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| Titel |
A potential vorticity-based determination of the transport barrier in the Asian summer monsoon anticyclone |
| VerfasserIn |
F. Ploeger, C. Gottschling, S. Griessbach, J.-U. Grooß, G. Guenther, P. Konopka, R. Müller, M. Riese, F. Stroh, M. Tao, J. Ungermann, B. Vogel, M. Hobe |
| 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 ; 15, no. 22 ; Nr. 15, no. 22 (2015-11-27), S.13145-13159 |
| Datensatznummer |
250120189
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| Publikation (Nr.) |
 copernicus.org/acp-15-13145-2015.pdf |
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| Zusammenfassung |
| The Asian summer monsoon provides an important pathway of tropospheric source
gases and pollution into the lower stratosphere. This transport is
characterized by deep convection and steady upwelling, combined with
confinement inside a large-scale anticyclonic circulation in the upper
troposphere and lower stratosphere (UTLS). In this paper, we show that a
barrier to horizontal transport along the 380 K isentrope in the monsoon
anticyclone can be determined from a local maximum in the gradient of
potential vorticity (PV), following methods developed for the polar vortex
(e.g., Nash et al., 1996). The monsoon anticyclone is dynamically highly
variable and the maximum in the PV gradient is weak, such that additional
constraints are needed (e.g., time averaging). Nevertheless, PV contours in
the monsoon anticyclone agree well with contours of trace gas mixing ratios
(CO, O3) and mean age from model simulations with a Lagrangian chemistry
transport model (CLaMS) and satellite observations from the Microwave Limb
Sounder (MLS) instrument. Hence, the PV-based transport barrier reflects the
separation between air inside the core of the anticyclone and the background
atmosphere well. For the summer season 2011 we find an average PV value of
3.6 PVU for the transport barrier in the anticyclone on the 380 K
isentrope. |
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