Articles | Volume 12, issue 6
https://doi.org/10.5194/amt-12-3183-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-12-3183-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
14 Jun 2019
Research article |
| 14 Jun 2019
| 14 Jun 2019
A high-speed particle phase discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber
Institute for Atmospheric and Climate Science, ETH Zurich, 8092 Zurich, Switzerland
Jörg Wieder
Institute for Atmospheric and Climate Science, ETH Zurich, 8092 Zurich, Switzerland
Remo Dietlicher
Institute for Atmospheric and Climate Science, ETH Zurich, 8092 Zurich, Switzerland
now at: Center for Climate System Modeling, ETH Zurich, 8092 Zurich, Switzerland
Helen R. Smith
Centre for Atmospheric and Climate Physics, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK
Chris Stopford
Centre for Atmospheric and Climate Physics, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK
Institute for Atmospheric and Climate Science, ETH Zurich, 8092 Zurich, Switzerland
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Kunfeng Gao, Chong-Wen Zhou, Eszter J. Barthazy Meier, and Zamin A. Kanji
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Incomplete combustion of fossil fuel produces carbonaceous particles called soot. These particles can affect cloud formation by acting as centres for droplet or ice formation. The atmospheric residence time of soot particles is of the order of days to weeks, which can result in them becoming coated by various trace species in the atmosphere such as acids. In this study, we quantify the cirrus cloud-forming ability of soot particles coated with the atmospherically ubiquitous sulfuric acid.
Zoé Brasseur, Dimitri Castarède, Erik S. Thomson, Michael P. Adams, Saskia Drossaart van Dusseldorp, Paavo Heikkilä, Kimmo Korhonen, Janne Lampilahti, Mikhail Paramonov, Julia Schneider, Franziska Vogel, Yusheng Wu, Jonathan P. D. Abbatt, Nina S. Atanasova, Dennis H. Bamford, Barbara Bertozzi, Matthew Boyer, David Brus, Martin I. Daily, Romy Fösig, Ellen Gute, Alexander D. Harrison, Paula Hietala, Kristina Höhler, Zamin A. Kanji, Jorma Keskinen, Larissa Lacher, Markus Lampimäki, Janne Levula, Antti Manninen, Jens Nadolny, Maija Peltola, Grace C. E. Porter, Pyry Poutanen, Ulrike Proske, Tobias Schorr, Nsikanabasi Silas Umo, János Stenszky, Annele Virtanen, Dmitri Moisseev, Markku Kulmala, Benjamin J. Murray, Tuukka Petäjä, Ottmar Möhler, and Jonathan Duplissy
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Kunfeng Gao, Franz Friebel, Chong-Wen Zhou, and Zamin A. Kanji
Atmos. Chem. Phys., 22, 4985–5016, https://doi.org/10.5194/acp-22-4985-2022, https://doi.org/10.5194/acp-22-4985-2022, 2022
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Joseph Girdwood, Warren Stanley, Chris Stopford, and David Brus
Atmos. Meas. Tech., 15, 2061–2076, https://doi.org/10.5194/amt-15-2061-2022, https://doi.org/10.5194/amt-15-2061-2022, 2022
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Jörg Wieder, Claudia Mignani, Mario Schär, Lucie Roth, Michael Sprenger, Jan Henneberger, Ulrike Lohmann, Cyril Brunner, and Zamin A. Kanji
Atmos. Chem. Phys., 22, 3111–3130, https://doi.org/10.5194/acp-22-3111-2022, https://doi.org/10.5194/acp-22-3111-2022, 2022
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Cyril Brunner, Benjamin T. Brem, Martine Collaud Coen, Franz Conen, Maxime Hervo, Stephan Henne, Martin Steinbacher, Martin Gysel-Beer, and Zamin A. Kanji
Atmos. Chem. Phys., 21, 18029–18053, https://doi.org/10.5194/acp-21-18029-2021, https://doi.org/10.5194/acp-21-18029-2021, 2021
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Larissa Lacher, Hans-Christian Clemen, Xiaoli Shen, Stephan Mertes, Martin Gysel-Beer, Alireza Moallemi, Martin Steinbacher, Stephan Henne, Harald Saathoff, Ottmar Möhler, Kristina Höhler, Thea Schiebel, Daniel Weber, Jann Schrod, Johannes Schneider, and Zamin A. Kanji
Atmos. Chem. Phys., 21, 16925–16953, https://doi.org/10.5194/acp-21-16925-2021, https://doi.org/10.5194/acp-21-16925-2021, 2021
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Paraskevi Georgakaki, Aikaterini Bougiatioti, Jörg Wieder, Claudia Mignani, Fabiola Ramelli, Zamin A. Kanji, Jan Henneberger, Maxime Hervo, Alexis Berne, Ulrike Lohmann, and Athanasios Nenes
Atmos. Chem. Phys., 21, 10993–11012, https://doi.org/10.5194/acp-21-10993-2021, https://doi.org/10.5194/acp-21-10993-2021, 2021
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Aerosol and cloud observations coupled with a droplet activation parameterization was used to investigate the aerosol–cloud droplet link in alpine mixed-phase clouds. Predicted droplet number, Nd, agrees with observations and never exceeds a characteristic “limiting droplet number”, Ndlim, which depends solely on σw. Nd becomes velocity limited when it is within 50 % of Ndlim. Identifying when dynamical changes control Nd variability is central for understanding aerosol–cloud interactions.
Claudia Marcolli, Fabian Mahrt, and Bernd Kärcher
Atmos. Chem. Phys., 21, 7791–7843, https://doi.org/10.5194/acp-21-7791-2021, https://doi.org/10.5194/acp-21-7791-2021, 2021
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Pores are aerosol particle features that trigger ice nucleation, as they take up water by capillary condensation below water saturation that freezes at low temperatures. The pore ice can then grow into macroscopic ice crystals making up cirrus clouds. Here, we investigate the pores in soot aggregates responsible for pore condensation and freezing (PCF). Moreover, we present a framework to parameterize soot PCF that is able to predict the ice nucleation activity based on soot properties.
Maria Kezoudi, Matthias Tesche, Helen Smith, Alexandra Tsekeri, Holger Baars, Maximilian Dollner, Víctor Estellés, Johannes Bühl, Bernadett Weinzierl, Zbigniew Ulanowski, Detlef Müller, and Vassilis Amiridis
Atmos. Chem. Phys., 21, 6781–6797, https://doi.org/10.5194/acp-21-6781-2021, https://doi.org/10.5194/acp-21-6781-2021, 2021
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Mineral dust concentrations in the diameter range from 0.4 to 14.0 μm were measured with the balloon-borne UCASS optical particle counter. Launches were coordinated with ground-based remote-sensing and airborne in situ measurements during a Saharan dust outbreak over Cyprus. Particle number concentrations reached 50 cm−3 for the diameter range 0.8–13.9 μm. Comparisons with aircraft data show reasonable agreement in magnitude and shape of the particle size distribution.
Fabiola Ramelli, Jan Henneberger, Robert O. David, Johannes Bühl, Martin Radenz, Patric Seifert, Jörg Wieder, Annika Lauber, Julie T. Pasquier, Ronny Engelmann, Claudia Mignani, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys., 21, 6681–6706, https://doi.org/10.5194/acp-21-6681-2021, https://doi.org/10.5194/acp-21-6681-2021, 2021
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Orographic mixed-phase clouds are an important source of precipitation, but the ice formation processes within them remain uncertain. Here we investigate the origin of ice crystals in a mixed-phase cloud in the Swiss Alps using aerosol and cloud data from in situ and remote sensing observations. We found that ice formation primarily occurs in cloud top generating cells. Our results indicate that secondary ice processes are active in the feeder region, which can enhance orographic precipitation.
