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The ionosphere of Triton
Author(s) -
Majeed T.,
McConnell J. C.,
Strobel D. P.,
Summers M. E.
Publication year - 1990
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/gl017i010p01721
Subject(s) - ionosphere , ion , ionization , dissociative recombination , physics , dissociation (chemistry) , atmosphere (unit) , electron density , electron ionization , thermosphere , electron , atomic physics , atmospheric sciences , astronomy , chemistry , meteorology , recombination , biochemistry , quantum mechanics , gene
We have used a model of the atmospheric temperature structure and composition inferred from the Voyager UVS solar occultations together with a 1‐D chemical diffusive model to interpret the Voyager RSS ingress measurements of Triton's electron density. Although N + 2 is the major ion created, N + produced by dissociative ionization is the dominant ion. Reaction of thermospheric H 2 , produced by Lyman‐α dissociation of CH 4 in the lower atmosphere, is the major loss for N + ions and maintains these ions in PCSS below 600 km. Solar EUV ionisation cannot generate electron densities at the magnitude measured by the RSS experiment and an additional ionosphere source ∼ 3 × 10 8 ions cm −2 s −1 is required. The ionosphere may undergo a transition from PCSS to diffusive control if the N + ion production rates were greater than the H 2 flax derived from CH 4 . In this case the upward flowing H 2 is totally converted to H by reaction with N + and the remaining N + ions recombine radiatively to create an ionosphere under diffusive control above the peak.