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@ARTICLE{Schtze:838131,
author = {Schütze, Katharina and Wilson, James C. and Weinbruch,
Stephan and Benker, Nathalie and Ebert, Martin and Günther,
Gebhard and Weigel, Ralf and Borrmann, Stephan},
title = {{S}ub 500nm refractory carbonaceous particles in the polar
stratosphere},
journal = {Atmospheric chemistry and physics / Discussions},
volume = {278},
issn = {1680-7375},
address = {Katlenburg-Lindau},
publisher = {EGU},
reportid = {FZJ-2017-06835},
pages = {1 - 35},
year = {2017},
abstract = {Eleven particle samples collected in the polar stratosphere
during SOLVE (SAGE III Ozone loss and validation experiment)
from January until March 2000 were characterized in detail
by high-resolution transmission and scanning electron
microscopy (TEM/SEM) combined with energy-dispersive X-ray
microanalysis. A total number of 4175 particles
(TEM = 3845; SEM = 330) was analyzed from these
samples which were collected mostly inside the polar vortex
in the altitude range between 17.3 and 19.9 km. By
particle volume, all samples are dominated by volatile
particles (ammonium sulfates/hydrogen sulfates). By number,
approximately $28–82 \%$ of the particles are refractory
carbonaceous with sizes between 20–830 nm. Internal
mixtures of refractory carbonaceous and volatile particles
comprise up to $16 \%,$ individual volatile particles
about 9 to $72 \%.Most$ of the refractory carbonaceous
particles are completely amorphous, a few of the particles
are partly ordered with a graphene sheet separation distance
of 0.37 ± 0.06 nm (mean value ± standard deviation).
Carbon and oxygen are the only detected major elements with
an atomic O / C ratio of 0.11 ± 0.07. Minor
elements observed include Si, S, Fe, Cr and Ni with the
following atomic ratios relative to C: Si / C:
0.010 ± 0.011; S / C: 0.0007 ± 0.0015;
Fe / C: 0.0052 ± 0.0074; Cr / C:
0.0012 ± 0.0017; Ni / C: 0.0006 ± 0.0011 (all
mean values ± standard deviation).High resolution element
distribution images reveal that the minor elements are
distributed within the carbonaceous matrix, i.e.,
heterogeneous inclusions are not observed. No difference in
size, nanostructure and elemental composition was found
between particles collected inside and outside the polar
vortex.Based on chemistry and nanostructure, aircraft
exhaust, volcanic emissions and biomass burning can
certainly be excluded as source. The same is true for the
less probable, but globally important sources: wood burning,
coal burning, diesel engines and ship emissions.Rocket
exhaust and carbonaceous material from interplanetary dust
particles remain as possible sources of the refractory
carbonaceous particles studied. However, additional work is
required in order to identify the sources unequivocally.},
cin = {IEK-7},
ddc = {550},
cid = {I:(DE-Juel1)IEK-7-20101013},
pnm = {244 - Composition and dynamics of the upper troposphere and
middle atmosphere (POF3-244)},
pid = {G:(DE-HGF)POF3-244},
typ = {PUB:(DE-HGF)16},
doi = {10.5194/acp-2017-278},
url = {https://juser.fz-juelich.de/record/838131},
}