. A.} and Kurth, {W. S.} and Hospodarsky, {G. B.} and Reeves, {G. D.} and Spence, {H. E.} and J. Wygant",

note = "Funding Information: The work of Q. M. was supported by JHU/APL contracts 967399 and 921647 under NASA{\textquoteright}s prime contract NAS5-01072 and by the EMFISIS subaward 1001057397:01 and ECT subaward 13-041. W. L. would like to acknowledge the NASA grants NNX17AD15G and NNX17AG07G, the NSF grant AGS-1723588, and the AFOSR grant FA9550-15-1-0158. The Van Allen Probes data from the EMFISIS instrument are available from http://emfisis.physics.uiowa.edu/ data/index/, data from the HOPE instrument are available from http://www.rbsp-ect.lanl.gov/data_pub/, and data from the EFW instrument are available from http://rbsp.space. umn.edu/data/rbsp/. Funding Information: The work of Q. M. was supported by JHU/APL contracts 967399 and 921647 under NASA's prime contract NAS5-01072 and by the EMFISIS subaward 1001057397:01 and ECT subaward 13-041. W. L. would like to acknowledge the NASA grants NNX17AD15G and NNX17AG07G, the NSF grant AGS-1723588, and the AFOSR grant FA9550-15-1-0158. The Van Allen Probes data from the EMFISIS instrument are available from http://emfisis.physics.uiowa.edu/data/index/, data from the HOPE instrument are available from http://www.rbsp-ect.lanl.gov/data_pub/, and data from the EFW instrument are available from http://rbsp.space.umn.edu/data/rbsp/. Publisher Copyright: {\textcopyright}2017. American Geophysical Union. All Rights Reserved.",

year = "2017",

month = dec,

day = "28",

doi = "10.1002/2017GL075892",

language = "English (US)",

volume = "44",

pages = "12,057--12,066",

journal = "Geophysical Research Letters",

issn = "0094-8276",

publisher = "American Geophysical Union",

number = "24",

}

TY - JOUR

T1 - Very Oblique Whistler Mode Propagation in the Radiation Belts

T2 - Effects of Hot Plasma and Landau Damping

AU - Ma, Q.

AU - Artemyev, A. V.

AU - Mourenas, D.

AU - Li, W.

AU - Thorne, R. M.

AU - Kletzing, C. A.

AU - Kurth, W. S.

AU - Hospodarsky, G. B.

AU - Reeves, G. D.

AU - Spence, H. E.

AU - Wygant, J.

N1 - Funding Information: The work of Q. M. was supported by JHU/APL contracts 967399 and 921647 under NASA’s prime contract NAS5-01072 and by the EMFISIS subaward 1001057397:01 and ECT subaward 13-041. W. L. would like to acknowledge the NASA grants NNX17AD15G and NNX17AG07G, the NSF grant AGS-1723588, and the AFOSR grant FA9550-15-1-0158. The Van Allen Probes data from the EMFISIS instrument are available from http://emfisis.physics.uiowa.edu/ data/index/, data from the HOPE instrument are available from http://www.rbsp-ect.lanl.gov/data_pub/, and data from the EFW instrument are available from http://rbsp.space. umn.edu/data/rbsp/. Funding Information: The work of Q. M. was supported by JHU/APL contracts 967399 and 921647 under NASA's prime contract NAS5-01072 and by the EMFISIS subaward 1001057397:01 and ECT subaward 13-041. W. L. would like to acknowledge the NASA grants NNX17AD15G and NNX17AG07G, the NSF grant AGS-1723588, and the AFOSR grant FA9550-15-1-0158. The Van Allen Probes data from the EMFISIS instrument are available from http://emfisis.physics.uiowa.edu/data/index/, data from the HOPE instrument are available from http://www.rbsp-ect.lanl.gov/data_pub/, and data from the EFW instrument are available from http://rbsp.space.umn.edu/data/rbsp/. Publisher Copyright: ©2017. American Geophysical Union. All Rights Reserved.

PY - 2017/12/28

Y1 - 2017/12/28

N2 - 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.

AB - 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.

KW - Landau damping

KW - Van Allen Probes observation

KW - maximum refractive index

KW - oblique chorus waves

KW - thermal electron effects

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U2 - 10.1002/2017GL075892

DO - 10.1002/2017GL075892

M3 - Article

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SN - 0094-8276

VL - 44

SP - 12,057-12,066

JO - Geophysical Research Letters

JF - Geophysical Research Letters

IS - 24

ER -

Very Oblique Whistler Mode Propagation in the Radiation Belts: Effects of Hot Plasma and Landau Damping

Abstract

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Keywords

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