Articles | Volume 23, issue 13
https://doi.org/10.5194/acp-23-7611-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-23-7611-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Investigating the vertical extent and short-wave radiative effects of the ice phase in Arctic summertime low-level clouds
Department of Atmospheric Aerosol Research of the Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
Franziska Nehlert
Department of Atmospheric Aerosol Research of the Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
Guanglang Xu
Department of Atmospheric Aerosol Research of the Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
Fritz Waitz
Department of Atmospheric Aerosol Research of the Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
Guillaume Mioche
Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne/OPGC/CNRS, Clermont Ferrand, France
Regis Dupuy
Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne/OPGC/CNRS, Clermont Ferrand, France
Olivier Jourdan
Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne/OPGC/CNRS, Clermont Ferrand, France
Martin Schnaiter
Department of Atmospheric Aerosol Research of the Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
schnaiTEC GmbH, Bruchsal, Germany
Related authors
Marco Zanatta, Stephan Mertes, Olivier Jourdan, Regis Dupuy, Emma Järvinen, Martin Schnaiter, Oliver Eppers, Johannes Schneider, Zsófia Jurányi, and Andreas Herber
Atmos. Chem. Phys., 23, 7955–7973, https://doi.org/10.5194/acp-23-7955-2023, https://doi.org/10.5194/acp-23-7955-2023, 2023
Short summary
Short summary
Black carbon (BC) particles influence the Arctic radiative balance. Vertical measurements of black carbon were conducted during the ACLOUD campaign in the European Arctic to study the interaction of BC with clouds. This study shows that clouds influence the vertical variability of BC properties across the inversion layer and that multiple activation and transformation mechanisms of BC may occur in the presence of low-level, persistent, mixed-phase clouds.
Franz Martin Schnaiter, Claudia Linke, Eija Asmi, Henri Servomaa, Antti-Pekka Hyvärinen, Sho Ohata, Yutaka Kondo, and Emma Järvinen
Atmos. Meas. Tech., 16, 2753–2769, https://doi.org/10.5194/amt-16-2753-2023, https://doi.org/10.5194/amt-16-2753-2023, 2023
Short summary
Short summary
Light-absorbing particles from combustion processes are important contributors to climate warming. Their highly variable spectral light absorption properties need to be monitored in the field. Commonly used methods show measurement artefacts that are difficult to correct. We introduce a new instrument that is based on the photoacoustic effect. Long-term operation in the Finnish Arctic demonstrates the applicability of the new instrument for unattended light absorption monitoring.
Fritz Waitz, Martin Schnaiter, Thomas Leisner, and Emma Järvinen
Atmos. Chem. Phys., 22, 7087–7103, https://doi.org/10.5194/acp-22-7087-2022, https://doi.org/10.5194/acp-22-7087-2022, 2022
Short summary
Short summary
Riming, i.e., the accretion of small droplets on the surface of ice particles via collision, is one of the major uncertainties in model prediction of mixed-phase clouds. We discuss the occurrence (up to 50% of particles) and aging of rimed ice particles and show correlations of the occurrence and the degree of riming with ambient meteorological parameters using data gathered by the Particle Habit Imaging and Polar Scattering (PHIPS) probe during three airborne in situ field campaigns.
Janne Lampilahti, Hanna E. Manninen, Tuomo Nieminen, Sander Mirme, Mikael Ehn, Iida Pullinen, Katri Leino, Siegfried Schobesberger, Juha Kangasluoma, Jenni Kontkanen, Emma Järvinen, Riikka Väänänen, Taina Yli-Juuti, Radovan Krejci, Katrianne Lehtipalo, Janne Levula, Aadu Mirme, Stefano Decesari, Ralf Tillmann, Douglas R. Worsnop, Franz Rohrer, Astrid Kiendler-Scharr, Tuukka Petäjä, Veli-Matti Kerminen, Thomas F. Mentel, and Markku Kulmala
Atmos. Chem. Phys., 21, 12649–12663, https://doi.org/10.5194/acp-21-12649-2021, https://doi.org/10.5194/acp-21-12649-2021, 2021
Short summary
Short summary
We studied aerosol particle formation and growth in different parts of the planetary boundary layer at two different locations (Po Valley, Italy, and Hyytiälä, Finland). The observations consist of airborne measurements on board an instrumented Zeppelin and a small airplane combined with comprehensive ground-based measurements.
Fritz Waitz, Martin Schnaiter, Thomas Leisner, and Emma Järvinen
Atmos. Meas. Tech., 14, 3049–3070, https://doi.org/10.5194/amt-14-3049-2021, https://doi.org/10.5194/amt-14-3049-2021, 2021
Short summary
Short summary
A major challenge in the observations of mixed-phase clouds remains the phase discrimination and sizing of cloud droplets and ice crystals, especially for particles with diameters smaller than 0.1 mm. Here, we present a new method to derive the phase and size of single cloud particles using their angular-light-scattering information. Comparisons with other in situ instruments in three case studies show good agreement.
André Ehrlich, Manfred Wendisch, Christof Lüpkes, Matthias Buschmann, Heiko Bozem, Dmitri Chechin, Hans-Christian Clemen, Régis Dupuy, Olliver Eppers, Jörg Hartmann, Andreas Herber, Evelyn Jäkel, Emma Järvinen, Olivier Jourdan, Udo Kästner, Leif-Leonard Kliesch, Franziska Köllner, Mario Mech, Stephan Mertes, Roland Neuber, Elena Ruiz-Donoso, Martin Schnaiter, Johannes Schneider, Johannes Stapf, and Marco Zanatta
Earth Syst. Sci. Data, 11, 1853–1881, https://doi.org/10.5194/essd-11-1853-2019, https://doi.org/10.5194/essd-11-1853-2019, 2019
Short summary
Short summary
During the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign, two research aircraft (Polar 5 and 6) jointly performed 22 research flights over the transition zone between open ocean and closed sea ice. The data set combines remote sensing and in situ measurement of cloud, aerosol, and trace gas properties, as well as turbulent and radiative fluxes, which will be used to study Arctic boundary layer and mid-level clouds and their role in Arctic amplification.
