Global impact of the Antarctic ozone hole: Chemical Propagation
- NASA Goddard Space Flight Center, New York, NY (United States)
A model is presented for the chemical mixing of stratosphere air over spatial scales from tens of kilometers to meters. Photochemistry, molecular diffusion, and strain (the stretching of air parcels due to wind shear) are combined into a single one-dimensional model. The model is applied to the case in which chemically perturbed air parcels from the Antarctic stratosphere are transported to mid-latitudes and strained into thin ribbon-like filaments until they are diffusively mixed with the ambient stratosphere. For this sensitivity study the authors consider four types of Antarctic air: a control case representing unprocessed polar air; heterogeneous processing by polar stratospheric clouds (PSCs) that has repartitioned the Cl{sub x} and NO{sub y} families; processing that also includes denitrification and dehydration; and all processing plus 90% ozone depletion. Large abundances of ClO, resulting initially from heterogeneous processing of stratospheric air on PSCs, are sustained by extensive denitrification. (One exception is the case of Antarctic air with major ozone depletion in which ClO is converted rapidly to HCl upon release of small amounts of NO{sub x} as a result of the extremely nonlinear Cl{sub x}-NO{sub y} chemical system.) ClO concentrations in the mid-latitude stratosphere should be enhanced by as much as a factor of 5 due to the mixing of air processed around the Antarctic vortex and will remain elevated for most of the following season. Chemical propagation of the Antarctic ozone hole occurs in two phases: rapid loss of ozone in the heterogeneously processed parcels as they evolve in isolation, and more slowly, a relative recovery of ozone over the following months. Another important effect is the transport of denitrified Antarctic air reducing NO{sub x} and hence the total catalytic destruction of ozone throughout the southern mid-latitudes.
- OSTI ID:
- 5078375
- Journal Information:
- Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:D4; 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-)
ANTARCTIC REGIONS
ANTARCTICA
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINE
CHLORINE COMPOUNDS
CHLORINE OXIDES
CLOUDS
DEHYDRATION
DENITRIFICATION
DIFFUSION
EARTH ATMOSPHERE
ELEMENTS
GENERAL CIRCULATION MODELS
HALOGEN COMPOUNDS
HALOGENS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LAYERS
LOSSES
MATHEMATICAL MODELS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ONE-DIMENSIONAL CALCULATIONS
OXIDES
OXYGEN COMPOUNDS
OZONE
OZONE LAYER
PARAMETRIC ANALYSIS
PHOTOCHEMICAL REACTIONS
POLAR REGIONS
STRATOSPHERE
VORTICES
WIND