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| Titel |
Airborne measurements of aerosol optical properties related to early spring transport of mid-latitude sources into the Arctic |
| VerfasserIn |
R. A. Villiers, G. Ancellet, J. Pelon, B. Quennehen, A. Schwarzenboeck, J. F. Gayet, K. S. Law |
| 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 ; 10, no. 11 ; Nr. 10, no. 11 (2010-06-01), S.5011-5030 |
| Datensatznummer |
250008511
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| Publikation (Nr.) |
 copernicus.org/acp-10-5011-2010.pdf |
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| Zusammenfassung |
| Airborne lidar and in-situ measurements of the aerosol properties were
conducted between Svalbard Island and Scandinavia in April 2008. Evidence of
aerosol transport from Europe and Asia is given. The analysis of the aerosol
optical properties based on a multiwavelength lidar (355, 532, 1064 nm)
including volume depolarization at 355 nm aims at distinguishing the role of
the different aerosol sources (Siberian wild fires, Eastern Asia and European
anthropogenic emissions). Combining, first aircraft measurements, second
FLEXPART simulations with a calculation of the PBL air fraction originating
from the three different mid-latitude source regions, and third level-2
CALIPSO data products (i.e. backscatter coefficient 532 nm,volume
depolarization and color ratio between 1064 and 532 nm in aerosol layers)
along the transport pathways, appears a valuable approach to identify the
role of the different aerosol sources even after a transport time larger than
4 days. Optical depth of the aerosol layers are always rather small (<4%)
while transported over the Arctic and ratio of the total attenuated
backscatter (i.e. including molecular contribution) provide more stable
result than conventional aerosol backscatter ratio. Above Asia, CALIPSO data
indicate more depolarization (up to 15%) and largest color ratio (>0.5)
for the northeastern Asia emissions (i.e. an expected mixture of Asian
pollution and dust), while low depolarization together with smaller and quasi
constant color ratio (≈0.3) are observed for the Siberian biomass
burning emissions. A similar difference is visible between two layers
observed by the aircraft above Scandinavia. The analysis of the time
evolution of the aerosol optical properties revealed by CALIPSO between Asia
and Scandinavia shows a gradual decrease of the aerosol backscatter,
depolarization ratio and color ratio which suggests the removal of the
largest particles in the accumulation mode. A similar study conducted for a
European plume has shown aerosol optical properties intermediate between the
two Asian sources with color ratio never exceeding 0.4 and moderate
depolarization ratio being always less than 8%, i.e. less aerosol from the
accumulation mode. |
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