Emma Järvinen, Olivier Jourdan, David Neubauer, Bin Yao, Chao Liu, Meinrat O. Andreae, Ulrike Lohmann, Manfred Wendisch, Greg M. McFarquhar, Thomas Leisner, and Martin Schnaiter
Atmos. Chem. Phys., 18, 15767–15781, https://doi.org/10.5194/acp-18-15767-2018, https://doi.org/10.5194/acp-18-15767-2018, 2018
Short summary
Short summary
Using light diffraction it is possible to detect microscopic features within ice particles that have not yet been fully characterized. Here, this technique was applied in airborne measurements, where it was found that majority of atmospheric ice particles have features that significantly change the way ice particles interact with solar light. The microscopic features make ice-containing clouds more reflective than previously thought, which could have consequences for predicting our climate.
Meinrat O. Andreae, Armin Afchine, Rachel Albrecht, Bruna Amorim Holanda, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Micael A. Cecchini, Anja Costa, Maximilian Dollner, Daniel Fütterer, Emma Järvinen, Tina Jurkat, Thomas Klimach, Tobias Konemann, Christoph Knote, Martina Krämer, Trismono Krisna, Luiz A. T. Machado, Stephan Mertes, Andreas Minikin, Christopher Pöhlker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, Daniel Sauer, Hans Schlager, Martin Schnaiter, Johannes Schneider, Christiane Schulz, Antonio Spanu, Vinicius B. Sperling, Christiane Voigt, Adrian Walser, Jian Wang, Bernadett Weinzierl, Manfred Wendisch, and Helmut Ziereis
Atmos. Chem. Phys., 18, 921–961, https://doi.org/10.5194/acp-18-921-2018, https://doi.org/10.5194/acp-18-921-2018, 2018
Short summary
Short summary
We made airborne measurements of aerosol particle concentrations and properties over the Amazon Basin. We found extremely high concentrations of very small particles in the region between 8 and 14 km altitude all across the basin, which had been recently formed by gas-to-particle conversion at these altitudes. This makes the upper troposphere a very important source region of atmospheric particles with significant implications for the Earth's climate system.
Martin Schnaiter, Emma Järvinen, Ahmed Abdelmonem, and Thomas Leisner
Atmos. Meas. Tech., 11, 341–357, https://doi.org/10.5194/amt-11-341-2018, https://doi.org/10.5194/amt-11-341-2018, 2018
Short summary
Short summary
PHIPS-HALO is a novel aircraft instrument for cloud research. It combines microscopic imaging of single cloud particles with the measurement of their spacial light scattering properties. The knowledge of how atmospheric ice particles in clouds scatter visible light is important for improving future climate models.
Leonid Nichman, Emma Järvinen, James Dorsey, Paul Connolly, Jonathan Duplissy, Claudia Fuchs, Karoliina Ignatius, Kamalika Sengupta, Frank Stratmann, Ottmar Möhler, Martin Schnaiter, and Martin Gallagher
Atmos. Meas. Tech., 10, 3231–3248, https://doi.org/10.5194/amt-10-3231-2017, https://doi.org/10.5194/amt-10-3231-2017, 2017
Short summary
Short summary
Optical probes are frequently used for the detection of cloud particles. The detected microphysical properties may affect particle growth and accretion mechanisms and the light scattering properties of cirrus clouds. In the CLOUD chamber study at CERN, we compared four optical measurement techniques. We show that shape derivation alone is not sufficient to determine the phase of the small cloud particles. None of the instruments were able to unambiguously determine the phase of small particles.
Naruki Hiranuma, Ottmar Möhler, Gourihar Kulkarni, Martin Schnaiter, Steffen Vogt, Paul Vochezer, Emma Järvinen, Robert Wagner, David M. Bell, Jacqueline Wilson, Alla Zelenyuk, and Daniel J. Cziczo
Atmos. Meas. Tech., 9, 3817–3836, https://doi.org/10.5194/amt-9-3817-2016, https://doi.org/10.5194/amt-9-3817-2016, 2016
Short summary
Short summary
A new pumped counterflow virtual impactor (PCVI) called the ice-selecting PCVI (IS-PCVI) has been developed to collect ice crystal residuals for investigating physico-chemical properties of ice-nucleating particles. The results show that the ice crystals of volume-equivalent diameter ~ 10 to 30 µm can be efficiently separated from the supercooled droplets and interstitial particles. The IS-PCVI is efficient when the counterflow-to-input flow ratio is within 0.09 to 0.18.
Ahmed Abdelmonem, Emma Järvinen, Denis Duft, Edwin Hirst, Steffen Vogt, Thomas Leisner, and Martin Schnaiter
Atmos. Meas. Tech., 9, 3131–3144, https://doi.org/10.5194/amt-9-3131-2016, https://doi.org/10.5194/amt-9-3131-2016, 2016
Short summary
Short summary
The properties of ice crystals present in mixed-phase and ice clouds influence the radiation properties, precipitation occurrence and lifetime of these clouds. It is necessary to investigate the optical and microphysical properties of cloud particles particularly in situ, and to get correlation between these properties. To this end we have developed PHIPS-HALO to measure the optical properties and the corresponding microphysical parameters of individual cloud particles simultaneously.
Karoliina Ignatius, Thomas B. Kristensen, Emma Järvinen, Leonid Nichman, Claudia Fuchs, Hamish Gordon, Paul Herenz, Christopher R. Hoyle, Jonathan Duplissy, Sarvesh Garimella, Antonio Dias, Carla Frege, Niko Höppel, Jasmin Tröstl, Robert Wagner, Chao Yan, Antonio Amorim, Urs Baltensperger, Joachim Curtius, Neil M. Donahue, Martin W. Gallagher, Jasper Kirkby, Markku Kulmala, Ottmar Möhler, Harald Saathoff, Martin Schnaiter, Antonio Tomé, Annele Virtanen, Douglas Worsnop, and Frank Stratmann
Atmos. Chem. Phys., 16, 6495–6509, https://doi.org/10.5194/acp-16-6495-2016, https://doi.org/10.5194/acp-16-6495-2016, 2016
Short summary
Short summary
Viscous solid or semi-solid secondary organic aerosol (SOA) may influence cloud properties through ice nucleation in the atmosphere. Here, we observed heterogeneous ice nucleation of viscous α-pinene SOA at temperatures between −39 °C and −37.2 °C with ice saturation ratios significantly below the homogeneous freezing limit. Global modelling suggests that viscous biogenic SOA are present in regions where cirrus formation takes place and could contribute to the global ice nuclei budget.