Anna J. Miller, Killian P. Brennan, Claudia Mignani, Jörg Wieder, Robert O. David, and Nadine Borduas-Dedekind
Atmos. Meas. Tech., 14, 3131–3151, https://doi.org/10.5194/amt-14-3131-2021, https://doi.org/10.5194/amt-14-3131-2021, 2021
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To characterize atmospheric ice nuclei, we present (1) the development of our home-built droplet freezing technique (DFT), which involves the Freezing Ice Nuclei Counter (FINC), (2) an intercomparison campaign using NX-illite and an ambient sample with two other DFTs, and (3) the application of lignin as a soluble and commercial ice nuclei standard with three DFTs. We further compiled the growing number of DFTs in use for atmospheric ice nucleation since 2000 and add FINC.
Fabiola Ramelli, Jan Henneberger, Robert O. David, Annika Lauber, Julie T. Pasquier, Jörg Wieder, Johannes Bühl, Patric Seifert, Ronny Engelmann, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys., 21, 5151–5172, https://doi.org/10.5194/acp-21-5151-2021, https://doi.org/10.5194/acp-21-5151-2021, 2021
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Interactions between dynamics, microphysics and orography can enhance precipitation. Yet the exact role of these interactions is still uncertain. Here we investigate the role of low-level blocking and turbulence for precipitation by combining remote sensing and in situ observations. The observations show that blocked flow can induce the formation of feeder clouds and that turbulence can enhance hydrometeor growth, demonstrating the importance of local flow effects for orographic precipitation.
Annika Lauber, Jan Henneberger, Claudia Mignani, Fabiola Ramelli, Julie T. Pasquier, Jörg Wieder, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys., 21, 3855–3870, https://doi.org/10.5194/acp-21-3855-2021, https://doi.org/10.5194/acp-21-3855-2021, 2021
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An accurate prediction of the ice crystal number concentration (ICNC) is important to determine the radiation budget, lifetime, and precipitation formation of clouds. Even though secondary-ice processes can increase the ICNC by several orders of magnitude, they are poorly constrained and lack a well-founded quantification. During measurements on a mountain slope, a high ICNC of small ice crystals was observed just below 0 °C, attributed to a secondary-ice process and parametrized in this study.
Claudia Mignani, Jörg Wieder, Michael A. Sprenger, Zamin A. Kanji, Jan Henneberger, Christine Alewell, and Franz Conen
Atmos. Chem. Phys., 21, 657–664, https://doi.org/10.5194/acp-21-657-2021, https://doi.org/10.5194/acp-21-657-2021, 2021
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Most precipitation above land starts with ice in clouds. It is promoted by extremely rare particles. Some ice-nucleating particles (INPs) cause cloud droplets to already freeze above −15°C, a temperature at which many clouds begin to snow. We found that the abundance of such INPs among other particles of similar size is highest in precipitating air masses and lowest when air carries desert dust. This brings us closer to understanding the interactions between land, clouds, and precipitation.
Cyril Brunner and Zamin A. Kanji
Atmos. Meas. Tech., 14, 269–293, https://doi.org/10.5194/amt-14-269-2021, https://doi.org/10.5194/amt-14-269-2021, 2021
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Subvisual microscopic particles in the atmosphere are needed to act as seeds for cloud droplets or ice crystals to form. The microscopic particles, called ice-nucleating particles (INPs), form ice crystals and are rare, and their properties are not well understood, in part because measuring them is challenging and time consuming, and to date has not been automated. Here, we present the first online instrument that can continuously and autonomously measure INP concentration at 243 K.
Joseph Girdwood, Helen Smith, Warren Stanley, Zbigniew Ulanowski, Chris Stopford, Charles Chemel, Konstantinos-Matthaios Doulgeris, David Brus, David Campbell, and Robert Mackenzie
Atmos. Meas. Tech., 13, 6613–6630, https://doi.org/10.5194/amt-13-6613-2020, https://doi.org/10.5194/amt-13-6613-2020, 2020
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We present the design and validation of an unmanned aerial vehicle (UAV) equipped with a bespoke optical particle counter (OPC). This is used to monitor atmospheric particles, which have significant effects on our weather and climate. These effects are hard to characterise properly, partly because they occur in regions that are not commonly accessible to traditional instrumentation. Our new platform gives us the capability to access these regions.
Anna J. Miller, Killian P. Brennan, Claudia Mignani, Jörg Wieder, Assaf Zipori, Robert O. David, and Nadine Borduas-Dedekind
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-361, https://doi.org/10.5194/amt-2020-361, 2020
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For characterizing atmospheric ice nuclei, we present (1) the development of our home-built droplet freezing technique (DFT), the Freezing Ice Nuclei Counter (FINC), (2) an intercomparison campaign using NX-illite and an ambient sample with three DFTs, and (3) the application of lignin as a soluble and commercial ice nuclei standard with four DFTs. We further compiled the growing number of DFTs in use for atmospheric ice nucleation since 2000, to which we add FINC.
Robert O. David, Jonas Fahrni, Claudia Marcolli, Fabian Mahrt, Dominik Brühwiler, and Zamin A. Kanji
Atmos. Chem. Phys., 20, 9419–9440, https://doi.org/10.5194/acp-20-9419-2020, https://doi.org/10.5194/acp-20-9419-2020, 2020
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Ice crystal formation plays an important role in controlling the Earth's climate. However, the mechanisms responsible for ice formation in the atmosphere are still uncertain. Here we use surrogates for atmospherically relevant porous particles to determine the role of pore diameter and wettability on the ability of porous particles to nucleate ice in the atmosphere. Our results are consistent with the pore condensation and freeing mechanism.
Mikhail Paramonov, Saskia Drossaart van Dusseldorp, Ellen Gute, Jonathan P. D. Abbatt, Paavo Heikkilä, Jorma Keskinen, Xuemeng Chen, Krista Luoma, Liine Heikkinen, Liqing Hao, Tuukka Petäjä, and Zamin A. Kanji
Atmos. Chem. Phys., 20, 6687–6706, https://doi.org/10.5194/acp-20-6687-2020, https://doi.org/10.5194/acp-20-6687-2020, 2020
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Ice-nucleating particle (INP) measurements were performed in the boreal environment of southern Finland in the winter–spring of 2018. It was found that no single parameter could be used to predict the INP number concentration at the measurement location during the examined time period. It was also not possible to identify physical and chemical properties of ambient INPs despite the complexity of the instrumental set-up. Therefore, this paper addresses the necessity for future INP measurements.
Robert O. David, Maria Cascajo-Castresana, Killian P. Brennan, Michael Rösch, Nora Els, Julia Werz, Vera Weichlinger, Lin S. Boynton, Sophie Bogler, Nadine Borduas-Dedekind, Claudia Marcolli, and Zamin A. Kanji
Atmos. Meas. Tech., 12, 6865–6888, https://doi.org/10.5194/amt-12-6865-2019, https://doi.org/10.5194/amt-12-6865-2019, 2019
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Here we present the development and applicability of the DRoplet Ice Nuclei Counter Zurich (DRINCZ). DRINCZ allows for ice nuclei in the immersion mode to be quantified between 0 and -25 °C with an uncertainty of ±0.9 °C. Furthermore, we present a new method for assessing biases in drop-freezing apparatuses and cumulative ice-nucleating-particle concentrations from snow samples collected in the Austrian Alps at the Sonnblick Observatory.
