% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{deReus:7553,
author = {de Reus, M. and Borrmann, S. and Bansemer, A. and
Heymsfield, A.J. and Weigel, R. and Schiller, C. and Mitev,
V. and Frey, W. and Kunkel, D. and Kürten, A. and Curtius,
J. and Sitnikov, N.M. and Ulanovsky, A. and Ravegnani, F.},
title = {{E}vidence for ice particles in the tropical stratosphere
from in-situ measurements},
journal = {Atmospheric chemistry and physics},
volume = {9},
issn = {1680-7316},
address = {Katlenburg-Lindau},
publisher = {EGU},
reportid = {PreJuSER-7553},
pages = {6775 - 6792},
year = {2009},
note = {We thank Sebastian Raupach, Christian von Glahn and Hermann
Vossing from the University of Mainz for carrying out the
CIP and FSSP instrument preparation and data collection
during the SCOUT-O<INF>3</INF> campaign. The
SCOUT-O<INF>3</INF> project was funded by the European
Commission (GOCE-CT-2004-505390) and additional financial
support was provided by the Max Planck Society and the
Collaborative Research Centre "The Tropospheric Ice Phase"
(SFB-641). The participation of Aaron Bansemer and Andrew
Heymsfield to the SCOUT/ACTIVE project was funded by the
University of Manchester. Special thanks to the entire
"Geophysica" crew and the local authorities in Darwin (
Australia) and Ouagadougou ( Burkina Faso) for their
excellent collaboration during the campaign. Many helpful
comments from the participants of the Oral Session 5 on
Cirrus Clouds during the 15th International Conference on
Clouds and Precipitation, July 2008 in Cancun, Mexico are
greatly appreciated as is the diligent handling of the
manuscript by the editor Dominik Brunner.},
abstract = {In-situ ice crystal size distribution measurements are
presented within the tropical troposphere and lower
stratosphere. The measurements were performed using a
combination of a Forward Scattering Spectrometer Probe
(FSSP-100) and a Cloud Imaging Probe (CIP), which were
installed on the Russian high altitude research aircraft M55
"Geophysica" during the SCOUT-O-3 campaign in Darwin,
Australia. One of the objectives of the campaign was to
characterise the Hector convective system, which appears on
an almost daily basis during the pre-monsoon season over the
Tiwi Islands, north of Darwin. In total 90 encounters with
ice clouds, between 10 and 19 km altitude were selected from
the dataset and were analysed. Six of these encounters were
observed in the lower stratosphere, up to 1.4 km above the
local tropopause. Concurrent lidar measurements on board
"Geophysica" indicate that these ice clouds were a result of
overshooting convection. Large ice crystals, with a maximum
dimension up to 400 mu m, were observed in the stratosphere.
The stratospheric ice clouds included an ice water content
ranging from 7.7x10(-5) to 8.5x10(-4) gm(-3) and were
observed at ambient relative humidities ( with respect to
ice) between 75 and $157\%.$ Three modal lognormal size
distributions were fitted to the average size distributions
for different potential temperature intervals, showing that
the shape of the size distribution of the stratospheric ice
clouds are similar to those observed in the upper
troposphere.In the tropical troposphere the effective radius
of the ice cloud particles decreases from 100 mu m at about
10 km altitude, to 3 mu m at the tropopause, while the ice
water content decreases from 0.04 to 10(-5) gm(-3). No clear
trend in the number concentration was observed with
altitude, due to the thin and inhomogeneous characteristics
of the observed cirrus clouds.The ice water content
calculated from the observed ice crystal size distribution
is compared to the ice water content derived from two
hygrometer instruments. This independent measurement of the
ice water content agrees within the combined uncertainty of
the instruments for ice water contents exceeding 3x10(-4)
gm(-3).Stratospheric residence times, calculated based on
gravitational settling, and evaporation rates show that the
ice crystals observed in the stratosphere over the Hector
storm system had a high potential of humidifying the
stratosphere locally.Utilizing total aerosol number
concentration measurements from a four channel condensation
particle counter during two separate campaigns, it can be
shown that the fraction of ice particles to the number of
aerosol particles remaining ranges from 1: 300 to 1: 30 000
for tropical upper tropospheric ice clouds with ambient
temperatures below -75 degrees C.},
keywords = {J (WoSType)},
cin = {ICG-1},
ddc = {550},
cid = {I:(DE-Juel1)VDB790},
pnm = {Atmosphäre und Klima},
pid = {G:(DE-Juel1)FUEK406},
shelfmark = {Meteorology $\&$ Atmospheric Sciences},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000270131400009},
url = {https://juser.fz-juelich.de/record/7553},
}