Martin Schnaiter, Emma Järvinen, Paul Vochezer, Ahmed Abdelmonem, Robert Wagner, Olivier Jourdan, Guillaume Mioche, Valery N. Shcherbakov, Carl G. Schmitt, Ugo Tricoli, Zbigniew Ulanowski, and Andrew J. Heymsfield
Atmos. Chem. Phys., 16, 5091–5110, https://doi.org/10.5194/acp-16-5091-2016, https://doi.org/10.5194/acp-16-5091-2016, 2016
Emma Järvinen, Karoliina Ignatius, Leonid Nichman, Thomas B. Kristensen, Claudia Fuchs, Christopher R. Hoyle, Niko Höppel, Joel C. Corbin, Jill Craven, Jonathan Duplissy, Sebastian Ehrhart, Imad El Haddad, Carla Frege, Hamish Gordon, Tuija Jokinen, Peter Kallinger, Jasper Kirkby, Alexei Kiselev, Karl-Heinz Naumann, Tuukka Petäjä, Tamara Pinterich, Andre S. H. Prevot, Harald Saathoff, Thea Schiebel, Kamalika Sengupta, Mario Simon, Jay G. Slowik, Jasmin Tröstl, Annele Virtanen, Paul Vochezer, Steffen Vogt, Andrea C. Wagner, Robert Wagner, Christina Williamson, Paul M. Winkler, Chao Yan, Urs Baltensperger, Neil M. Donahue, Rick C. Flagan, Martin Gallagher, Armin Hansel, Markku Kulmala, Frank Stratmann, Douglas R. Worsnop, Ottmar Möhler, Thomas Leisner, and Martin Schnaiter
Atmos. Chem. Phys., 16, 4423–4438, https://doi.org/10.5194/acp-16-4423-2016, https://doi.org/10.5194/acp-16-4423-2016, 2016
Leonid Nichman, Claudia Fuchs, Emma Järvinen, Karoliina Ignatius, Niko Florian Höppel, Antonio Dias, Martin Heinritzi, Mario Simon, Jasmin Tröstl, Andrea Christine Wagner, Robert Wagner, Christina Williamson, Chao Yan, Paul James Connolly, James Robert Dorsey, Jonathan Duplissy, Sebastian Ehrhart, Carla Frege, Hamish Gordon, Christopher Robert Hoyle, Thomas Bjerring Kristensen, Gerhard Steiner, Neil McPherson Donahue, Richard Flagan, Martin William Gallagher, Jasper Kirkby, Ottmar Möhler, Harald Saathoff, Martin Schnaiter, Frank Stratmann, and António Tomé
Atmos. Chem. Phys., 16, 3651–3664, https://doi.org/10.5194/acp-16-3651-2016, https://doi.org/10.5194/acp-16-3651-2016, 2016
Short summary
Short summary
Processes in the atmosphere are often governed by the physical and chemical properties of small cloud particles. Ice, water, and mixed clouds, as well as viscous aerosols, were formed under controlled conditions at the CLOUD-CERN facility. The experimental results show a link between cloud particle properties and their unique optical fingerprints. The classification map presented here allows easier discrimination between various particles such as viscous organic aerosol, salt, ice, and liquid.
Jenni Kontkanen, Emma Järvinen, Hanna E. Manninen, Katrianne Lehtipalo, Juha Kangasluoma, Stefano Decesari, Gian Paolo Gobbi, Ari Laaksonen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 16, 1919–1935, https://doi.org/10.5194/acp-16-1919-2016, https://doi.org/10.5194/acp-16-1919-2016, 2016
C. R. Hoyle, C. Fuchs, E. Järvinen, H. Saathoff, A. Dias, I. El Haddad, M. Gysel, S. C. Coburn, J. Tröstl, A.-K. Bernhammer, F. Bianchi, M. Breitenlechner, J. C. Corbin, J. Craven, N. M. Donahue, J. Duplissy, S. Ehrhart, C. Frege, H. Gordon, N. Höppel, M. Heinritzi, T. B. Kristensen, U. Molteni, L. Nichman, T. Pinterich, A. S. H. Prévôt, M. Simon, J. G. Slowik, G. Steiner, A. Tomé, A. L. Vogel, R. Volkamer, A. C. Wagner, R. Wagner, A. S. Wexler, C. Williamson, P. M. Winkler, C. Yan, A. Amorim, J. Dommen, J. Curtius, M. W. Gallagher, R. C. Flagan, A. Hansel, J. Kirkby, M. Kulmala, O. Möhler, F. Stratmann, D. R. Worsnop, and U. Baltensperger
Atmos. Chem. Phys., 16, 1693–1712, https://doi.org/10.5194/acp-16-1693-2016, https://doi.org/10.5194/acp-16-1693-2016, 2016
Short summary
Short summary
A significant portion of sulphate, an important constituent of atmospheric aerosols, is formed via the aqueous phase oxidation of sulphur dioxide by ozone. The rate of this reaction has previously only been measured over a relatively small temperature range. Here, we use the state of the art CLOUD chamber at CERN to perform the first measurements of this reaction rate in super-cooled droplets, confirming that the existing extrapolation of the reaction rate to sub-zero temperatures is accurate.
P. Vochezer, E. Järvinen, R. Wagner, P. Kupiszewski, T. Leisner, and M. Schnaiter
Atmos. Meas. Tech., 9, 159–177, https://doi.org/10.5194/amt-9-159-2016, https://doi.org/10.5194/amt-9-159-2016, 2016
Short summary
Short summary
To study clouds constituting of liquid droplets as well as ice particles we used the latest versions of the Small Ice Detector which record high resolution scattering patterns of individual small cloud particles. In the case of a droplet its precise size is obtained and for ice particles its shape is deduced from the scattering pattern.We present results from artificial clouds at the AIDA cloud chamber and natural clouds probed at a mountain top station as well as from an aircraft in the arctic.
Shawn Wendell Wagner, Martin Schnaiter, Guanglang Xu, Franziska Nehlert, and Emma Järvinen
EGUsphere, https://doi.org/10.5194/egusphere-2024-3316, https://doi.org/10.5194/egusphere-2024-3316, 2024
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Understanding the interaction between cirrus clouds and solar radiation is critical for modeling the Earth’s climate. A common crystal type found in cirrus clouds is the bullet rosette. Here, atmospheric bullet rosettes measured from jet aircraft are analyzed for their morphological and radiative properties. Atmospheric bullet rosettes are found to be more morphologically complex than previously assumed. This complexity has a significant impact on their radiative properties.