Helen R. Smith, Zbigniew Ulanowski, Paul H. Kaye, Edwin Hirst, Warren Stanley, Richard Kaye, Andreas Wieser, Chris Stopford, Maria Kezoudi, Joseph Girdwood, Richard Greenaway, and Robert Mackenzie
Atmos. Meas. Tech., 12, 6579–6599, https://doi.org/10.5194/amt-12-6579-2019, https://doi.org/10.5194/amt-12-6579-2019, 2019
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The Universal Cloud and Aerosol Sounding System (UCASS) is a low-cost miniature optical particle counter (OPC) capable of sizing particles in the size range 0.4–40 μm. The open-geometry design makes the instrument suitable for deployment on balloon-borne sounding systems, dropsonde systems or as part of an unmanned aerial vehicle (UAV). Laboratory and field experiments show good agreement with reference instruments in a range of cloudy and dusty environments.
Albert Ansmann, Rodanthi-Elisavet Mamouri, Johannes Bühl, Patric Seifert, Ronny Engelmann, Julian Hofer, Argyro Nisantzi, James D. Atkinson, Zamin A. Kanji, Berko Sierau, Mihalis Vrekoussis, and Jean Sciare
Atmos. Chem. Phys., 19, 15087–15115, https://doi.org/10.5194/acp-19-15087-2019, https://doi.org/10.5194/acp-19-15087-2019, 2019
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For the first time, a closure study of the relationship between the ice-nucleating particle concentration (INPC) and ice crystal number concentration (ICNC) in altocumulus and cirrus layers, solely based on ground-based active remote sensing, is presented. The closure studies were conducted in Cyprus. A focus was on altocumulus and cirrus layers which developed in pronounced Saharan dust layers. The closure studies show that heterogeneous ice nucleation can play a dominant role in ice formation.
Nadine Borduas-Dedekind, Rachele Ossola, Robert O. David, Lin S. Boynton, Vera Weichlinger, Zamin A. Kanji, and Kristopher McNeill
Atmos. Chem. Phys., 19, 12397–12412, https://doi.org/10.5194/acp-19-12397-2019, https://doi.org/10.5194/acp-19-12397-2019, 2019
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During atmospheric transport, dissolved organic matter (DOM) within aqueous aerosols undergoes photochemistry. We find that photochemical processing of DOM increases its ability to form cloud droplets but decreases its ability to form ice crystals over a simulated 4.6 days in the atmosphere. A photomineralization mechanism involving the loss of organic carbon and the production of organic acids, CO and CO2 explains the observed changes and affects the liquid-water-to-ice ratio in clouds.
André Welti, Ulrike Lohmann, and Zamin A. Kanji
Atmos. Chem. Phys., 19, 10901–10918, https://doi.org/10.5194/acp-19-10901-2019, https://doi.org/10.5194/acp-19-10901-2019, 2019
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The ice nucleation ability of singly immersed feldspar particles in suspended water droplets relevant for ice crystal formation under mixed-phase cloud conditions is presented. The effects of particle size, crystal structure, trace metal and mineralogical composition are discussed by testing up to five different diameters in the submicron range and nine different feldspar samples at conditions relevant for ice nucleation in mixed-phase clouds.
Remo Dietlicher, David Neubauer, and Ulrike Lohmann
Atmos. Chem. Phys., 19, 9061–9080, https://doi.org/10.5194/acp-19-9061-2019, https://doi.org/10.5194/acp-19-9061-2019, 2019
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Ice crystals in clouds cover a spectrum of shapes and sizes. We show the first results of a consistent representation of the cloud ice spectrum in the climate model ECHAM6-HAM2. The simulated cloud fields are linked to their sources by new diagnostics. We find that only a small fraction of ice clouds is initiated by freezing of cloud droplets in the mixed-phase temperature regime while most ice forms at temperatures colder than −35 °C.
Zamin A. Kanji, Ryan C. Sullivan, Monika Niemand, Paul J. DeMott, Anthony J. Prenni, Cédric Chou, Harald Saathoff, and Ottmar Möhler
Atmos. Chem. Phys., 19, 5091–5110, https://doi.org/10.5194/acp-19-5091-2019, https://doi.org/10.5194/acp-19-5091-2019, 2019
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The ice nucleation ability of two natural desert dusts coated with a proxy of secondary organic aerosol is presented for temperatures and relative humidity conditions relevant for mixed-phase clouds. We find that at the tested conditions, there is no effect on the ice nucleation ability of the particles due to the organic coating. Furthermore, the two dust samples do not show variability within measurement uncertainty. Particle size and surface area may play a role in any difference observed.
Yvonne Boose, Philipp Baloh, Michael Plötze, Johannes Ofner, Hinrich Grothe, Berko Sierau, Ulrike Lohmann, and Zamin A. Kanji
Atmos. Chem. Phys., 19, 1059–1076, https://doi.org/10.5194/acp-19-1059-2019, https://doi.org/10.5194/acp-19-1059-2019, 2019
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The role non-mineral components play in the freezing behavior of atmospheric desert dust is not well known. In this study, we use chemical imaging methods to investigate this for airborne and surface-collected desert dust samples. We find that in most cases the ice nucleation behavior is determined by the dust mineralogical composition. However, volatile organic material can coat active sites and decrease the dust ice nucleation ability, while biological particles can significantly increase it.
Mikhail Paramonov, Robert O. David, Ruben Kretzschmar, and Zamin A. Kanji
Atmos. Chem. Phys., 18, 16515–16536, https://doi.org/10.5194/acp-18-16515-2018, https://doi.org/10.5194/acp-18-16515-2018, 2018
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The paper presents an overview of the ice nucleation activity of surface-collected mineral and soil dust. Emphasis is placed on disentangling the effects of mineral, biogenic and soluble components of the dust on its ice nucleation activity. The results revealed that it is not possible to predict the ice nucleation activity of the surface-collected dust based on the presence and amount of certain minerals or any particular class of compounds, such as soluble or proteinaceous/organic compounds.
Paul J. DeMott, Ottmar Möhler, Daniel J. Cziczo, Naruki Hiranuma, Markus D. Petters, Sarah S. Petters, Franco Belosi, Heinz G. Bingemer, Sarah D. Brooks, Carsten Budke, Monika Burkert-Kohn, Kristen N. Collier, Anja Danielczok, Oliver Eppers, Laura Felgitsch, Sarvesh Garimella, Hinrich Grothe, Paul Herenz, Thomas C. J. Hill, Kristina Höhler, Zamin A. Kanji, Alexei Kiselev, Thomas Koop, Thomas B. Kristensen, Konstantin Krüger, Gourihar Kulkarni, Ezra J. T. Levin, Benjamin J. Murray, Alessia Nicosia, Daniel O'Sullivan, Andreas Peckhaus, Michael J. Polen, Hannah C. Price, Naama Reicher, Daniel A. Rothenberg, Yinon Rudich, Gianni Santachiara, Thea Schiebel, Jann Schrod, Teresa M. Seifried, Frank Stratmann, Ryan C. Sullivan, Kaitlyn J. Suski, Miklós Szakáll, Hans P. Taylor, Romy Ullrich, Jesus Vergara-Temprado, Robert Wagner, Thomas F. Whale, Daniel Weber, André Welti, Theodore W. Wilson, Martin J. Wolf, and Jake Zenker
Atmos. Meas. Tech., 11, 6231–6257, https://doi.org/10.5194/amt-11-6231-2018, https://doi.org/10.5194/amt-11-6231-2018, 2018
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The ability to measure ice nucleating particles is vital to quantifying their role in affecting clouds and precipitation. Methods for measuring droplet freezing were compared while co-sampling relevant particle types. Measurement correspondence was very good for ice nucleating particles of bacterial and natural soil origin, and somewhat more disparate for those of mineral origin. Results reflect recently improved capabilities and provide direction toward addressing remaining measurement issues.
