Aircraft pollution – a futuristic view O. A. Søvde1, M. Gauss1, I. S. A. Isaksen1, G. Pitari2, and C. Marizy3 1Department of Geosciences, University of Oslo, Norway 2Dipartimento di Fisica, University of L'Aquila, Italy 3Airbus France, Acoustics & Environment Department, Toulouse, France
Abstract. Impacts of NOx, H2O and aerosol emissions from a projected
2050 aircraft fleet are investigated using the Oslo CTM2,
with emissions provided through the EU project SCENIC.
The aircraft emission scenarios consist of emissions from subsonic and
In particular it is shown that aerosol emissions from such an
aircraft fleet can have a relatively large impact on ozone, and
possibly reduce the total atmospheric NOx by more than what is
emitted by aircraft.
Without aerosol emissions this aircraft fleet leads to similar NOx
increases for subsonic (at 11–12 km) and supersonic (at 18–20 km)
emissions, 1.35 ppbv and 0.83 ppbv as annual zonal means, respectively.
H2O increases are also comparable at these altitudes: 630 and
599 ppbv, respectively.
Tropospheric ozone increases are about 10 ppbv in the Northern
Hemisphere due to emissions from subsonic aircraft.
Increased ozone loss from supersonic aircraft at higher altitudes
leads to ozone reductions of about 39 ppbv in the Northern Hemisphere
and 22 ppbv in the Southern Hemisphere.
The latter reduction is a result of transport of ozone depleted air
from northern latitudes.
When including aircraft aerosol emissions, NOx is reduced due to
heterogeneous chemistry. The reduced NOx seems to counterweight the
reduction of ozone from emissions of NOx and H2O above 20 km.
At these altitudes the NOx (and thus ozone loss) reduction is large
enough to give an aircraft emissions induced increase in ozone.
In the height range 11–20 km altitude, however, ozone production is
reduced. Heterogeneous reactions and reduced NOx enhances ClO,
further enhancing ozone loss in the lower stratosphere.
This results in a 14 ppbv additional reduction of ozone.
Although supersonic aircraft have opposite effects on ozone in the
upper and lower stratosphere, the change in ozone columns is clearly
dominated by the upper stratospheric loss, thus supersonic aircraft
aerosol emissions lead to enhanced ozone columns.
The largest increase in the ozone column due to aerosol emissions is
therefore seen in the Northern Hemispheric autumn and winter, giving
a column increase of 4.5 DU.
It is further found that at high northern latitudes during spring the
heterogeneous chemistry on PSCs is particularly efficient, thereby
increasing the ozone loss.
Citation: Søvde, O. A., Gauss, M., Isaksen, I. S. A., Pitari, G., and Marizy, C.: Aircraft pollution – a futuristic view, Atmos. Chem. Phys., 7, 3621-3632, doi:10.5194/acp-7-3621-2007, 2007.