Manfred Wendisch, Susanne Crewell, André Ehrlich, Andreas Herber, Benjamin Kirbus, Christof Lüpkes, Mario Mech, Steven J. Abel, Elisa F. Akansu, Felix Ament, Clémantyne Aubry, Sebastian Becker, Stephan Borrmann, Heiko Bozem, Marlen Brückner, Hans-Christian Clemen, Sandro Dahlke, Georgios Dekoutsidis, Julien Delanoë, Elena De La Torre Castro, Henning Dorff, Regis Dupuy, Oliver Eppers, Florian Ewald, Geet George, Irina V. Gorodetskaya, Sarah Grawe, Silke Groß, Jörg Hartmann, Silvia Henning, Lutz Hirsch, Evelyn Jäkel, Philipp Joppe, Olivier Jourdan, Zsofia Jurányi, Michail Karalis, Mona Kellermann, Marcus Klingebiel, Michael Lonardi, Johannes Lucke, Anna E. Luebke, Maximilian Maahn, Nina Maherndl, Marion Maturilli, Bernhard Mayer, Johanna Mayer, Stephan Mertes, Janosch Michaelis, Michel Michalkov, Guillaume Mioche, Manuel Moser, Hanno Müller, Roel Neggers, Davide Ori, Daria Paul, Fiona M. Paulus, Christian Pilz, Felix Pithan, Mira Pöhlker, Veronika Pörtge, Maximilian Ringel, Nils Risse, Gregory C. Roberts, Sophie Rosenburg, Johannes Röttenbacher, Janna Rückert, Michael Schäfer, Jonas Schaefer, Vera Schemann, Imke Schirmacher, Jörg Schmidt, Sebastian Schmidt, Johannes Schneider, Sabrina Schnitt, Anja Schwarz, Holger Siebert, Harald Sodemann, Tim Sperzel, Gunnar Spreen, Bjorn Stevens, Frank Stratmann, Gunilla Svensson, Christian Tatzelt, Thomas Tuch, Timo Vihma, Christiane Voigt, Lea Volkmer, Andreas Walbröl, Anna Weber, Birgit Wehner, Bruno Wetzel, Martin Wirth, and Tobias Zinner
Atmos. Chem. Phys., 24, 8865–8892, https://doi.org/10.5194/acp-24-8865-2024, https://doi.org/10.5194/acp-24-8865-2024, 2024
Short summary
Short summary
The Arctic is warming faster than the rest of the globe. Warm-air intrusions (WAIs) into the Arctic may play an important role in explaining this phenomenon. Cold-air outbreaks (CAOs) out of the Arctic may link the Arctic climate changes to mid-latitude weather. In our article, we describe how to observe air mass transformations during CAOs and WAIs using three research aircraft instrumented with state-of-the-art remote-sensing and in situ measurement devices.
André Ehrlich, Susanne Crewell, Andreas Herber, Marcus Klingebiel, Christof Lüpkes, Mario Mech, Sebastian Becker, Stephan Borrmann, Heiko Bozem, Matthias Buschmann, Hans-Christian Clemen, Elena De La Torre Castro, Henning Dorff, Regis Dupuy, Oliver Eppers, Florian Ewald, Geet George, Andreas Giez, Sarah Grawe, Christophe Gourbeyre, Jörg Hartmann, Evelyn Jäkel, Philipp Joppe, Olivier Jourdan, Zsófia Jurányi, Benjamin Kirbus, Johannes Lucke, Anna E. Luebke, Maximilian Maahn, Nina Maherndl, Christian Mallaun, Johanna Mayer, Stephan Mertes, Guillaume Mioche, Manuel Moser, Hanno Müller, Veronika Pörtge, Nils Risse, Greg Roberts, Sophie Rosenburg, Johannes Röttenbacher, Michael Schäfer, Jonas Schaefer, Andreas Schäfler, Imke Schirmacher, Johannes Schneider, Sabrina Schnitt, Frank Stratmann, Christian Tatzelt, Christiane Voigt, Andreas Walbröl, Anna Weber, Bruno Wetzel, Martin Wirth, and Manfred Wendisch
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-281, https://doi.org/10.5194/essd-2024-281, 2024
Preprint under review for ESSD
Short summary
Short summary
This paper provides an overview of the HALO–(AC)3 aircraft campaign data sets, the campaign specific instrument operation, data processing, and data quality. The data set comprises in-situ and remote sensing observations from three research aircraft, HALO, Polar 5, and Polar 6. All data are published in the PANGAEA database by instrument-separated data subsets. It is highlighted how the scientific analysis of the HALO–(AC)3 data benefits from the coordinated operation of three aircraft.
Clémantyne Aubry, Julien Delanoë, Silke Groß, Florian Ewald, Frédéric Tridon, Olivier Jourdan, and Guillaume Mioche
Atmos. Meas. Tech., 17, 3863–3881, https://doi.org/10.5194/amt-17-3863-2024, https://doi.org/10.5194/amt-17-3863-2024, 2024
Short summary
Short summary
Radar–lidar synergy is used to retrieve ice, supercooled water and mixed-phase cloud properties, making the most of the radar sensitivity to ice crystals and the lidar sensitivity to supercooled droplets. A first analysis of the output of the algorithm run on the satellite data is compared with in situ data during an airborne Arctic field campaign, giving a mean percent error of 49 % for liquid water content and 75 % for ice water content.
Valery Shcherbakov, Frédéric Szczap, Guillaume Mioche, and Céline Cornet
Atmos. Meas. Tech., 17, 3011–3028, https://doi.org/10.5194/amt-17-3011-2024, https://doi.org/10.5194/amt-17-3011-2024, 2024
Short summary
Short summary
We performed Monte Carlo simulations of single-wavelength lidar signals from multi-layered clouds with special attention focused on the multiple-scattering (MS) effect in regions of the cloud-free molecular atmosphere. The MS effect on lidar signals always decreases with the increasing distance from the cloud far edge. The decrease is the direct consequence of the fact that the forward peak of particle phase functions is much larger than the receiver field of view.
Marco Zanatta, Stephan Mertes, Olivier Jourdan, Regis Dupuy, Emma Järvinen, Martin Schnaiter, Oliver Eppers, Johannes Schneider, Zsófia Jurányi, and Andreas Herber
Atmos. Chem. Phys., 23, 7955–7973, https://doi.org/10.5194/acp-23-7955-2023, https://doi.org/10.5194/acp-23-7955-2023, 2023
Short summary
Short summary
Black carbon (BC) particles influence the Arctic radiative balance. Vertical measurements of black carbon were conducted during the ACLOUD campaign in the European Arctic to study the interaction of BC with clouds. This study shows that clouds influence the vertical variability of BC properties across the inversion layer and that multiple activation and transformation mechanisms of BC may occur in the presence of low-level, persistent, mixed-phase clouds.
