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Titel |
Impact of deep convection in the tropical tropopause layer in West Africa: in-situ observations and mesoscale modelling |
VerfasserIn |
F. Fierli, E. Orlandi, K. S. Law, C. Cagnazzo, F. Cairo, C. Schiller, S. Borrmann, G. Donfrancesco, F. Ravegnani, C. M. Volk |
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. 1 ; Nr. 11, no. 1 (2011-01-11), S.201-214 |
Datensatznummer |
250009066
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Publikation (Nr.) |
copernicus.org/acp-11-201-2011.pdf |
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Zusammenfassung |
We present the analysis of the impact of convection on the composition of the
tropical tropopause layer region (TTL) in West-Africa during the AMMA-SCOUT
campaign. Geophysica M55 aircraft observations of water vapor, ozone, aerosol
and CO2 during August 2006 show perturbed values at altitudes ranging from
14 km to 17 km (above the main convective outflow) and satellite data
indicates that air detrainment is likely to have originated from convective cloud
east of the flights. Simulations of the BOLAM mesoscale model, nudged with
infrared radiance temperatures, are used to estimate the convective impact in
the upper troposphere and to assess the fraction of air processed by
convection. The analysis shows that BOLAM correctly reproduces the location
and the vertical structure of convective outflow. Model-aided analysis
indicates that convection can influence the composition of the upper
troposphere above the level of main outflow for an event of deep convection
close to the observation site. Model analysis also shows that deep convection
occurring in the entire Sahelian transect (up to 2000 km E of the measurement
area) has a non negligible role in determining TTL composition. |
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