Fabian Mahrt, Claudia Marcolli, Robert O. David, Philippe Grönquist, Eszter J. Barthazy Meier, Ulrike Lohmann, and Zamin A. Kanji
Atmos. Chem. Phys., 18, 13363–13392, https://doi.org/10.5194/acp-18-13363-2018, https://doi.org/10.5194/acp-18-13363-2018, 2018
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The ice nucleation ability of different soot particles in the cirrus and mixed-phase cloud temperature regime is presented. The impact of aerosol particle size, particle morphology, organic matter and hydrophilicity on ice nucleation is examined. We propose ice nucleation proceeds via a pore condensation freezing mechanism for soot particles with the necessary physicochemical properties that nucleated ice well below water saturation.
Remo Dietlicher, David Neubauer, and Ulrike Lohmann
Geosci. Model Dev., 11, 1557–1576, https://doi.org/10.5194/gmd-11-1557-2018, https://doi.org/10.5194/gmd-11-1557-2018, 2018
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A new cloud scheme was implemented in the aerosol–climate model ECHAM6-HAM2. Unlike traditional schemes, it does not categorize ice particles by in-cloud and precipitation types but uses a single category with prognostic bulk particle properties. The new scheme is not only conceptually simpler but also closer to first principles as it does not rely on weakly constrained conversion rates between predefined categories and resolves falling ice by local sub-time-stepping.
Larissa Lacher, Ulrike Lohmann, Yvonne Boose, Assaf Zipori, Erik Herrmann, Nicolas Bukowiecki, Martin Steinbacher, and Zamin A. Kanji
Atmos. Chem. Phys., 17, 15199–15224, https://doi.org/10.5194/acp-17-15199-2017, https://doi.org/10.5194/acp-17-15199-2017, 2017
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We characterize the new Horizontal Ice Nucleation Chamber HINC to measure ambient ice nucleating particle concentrations at mixed‐phase cloud conditions. Results from winter measurements at the High Altitude Research Station Jungfraujoch compare well to previous measurements. We find increased ice nucleating particle concentrations during the influence of Saharan dust events and marine events, which highlights the importance of these species on ice nucleation in the free troposphere.
Monika Burkert-Kohn, Heike Wex, André Welti, Susan Hartmann, Sarah Grawe, Lisa Hellner, Paul Herenz, James D. Atkinson, Frank Stratmann, and Zamin A. Kanji
Atmos. Chem. Phys., 17, 11683–11705, https://doi.org/10.5194/acp-17-11683-2017, https://doi.org/10.5194/acp-17-11683-2017, 2017
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Several instruments can investigate properties of ice-nucleating particles (INPs), which are crucial to understanding ice cloud formation. We intercompare four online ice nucleation counters and reasonable agreement is found when the same ice nucleation mode is tested. A variable scaling factor was necessary to reconcile condensation freezing results with immersion freezing. Factors related to instrumental setup and aerosol generation are discussed to explain observed differences.
Sarvesh Garimella, Daniel A. Rothenberg, Martin J. Wolf, Robert O. David, Zamin A. Kanji, Chien Wang, Michael Rösch, and Daniel J. Cziczo
Atmos. Chem. Phys., 17, 10855–10864, https://doi.org/10.5194/acp-17-10855-2017, https://doi.org/10.5194/acp-17-10855-2017, 2017
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This study investigates systematic and variable low bias in the measurement of ice nucleating particle concentration using continuous flow diffusion chambers. We find that non-ideal instrument behavior exposes particles to different humidities and/or temperatures than predicted from theory. We use a machine learning approach to quantify and minimize the uncertainty associated with this measurement bias.
Yvonne Boose, André Welti, James Atkinson, Fabiola Ramelli, Anja Danielczok, Heinz G. Bingemer, Michael Plötze, Berko Sierau, Zamin A. Kanji, and Ulrike Lohmann
Atmos. Chem. Phys., 16, 15075–15095, https://doi.org/10.5194/acp-16-15075-2016, https://doi.org/10.5194/acp-16-15075-2016, 2016
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We compare the immersion freezing behavior of four airborne to 11 surface-collected dust samples to investigate the role of different minerals for atmospheric ice nucleation on desert dust. We find that present K-feldspars dominate at T > 253 K, while quartz does at colder temperatures, and surface-collected dust samples are not necessarily representative for airborne dust. For improved ice cloud prediction, modeling of quartz and feldspar emission and transport are key.
Yvonne Boose, Berko Sierau, M. Isabel García, Sergio Rodríguez, Andrés Alastuey, Claudia Linke, Martin Schnaiter, Piotr Kupiszewski, Zamin A. Kanji, and Ulrike Lohmann
Atmos. Chem. Phys., 16, 9067–9087, https://doi.org/10.5194/acp-16-9067-2016, https://doi.org/10.5194/acp-16-9067-2016, 2016
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Mineral dust is known to be among the most prevalent ice-nucleating particles (INPs) in the atmosphere, playing a crucial role for ice cloud formation. We present 2 months of ground-based in situ measurements of INP concentrations in the free troposphere close to the largest global dust source, the Sahara. We find that some atmospheric processes such as mixing with biological particles and ammonium increase the dust INP ability. This is important when predicting INPs based on emissions.
N. Hiranuma, S. Augustin-Bauditz, H. Bingemer, C. Budke, J. Curtius, A. Danielczok, K. Diehl, K. Dreischmeier, M. Ebert, F. Frank, N. Hoffmann, K. Kandler, A. Kiselev, T. Koop, T. Leisner, O. Möhler, B. Nillius, A. Peckhaus, D. Rose, S. Weinbruch, H. Wex, Y. Boose, P. J. DeMott, J. D. Hader, T. C. J. Hill, Z. A. Kanji, G. Kulkarni, E. J. T. Levin, C. S. McCluskey, M. Murakami, B. J. Murray, D. Niedermeier, M. D. Petters, D. O'Sullivan, A. Saito, G. P. Schill, T. Tajiri, M. A. Tolbert, A. Welti, T. F. Whale, T. P. Wright, and K. Yamashita
Atmos. Chem. Phys., 15, 2489–2518, https://doi.org/10.5194/acp-15-2489-2015, https://doi.org/10.5194/acp-15-2489-2015, 2015
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Seventeen ice nucleation measurement techniques contributed to investigate the immersion freezing behavior of illite NX. All data showed a similar temperature trend, but the measured ice nucleation activity was on average smaller for the wet suspended samples and higher for the dry-dispersed aerosol samples at high temperatures. A continued investigation and collaboration is necessary to obtain further insights into consistency or diversity of ice nucleation measurements.
