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| Titel |
The present-day and future impact of NOx emissions from subsonic aircraft on the atmosphere in relation to the impact of NOx surface sources |
| VerfasserIn |
P. J. M. Valks, G. J. M. Velders |
| 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 ; 17, no. 8 ; Nr. 17, no. 8, S.1064-1079 |
| Datensatznummer |
250013800
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| Publikation (Nr.) |
 copernicus.org/angeo-17-1064-1999.pdf |
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| Zusammenfassung |
The effect of present-day and future NOx
emissions from aircraft on the NOx and ozone concentrations in the
atmosphere and the corresponding radiative forcing were studied using a
three-dimensional chemistry transport model (CTM) and a radiative model. The
effects of the aircraft emissions were compared with the effects of the three
most important anthropogenic NOx surface sources: road traffic,
electricity generation and industrial combustion. From the model results, NOx
emissions from aircraft are seen to cause an increase in the NOx and
ozone concentrations in the upper troposphere and lower stratosphere, and a
positive radiative forcing. For the reference year 1990, the aircraft emissions
result in an increase in the NOx concentration at 250 hPa of about 20
ppt in January and 50 ppt in July over the eastern USA, the North Atlantic
Flight Corridor and Western Europe, corresponding to a relative increase of
about 50%. The maximum increase in the ozone concentrations due to the aircraft
emissions is about 3-4 ppb in July over the northern mid-latitudes,
corresponding to a relative increase of about 3-4%. The aircraft-induced ozone
changes cause a global average radiative forcing of 0.025 W/m2 in
July. According to the ANCAT projection for the year 2015, the aircraft NOx
emissions in that year will be 90% higher than in the year 1990. As a
consequence of this, the calculated NOx perturbation by aircraft
emissions increases by about 90% between 1990 and 2015, and the ozone
perturbation by about 50-70%. The global average radiative forcing due to the
aircraft-induced ozone changes increases by about 50% between 1990 and 2015. In
the year 2015, the effects of the aircraft emissions on the ozone burden and
radiative forcing are clearly larger than the individual effects of the NOx
surface sources. Taking chemical conversion in the aircraft plume into account
in the CTM explicitly, by means of modified aircraft NOx emissions, a
significant reduction of the aircraft-induced NOx and ozone
perturbations is realised. The NOx perturbation decreases by about
40% and the ozone perturbation by about 30% in July over Western Europe, the
eastern USA and the North Atlantic Flight Corridor.
Keywords. Atmospheric composition and structure
(troposphere · composition and chemistry) · Meteorology and atmospheric
dynamics (radiative processes) |
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