Manuel Moser, Christiane Voigt, Tina Jurkat-Witschas, Valerian Hahn, Guillaume Mioche, Olivier Jourdan, Régis Dupuy, Christophe Gourbeyre, Alfons Schwarzenboeck, Johannes Lucke, Yvonne Boose, Mario Mech, Stephan Borrmann, André Ehrlich, Andreas Herber, Christof Lüpkes, and Manfred Wendisch
Atmos. Chem. Phys., 23, 7257–7280, https://doi.org/10.5194/acp-23-7257-2023, https://doi.org/10.5194/acp-23-7257-2023, 2023
Short summary
Short summary
This study provides a comprehensive microphysical and thermodynamic phase analysis of low-level clouds in the northern Fram Strait, above the sea ice and the open ocean, during spring and summer. Using airborne in situ cloud data, we show that the properties of Arctic low-level clouds vary significantly with seasonal meteorological situations and surface conditions. The observations presented in this study can help one to assess the role of clouds in the Arctic climate system.
Robert Wagner, Alexander D. James, Victoria L. Frankland, Ottmar Möhler, Benjamin J. Murray, John M. C. Plane, Harald Saathoff, Ralf Weigel, and Martin Schnaiter
Atmos. Chem. Phys., 23, 6789–6811, https://doi.org/10.5194/acp-23-6789-2023, https://doi.org/10.5194/acp-23-6789-2023, 2023
Short summary
Short summary
Polar stratospheric clouds (PSCs) play an important role in the depletion of stratospheric ozone. They can consist of different chemical species, including crystalline nitric acid hydrates. We found that mineral dust or meteoric ablation material can efficiently catalyse the formation of a specific phase of nitric acid dihydrate crystals. We determined predominant particle shapes and infrared optical properties of these crystals, which are important inputs for remote sensing detection of PSCs.
Franz Martin Schnaiter, Claudia Linke, Eija Asmi, Henri Servomaa, Antti-Pekka Hyvärinen, Sho Ohata, Yutaka Kondo, and Emma Järvinen
Atmos. Meas. Tech., 16, 2753–2769, https://doi.org/10.5194/amt-16-2753-2023, https://doi.org/10.5194/amt-16-2753-2023, 2023
Short summary
Short summary
Light-absorbing particles from combustion processes are important contributors to climate warming. Their highly variable spectral light absorption properties need to be monitored in the field. Commonly used methods show measurement artefacts that are difficult to correct. We introduce a new instrument that is based on the photoacoustic effect. Long-term operation in the Finnish Arctic demonstrates the applicability of the new instrument for unattended light absorption monitoring.
Fritz Waitz, Martin Schnaiter, Thomas Leisner, and Emma Järvinen
Atmos. Chem. Phys., 22, 7087–7103, https://doi.org/10.5194/acp-22-7087-2022, https://doi.org/10.5194/acp-22-7087-2022, 2022
Short summary
Short summary
Riming, i.e., the accretion of small droplets on the surface of ice particles via collision, is one of the major uncertainties in model prediction of mixed-phase clouds. We discuss the occurrence (up to 50% of particles) and aging of rimed ice particles and show correlations of the occurrence and the degree of riming with ambient meteorological parameters using data gathered by the Particle Habit Imaging and Polar Scattering (PHIPS) probe during three airborne in situ field campaigns.
Valery Shcherbakov, Frédéric Szczap, Alaa Alkasem, Guillaume Mioche, and Céline Cornet
Atmos. Meas. Tech., 15, 1729–1754, https://doi.org/10.5194/amt-15-1729-2022, https://doi.org/10.5194/amt-15-1729-2022, 2022
Short summary
Short summary
We performed extensive Monte Carlo (MC) simulations of lidar signals and developed an empirical model to account for the multiple scattering in the lidar signals. The simulations have taken into consideration four types of lidar configurations (the ground based, the airborne, the CALIOP, and the ATLID) and four types of particles (coarse aerosol, water cloud, jet-stream cirrus, and cirrus).
The empirical model has very good quality of MC data fitting for all considered cases.
Julia Schneider, Kristina Höhler, Robert Wagner, Harald Saathoff, Martin Schnaiter, Tobias Schorr, Isabelle Steinke, Stefan Benz, Manuel Baumgartner, Christian Rolf, Martina Krämer, Thomas Leisner, and Ottmar Möhler
Atmos. Chem. Phys., 21, 14403–14425, https://doi.org/10.5194/acp-21-14403-2021, https://doi.org/10.5194/acp-21-14403-2021, 2021
Short summary
Short summary
Homogeneous freezing is a relevant mechanism for the formation of cirrus clouds in the upper troposphere. Based on an extensive set of homogeneous freezing experiments at the AIDA chamber with aqueous sulfuric acid aerosol, we provide a new fit line for homogeneous freezing onset conditions of sulfuric acid aerosol focusing on cirrus temperatures. In the atmosphere, homogeneous freezing thresholds have important implications on the cirrus cloud occurrence and related cloud radiative effects.
Janne Lampilahti, Hanna E. Manninen, Tuomo Nieminen, Sander Mirme, Mikael Ehn, Iida Pullinen, Katri Leino, Siegfried Schobesberger, Juha Kangasluoma, Jenni Kontkanen, Emma Järvinen, Riikka Väänänen, Taina Yli-Juuti, Radovan Krejci, Katrianne Lehtipalo, Janne Levula, Aadu Mirme, Stefano Decesari, Ralf Tillmann, Douglas R. Worsnop, Franz Rohrer, Astrid Kiendler-Scharr, Tuukka Petäjä, Veli-Matti Kerminen, Thomas F. Mentel, and Markku Kulmala
Atmos. Chem. Phys., 21, 12649–12663, https://doi.org/10.5194/acp-21-12649-2021, https://doi.org/10.5194/acp-21-12649-2021, 2021
Short summary
Short summary
We studied aerosol particle formation and growth in different parts of the planetary boundary layer at two different locations (Po Valley, Italy, and Hyytiälä, Finland). The observations consist of airborne measurements on board an instrumented Zeppelin and a small airplane combined with comprehensive ground-based measurements.
