Journal Highlights

New results on the composition of energetic ions in the middle and outer magnetosphere

Editor’s Highlight—

 

This paper examines the nature and source of energetic heavy ions in the middle and outer magnetosphere. This is important for understanding the dynamics of magnetosphere, the sources of magnetospheric plasmas, and the processes of ion energization. The authors analyze measurements from two instruments on NASA’s Magnetospheric Multiscale Mission (MMS) which is studying the Earth’s magnetosphere. The Fly’s Eye Energetic Particle Spectrometer (FEEPS) measures total ion flux while the Energetic Ion Spectrometer (EIS) measures only protons. A comparison of measurements from the two instruments found that at the ion energies above 150 keV, the dominating ions in the middle to outer magnetosphere are heavy ions (helium and oxygen of the solar wind origin). These results contradict many previous results that were obtained on the assumption that the heavy energetic ions populating this region of the magnetosphere are protons. In light of their findings, the authors emphasize the need to use unambiguous measurements of energetic heavy ions.

Article Category
Research Articles
Magnetospheric Physics

Dominance of high‐energy (>150 keV) heavy ion intensities in Earth's middle to outer magnetosphere

Ian J. Cohen, Donald G. Mitchell, Lynn M. Kistler, Barry H. Mauk, Brian J. Anderson, Joseph H. Westlake, Shinichi Ohtani, Douglas C. Hamilton, Drew L. Turner, J. Bernard Blake, Joseph F. Fennell, Allison N. Jaynes, Trevor W. Leonard, Andrew J. Gerrard, Louis J. Lanzerotti, Robert C. Allen, James L. Burch
First Published:
| DOI:
10.1002/2017JA024351