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| Titel |
Biogenic and biomass burning organic aerosol in a boreal forest at Hyytiälä, Finland, during HUMPPA-COPEC 2010 |
| VerfasserIn |
A. L. Corrigan, L. M. Russell, S. Takahama, M. Äijälä, M. Ehn, H. Junninen, J. Rinne, T. Petäjä, M. Kulmala  , A. L. Vogel, T. Hoffmann, C. J. Ebben, F. M. Geiger, P. Chhabra, J. H. Seinfeld, D. R. Worsnop, W. Song, J. Auld, J. Williams |
| 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 ; 13, no. 24 ; Nr. 13, no. 24 (2013-12-17), S.12233-12256 |
| Datensatznummer |
250085886
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| Publikation (Nr.) |
 copernicus.org/acp-13-12233-2013.pdf |
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| Zusammenfassung |
| Submicron aerosol particles were collected during July and August 2010 in
Hyytiälä, Finland, to determine the composition and sources of
aerosol at that boreal forest site. Submicron particles were collected on
Teflon filters and analyzed by Fourier transform infrared (FTIR) spectroscopy
for organic functional groups (OFGs). Positive matrix factorization (PMF) was
applied to aerosol mass spectrometry (AMS) measurements and FTIR spectra to
identify summertime sources of submicron aerosol mass at the sampling site.
The two largest sources of organic mass (OM) in particles identified at
Hyytiälä were (1) biogenic aerosol from surrounding local forest and
(2) biomass burning aerosol, transported 4–5 days from large wildfires
burning near Moscow, Russia, and northern Ukraine. The robustness of this
apportionment is supported by the agreement of two independent analytical
methods for organic measurements with three statistical techniques. FTIR
factor analysis was more sensitive to the chemical differences between
biogenic and biomass burning organic components, while AMS factor analysis
had a higher time resolution that more clearly linked the temporal behavior
of separate OM factors to that of different source tracers even though their
fragment mass spectrum were similar. The greater chemical sensitivity of the
FTIR is attributed to the nondestructive preparation and the functional group
specificity of spectroscopy. The FTIR spectra show strong similarities among
biogenic and biomass burning factors from different regions as well as with
reference OM (namely olive tree burning organic aerosol and α-pinene chamber
secondary organic aerosol (SOA)). The biogenic factor correlated strongly
with temperature and oxidation products of biogenic volatile organic
compounds (BVOCs), included more than half of the oxygenated OFGs (carbonyl groups
at 29% and carboxylic acid groups at 22%), and represented 35%
of the submicron OM. Compared to previous studies at Hyytiälä, the
summertime biogenic OM is 1.5 to 3 times larger than springtime biogenic OM
(0.64 μg m−3 and 0.4 μg m−3, measured in 2005
and 2007, respectively), even though it contributed only 35% of OM. The
biomass burning factor contributed 25% of OM on average and up to 62%
of OM during three periods of transported biomass burning emissions: 26–28
July, 29–30 July, and 8–9 August, with OFG consisting mostly of carbonyl
(41%) and alcohol (25%) groups. The high summertime terrestrial
biogenic OM (1.7 μg m−3) and the high biomass burning
contributions (1.2 μg m−3) were likely due to the abnormally
high temperatures that resulted in both stressed boreal forest conditions
with high regional BVOC emissions and numerous wildfires in upwind regions. |
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