@article{bd62388e59414a00a68679602d35b69a,
title = "The Relationship Between EMIC Wave Properties and Proton Distributions Based on Van Allen Probes Observations",
abstract = "Plasma kinetic theory predicts that sufficiently anisotropic proton distribution will excite electromagnetic ion cyclotron (EMIC) waves, which in turn relax the proton distribution to a marginally stable state creating an upper bound on the relaxed proton anisotropy. Here, using EMIC wave observations and coincident plasma measurements made by Van Allen Probes in the inner magnetosphere, we show that the proton distributions are well constrained by this instability to a marginally stable state. Near the threshold, the probability of EMIC wave occurrence is highest, having left-handed polarization and observed near the magnetic equator with relatively small wave normal angles, indicating that these waves are locally generated. In addition, EMIC waves are distributed in two magnetic local time regions with different intensity. Compared with helium band waves, hydrogen band waves behave similarly except that they are often observed in low-density regions. These results reveal several important features regarding EMIC waves excitation and propagation.",
keywords = "EMIC waves, Van Allen Probes, helium band, hydrogen band, plasma beta, proton temperature anisotropy",
author = "Chao Yue and Jun, {Chae Woo} and Jacob Bortnik and Xin An and Qianli Ma and Reeves, {Geoffrey D.} and Spence, {Harlan E.} and Gerrard, {Andrew J.} and Matina Gkioulidou and Mitchell, {Donald G.} and Kletzing, {Craig A.}",
note = "Funding Information: This work was supported by the NASA LWS grant NNX14AN85G and NASA HTIDeS NNX16AG21G. We acknowledge use of Van Allen Probes new release 04 data of the Level 3 HOPE unidimensional particle flux data obtained from the RBSP‐ECT website (rbsp‐ect.lanl.gov/data_pub/ rbspb/hope/level3/PA/), made publicly available through NASA Prime contract NAS5‐01072; the Level 3 RBSPICE unidimensional particle flux data obtained from the RBSPICE website (http://rbspicea.ftecs.com/Level_ 3PAP/); the Level 3 magnetometer data obtained from the RBSP EMFISIS website (emfisis.physics.uiowa.edu/ Flight/RBSP‐B/L3). We thank the Space Physics Data Facility at the NASA Goddard Space Flight Center for providing the OMNI data (ftp://spdf. gsfc.nasa.gov/pub/data/omni/omni_ cdaweb/). Funding Information: This work was supported by the NASA LWS grant NNX14AN85G and NASA HTIDeS NNX16AG21G. We acknowledge use of Van Allen Probes new release 04 data of the Level 3 HOPE unidimensional particle flux data obtained from the RBSP-ECT website (rbsp-ect.lanl.gov/data_pub/rbspb/hope/level3/PA/), made publicly available through NASA Prime contract NAS5-01072; the Level 3 RBSPICE unidimensional particle flux data obtained from the RBSPICE website (http://rbspicea.ftecs.com/Level_3PAP/); the Level 3 magnetometer data obtained from the RBSP EMFISIS website (emfisis.physics.uiowa.edu/Flight/RBSP-B/L3). We thank the Space Physics Data Facility at the NASA Goddard Space Flight Center for providing the OMNI data (ftp://spdf.gsfc.nasa.gov/pub/data/omni/omni_cdaweb/). Publisher Copyright: {\textcopyright}2019. American Geophysical Union. All Rights Reserved.",
year = "2019",
month = apr,
day = "28",
doi = "10.1029/2019GL082633",
language = "English (US)",
volume = "46",
pages = "4070--4078",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "8",
}