Tests of stratospheric models: The reactions of atomic chlorine with O sub 3 and CH sub 4 at low temperature
- California Inst. of Tech., Pasadena (USA)
The reactions of atomic chlorine with O{sub 3} and CH{sub 4} are very important in stratospheric ozone photochemistry. The relative rates of these reactions strongly influence the ClO/HCl ration. However, there remains considerable uncertainty in the absolute rate constants for the two reactions at stratospheric temperatures. Since only the relative rate is of primary importance in the stratosphere, experiments on the competitive chlorination of O{sub 3}/CH{sub 4} mixtures have been carried out at 197-217 K, with the objective of directly measuring the rate constant ratio in this temperature range. The results with the objective of directly measuring the rate constant ratio in this temperature range. The results show that the absolute rate constants recommended by the NASA Panel for Data Evaluation (DeMore et al., 1990) are accurate on a relative basis to within 15% at stratospheric temperatures. The following rate constant upper limits are also established for temperatures near 200 K: ClO + CH{sub 3}O{sub 2} {yields} ClOO + CH{sub 3}O, k < 4 {times} 10{sup {minus}12}; ClO + CH{sub 3}O{sub 2} {yields} OClO + CH{sub 3}O, k < 1 {times} 10{sup {minus}15} cm{sup 3} molec{sup {minus}1}s{sup {minus}1}.
- OSTI ID:
- 5398182
- Journal Information:
- Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:D3; ISSN 0148-0227; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Kinetics and temperature dependence of the BrO + ClO reaction
Stratospheric OClO measurements as a poor quantitative indicator of chlorine activation
Related Subjects
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ALKANES
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
CHLORINATION
CHLORINE
CHLORINE COMPOUNDS
CHLORINE OXIDES
EARTH ATMOSPHERE
ELEMENTS
HALOGEN COMPOUNDS
HALOGENATION
HALOGENS
HYDROCARBONS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
LOW TEMPERATURE
MATHEMATICAL MODELS
METHANE
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
OZONE
PHOTOCHEMICAL REACTIONS
REACTION KINETICS
STRATOSPHERE
TEMPERATURE DEPENDENCE