H. Wex, S. Augustin-Bauditz, Y. Boose, C. Budke, J. Curtius, K. Diehl, A. Dreyer, F. Frank, S. Hartmann, N. Hiranuma, E. Jantsch, Z. A. Kanji, A. Kiselev, T. Koop, O. Möhler, D. Niedermeier, B. Nillius, M. Rösch, D. Rose, C. Schmidt, I. Steinke, and F. Stratmann
Atmos. Chem. Phys., 15, 1463–1485, https://doi.org/10.5194/acp-15-1463-2015, https://doi.org/10.5194/acp-15-1463-2015, 2015
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Immersion freezing measurements from seven different measurement techniques were intercompared using a biological ice nucleating material from bacteria. Although different techniques examined differently concentrated droplets, it was possible to find a uniform description, which showed that results from all experiments were generally in good agreement and were also in agreement with parameterizations published earlier in literature.
Z. A. Kanji, A. Welti, C. Chou, O. Stetzer, and U. Lohmann
Atmos. Chem. Phys., 13, 9097–9118, https://doi.org/10.5194/acp-13-9097-2013, https://doi.org/10.5194/acp-13-9097-2013, 2013
C. Chou, Z. A. Kanji, O. Stetzer, T. Tritscher, R. Chirico, M. F. Heringa, E. Weingartner, A. S. H. Prévôt, U. Baltensperger, and U. Lohmann
Atmos. Chem. Phys., 13, 761–772, https://doi.org/10.5194/acp-13-761-2013, https://doi.org/10.5194/acp-13-761-2013, 2013
Related subject area
Subject: Clouds | Technique: Laboratory Measurement | Topic: Instruments and Platforms
Comment on “A universally applicable method of calculating confidence bands for ice nucleation spectra derived from droplet freezing experiments” by Fahy et al. (2022)
Icing wind tunnel measurements of supercooled large droplets using the 12 mm total water content cone of the Nevzorov probe
The Microfluidic Ice Nuclei Counter Zürich (MINCZ): a platform for homogeneous and heterogeneous ice nucleation
Effects of the large-scale circulation on temperature and water vapor distributions in the Π Chamber
Photoacoustic hygrometer for icing wind tunnel water content measurement: design, analysis, and intercomparison
SPIN modification for low-temperature experiments
Characterization and first results from LACIS-T: a moist-air wind tunnel to study aerosol–cloud–turbulence interactions
Low-temperature triple-capillary cryostat for ice crystal growth studies
The SPectrometer for Ice Nuclei (SPIN): an instrument to investigate ice nucleation
BINARY: an optical freezing array for assessing temperature and time dependence of heterogeneous ice nucleation
Experimental quantification of contact freezing in an electrodynamic balance
Application of linear polarized light for the discrimination of frozen and liquid droplets in ice nucleation experiments
Gabor Vali
Atmos. Meas. Tech., 16, 4303–4306, https://doi.org/10.5194/amt-16-4303-2023, https://doi.org/10.5194/amt-16-4303-2023, 2023
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Different methods for the calculation of nucleation spectra from drop-freezing experiments are discussed as the choice of data processing reflects on underlying principles.
Johannes Lucke, Tina Jurkat-Witschas, Romy Heller, Valerian Hahn, Matthew Hamman, Wolfgang Breitfuss, Venkateshwar Reddy Bora, Manuel Moser, and Christiane Voigt
Atmos. Meas. Tech., 15, 7375–7394, https://doi.org/10.5194/amt-15-7375-2022, https://doi.org/10.5194/amt-15-7375-2022, 2022
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Flight testing in icing conditions requires instruments that are able to accurately measure the liquid water content of supercooled large droplets (SLDs). This work finds that the 12 mm cone of the Nevzorov hot-wire probe has excellent collection properties for SLDs. We also derive a correction to compensate for the low collision efficiency of small droplets with the cone. The results provide a procedure to evaluate LWC measurements of the 12 mm cone during wind tunnel and airborne experiments.
Florin N. Isenrich, Nadia Shardt, Michael Rösch, Julia Nette, Stavros Stavrakis, Claudia Marcolli, Zamin A. Kanji, Andrew J. deMello, and Ulrike Lohmann
Atmos. Meas. Tech., 15, 5367–5381, https://doi.org/10.5194/amt-15-5367-2022, https://doi.org/10.5194/amt-15-5367-2022, 2022
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Ice nucleation in the atmosphere influences cloud properties and lifetimes. Microfluidic instruments have recently been used to investigate ice nucleation, but these instruments are typically made out of a polymer that contributes to droplet instability over extended timescales and relatively high temperature uncertainty. To address these drawbacks, we develop and validate a new microfluidic instrument that uses fluoropolymer tubing to extend droplet stability and improve temperature accuracy.
Jesse C. Anderson, Subin Thomas, Prasanth Prabhakaran, Raymond A. Shaw, and Will Cantrell
Atmos. Meas. Tech., 14, 5473–5485, https://doi.org/10.5194/amt-14-5473-2021, https://doi.org/10.5194/amt-14-5473-2021, 2021
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Fluctuations due to turbulence in Earth's atmosphere can play a role in how many droplets a cloud has and, eventually, whether that cloud rains or evaporates. We study such processes in Michigan Tech's cloud chamber. Here, we characterize the turbulent and large-scale motions of air in the chamber, measuring the spatial and temporal distributions of temperature and water vapor, which we can combine to get the distribution of relative humidity, which governs cloud formation and dissipation.
Benjamin Lang, Wolfgang Breitfuss, Simon Schweighart, Philipp Breitegger, Hugo Pervier, Andreas Tramposch, Andreas Klug, Wolfgang Hassler, and Alexander Bergmann
Atmos. Meas. Tech., 14, 2477–2500, https://doi.org/10.5194/amt-14-2477-2021, https://doi.org/10.5194/amt-14-2477-2021, 2021
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This work describes the design, calibration, and application of a hygrometer and sampling system, which have been developed and used for water content measurement in experimentally simulated atmospheric icing conditions with relevance in fundamental icing research as well as aviation testing and certification. Together with a general description of water content measurement and accompanying uncertainties, the results of a comparison to reference instruments in an icing wind tunnel are presented.
André Welti, Kimmo Korhonen, Pasi Miettinen, Ana A. Piedehierro, Yrjö Viisanen, Annele Virtanen, and Ari Laaksonen
Atmos. Meas. Tech., 13, 7059–7067, https://doi.org/10.5194/amt-13-7059-2020, https://doi.org/10.5194/amt-13-7059-2020, 2020
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We describe a modification of the SPectrometer for Ice Nuclei (SPIN) chamber to study ice nucleation at low temperatures, relevant for ice formation in cirrus clouds. Validation experiments of homogeneous freezing of aqueous ammonium sulfate droplets and heterogeneous ice nucleation on silver iodide particles are included to demonstrate the advantages of the modified SPIN chamber for the investigation of ice nucleation in the extended temperature range.
Dennis Niedermeier, Jens Voigtländer, Silvio Schmalfuß, Daniel Busch, Jörg Schumacher, Raymond A. Shaw, and Frank Stratmann
Atmos. Meas. Tech., 13, 2015–2033, https://doi.org/10.5194/amt-13-2015-2020, https://doi.org/10.5194/amt-13-2015-2020, 2020
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In this paper, we present the new moist-air wind tunnel LACIS-T (Turbulent Leipzig Aerosol Cloud Interaction Simulator). It is used to study cloud physical processes in general and interactions between turbulence and cloud microphysical processes in particular. The operating principle of LACIS-T is explained, and the first results are depicted from deliquescence and droplet formation experiments observing clear indications on the effect of turbulence on these microphysical processes.
