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| Titel |
Satellite observations of long range transport of a large BrO plume in the Arctic |
| VerfasserIn |
M. Begoin, A. Richter, M. Weber, L. Kaleschke, X. Tian-Kunze, A. Stohl, N. Theys, J. P. Burrows |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 14 ; Nr. 10, no. 14 (2010-07-16), S.6515-6526 |
| Datensatznummer |
250008633
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| Publikation (Nr.) |
 copernicus.org/acp-10-6515-2010.pdf |
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| Zusammenfassung |
Ozone Depletion Events (ODE) during polar springtime are a well known phenomenon
in the Arctic and Antarctic boundary layer. They are caused by the catalytic
destruction of ozone by halogens producing reactive halogen oxides like bromine
monoxide (BrO). The key halogen bromine can be rapidly transferred into the gas
phase in an autocatalytic process – the so called "Bromine Explosion". However,
the exact mechanism, which leads to an initial bromine release as well as the
influence of transport and chemical processes on BrO, is still not clearly understood.
In this study, BrO measurements from the satellite instrument GOME-2 are used
together with model calculations with the dispersion model FLEXPART to study
an arctic BrO event in March 2007, which could be tracked over several days
and a large area. Full BrO activation was observed within one day east of
Siberia with subsequent transport to Hudson Bay. The event was linked to
a cyclone with very high surface wind speeds, which could have been involved
in the production and lifting of aerosols or blowing snow. Considering the
short life time of BrO, transported aerosols or snow can also provide the
surface for BrO recycling within the plume for several days. The evolution
of the BrO plume could be reproduced by FLEXPART simulations of a passive
tracer indicating that the activated air mass was transported all the way
from Siberia to Hudson Bay. To localise the most probable transport height,
model runs initialised in different heights have been performed showing
similar transport patterns throughout the troposphere but best agreement
with the measurements between the surface and 3 km. The influence
of changes in tropopause height on measured BrO values has been considered,
but cannot completely explain the observed high BrO values. Backward
trajectories from the area of BrO initialisation show upward lifting from
the surface up to 3 km and no indication for intrusion of stratospheric
air. These observations are consistent with a scenario in which bromine
in the air mass was activated on the surface within the cyclone, lifted
upwards and transported over several thousand kilometres to Hudson Bay. |
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