The reaction probabilities of ClONO sub 2 and N sub 2 O sub 5 on polar stratospheric cloud materials
- National Oceanic and Atmospheric Administration, Boulder, CO (USA)
The reaction probabilities, {gamma}, of ClONO{sub 2} and N{sub 2}O{sub 5} on ice and nitric acid trihydrate (NAT) surfaces were determined, using reactant concentrations that are typical of the lower stratosphere, by measuring the first-order reactant loss rate coefficients over the substrate located on the walls of a fast-flow reactor. Reactants were detected using chemical ionization mass spectrometry, a sensitive technique which allows the use of low reactant concentrations. The reaction probabilities obtained for ClONO{sub 2} are: 0.3 ({sub {minus}0.1}{sup +0.7}) on pure ice, 0.006 ({plus minus}30%) over a NAT surface, and 0.3 ({sub {minus}0.1}{sup +0.7}) on an HCl-doped NAT surface. Those for N{sub 2}O{sub 5} are: 0.024 ({plus minus}30%) on pure ice, 0.0006 ({plus minus}50%) on a NAT surface, and 0.0032 ({plus minus}30%) on an HCl-doped ice surface in a relatively short time, and the authors present arguments that this surface consisted of a NAT layer. The large differences between the results and previous measurements for some of these {gamma} can be attributed to the relatively large reactant concentrations used in the previous work. The major implications of this work for polar stratospheric chlorine activation are: an efficient loss of ClONO{sub 2} on pure ice surfaces, a very rapid rate for the reaction ClONO{sub 2} + HCl on NAT surfaces, and that pure ice surfaces will become passivated when coated with one monolayer of NAT crystal.
- OSTI ID:
- 5458042
- 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
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Related Subjects
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AEROSOLS
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL REACTIONS
CHEMISTRY
CHLORINE
CHLORINE COMPOUNDS
CHLORINE NITRATES
CLOUDS
COLLOIDS
DEPOSITION
DISPERSIONS
EARTH ATMOSPHERE
ELEMENTS
HALOGEN COMPOUNDS
HALOGENS
HYDRATES
HYDROGEN COMPOUNDS
ICE
INORGANIC ACIDS
LOSSES
MASS SPECTROSCOPY
NITRATES
NITRIC ACID
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
SOLS
SPECTROSCOPY
STRATOSPHERE
SURFACE COATING
SURFACE PROPERTIES