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Double photoionization and doubly charged ions in the thermosphere
Author(s) -
Victor G. A.,
Constantinides E. R.
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/gl006i006p00519
Subject(s) - thermosphere , photoionization , ion , atomic physics , ionization , physics , charge exchange , ionosphere , sink (geography) , atmospheric sciences , astronomy , quantum mechanics , cartography , geography
We show that a plausible cross section for double photoionization of atomic oxygen, hν ( λ < 254 Å ) + O → O + + + 2 e yields the dominant source mechanism for O ++ in the thermosphere. With this large source, harmony is obtained between the measured O ++ concentrations and the large (k ∼ 10 −9 cm³ s −1 ) measured sink (by charge exchange with molecular species) at altitudes above about 250 km.