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Titel |
High-ozone layers in the middle and upper troposphere above Central Europe: potential import from the stratosphere along the subtropical jet stream |
VerfasserIn |
T. Trickl, N. Bärtsch-Ritter, H. Eisele, M. Furger, R. Mücke, M. Sprenger, A. Stohl |
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 ; 11, no. 17 ; Nr. 11, no. 17 (2011-09-09), S.9343-9366 |
Datensatznummer |
250010067
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Publikation (Nr.) |
copernicus.org/acp-11-9343-2011.pdf |
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Zusammenfassung |
Specific very dry high-ozone layers, starting roughly two days after the
onset of high-pressure periods during the warm season, have been
reproducibly observed in the middle and upper troposphere with the ozone
lidar in Garmisch-Partenkirchen (Germany). These episodes,
previously not understood, were recently analysed based on extending
backward simulations with the FLEXPART particle dispersion model to as
many as twenty days and on jet-stream analyses including calculations
with the LAGRANTO transport model. In all six cases analysed the model
results indicate ozone import from the stratosphere on an extremely
long path along the subtropical jet stream over the Pacific Ocean, Asia
and, in part, all the way back to the Atlantic Ocean. The analysis
suggests that stratospheric influence is the most important factor
for the increase in ozone and is related to rather shallow transfer of
air from the stratosphere into the upper- and mid-tropospheric air
streams observed with the lidar. Contributions from the boundary layers
of East Asia and North America are just occasionally present, in one
case documented by a very dense aerosol plume from the Asian deserts.
The considerable vertical and temporal extent of many of these layers
and peak ozone mixing ratios between 80 and 150 ppb suggest
that the observations are related to an important mechanism for
stratosphere-to-troposphere transport (STT) and also confirm
the model predictions of pronounced and persistent STT along the
subtropical jet stream. |
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