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| Titel |
Increase of the aerosol hygroscopicity by cloud processing in a mesoscale convective system: a case study from the AMMA campaign |
| VerfasserIn |
S. Crumeyrolle, L. Gomes, P. Tulet, A. Matsuki, A. Schwarzenboeck, K. Crahan |
| 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. 23 ; Nr. 8, no. 23 (2008-12-01), S.6907-6924 |
| Datensatznummer |
250006472
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| Publikation (Nr.) |
 copernicus.org/acp-8-6907-2008.pdf |
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| Zusammenfassung |
| Aerosol properties were measured during an airborne campaign experiment that
took place in July 2006 in West Africa within the framework of the African
Monsoon Multidisciplinary Analyses (AMMA). The goal of the present study was
to determine the main microphysical processes that affect the aerosols during
the passage of a mesoscale convective system (MCS) over the region of Niamey
in Niger. A significant change in the aerosol profiles measured before and after
the passage of the MCS was found in a layer located between 1300 and 3000 m,
where the aerosol concentration drastically decreased after the
passage of the MCS. Concurrently, a significant increase in the cloud
condensation nuclei (CCN) fraction was also observed during the post-MCS period in
the same layer. Moreover, the results of the elemental composition analyses
of individual particles collected in this layer after the MCS passage have
shown higher contributions of sulfate, nitrate and chloride to the total
aerosol mass. A mesoscale atmospheric model with on-line dust parameterization and
Lagrangian backtrajectories was used to interpret the impact of the MCS on
the aerosol properties. The results of the simulation show that the MCS 1)
generates dust particles at the surface in the gust front of the system and washout of
particles during the system precipitation, 2) modifies the aerosol mixing state (intensive
aerosol property) through cloud processing, and 3) enhances CCN activity of particles
through coating by soluble material. |
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