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Titel |
On the effect of emissions from aircraft engines on the state of the atmosphere |
VerfasserIn |
U. Schumann |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 12, no. 5 ; Nr. 12, no. 5, S.365-384 |
Datensatznummer |
250010783
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Publikation (Nr.) |
copernicus.org/angeo-12-365-1994.pdf |
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Zusammenfassung |
Emissions from aircraft engines include
carbon dioxide, water vapour, nitrogen oxides, sulphur components and various
other gases and particles. Such emissions from high-flying global civil subsonic
air traffic may cause anthropogenic climate changes by an increase of ozone and
cloudiness in the upper troposphere, and by an enhanced greenhouse effect. The
absolute emissions by air traffic are small (a few percent of the total)
compared to surface emissions. However, the greenhouse effect of emitted water
and of nitrogen oxides at cruise altitude is potentially large compared to that
of the same emissions near the earth's surface because of relatively large
residence times at flight altitudes, low background concentrations, low
temperature, and large radiative efficiency. Model computations indicate that
emission of nitrogen oxides has doubled the background concentration in the
upper troposphere between 40°N and 60°N. Models also indicate that this causes
an increase of ozone by about 5-20%. Regionally, the observed annual mean change
in cloudiness is 0.4%. It is estimated that the resultant greenhouse effect of
changes in ozone and thin cirrus cloud cover causes a climatic surface
temperature change of 0.01-0.1 K. These temperature changes are small compared
to the natural variability. Recent research indicates that the emissions at
cruise altitude may increase the amount of stratospheric aerosols and polar
stratospheric clouds and thereby have an impact on the atmospheric environment.
Air traffic is increasing about 5-6% per year, fuel consumption by about 3%,
hence the effects of the related emissions are expected to grow. This paper
surveys the state of knowledge and describes several results from recent and
ongoing research. |
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