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| Titel |
Filamentary structure in chemical tracer distributions near the subtropical jet following a wave breaking event |
| VerfasserIn |
J. Ungermann, L. L. Pan, C. Kalicinsky, F. Olschewski, P. Knieling, J. Blank, K. Weigel, T. Guggenmoser, F. Stroh, L. Hoffmann, M. Riese |
| 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 ; 13, no. 20 ; Nr. 13, no. 20 (2013-10-31), S.10517-10534 |
| Datensatznummer |
250085776
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| Publikation (Nr.) |
 copernicus.org/acp-13-10517-2013.pdf |
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| Zusammenfassung |
This paper presents a set of observations and analyses of trace gas
cross sections in the extratropical upper troposphere/lower stratosphere
(UTLS). The spatially highly resolved (≈0.5 km vertically and
12.5 km horizontally) cross sections of ozone (O3), nitric acid
(HNO3), and peroxyacetyl nitrate (PAN), retrieved from the measurements of
the CRISTA-NF infrared limb sounder flown on the Russian M55-Geophysica,
revealed intricate layer structures in the region of the subtropical
tropopause break. The chemical structure in this region shows an intertwined
stratosphere and troposphere. The observed filaments in all discussed trace
gases are of a spatial scale of less than 0.8 km vertically and about
200 km horizontally across the jet stream. Backward trajectory calculations
confirm that the observed filaments are the result of a breaking Rossby wave
in the preceding days. An analysis of the trace gas relationships between PAN
and O3 identifies four distinct groups of air mass: polluted subtropical
tropospheric air, clean tropical upper-tropospheric air, the lowermost
stratospheric air, and air from the deep stratosphere. The tracer
relationships further allow the identification of tropospheric,
stratospheric, and the transitional air mass made of a mixture of UT and LS
air. Mapping of these air mass types onto the geo-spatial location in the
cross sections reveals a highly structured extratropical transition layer
(ExTL). Finally, the ratio between the measured reactive nitrogen species
(HNO3 + PAN + ClONO2) and O3 is analysed to estimate the
influence of tropospheric pollution on the extratropical UTLS.
In combination, these diagnostics provide the first example of a
multi-species two-dimensional picture of the inhomogeneous distribution of
chemical species within the UTLS region. Since Rossby wave breaking occurs
frequently in the region of the tropopause break, these observed fine-scale
filaments are likely ubiquitous in the region. The implications of the
layered structure for chemistry and radiation need to be examined, and the
representation of this structure in chemistry-climate models is discussed. |
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