TY  - JOUR
A1  - Worringen, Annette
A1  - Kandler, Konrad
A1  - Benker, Nathalie
A1  - Dirsch, Thomas
A1  - Weinbruch, Stephan
A1  - Mertes, Stephan
A1  - Schenk, Ludwig
A1  - Kästner, Udo
A1  - Frank, Fabian
A1  - Nillius, Björn
A1  - Bundke, Ulrich
A1  - Rose, Diana
A1  - Curtius, Joachim
A1  - Kupiszewski, Piotr
A1  - Weingartner, Ernest
A1  - Schneider, Johannes
A1  - Schmidt, Susan
A1  - Ebert, Martin
T1  - Single-particle characterization of ice-nucleating particles and ice particle residuals sampled by three different techniques
T2  - Atmospheric chemistry and physics / Discussions
N2  - In the present work, three different techniques are used to separate ice-nucleating particles (INP) and ice particle residuals (IPR) from non-ice-active particles: the Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI), which sample ice particles from mixed phase clouds and allow for the analysis of the residuals, as well as the combination of the Fast Ice Nucleus Chamber (FINCH) and the Ice Nuclei Pumped Virtual Impactor (IN-PCVI), which provides ice-activating conditions to aerosol particles and extracts the activated ones for analysis. The collected particles were analyzed by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine their size, chemical composition and mixing state. Samples were taken during January/February 2013 at the High Alpine Research Station Jungfraujoch. All INP/IPR-separating techniques had considerable abundances (median 20–70%) of contamination artifacts (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH + IN-PCVI: steel particles). Also, potential measurement artifacts (soluble material) occurred (median abundance < 20%). After removal of the contamination particles, silicates and Ca-rich particles, carbonaceous material and metal oxides were the major INP/IPR particle types separated by all three techniques. Minor types include soot and Pb-bearing particles. Sea-salt and sulfates were identified by all three methods as INP/IPR. Lead was identified in less than 10% of the INP/IPR. It was mainly present as an internal mixture with other particle types, but also external lead-rich particles were found. Most samples showed a maximum of the INP/IPR size distribution at 400 nm geometric diameter. In a few cases, a second super-micron maximum was identified. Soot/carbonaceous material and metal oxides were present mainly in the submicron range. ISI and FINCH yielded silicates and Ca-rich particles mainly with diameters above 1 μm, while the Ice-CVI also sampled many submicron particles. Probably owing to the different meteorological conditions, the INP/IPR composition was highly variable on a sample to sample basis. Thus, some part of the discrepancies between the different techniques may result from the (unavoidable) non-parallel sampling. The observed differences of the particles group abundances as well as the mixing state of INP/IPR point to the need of further studies to better understand the influence of the separating techniques on the INP/IPR chemical composition.
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/37230
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-372309
SN  - 1680-7375
SN  - 1680-7367
N1  - © Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License.
VL  - 14
SP  - 23027
EP  - 23073
PB  - European Geosciences Union
CY  - Katlenburg-Lindau
ER  -