Premium
Positive Ion Chemistry of the D and E Regions
Author(s) -
Donahue T. M.
Publication year - 1972
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs007i001p00073
Subject(s) - ionization , ionosphere , daytime , ion , chemistry , competition (biology) , analytical chemistry (journal) , atmospheric sciences , physics , environmental chemistry , geophysics , ecology , organic chemistry , biology
A comparison of ion‐molecule reaction rates implied by E ‐ and F ‐region chemistry and measured in the laboratory shows on the whole good agreement except that the ionospheric analysis demands stronger temperature dependences. In the daytime D region, it is claimed that the reconciliation of positive ion densities with production rates and laboratory rate constants would best be achieved if (1) ionization of O 2 ( 1 Δ g ) and hydration of O 4 + in competition with the reduction of O 4 + to O 2 + by O were the dominant source of hydrates between 85 and 77 km, (2) ionization of NO by solar Lyman α followed by hydration was the dominant source of hydrates below 77 km, and (3) for some reason, Lyman α did not ionize NO effectively at pressures below those prevailing at 75 km. A discussion of large auroral NO densities will emphasize difficulties in accepting them but will offer no explanation for their observation.