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Energetic oxygen: A direct coupling mechanism between the magnetosphere and thermosphere
Author(s) -
Torr Marsha R.,
Torr D. G.
Publication year - 1979
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl006i009p00700
Subject(s) - thermosphere , ion , atmosphere (unit) , flux (metallurgy) , atomic physics , plasmasphere , magnetosphere , ionization , physics , electron precipitation , oxygen , energetic neutral atom , splash , ionosphere , atmospheric sciences , materials science , plasma , geophysics , nuclear physics , meteorology , quantum mechanics , metallurgy
This study investigates the effects of the precipitation of energetic O + ions (0.7 – 12 keV) into the atmosphere during magnetic storms. The energetic O + ion flux produces a splash of lower energy neutral oxygen atoms at the top of the atmosphere. As a result of the photo‐ionization and charge exchange with H + ions in the plasmaspherethese backscattered atoms produce a low energy O + flux that is more than 10 times larger in magnitude than the original energetic O + flux. The energetic O + events thus provide a potential source mechanism for the lower energy (≲30 eV) O + ions observed in the plasmasphere. We also suggest that the energetic ion events may be self‐sustaining in that some of the ionized ‘splash’ particles (≲10%) are subsequently accelerated by an as yet unidentified mechanism to the higher observed energies. We find that 96% of the incoming energy is transferred to the neutral atmosphere in the form of heating. Measured fluxes indicate heating rates as high as ∼0.4 ergs cm −2 sec −1 ster −1 .