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| Titel |
Low molecular weight organic acids in aerosol particles from Rondônia, Brazil, during the biomass-burning, transition and wet periods |
| VerfasserIn |
A. H. Falkovich, E. R. Graber, G. Schkolnik, Y. Rudich, W. Maenhaut, P. Artaxo |
| 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 ; 5, no. 3 ; Nr. 5, no. 3 (2005-03-10), S.781-797 |
| Datensatznummer |
250002507
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| Publikation (Nr.) |
 copernicus.org/acp-5-781-2005.pdf |
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| Zusammenfassung |
| Particles from biomass burning and regional haze were sampled in
Rondônia, Brazil, during dry, transition and wet periods from September
to November 2002, as part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere
Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate)
field campaign. Water soluble organic and inorganic compounds in bulk (High
Volume and Stacked Filter Unit sampler) and size-resolved (Micro Orifice
Uniform Deposit Impactor – MOUDI) smoke samples were determined by ion
chromatography. It was found that low molecular weight polar organic acids
account for a significant fraction of the water soluble organic carbon
(WSOC) in biomass burning aerosols (C2-C6 dicarboxylic acids
reached up to 3.7% and one-ring aromatic acids reached up to 2% of
fine fraction WSOC during burning period). Short dicarboxylic
(C2-C6) acids are dominated by oxalic acid followed by malonic and
succinic acids. The largest ionic species is ammonium sulfate (60–70% of
ionic mass). It was found that most of the ionic mass is concentrated in
submicrometer-sized particles. Based on the size distribution and
correlations with K+, a known biomass burning tracer, it is suggested
that many of the organic acids are directly emitted by vegetation fires.
Concentrations of dicarboxylic acids in the front and back filters of high
volume sampler were determined. Based on these measurements, it was
concluded that in the neutral or slightly basic smoke particles typical of
this region, dicarboxylic acids are mostly confined to the particulate
phase. Finally, it is shown that the distribution of water soluble species
shifts to larger aerosols sizes as the aerosol population ages and mixes
with other aerosol types in the atmosphere. |
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