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Energetic oxygen ions of ionospheric origin observed in the cusp
Author(s) -
Chen Jiasheng,
Fritz Theodore A.
Publication year - 2001
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 - 10.1029/2000gl012128
Subject(s) - ionosphere , physics , cusp (singularity) , ion , ring current , polar , daytime , geophysics , amplitude , satellite , astrophysics , atomic physics , magnetosphere , atmospheric sciences , astronomy , plasma , geometry , nuclear physics , optics , mathematics , quantum mechanics
On 8/27/96 from 8 to 10:36 UT the POLAR satellite crossed the dayside cusp and observed very energetic ionospheric O ≤ +2 ions which had a magnetic moment spectrum, M ( E ) that followed a power law. Later at 14:45 to 15:30 UT the satellite passed through the ring current at 15–16 MLT where the O ≤ +2 ions again had a M ( E ) power law form but with a spectral amplitude that was two orders of magnitude lower. During this period from 8 to 16 UT there were no magnetic storms as D st had an average value of ∼ −5 nT. The comparison of the fluxes at constant M means that the energetic ions in the cusp cannot have a source in the ring current. Arguments are given that the comparison of these sequential measurements of M ( E ) are valid and that a new mechanism is needed for producing these energetic ionospheric ions observed in the cusp.