Brian D. Swanson and Jon Nelson
Atmos. Meas. Tech., 12, 6143–6152, https://doi.org/10.5194/amt-12-6143-2019, https://doi.org/10.5194/amt-12-6143-2019, 2019
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We have built a triple-capillary cryostat designed to reduce potential instrumental effects that may have influenced earlier measurements and to improve our understanding of the processes responsible for ice crystal shapes and sizes. In this cryostat, a crystal forms on one of three well-separated and ultrafine capillaries. In this paper we describe the new instrument and present several observations made using the instrument to illustrate the instrument's advantages.
Sarvesh Garimella, Thomas Bjerring Kristensen, Karolina Ignatius, Andre Welti, Jens Voigtländer, Gourihar R. Kulkarni, Frank Sagan, Gregory Lee Kok, James Dorsey, Leonid Nichman, Daniel Alexander Rothenberg, Michael Rösch, Amélie Catharina Ruth Kirchgäßner, Russell Ladkin, Heike Wex, Theodore W. Wilson, Luis Antonio Ladino, Jon P. D. Abbatt, Olaf Stetzer, Ulrike Lohmann, Frank Stratmann, and Daniel James Cziczo
Atmos. Meas. Tech., 9, 2781–2795, https://doi.org/10.5194/amt-9-2781-2016, https://doi.org/10.5194/amt-9-2781-2016, 2016
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The SPectrometer for Ice Nuclei (SPIN) is a commercially available ice nuclei counter manufactured by Droplet Measurement Technologies in Boulder, CO. This study characterizes the SPIN chamber, reporting data from laboratory measurements and quantifying uncertainties. Overall, we report that the SPIN is able to reproduce previous CFDC ice nucleation measurements.
C. Budke and T. Koop
Atmos. Meas. Tech., 8, 689–703, https://doi.org/10.5194/amt-8-689-2015, https://doi.org/10.5194/amt-8-689-2015, 2015
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A new optical freezing array for the study of heterogeneous ice nucleation in microliter-sized droplets is introduced, tested and applied to the study of immersion freezing in aqueous Snomax suspensions. Using different cooling rates, a small time dependence of ice nucleation induced by two different classes of ice nucleators was detected and the corresponding heterogeneous ice nucleation rate coefficient was quantified.
N. Hoffmann, A. Kiselev, D. Rzesanke, D. Duft, and T. Leisner
Atmos. Meas. Tech., 6, 2373–2382, https://doi.org/10.5194/amt-6-2373-2013, https://doi.org/10.5194/amt-6-2373-2013, 2013
T. Clauss, A. Kiselev, S. Hartmann, S. Augustin, S. Pfeifer, D. Niedermeier, H. Wex, and F. Stratmann
Atmos. Meas. Tech., 6, 1041–1052, https://doi.org/10.5194/amt-6-1041-2013, https://doi.org/10.5194/amt-6-1041-2013, 2013
Cited articles
Abdelmonem, A., Schnaiter, M., Amsler, P., Hesse, E., Meyer, J., and Leisner, T.: First correlated measurements of the shape and light scattering properties of cloud particles using the new Particle Habit Imaging and Polar Scattering (PHIPS) probe, Atmos. Meas. Tech., 4, 2125–2142, https://doi.org/10.5194/amt-4-2125-2011, 2011. a
Baumgardner, D., Brenguier, J. L., Bucholtz, A., Coe, H., DeMott, P., Garrett,
T. J., Gayet, J. F., Hermann, M., Heymsfield, A., Korolev, A., Krämer, M.,
Petzold, A., Strapp, W., Pilewskie, P., Taylor, J., Twohy, C., Wendisch, M.,
Bachalo, W., and Chuang, P.: Airborne instruments to measure atmospheric
aerosol particles, clouds and radiation: A cook's tour of mature and emerging
technology, Atmos. Res., 102, 10–29, 2011. a, b
Baumgardner, D., Abel, S. J., Axisa, D., Cotton, R., Crosier, J., Field, P.,
Gurganus, C., Heymsfield, A., Korolev, A., Krämer, M., Lawson, P.,
McFarquhar, G., Ulanowski, Z., and Um, J.: Cloud Ice Properties: In Situ
Measurement Challenges, Meteor. Mon., 58, 9.1–9.23, 2017. a
Beck, A., Henneberger, J., Schöpfer, S., Fugal, J., and Lohmann, U.: HoloGondel: in situ cloud observations on a cable car in the Swiss Alps using a holographic imager, Atmos. Meas. Tech., 10, 459–476, https://doi.org/10.5194/amt-10-459-2017, 2017. a
Bernauer, F., Hürkamp, K., Rühm, W., and Tschiersch, J.: Snow event
classification with a 2D video disdrometer – A decision tree approach,
Atmos. Res., 172–173, 186–195, 2016. a
Bohren, C. F. and Huffman, D. H.: Absorption and scattering of light by small
particles, Wiley Interscience, New York, 1983. a
Borrmann, S., Luo, B., and Mishchenko, M.: Aplication of the T-matrix method to
the measurement of aspherical (ellipsoidal) particles with forward scattering
optical particle counters, J. Aerosol Sci., 31, 789–799, 2000. a
Breiman, L.: Bagging predictors, Mach. Learn., 24, 123–140, 1996. a
Breiman, L.: Random Forests, Mach. Learn., 45, 5–32, 2001. a
Christopoulos, C. D., Garimella, S., Zawadowicz, M. A., Möhler, O., and Cziczo, D. J.: A machine learning approach to aerosol classification for single-particle mass spectrometry, Atmos. Meas. Tech., 11, 5687–5699, https://doi.org/10.5194/amt-11-5687-2018, 2018. a
Cotton, R., Osborne, S., Ulanowski, Z., Hirst, E., Kaye, P. H., and Greenaway,
R. S.: The Ability of the Small Ice Detector (SID-2) to Characterize Cloud
Particle and Aerosol Morphologies Obtained during Flights of the FAAM BAe-146
Research Aircraft, J. Atmos. Ocean. Tech., 27,
290–303, 2010. a
El-Desouki, M., Deen, M. J., Fang, Q., Liu, L., Tse, F., and Armstrong, D.:
CMOS Image Sensors for High Speed Applications, Sensors,
9, 430–444, 2009. a
Gardiner, B. A. and Hallett, J.: Degradation of In-Cloud Forward Scattering
Spectrometer Probe Measurements in the Presence of Ice Particles, J.
Atmos. Ocean. Tech., 2, 171–180, 1985. a
Garimella, S., Kristensen, T. B., Ignatius, K., Welti, A., Voigtländer, J., Kulkarni, G. R., Sagan, F., Kok, G. L., Dorsey, J., Nichman, L., Rothenberg, D. A., Rösch, M., Kirchgäßner, A. C. R., Ladkin, R., Wex, H., Wilson, T. W., Ladino, L. A., Abbatt, J. P. D., Stetzer, O., Lohmann, U., Stratmann, F., and Cziczo, D. J.: The SPectrometer for Ice Nuclei (SPIN): an instrument to investigate ice nucleation, Atmos. Meas. Tech., 9, 2781–2795, https://doi.org/10.5194/amt-9-2781-2016, 2016. a, b
Garrett, T. J., Navarro, B. C., Twohy, C. H., Jensen, E. J., Baumgardner,
D. G., Bui, P. T., Gerber, H., Herman, R. L., Heymsfield, A. J., Lawson, P.,
Minnis, P., Nguyen, L., Poellot, M., Pope, S. K., Valero, F. P. J., and
Weinstock, E. M.: Evolution of a Florida Cirrus Anvil, J.
