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Observations of the spatial distribution of energetic O 3+ , O 4+ , and O 5+ ions in the magnetosphere
Author(s) -
Kremser G.,
Stüdemann W.,
Wilken B.,
Gloeckler G.
Publication year - 1987
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/gl014i007p00685
Subject(s) - ion , magnetosphere , physics , solar wind , atomic physics , flux (metallurgy) , plasma , materials science , nuclear physics , quantum mechanics , metallurgy
The Charge‐Energy‐Mass Spectrometer CHEM on the AMPTE/CCE spacecraft provides measurements of oxygen ions with charge states between 1 and 6 in the magnetosphere close to the equatorial plane. The first investigations of the spatial distribution of O 3+ , O 4+ , and O 5+ ions revealed that these ions are continuously present in the magnetosphere. Their L profiles exhibit broad maxima that are located at 6 ⩽ L ⩽ 7 for O 3+ and O 4+ and at 7 ⩽ L ⩽ 8 for O 5+ ions during periods of low to medium geomagnetic activity (Kp < 4). With increasing Kp the flux versus L distributions extend further earthward and the maxima move to slightly lower L values. While the flux decrease earthward of the maximum is very steep, the gradual decrease outward of the maximum becomes flatter with increasing charge state. Comparison of these profiles to those of O + , O 2+ , and O 6+ ions suggests that O 3+ , O 4+ , and O 5+ ions are produced predominantly by charge exchange processes, and that the O 4+ and O 5+ ions are produced from the solar wind origin O 6+ . Our measurements of O 3+ indicate that both the solar wind O 6+ and the terrestrial ions O + and O 2+ contribute to the production of this ion species.