Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory
12 days).
These aged aerosol WSOM compounds had an average O /C
ratio of ∼ 0.45, which is relatively low compared to O /C
ratios of other aged aerosol. The increase in aerosol loading during the measurement period of 9/24 was linked to
biomass burning emissions from North America by FLEXPART retroplume analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts. This was confirmed with biomass burning markers detected in the WSOM
and with the morphology and mixing state of particles as
determined by scanning electron microscopy. The presence
of markers characteristic of aqueous-phase reactions of phenolic species suggests that the aerosol collected at the Pico Mountain Observatory had undergone cloud processing before reaching the site. Finally, the air masses of 9/25 were
more aged and influenced by marine emissions, as indicated
by the presence of organosulfates and other species characteristic of marine aerosol. The change in the air masses for
the two samples was corroborated by the changes in ethane,
propane, and ozone, morphology of particles, as well as by
the FLEXPART retroplume simulations. This paper presents
the first detailed molecular characterization of free tropospheric aged aerosol intercepted at a lower free troposphere
remote location and provides evidence of low oxygenation
after long-range transport. We hypothesize this is a result of
the selective removal of highly aged and polar species during long-range transport, because the aerosol underwent a
combination of atmospheric processes during transport facilitating aqueous-phase removal (e.g., clouds processing) and
fragmentation (e.g., photolysis) of components.]]>
2015
2021-04-10 19:13:17
1033
organic aerosol, ultrahigh-resolution FT-ICR MS, electron microscopy,, remote marine atmosphere, Pico Mountain Observatory
Katja
Džepina
70
Claudio
Mazzoleni
70
Paulo
Fialho
70
Swarup
China
70
Bo
Zhang
70
R. Chris
Owen
70
D.
Helmig
70
J.
Hueber
70
Sumit
Kumar
70
J. A.
Perlinger
70
COBISS_ID
3
59042563
UDK
4
54
ISSN pri članku
9
1680-7316
DOI
15
10.5194/acp-15-5047-2015
NUK URN
18
URN:SI:UNG:REP:FDGQV8QA
Dzepina_ACP_2015.pdf
4575901
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Izvorni URL
2021-04-10 19:13:18