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Near‐resonant energy transfer from vibrationally excited OH( v ), v = 9, 8, 1 to CO 2
Author(s) -
Burtt Kelly D.,
Sharma Ramesh D.
Publication year - 2008
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 - 10.1029/2008gl035204
Subject(s) - excited state , atomic physics , mars exploration program , analytical chemistry (journal) , atmosphere (unit) , atmosphere of mars , venus , airglow , energy transfer , chemistry , martian , physics , thermodynamics , atmospheric sciences , astrobiology , chromatography
The transfer of vibrational energy from chemiluminescent OH, produced predominately by the H + O 3 → OH ( v ) + O 2 reaction, is of importance in modeling the airglow from the atmospheres of Earth, Mars, and Venus. We have calculated the energy transfer probability per collision as function of temperature for the near‐resonant processes OH ( v ) + CO 2 (00001) → OH ( v − 1) + CO 2 ( mnpqr ) for v = 1, 8, and 9 in the 100 – 350 K temperature range. We show that the measured room temperature values of the removal rate coefficient of OH( v = 9, 8) and OH( v = 1) by CO 2 , are in agreement with the ones calculated for the vibration‐to‐vibration (VV) energy transfer (ET) processes OH ( v ) + CO 2 (00001) → OH ( v − 1) + CO 2 (00011) and OH (1) + CO 2 (00001) → OH (0) + CO 2 (1001 n ) n =1, 2, respectively. The emission from the latter levels of CO 2 in the terrestrial mesosphere is not self‐absorbed leading to the possibility that these levels may be important contributors to the 4.3 μ m emission. Our calculation favors the “Collisional Cascade” model of vibrational energy transfer from OH to CO 2 that predicts about 50 times more radiation in the Martian Meinel bands over that predicted by the “Sudden Death” model. These two models of Martian atmosphere predict vastly different steady‐state populations of the vibrational levels of OH and should, because of the chemical reactions, of other trace species, e.g., H, O, and CO, as well.