Fritz Waitz, Martin Schnaiter, Thomas Leisner, and Emma Järvinen
Atmos. Meas. Tech., 14, 3049–3070, https://doi.org/10.5194/amt-14-3049-2021, https://doi.org/10.5194/amt-14-3049-2021, 2021
Short summary
Short summary
A major challenge in the observations of mixed-phase clouds remains the phase discrimination and sizing of cloud droplets and ice crystals, especially for particles with diameters smaller than 0.1 mm. Here, we present a new method to derive the phase and size of single cloud particles using their angular-light-scattering information. Comparisons with other in situ instruments in three case studies show good agreement.
Frédéric Szczap, Alaa Alkasem, Guillaume Mioche, Valery Shcherbakov, Céline Cornet, Julien Delanoë, Yahya Gour, Olivier Jourdan, Sandra Banson, and Edouard Bray
Atmos. Meas. Tech., 14, 199–221, https://doi.org/10.5194/amt-14-199-2021, https://doi.org/10.5194/amt-14-199-2021, 2021
Short summary
Short summary
Spaceborne lidar and radar are suitable tools to investigate cloud vertical properties on a global scale. This paper presents the McRALI code that provides simulations of lidar and radar signals from the EarthCARE mission. Regarding radar signals, cloud heterogeneity induces a severe bias in velocity estimates. Regarding lidar signals, multiple scattering is not negligible. Our results also give some insight into the reliability of lidar signal modeling using independent column approximation.
André Ehrlich, Manfred Wendisch, Christof Lüpkes, Matthias Buschmann, Heiko Bozem, Dmitri Chechin, Hans-Christian Clemen, Régis Dupuy, Olliver Eppers, Jörg Hartmann, Andreas Herber, Evelyn Jäkel, Emma Järvinen, Olivier Jourdan, Udo Kästner, Leif-Leonard Kliesch, Franziska Köllner, Mario Mech, Stephan Mertes, Roland Neuber, Elena Ruiz-Donoso, Martin Schnaiter, Johannes Schneider, Johannes Stapf, and Marco Zanatta
Earth Syst. Sci. Data, 11, 1853–1881, https://doi.org/10.5194/essd-11-1853-2019, https://doi.org/10.5194/essd-11-1853-2019, 2019
Short summary
Short summary
During the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign, two research aircraft (Polar 5 and 6) jointly performed 22 research flights over the transition zone between open ocean and closed sea ice. The data set combines remote sensing and in situ measurement of cloud, aerosol, and trace gas properties, as well as turbulent and radiative fluxes, which will be used to study Arctic boundary layer and mid-level clouds and their role in Arctic amplification.
Martin Schnaiter, Claudia Linke, Inas Ibrahim, Alexei Kiselev, Fritz Waitz, Thomas Leisner, Stefan Norra, and Till Rehm
Atmos. Chem. Phys., 19, 10829–10844, https://doi.org/10.5194/acp-19-10829-2019, https://doi.org/10.5194/acp-19-10829-2019, 2019
Short summary
Short summary
When combustion particles are deposited to the ground, they darken Earth's snow and ice surfaces by even tiny quantities. This darkening reduces the back reflection of sunlight and induces an additional climate warming. Particles from fresh snow samples were investigated according to their light absorption strength. Enhanced absorption was found in the snow that cannot fully be attributed to combustion particles. Dust and biogenic matter are likely the cause of this additional snow darkening.
Shiwen Teng, Chao Liu, Martin Schnaiter, Rajan K. Chakrabarty, and Fengshan Liu
Atmos. Chem. Phys., 19, 2917–2931, https://doi.org/10.5194/acp-19-2917-2019, https://doi.org/10.5194/acp-19-2917-2019, 2019
Short summary
Short summary
Black carbon (BC) possesses complex minor structures besides the overall aggregate geometry, thus altering their optical properties. This study introduces volume variation to quantify and unify different minor structures and develops an empirical relation to account for their effects on BC optical properties. We find the effects of minor structures are mainly contributed by their influence on particle volume/mass, and a relative difference of 5 % is noticed after removing volume differences.
Emma Järvinen, Olivier Jourdan, David Neubauer, Bin Yao, Chao Liu, Meinrat O. Andreae, Ulrike Lohmann, Manfred Wendisch, Greg M. McFarquhar, Thomas Leisner, and Martin Schnaiter
Atmos. Chem. Phys., 18, 15767–15781, https://doi.org/10.5194/acp-18-15767-2018, https://doi.org/10.5194/acp-18-15767-2018, 2018
Short summary
Short summary
Using light diffraction it is possible to detect microscopic features within ice particles that have not yet been fully characterized. Here, this technique was applied in airborne measurements, where it was found that majority of atmospheric ice particles have features that significantly change the way ice particles interact with solar light. The microscopic features make ice-containing clouds more reflective than previously thought, which could have consequences for predicting our climate.
Chao Liu, Chul Eddy Chung, Yan Yin, and Martin Schnaiter
Atmos. Chem. Phys., 18, 6259–6273, https://doi.org/10.5194/acp-18-6259-2018, https://doi.org/10.5194/acp-18-6259-2018, 2018
Short summary
Short summary
The absorption Ångström exponent (AAE) of black carbon (BC) is widely accepted to be 1.0, although observational estimates give a quite wide range of 0.6–1.1. This study investigates BC AAE numerically using realistic particle properties and accurate numerical models. The significantly influence of BC microphysical properties on BC AAE is revealed by simple linear formulas, and the widely accepted BC AAE value of 1.0 is not correct for even small BC with wavelength-independent refractive index.
Meinrat O. Andreae, Armin Afchine, Rachel Albrecht, Bruna Amorim Holanda, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Micael A. Cecchini, Anja Costa, Maximilian Dollner, Daniel Fütterer, Emma Järvinen, Tina Jurkat, Thomas Klimach, Tobias Konemann, Christoph Knote, Martina Krämer, Trismono Krisna, Luiz A. T. Machado, Stephan Mertes, Andreas Minikin, Christopher Pöhlker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, Daniel Sauer, Hans Schlager, Martin Schnaiter, Johannes Schneider, Christiane Schulz, Antonio Spanu, Vinicius B. Sperling, Christiane Voigt, Adrian Walser, Jian Wang, Bernadett Weinzierl, Manfred Wendisch, and Helmut Ziereis
Atmos. Chem. Phys., 18, 921–961, https://doi.org/10.5194/acp-18-921-2018, https://doi.org/10.5194/acp-18-921-2018, 2018
Short summary
Short summary
We made airborne measurements of aerosol particle concentrations and properties over the Amazon Basin. We found extremely high concentrations of very small particles in the region between 8 and 14 km altitude all across the basin, which had been recently formed by gas-to-particle conversion at these altitudes. This makes the upper troposphere a very important source region of atmospheric particles with significant implications for the Earth's climate system.
