Open AccessThermospheric distribution of fast O( 1 D) atoms
Author(s) -
Kharchenko V.,
Dalgarno A.,
Fox J. L.
Publication year - 2005
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005ja011232
Subject(s) - metastability , atomic physics , excited state , thermalisation , quenching (fluorescence) , physics , hot atom , photodissociation , relaxation (psychology) , atmosphere (unit) , materials science , chemistry , thermodynamics , fluorescence , photochemistry , psychology , social psychology , quantum mechanics
Detailed calculations are carried out of the sources of energetic metastable O( 1 D) atoms in the atmosphere at altitudes between 80 km and 200 km, and the corresponding energy distribution functions are derived, taking account of energy transfer and quenching in collisions of the metastable atoms with the ambient atmospheric gas constituents. The energy relaxation of metastable oxygen atoms produced by O 2 and O 3 photolysis and O 2 + dissociative recombination is determined by solving the time‐dependent Boltzmann equation. The O( 1 D) thermalization and quenching times are obtained as functions of the altitude. The steady state distributions of metastable O( 1 D) are computed and used for the determination of the parameters characterizing the nonthermal O( 1 D) atoms. The nonthermal atoms comprise 4–6% of the distribution, and their effective temperatures are larger by 25–46% than the local temperatures of the ambient gas. The role of hot metastable oxygen atoms in the production of vibrationally excited OH molecules is analyzed.