Atmos. Sci., 62, 2352–2372, 2005. a
Grawe, S., Augustin-Bauditz, S., Hartmann, S., Hellner, L., Pettersson, J. B. C., Prager, A., Stratmann, F., and Wex, H.: The immersion freezing behavior of ash particles from wood and brown coal burning, Atmos. Chem. Phys., 16, 13911–13928, https://doi.org/10.5194/acp-16-13911-2016, 2016. a
Grawe, S., Augustin-Bauditz, S., Clemen, H.-C., Ebert, M., Eriksen Hammer, S., Lubitz, J., Reicher, N., Rudich, Y., Schneider, J., Staacke, R., Stratmann, F., Welti, A., and Wex, H.: Coal fly ash: linking immersion freezing behavior and physicochemical particle properties, Atmos. Chem. Phys., 18, 13903–13923, https://doi.org/10.5194/acp-18-13903-2018, 2018. a
Heymsfield, A. J., Schmitt, C., Bansemer, A., Zadelhoff, G.-J. v., McGill,
M. J., Twohy, C., and Baumgardner, D.: Effective Radius of Ice Cloud Particle
Populations Derived from Aircraft Probes, J. Atmos. Ocean.
Tech., 23, 361–380, 2006. a
Hiranuma, N., Augustin-Bauditz, S., Bingemer, H., Budke, C., Curtius, J., Danielczok, A., Diehl, K., Dreischmeier, K., Ebert, M., Frank, F., Hoffmann, N., Kandler, K., Kiselev, A., Koop, T., Leisner, T., Möhler, O., Nillius, B., Peckhaus, A., Rose, D., Weinbruch, S., Wex, H., Boose, Y., DeMott, P. J., Hader, J. D., Hill, T. C. J., Kanji, Z. A., Kulkarni, G., Levin, E. J. T., McCluskey, C. S., Murakami, M., Murray, B. J., Niedermeier, D., Petters, M. D., O'Sullivan, D., Saito, A., Schill, G. P., Tajiri, T., Tolbert, M. A., Welti, A., Whale, T. F., Wright, T. P., and Yamashita, K.: A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques, Atmos. Chem. Phys., 15, 2489–2518, https://doi.org/10.5194/acp-15-2489-2015, 2015. a
Jaenicke, R. and Hanusch, T.: Simulation of the Optical Particle Counter
Forward Scattering Spectrometer Probe 100 (FSSP-100) AU – Jaenicke, Ruprecht,
Aerosol Sci. Technol., 18, 309–322, 1993. a
Johnson, A., Lasher-Trapp, S., Bansemer, A., Ulanowski, Z., and Heymsfield,
A. J.: Difficulties in Early Ice Detection with the Small Ice Detector-2
HIAPER (SID-2H) in Maritime Cumuli, J. Atmos. Ocean.
Tech., 31, 1263–1275, 2014. a
Järvinen, E., Schnaiter, M., Mioche, G., Jourdan, O., Shcherbakov, V. N.,
Costa, A., Afchine, A., Krämer, M., Heidelberg, F., Jurkat, T., Voigt, C.,
Schlager, H., Nichman, L., Gallagher, M., Hirst, E., Schmitt, C., Bansemer,
A., Heymsfield, A., Lawson, P., Tricoli, U., Pfeilsticker, K., Vochezer, P.,
Möhler, O., and Leisner, T.: Quasi-Spherical Ice in Convective Clouds,
J. Atmos. Sci., 73, 3885–3910, 2016. a, b, c
Kanji, Z. A., Ladino, L. A., Wex, H., Boose, Y., Burkert-Kohn, M., Cziczo,
D. J., and Krämer, M.: Overview of Ice Nucleating Particles, Meteor.
Mon., 58, 1.1–1.33, 2017. a
Kaye, P. H., Hirst, E., Greenaway, R. S., Ulanowski, Z., Hesse, E., DeMott,
P. J., Saunders, C., and Connolly, P.: Classifying atmospheric ice crystals
by spatial light scattering, Opt. Lett., 33, 1545–1547, 2008. a
Kohn, M., Lohmann, U., Welti, A., and Kanji, Z. A.: Immersion mode ice
nucleation measurements with the new Portable Immersion Mode Cooling chAmber
(PIMCA), J. Geophys. Res.-Atmos., 121, 4713–4733, 2016. a
Korolev, A. and Isaac, G.: Roundness and aspect ratio of particles in ice
clouds, J. Atmos. Sci., 60, 1795–1808, 2003. a
Korolev, A. and Isaac, G. A.: Relative Humidity in Liquid, Mixed-Phase, and Ice
Clouds, J. Atmos. Sci., 63, 2865–2880, 2006. a
Korolev, A., McFarquhar, G., Field, P. R., Franklin, C., Lawson, P., Wang, Z.,
Williams, E., Abel, S. J., Axisa, D., Borrmann, S., Crosier, J., Fugal, J.,
Krämer, M., Lohmann, U., Schlenczek, O., Schnaiter, M., and Wendisch, M.:
Mixed-Phase Clouds: Progress and Challenges, Meteor. Mon., 58,
5.1–5.50, 2017. a
Korolev, A. V., Isaac, G. A., Cober, S. G., Strapp, J. W., and Hallett, J.:
Microphysical characterization of mixed-phase clouds, Q. J.
Roy. Meteor. Soc., 129, 39–65, 2003. a
Lacher, L., Lohmann, U., Boose, Y., Zipori, A., Herrmann, E., Bukowiecki, N., Steinbacher, M., and Kanji, Z. A.: The Horizontal Ice Nucleation Chamber (HINC): INP measurements at conditions relevant for mixed-phase clouds at the High Altitude Research Station Jungfraujoch, Atmos. Chem. Phys., 17, 15199–15224, https://doi.org/10.5194/acp-17-15199-2017, 2017. a, b
Lance, S., Brock, C. A., Rogers, D., and Gordon, J. A.: Water droplet calibration of the Cloud Droplet Probe (CDP) and in-flight performance in liquid, ice and mixed-phase clouds during ARCPAC, Atmos. Meas. Tech., 3, 1683–1706, https://doi.org/10.5194/amt-3-1683-2010, 2010. a
Lawson, R. P., Baker, B. A., Schmitt, C. G., and Jensen, T. L.: An overview of
microphysical properties of Arctic clouds observed in May and July 1998
during FIRE ACE, J. Geophys. Res.-Atmos., 106, 14989–15014, 2001. a
Libbrecht, K. G.: The physics of snow crystals, Rep. Prog. Phys.,
68, 855–895, 2005. a
Lin, J. Z., Zhang, W. F., and Yu, Z. S.: Numerical research on the orientation
distribution of fibers immersed in laminar and turbulent pipe flows, J.
