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| Titel |
Single-particle characterization of the high-Arctic summertime aerosol |
| VerfasserIn |
B. Sierau, R. Y.-W. Chang, C. Leck, J. Paatero, U. Lohmann |
| 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 ; 14, no. 14 ; Nr. 14, no. 14 (2014-07-18), S.7409-7430 |
| Datensatznummer |
250118898
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| Publikation (Nr.) |
 copernicus.org/acp-14-7409-2014.pdf |
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| Zusammenfassung |
| Single-particle mass-spectrometric measurements were carried out in
the high Arctic north of 80° during summer 2008. The
campaign took place onboard the icebreaker Oden and was
part of the Arctic Summer Cloud Ocean Study (ASCOS). The instrument
deployed was an aerosol time-of-flight mass spectrometer (ATOFMS)
that provides information on the chemical composition of individual
particles and their mixing state in real time. Aerosols were sampled
in the marine boundary layer at stations in the open ocean, in the
marginal ice zone, and in the pack ice region. The largest fraction
of particles detected for subsequent analysis in the size range of
the ATOFMS between approximately 200 and 3000 nm in diameter
showed mass-spectrometric patterns, indicating an internal mixing
state and a biomass burning and/or biofuel source. The majority of
these particles were connected to an air mass layer of elevated
particle concentration mixed into the surface mixed layer from the
upper part of the marine boundary layer. The second largest fraction
was represented by sea salt particles. The chemical analysis of the
over-ice sea salt aerosol revealed tracer compounds that reflect
chemical aging of the particles during their long-range advection
from the marginal ice zone, or open waters south thereof prior to
detection at the ship. From our findings we conclude that long-range
transport of particles is one source of aerosols in the high
Arctic. To assess the importance of long-range particle sources for
aerosol–cloud interactions over the inner Arctic in comparison to
local and regional biogenic primary aerosol sources, the chemical
composition of the detected particles was analyzed for indicators of
marine biological origin. Only a minor fraction showed chemical
signatures of potentially ocean-derived primary particles of that
kind. However, a chemical bias in the ATOFMS's detection
capabilities observed during ASCOS might suggest the presence of
a particle type of unknown composition and source. In general, the
study suffered from low counting statistics due to the overall small
number of particles found in this pristine environment, the small
sizes of the prevailing aerosol below the detection limit of the
ATOFMS, and its low hit rate. To our knowledge, this study reports on
the first in situ single-particle mass-spectrometric measurements in
the marine boundary layer of the high-Arctic pack ice region. |
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