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Titel |
Air pollution during the 2003 European heat wave as seen by MOZAIC airliners |
VerfasserIn |
M. Tressol, C. Ordóñez, R. Zbinden, J. Brioude, V. Thouret, C. Mari, P. Nédélec, J.-P. Cammas, H. Smit, H.-W. Pätz, A. Volz-Thomas |
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 ; 8, no. 8 ; Nr. 8, no. 8 (2008-04-15), S.2133-2150 |
Datensatznummer |
250006057
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Publikation (Nr.) |
copernicus.org/acp-8-2133-2008.pdf |
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Zusammenfassung |
This study presents an analysis of both MOZAIC profiles above Frankfurt and
Lagrangian dispersion model simulations for the 2003 European heat wave. The
comparison of MOZAIC measurements in summer 2003 with the 11-year MOZAIC
climatology reflects strong temperature anomalies (exceeding 4°C)
throughout the lower troposphere. Higher positive anomalies of temperature
and negative anomalies of both wind speed and relative humidity are found for
the period defined here as the heat wave (2–14 August 2003), compared to the
periods before (16–31 July 2003) and after (16–31 August 2003) the heat
wave. In addition, Lagrangian model simulations in backward mode indicate the
suppressed long-range transport in the mid- to lower troposphere and the
enhanced southern origin of air masses for all tropospheric levels during the
heat wave. Ozone and carbon monoxide also present strong anomalies (both
~+40 ppbv) during the heat wave, with a maximum vertical extension
reaching 6 km altitude around 11 August 2003. Pollution in the planetary
boundary layer (PBL) is enhanced during the day, with ozone mixing ratios two
times higher than climatological values. This is due to a combination of
factors, such as high temperature and radiation, stagnation of air masses and
weak dry deposition, which favour the accumulation of ozone precursors and
the build-up of ozone. A negligible role of a stratospheric-origin ozone
tracer has been found for the lower troposphere in this study. From 29 July
to 15 August 2003 forest fires burnt around 0.3×106 ha in
Portugal and added to atmospheric pollution in Europe. Layers with enhanced
CO and NOy mixing ratios, advected from Portugal, were crossed by the
MOZAIC aircraft in the free troposphere over Frankfurt. A series of forward
and backward Lagrangian model simulations have been performed to investigate
the origin of anomalies during the whole heat wave. European anthropogenic
emissions present the strongest contribution to the measured CO levels in the
lower troposphere (near 30%). This source is followed by Portuguese forest
fires which affect the lower troposphere after 6 August 2003 and even the PBL
around 10 August 2003. The averaged biomass burning contribution reaches 35%
during the affected period. Anthropogenic CO of North American origin only
marginally influences CO levels over Europe during that period. |
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