IMP | Institute
of Meteorology and Physics
Universität für Bodenkultur Wien, Austria |
Vertical Ozone Transports in the Alps | |
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Summary VOTALP I:
The EU research project VOTALP investigated transport and formation
of ozone in the Alps, focusing on processes which can cause increased ozone
concentrations, namely stratospheric intrusions, horizontal advection of
polluted air, and in-situ production of ozone due to emissions in Alpine
valleys. It was found that the average ozone concentrations in the Alpine
area seem to be mainly determined by emissions in the surroundings and
horizontal advection in the lower troposphere. Peak values are mostly ascribed
to horizontal transport of polluted air, for instance during foehn, or
stratospheric intrusions. Due to the enhanced deposition of pollutants
the Alps probably act as a net sink for photo-oxidants. This implies a
high impact of pollutants on the sensitive Alpine ecosystems, since deposition
mainly means interception by plants.
Summary VOTALP II:
The EU research project VOTALP II investigated the enhanced vertical
exchange above the Alps as well as other processes which might be relevant
for increased ozone concentrations. The role of stratospheric intrusions
for mountain peaks and of horizontal advection of polluted air for the
foothill area causing a high ozone abundance has been quantified for selected
locations. Above the Alpine foothills a so called “injection layer” above
the boundary layer was detected, into which pollutants from below are transported.
The Alps also play a crucial role for transport of boundary layer air up
to the mid troposphere. The upper troposphere and the tropopause region,
however, seem to be less affected.