Martin Schnaiter, Emma Järvinen, Ahmed Abdelmonem, and Thomas Leisner
Atmos. Meas. Tech., 11, 341–357, https://doi.org/10.5194/amt-11-341-2018, https://doi.org/10.5194/amt-11-341-2018, 2018
Short summary
Short summary
PHIPS-HALO is a novel aircraft instrument for cloud research. It combines microscopic imaging of single cloud particles with the measurement of their spacial light scattering properties. The knowledge of how atmospheric ice particles in clouds scatter visible light is important for improving future climate models.
Guillaume Mioche, Olivier Jourdan, Julien Delanoë, Christophe Gourbeyre, Guy Febvre, Régis Dupuy, Marie Monier, Frédéric Szczap, Alfons Schwarzenboeck, and Jean-François Gayet
Atmos. Chem. Phys., 17, 12845–12869, https://doi.org/10.5194/acp-17-12845-2017, https://doi.org/10.5194/acp-17-12845-2017, 2017
Short summary
Short summary
This paper is a study about the mixed-phase clouds frequently occurring in the Arctic region. It is based on airborne measurements and highlights the microphysical properties of these particular clouds composed of liquid droplets at cloud top and ice crystals below precipitating down to the surface. This work may help to improve the representation of the mixed-phase clouds in numerical prediction models as well as the retrieval of their properties from remote sensing observations.
Leonid Nichman, Emma Järvinen, James Dorsey, Paul Connolly, Jonathan Duplissy, Claudia Fuchs, Karoliina Ignatius, Kamalika Sengupta, Frank Stratmann, Ottmar Möhler, Martin Schnaiter, and Martin Gallagher
Atmos. Meas. Tech., 10, 3231–3248, https://doi.org/10.5194/amt-10-3231-2017, https://doi.org/10.5194/amt-10-3231-2017, 2017
Short summary
Short summary
Optical probes are frequently used for the detection of cloud particles. The detected microphysical properties may affect particle growth and accretion mechanisms and the light scattering properties of cirrus clouds. In the CLOUD chamber study at CERN, we compared four optical measurement techniques. We show that shape derivation alone is not sufficient to determine the phase of the small cloud particles. None of the instruments were able to unambiguously determine the phase of small particles.
Claudia Linke, Inas Ibrahim, Nina Schleicher, Regina Hitzenberger, Meinrat O. Andreae, Thomas Leisner, and Martin Schnaiter
Atmos. Meas. Tech., 9, 5331–5346, https://doi.org/10.5194/amt-9-5331-2016, https://doi.org/10.5194/amt-9-5331-2016, 2016
Short summary
Short summary
Various carbonaceous materials are present in the atmosphere. Besides gaseous organic compounds, carbonaceous particles like soot are emitted into the air from traffic sources, residential wood combustion, or wildfires. Variable chemical compositions of such materials, which often result from incomplete combustion processes, show differences in the absorption behavior at visible wavelengths. Our instrument is able to measure the absorption at three visible wavelengths.
Naruki Hiranuma, Ottmar Möhler, Gourihar Kulkarni, Martin Schnaiter, Steffen Vogt, Paul Vochezer, Emma Järvinen, Robert Wagner, David M. Bell, Jacqueline Wilson, Alla Zelenyuk, and Daniel J. Cziczo
Atmos. Meas. Tech., 9, 3817–3836, https://doi.org/10.5194/amt-9-3817-2016, https://doi.org/10.5194/amt-9-3817-2016, 2016
Short summary
Short summary
A new pumped counterflow virtual impactor (PCVI) called the ice-selecting PCVI (IS-PCVI) has been developed to collect ice crystal residuals for investigating physico-chemical properties of ice-nucleating particles. The results show that the ice crystals of volume-equivalent diameter ~ 10 to 30 µm can be efficiently separated from the supercooled droplets and interstitial particles. The IS-PCVI is efficient when the counterflow-to-input flow ratio is within 0.09 to 0.18.
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
Short summary
Short summary
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.
Ahmed Abdelmonem, Emma Järvinen, Denis Duft, Edwin Hirst, Steffen Vogt, Thomas Leisner, and Martin Schnaiter
Atmos. Meas. Tech., 9, 3131–3144, https://doi.org/10.5194/amt-9-3131-2016, https://doi.org/10.5194/amt-9-3131-2016, 2016
Short summary
Short summary
The properties of ice crystals present in mixed-phase and ice clouds influence the radiation properties, precipitation occurrence and lifetime of these clouds. It is necessary to investigate the optical and microphysical properties of cloud particles particularly in situ, and to get correlation between these properties. To this end we have developed PHIPS-HALO to measure the optical properties and the corresponding microphysical parameters of individual cloud particles simultaneously.
Karoliina Ignatius, Thomas B. Kristensen, Emma Järvinen, Leonid Nichman, Claudia Fuchs, Hamish Gordon, Paul Herenz, Christopher R. Hoyle, Jonathan Duplissy, Sarvesh Garimella, Antonio Dias, Carla Frege, Niko Höppel, Jasmin Tröstl, Robert Wagner, Chao Yan, Antonio Amorim, Urs Baltensperger, Joachim Curtius, Neil M. Donahue, Martin W. Gallagher, Jasper Kirkby, Markku Kulmala, Ottmar Möhler, Harald Saathoff, Martin Schnaiter, Antonio Tomé, Annele Virtanen, Douglas Worsnop, and Frank Stratmann
Atmos. Chem. Phys., 16, 6495–6509, https://doi.org/10.5194/acp-16-6495-2016, https://doi.org/10.5194/acp-16-6495-2016, 2016
Short summary
Short summary
Viscous solid or semi-solid secondary organic aerosol (SOA) may influence cloud properties through ice nucleation in the atmosphere. Here, we observed heterogeneous ice nucleation of viscous α-pinene SOA at temperatures between −39 °C and −37.2 °C with ice saturation ratios significantly below the homogeneous freezing limit. Global modelling suggests that viscous biogenic SOA are present in regions where cirrus formation takes place and could contribute to the global ice nuclei budget.
