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| Titel |
Source-receptor relationships for airborne measurements of CO2, CO and O3 above Siberia: a cluster-based approach |
| VerfasserIn |
J.-D. Paris, A. Stohl, P. Ciais, P. Nédélec, B. D. Belan, M. Yu. Arshinov, M. Ramonet |
| 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. 4 ; Nr. 10, no. 4 (2010-02-15), S.1671-1687 |
| Datensatznummer |
250008110
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| Publikation (Nr.) |
 copernicus.org/acp-10-1671-2010.pdf |
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| Zusammenfassung |
| We analysed results of three intensive aircraft campaigns above Siberia
(April and September 2006, August 2007) with a total of ~70 h of
continuous CO2, CO and O3 measurements. The flight route consists
of consecutive ascents and descents between Novosibirsk (55° N, 82° E)
and Yakutsk (62° N, 129° E). We performed retroplume calculations with
the Lagrangian particle dispersion model FLEXPART for many short segments
along the flight tracks. To reduce the extremely rich information on source
regions provided by the model calculation into a small number of distinct
cases, we performed a statistical clustering – to our knowledge for the
first time – into potential source regions of the footprint emission
sensitivities obtained from the model calculations. This technique not only
worked well to separate source region influences but also resulted in
clearly distinct tracer concentrations for the various clusters obtained.
High CO and O3 concentrations were found associated with agricultural
fire plumes originating from Kazakhstan in September 2006. A statistical
analysis indicates that summer uptake of CO2 is largely explained
(~50% of variance) by air mass exposure to uptake by Siberian and
sub-arctic ecosystems. This resulted in an average 5 to 10 ppm difference
with overlaying air masses. Stratosphere-troposphere exchange is found to
strongly influence the observed O3 mixing ratios in spring, but not in
summer. European emissions contributed to high O3 concentrations above
Siberia in April 2006 and August 2007, while emissions from North Eastern
China also contributed to higher O3 mixing ratios in summer, but tend
to lower mixing ratios in spring, when the airmass aerosol burden is
important. In the lower troposphere, large-scale deposition processes in the
boreal and sub-arctic boundary layer is a large O3 sink, resulting in a
~20 ppb difference with overlaying air masses. Lagrangian footprint
clustering is very promising and could also be advantageously applied to the
interpretation of ground based measurements including calculation of
tracers' sources and sinks. |
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