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| Titel |
Measurements of Ultra-fine and Fine Aerosol Particles over Siberia: Large-scale Airborne Campaigns |
| VerfasserIn |
Mikhail Arshinov, Jean-Daniel Paris, Andreas Stohl, Boris Belan, Philippe Ciais, Philippe Nédélec |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037193
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| Zusammenfassung |
| In this paper we discuss the results of in-situ measurements of ultra-fine and fine aerosol
particles carried out in the troposphere from 500 to 7000 m in the framework of several
International and Russian State Projects. Number concentrations of ultra-fine and fine aerosol
particles measured during intensive airborne campaigns are presented. Measurements carried
over a great part of Siberia were focused on particles with diameters from 3 to 21 nm to
study new particle formation in the free/upper troposphere over middle and high
latitudes of Asia, which is the most unexplored region of the Northern Hemisphere.
Joint International airborne surveys were performed along the following routes:
Novosibirsk-Salekhard-Khatanga-Chokurdakh-Pevek-Yakutsk-Mirny-Novosibirsk
(YAK-AEROSIB/PLARCAT2008 Project) and Novosibirsk-Mirny-Yakutsk-Lensk-Bratsk-Novosibirsk
(YAK-AEROSIB Project). The flights over Lake Baikal was conducted under Russian State
contract.
Concentrations of ultra-fine and fine particles were measured with automated diffusion
battery (ADB, designed by ICKC SB RAS, Novosibirsk, Russia) modified for airborne
applications. The airborne ADB coupled with CPC has an additional aspiration unit to
compensate ambient pressure and changing flow rate. It enabled to classify nanoparticles in
three size ranges: 3-6 nm, 6-21 nm, and 21-200 nm.
To identify new particle formation events we used similar specific criteria as Young et al.
(2007): (1) N3-6nm >10 cm-3, (2) R1=N3-6/N621 >1 and R2=N321/N21200 >0.5. So when
one of the ratios R1 or R2 tends to decrease to the above limits the new particle formation is
weakened. It is very important to notice that space scale where new particle formation was
observed is rather large. All the events revealed in the FT occurred under clean air conditions
(low CO mixing ratios).
Measurements carried out in the atmospheric boundary layer over Baikal Lake did not
reveal any event of new particle formation. Concentrations of ultra-fine particles were even
lower than ones observed in the polar FT.
Summarising the data obtained during two intensive measurement campaigns carried out
over the vast territory of Siberia we can draw the conclusion that remote Siberian troposphere
is a relatively efficient source of recently formed particles. Measurements carried out in the
FT (3-7 km) showed that about 44% of them satisfied criteria of new particle formation.
At the same time, more favourable conditions are observed between 5 and 7 km
(48%).
The present work was funded by ANR grant BLAN06-1_137670, CNRS, CEA, the
French Ministry of Research, the French Ministry of Foreign Affairs (YAK-AEROSIB
project) and by RFBR (grants 07-05-00645, 08-05-10033 and 08-05-92499) and by the
Norwegian Research Council as part of POLARCAT-Norway. Flights over Baikal Lake were
financed by Russian Government (State Contract No 02.515.11.5087).
Young, L.H., Benson, D.R., Montanaro, W.M., Lee, S.H., Pan, L.L., Rogers, D.C.,
Jensen, J., Stith, J.L., Davis, C.A., Campos, T.L., Bowman, K.P., Cooper,W.A., Lait,
L.R., 2007. Enhanced new particle formation observed in the northern midlatitude
tropopause region. Journal of Geophysical Research 112. doi:10.1029/2006JD008109 |
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