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Title: The occurrence and wave properties of H⁺-, He⁺-, and O⁺-band EMIC waves observed by the Van Allen Probes

We perform a statistical study of electromagnetic ion cyclotron (EMIC) waves detected by the Van Allen Probes mission to investigate the spatial distribution of their occurrence, wave power, ellipticity, and normal angle. The Van Allen Probes have been used which allow us to explore the inner magnetosphere (1.1 to 5.8 RE). Magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes are used to identify EMIC wave events for the first 22 months of the mission operation (8 September 2012 to 30 June 2014). EMIC waves are examined in H⁺-, He⁺-, and O⁺-bands. Over 700 EMIC wave events have been identified over the three different wave bands (265 H⁺-band events, 438 He⁺-band events, and 68 O⁺-band events). EMIC wave events are observed between L = 2 – 8, with over 140 EMIC wave events observed below L = 4. The results show that H⁺-band EMIC waves have two peak magnetic local time (MLT) occurrence regions: pre-noon (09:00 < MLT ≤ 12:00) and afternoon (15:00 < MLT ≤ 17:00) sectors. He⁺-band EMIC waves feature an overall stronger dayside occurrence. O⁺-band EMIC waves have one peak region located in the morning sectormore » at lower L shells (L < 4). He⁺-band EMIC waves average the highest wave power overall (>0.1 nT²/Hz), especially in the afternoon sector. Ellipticity observations reveal that linearly polarized EMIC waves dominate in lower L shells.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [3] ;  [4]
  1. Univ. of New Hampshire, Durham, NH (United States)
  2. Univ. of Texas at San Antonio, TX (United States); Southwest Research Institute, San Antonio, TX (United States)
  3. Univ. of Iowa, Iowa City, IA (United States)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
OSTI Identifier:
1221606
Report Number(s):
LA-UR--15-23068
Journal ID: ISSN 2169-9380
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Name: Journal of Geophysical Research. Space Physics; Journal ID: ISSN 2169-9380
Publisher:
American Geophysical Union
Research Org:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES EMIC waves; Van Allen Probes; Fast Fourier Transform; spatial distribution; band separation