Aerosol Sci., 35, 63–82, 2004. a
Liou, K.-N. and Lahore, H.: Laser Sensing of Cloud Composition: A Backscattered
Depolarization Technique, J. Appl. Meteor., 13, 257–263, 1974. a
Lohmann, U.: Anthropogenic Aerosol Influences on Mixed-Phase Clouds, Current
Climate Change Reports, 1–13, 2017. a
Lohmann, U., Lüönd, F., and Mahrt, F.: An Introduction to Clouds: From the
Microscale to Climate, Cambridge University Press, Cambridge,
https://doi.org/10.1017/CBO9781139087513, 2016. a
Lüönd, F., Stetzer, O., Welti, A., and Lohmann, U.: Experimental study on the
ice nucleation ability of size-selected kaolinite particles in the immersion
mode, J. Geophys. Res.-Atmos., 115, D14201, https://doi.org/10.1029/2009jd012959, 2010. a
Magee, N. B., Miller, A., Amaral, M., and Cumiskey, A.: Mesoscopic surface roughness of ice crystals pervasive across a wide range of ice crystal conditions, Atmos. Chem. Phys., 14, 12357–12371, https://doi.org/10.5194/acp-14-12357-2014, 2014. a
Mahrt, F., Marcolli, C., David, R. O., Grönquist, P., Barthazy Meier, E. J., Lohmann, U., and Kanji, Z. A.: Ice nucleation abilities of soot particles determined with the Horizontal Ice Nucleation Chamber, Atmos. Chem. Phys., 18, 13363–13392, https://doi.org/10.5194/acp-18-13363-2018, 2018. a, b, c
Mahrt, F., Wieder, J., Dietlicher, R., Smith, H. R., Stopford, C., and Kanji, Z. A.: A High Speed Particle Phase Discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber, data set, https://doi.org/10.3929/ethz-b-000313787, 2019.
Matus, A. V. and L'Ecuyer, T. S.: The role of cloud phase in Earth's radiation
budget, J. Geophys. Res.-Atmos., 122, 2559–2578, 2017. a
McCoy, D. T., Tan, I., Hartmann, D. L., Zelinka, M. D., and Storelvmo, T.: On
the relationships among cloud cover, mixed-phase partitioning, and planetary
albedo in GCMs, J. Adv. Model. Earth Sys., 8, 650–668,
2016. a
Mie, G.: Beiträge zur Optik trüber Medien, speziell kolloidaler
Metallösungen, Annal. Phys., 330, 377–445, 1908. a
Mohri, M., Rostamizadeh, A., and Talwalkar, A.: Foundations of machine
learning, The MIT Press, Cambridge, MA, 2018. a
Mülmenstädt, J., Sourdeval, O., Delanoë, J., and Quaas, J.: Frequency of
occurrence of rain from liquid-, mixed-, and ice-phase clouds derived from
A-Train satellite retrievals, Geophys. Res. Lett., 42, 6502–6509,
2015. a
Nichman, L., Järvinen, E., Dorsey, J., Connolly, P., Duplissy, J., Fuchs, C., Ignatius, K., Sengupta, K., Stratmann, F., Möhler, O., Schnaiter, M., and Gallagher, M.: Intercomparison study and optical asphericity measurements of small ice particles in the CERN CLOUD experiment, Atmos. Meas. Tech., 10, 3231–3248, https://doi.org/10.5194/amt-10-3231-2017, 2017. a
Nicolet, M., Stetzer, O., and Lohmann, U.: Depolarization ratios of single ice
particles assuming finite circular cylinders, Appl. Opt., 46, 4465–4476,
2007. a
Ottani, S., Vitalini, D., Comelli, F., and Castellari, C.: Densities,
Viscosities, and Refractive Indices of Poly(ethylene glycol) 200 and 400+
Cyclic Ethers at 303.15 K, J. Chem. Eng. Data, 47,
1197–1204, 2002. a
Ruske, S., Topping, D. O., Foot, V. E., Morse, A. P., and Gallagher, M. W.: Machine learning for improved data analysis of biological aerosol using the WIBS, Atmos. Meas. Tech., 11, 6203–6230, https://doi.org/10.5194/amt-11-6203-2018, 2018.
a, b
Schnaiter, M., Järvinen, E., Vochezer, P., Abdelmonem, A., Wagner, R., Jourdan, O., Mioche, G., Shcherbakov, V. N., Schmitt, C. G., Tricoli, U., Ulanowski, Z., and Heymsfield, A. J.: Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds, Atmos. Chem. Phys., 16, 5091–5110, https://doi.org/10.5194/acp-16-5091-2016, 2016. a
Stetzer, O., Baschek, B., Lueoeond, F., and Lohmann, U.: The Zurich Ice
Nucleation Chamber (ZINC) – A new instrument to investigate atmospheric ice
formation, Aerosol Sci. Technol., 42, 64–74, 2008. a
Tan, I., Storelvmo, T., and Zelinka, M. D.: Observational constraints on
mixed-phase clouds imply higher climate sensitivity, Science, 352, 224–227,
2016. a
Ulanowski, Z., Hirst, E., Kaye, P. H., and Greenaway, R.: Retrieving the size
of particles with rough and complex surfaces from two-dimensional scattering
patterns, J. Quant. Spectrosc. Ra., 113,
2457–2464, 2012. a
Ulanowski, Z., Kaye, P. H., Hirst, E., Greenaway, R. S., Cotton, R. J., Hesse, E., and Collier, C. T.: Incidence of rough and irregular atmospheric ice particles from Small Ice Detector 3 measurements, Atmos. Chem. Phys., 14, 1649–1662, https://doi.org/10.5194/acp-14-1649-2014, 2014. a, b, c
Vochezer, P., Järvinen, E., Wagner, R., Kupiszewski, P., Leisner, T., and Schnaiter, M.: In situ characterization of mixed phase clouds using the Small Ice Detector and the Particle Phase Discriminator, Atmos. Meas. Tech., 9, 159–177, https://doi.org/10.5194/amt-9-159-2016, 2016. a, b
Voigtländer, J., Chou, C., Bieligk, H., Clauss, T., Hartmann, S., Herenz, P., Niedermeier, D., Ritter, G., Stratmann, F., and Ulanowski, Z.: Surface roughness during depositional growth and sublimation of ice crystals, Atmos. Chem. Phys., 18, 13687–13702, https://doi.org/10.5194/acp-18-13687-2018, 2018. a
Welti, A., Lüönd, F., Stetzer, O., and Lohmann, U.: Influence of particle size on the ice nucleating ability of mineral dusts, Atmos. Chem. Phys., 9, 6705–6715, https://doi.org/10.5194/acp-9-6705-2009, 2009. a
Zenker, J., Collier, K. N., Xu, G., Yang, P., Levin, E. J. T., Suski, K. J., DeMott, P. J., and Brooks, S. D.: Using depolarization to quantify ice nucleating particle concentrations: a new method, Atmos. Meas. Tech., 10, 4639–4657, https://doi.org/10.5194/amt-10-4639-2017, 2017. a
Zhang, J. B., Ding, L., Wang, Y. P., Zhang, L., Wu, J. L., Zheng, H. Y., and
Fang, L.: Theoretical studies on particle shape classification based on
simultaneous small forward angle light scattering and aerodynamic sizing,
Chinese Phys. B, 25, 034201, https://doi.org/10.1088/1674-1056/25/3/034201, 2016. a
Short summary
A new instrument, the High Speed Particle Phase Discriminator (PPD-HS), is presented, with the goal of quantifying liquid and ice fraction in conditions relevant for mixed-phase clouds. PPD-HS captures the near-forward spatial intensity distribution of scattered light on a single particle basis. Symmetry analysis of the scattering pattern is used to determine the shape of the particles, with cloud droplets and ice crystals producing symmetrical and asymmetrical scattering patterns, respectively.
A new instrument, the High Speed Particle Phase Discriminator (PPD-HS), is presented, with the...
