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Title: Modulation of chorus intensity by ULF waves deep in the inner magnetosphere

Previous studies have shown that chorus wave intensity can be modulated by Pc4-Pc5 compressional ULF waves. In this paper, we present Van Allen Probes observation of ULF wave modulating chorus wave intensity, which occurred deep in the magnetosphere. The ULF wave shows fundamental poloidal mode signature and mirror mode compressional nature. The observed ULF wave can modulate not only the chorus wave intensity but also the distribution of both protons and electrons. Linear growth rate analysis shows consistence with observed chorus intensity variation at low frequency (f <~ 0.3f ce), but cannot account for the observed higher-frequency chorus waves, including the upper band chorus waves. This suggests the chorus waves at higher-frequency ranges require nonlinear mechanisms. Finally, in addition, we use combined observations of Radiation Belt Storm Probes (RBSP) A and B to verify that the ULF wave event is spatially local and does not last long.
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ; ORCiD logo [6]
  1. Univ. of Texas, Dallas, TX (United States). Dept. of Physics
  2. Chinese Academy of Sciences (CAS), Beijing (China). State Key Lab. of Space Weather. National Space Science Center
  3. Aerospace Corporation, El Segundo, CA (United States)
  4. Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy
  5. New Jersey Inst. of Technology, Newark, NJ (United States)
  6. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0094-8276; TRN: US1702880
Grant/Contract Number:
AC52-06NA25396; AGS 1405041; NNX15AI93G; NNX14AN55G
Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Volume: 43; Journal Issue: 18; Journal ID: ISSN 0094-8276
American Geophysical Union
Research Org:
Univ. of Texas, Dallas, TX (United States); Rice Univ., Houston, TX (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE; National Science Foundation (NSF); National Aeronautic and Space Administration (NASA)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; chorus modulation; ULF wave; whistler wave; inner magnetosphere
OSTI Identifier: