Stratospheric photodissociation of several saturated perhalo chlorofluorocarbon compounds in current technological use (fluorocarbons-13, -113, -114, and -115)

Journal Article · Thu Jan 12 00:00:00 EST 1978 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100490a001· OSTI ID:5307379

Chou, C C; Milstein, R J; Smith, W S; Ruiz, H V; Molina, M J; Rowland, F S

Photon absorption cross sections have been measured in the stratospherically important 1849 to 2273-A range for CClF/sub 3/ (fluorocarbon-13), CCl/sub 2/FCClF/sub 2/ (FC-113), CClF/sub 2/CClF/sub 2/ (FC-114), and CClF/sub 2/CF/sub 3/ (FC-115). Atmospheric residence times have been calculated for these four compounds, and for CCl/sub 3/F (FC-11) and CCl/sub 2/F/sub 2/ (FC-12), with the assumption that the molecules are removed only by direct solar photolysis or by reaction with O(/sup 1/D) atoms. Four different eddy diffusion models were used for stratospheric mixing. Direct photolysis accounts for >90% of the removal of FC-11, >80% for FC-12 and FC-113, and <20% for FC-13 and FC-115. Direct photolysis and reaction with O(/sup 1/D) atoms are roughly comparable in importance for the removal of FC-114. The calculated atmospheric residence times range from 40 to 550 years, with especially long calculated residence times for FC-13 and FC-115 which have very low photon absorption cross sections and which are therefore primarily removed from the stratosphere by reaction with O(/sup 1/D) atoms.

• Research Organization: Univ. of California, Irvine
• OSTI ID: 5307379
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 82:1; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
500200 -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
DECOMPOSITION
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATIONS
STRATOSPHERE
ULTRAVIOLET RADIATION