 |
| Titel |
Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe |
| VerfasserIn |
J. V. Niemi, H. Tervahattu, H. Vehkamäki, J. Martikainen, L. Laakso, M. Kulmala  , P. Aarnio, T. Koskentalo, M. Sillanpää, U. Makkonen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 8 ; Nr. 5, no. 8 (2005-08-30), S.2299-2310 |
| Datensatznummer |
250003042
|
| Publikation (Nr.) |
 copernicus.org/acp-5-2299-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| We studied the sources, compositions and size distributions of aerosol
particles during long-range transport (LRT) PM2.5 episodes which
occurred on 12–15 August, 26–28 August and 5–6 September 2002 in Finland. Backward air mass
trajectories, satellite detections of fire areas and dispersion modelling
results indicate that emissions from wildfires in Russia and other Eastern
European countries arrived in Finland during these episodes. Elemental
analyses using scanning electron microscopy (SEM) coupled with energy
dispersive X-ray microanalyses (EDX) showed that the proportions of S-rich
particles and agglomerates (agglomeration was caused partly by the sampling
method used) increased during the episodes, and they contained elevated
fractions of K, indicating emissions from biomass burning. These aerosols
were mixed with S-rich emissions from fossil fuel burning during transport
since air masses came through polluted areas of Europe. Minor amounts of
coarse Ca-rich particles were also brought by LRT during the episodes, and
they probably originated from wildfires and/or from Estonian and Russian
oil-shale-burning industrial areas. Ion chromatography analysis showed that
concentrations of sulphate (SO42-), total nitrate (NO3-+HNO3(g))
and total ammonium (NH4++NH3(g)) increased
during the episodes, but the ratio of the total amount of these ions to
PM10 concentration decreased, indicating unusually high fractions of
other chemical components. Particle number size distribution measurements
with differential mobility particle sizer (DMPS) revealed that
concentrations of particles 90–500 nm increased during the episodes, while
concentrations of particles smaller than 90 nm decreased. The reduction of
the smallest particles was caused by suppressed new particle formation due
to vapour and molecular cluster uptake of LRT particles. Our results show
that emissions from wildfires in Russian and other Eastern European
countries deteriorated air quality of very large areas, even at distances of
over 1000 km from the fire areas. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|