In:
Chemie in unserer Zeit, Wiley, Vol. 41, No. 3 ( 2007-06), p. 152-168
Abstract:
Ozone in the atmosphere is one of the longest and most comprehensively observed trace gases. The pattern of its distribution in global atmospheric space is well understood, although its importance with respect to chemistry and climatology differs significantly in different altitude regions. Whilst ozone in the lower troposphere is mainly important as a source of photooxidants (such as the OH radical) and contributes to global warming via its greenhouse effect, the role of stratospheric ozone is mainly as a protective shield of the terrestrial biosphere against the short wavelength radiation of the sun. In both regions ozone has different mechanisms of formation and destruction. Ozone in the stratosphere is formed via the photochemistry of oxygen. As a result a certain concentration of ozone is establish in an oxygen‐only atmosphere. However, the appearance of anthropogenic trace gases such as N 2 O and CFCs have reduced this concentration since they have accelerated the processes of ozone destruction. The reduction of the stratospheric ozone concentration has seen its largest extent over the polar regions in winter/spring. Next to a number of gas phase reactions these reductions have been identified to be caused by surface reactions occurring on polar stratospheric clouds (PSCs). As a consequence the annual extents of destruction are also dependent on the microphysical conditions (temperature, rate of particle formation) of the polar stratosphere in winter. These are in average much more favourable for destruction in the south over Antarctica compared to the north over Arctica. As a result of the Montreal Protocol for the protection of the ozone layer and the associated cease of the production of CFCs and other halogenated compounds the ozone hole is expected to close in some decades to come. The interesting question, however, is how the expected recovery of the ozone layer might be modified or even delayed by climate change, which has an opposite sign – namely a net cooling effect – in the stratosphere and hence will intensify PSC formation.
Type of Medium:
Online Resource
ISSN:
0009-2851
,
1521-3781
DOI:
10.1002/ciuz.200700418
Language:
English
Publisher:
Wiley
Publication Date:
2007
detail.hit.zdb_id:
2006650-8
detail.hit.zdb_id:
6904-8
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