Martin Schnaiter, Emma Järvinen, Paul Vochezer, Ahmed Abdelmonem, Robert Wagner, Olivier Jourdan, Guillaume Mioche, Valery N. Shcherbakov, Carl G. Schmitt, Ugo Tricoli, Zbigniew Ulanowski, and Andrew J. Heymsfield
Atmos. Chem. Phys., 16, 5091–5110, https://doi.org/10.5194/acp-16-5091-2016, https://doi.org/10.5194/acp-16-5091-2016, 2016
Emma Järvinen, Karoliina Ignatius, Leonid Nichman, Thomas B. Kristensen, Claudia Fuchs, Christopher R. Hoyle, Niko Höppel, Joel C. Corbin, Jill Craven, Jonathan Duplissy, Sebastian Ehrhart, Imad El Haddad, Carla Frege, Hamish Gordon, Tuija Jokinen, Peter Kallinger, Jasper Kirkby, Alexei Kiselev, Karl-Heinz Naumann, Tuukka Petäjä, Tamara Pinterich, Andre S. H. Prevot, Harald Saathoff, Thea Schiebel, Kamalika Sengupta, Mario Simon, Jay G. Slowik, Jasmin Tröstl, Annele Virtanen, Paul Vochezer, Steffen Vogt, Andrea C. Wagner, Robert Wagner, Christina Williamson, Paul M. Winkler, Chao Yan, Urs Baltensperger, Neil M. Donahue, Rick C. Flagan, Martin Gallagher, Armin Hansel, Markku Kulmala, Frank Stratmann, Douglas R. Worsnop, Ottmar Möhler, Thomas Leisner, and Martin Schnaiter
Atmos. Chem. Phys., 16, 4423–4438, https://doi.org/10.5194/acp-16-4423-2016, https://doi.org/10.5194/acp-16-4423-2016, 2016
Leonid Nichman, Claudia Fuchs, Emma Järvinen, Karoliina Ignatius, Niko Florian Höppel, Antonio Dias, Martin Heinritzi, Mario Simon, Jasmin Tröstl, Andrea Christine Wagner, Robert Wagner, Christina Williamson, Chao Yan, Paul James Connolly, James Robert Dorsey, Jonathan Duplissy, Sebastian Ehrhart, Carla Frege, Hamish Gordon, Christopher Robert Hoyle, Thomas Bjerring Kristensen, Gerhard Steiner, Neil McPherson Donahue, Richard Flagan, Martin William Gallagher, Jasper Kirkby, Ottmar Möhler, Harald Saathoff, Martin Schnaiter, Frank Stratmann, and António Tomé
Atmos. Chem. Phys., 16, 3651–3664, https://doi.org/10.5194/acp-16-3651-2016, https://doi.org/10.5194/acp-16-3651-2016, 2016
Short summary
Short summary
Processes in the atmosphere are often governed by the physical and chemical properties of small cloud particles. Ice, water, and mixed clouds, as well as viscous aerosols, were formed under controlled conditions at the CLOUD-CERN facility. The experimental results show a link between cloud particle properties and their unique optical fingerprints. The classification map presented here allows easier discrimination between various particles such as viscous organic aerosol, salt, ice, and liquid.
Jenni Kontkanen, Emma Järvinen, Hanna E. Manninen, Katrianne Lehtipalo, Juha Kangasluoma, Stefano Decesari, Gian Paolo Gobbi, Ari Laaksonen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 16, 1919–1935, https://doi.org/10.5194/acp-16-1919-2016, https://doi.org/10.5194/acp-16-1919-2016, 2016
C. R. Hoyle, C. Fuchs, E. Järvinen, H. Saathoff, A. Dias, I. El Haddad, M. Gysel, S. C. Coburn, J. Tröstl, A.-K. Bernhammer, F. Bianchi, M. Breitenlechner, J. C. Corbin, J. Craven, N. M. Donahue, J. Duplissy, S. Ehrhart, C. Frege, H. Gordon, N. Höppel, M. Heinritzi, T. B. Kristensen, U. Molteni, L. Nichman, T. Pinterich, A. S. H. Prévôt, M. Simon, J. G. Slowik, G. Steiner, A. Tomé, A. L. Vogel, R. Volkamer, A. C. Wagner, R. Wagner, A. S. Wexler, C. Williamson, P. M. Winkler, C. Yan, A. Amorim, J. Dommen, J. Curtius, M. W. Gallagher, R. C. Flagan, A. Hansel, J. Kirkby, M. Kulmala, O. Möhler, F. Stratmann, D. R. Worsnop, and U. Baltensperger
Atmos. Chem. Phys., 16, 1693–1712, https://doi.org/10.5194/acp-16-1693-2016, https://doi.org/10.5194/acp-16-1693-2016, 2016
Short summary
Short summary
A significant portion of sulphate, an important constituent of atmospheric aerosols, is formed via the aqueous phase oxidation of sulphur dioxide by ozone. The rate of this reaction has previously only been measured over a relatively small temperature range. Here, we use the state of the art CLOUD chamber at CERN to perform the first measurements of this reaction rate in super-cooled droplets, confirming that the existing extrapolation of the reaction rate to sub-zero temperatures is accurate.
P. Vochezer, E. Järvinen, R. Wagner, P. Kupiszewski, T. Leisner, and M. Schnaiter
Atmos. Meas. Tech., 9, 159–177, https://doi.org/10.5194/amt-9-159-2016, https://doi.org/10.5194/amt-9-159-2016, 2016
Short summary
Short summary
To study clouds constituting of liquid droplets as well as ice particles we used the latest versions of the Small Ice Detector which record high resolution scattering patterns of individual small cloud particles. In the case of a droplet its precise size is obtained and for ice particles its shape is deduced from the scattering pattern.We present results from artificial clouds at the AIDA cloud chamber and natural clouds probed at a mountain top station as well as from an aircraft in the arctic.
P. Kupiszewski, E. Weingartner, P. Vochezer, M. Schnaiter, A. Bigi, M. Gysel, B. Rosati, E. Toprak, S. Mertes, and U. Baltensperger
Atmos. Meas. Tech., 8, 3087–3106, https://doi.org/10.5194/amt-8-3087-2015, https://doi.org/10.5194/amt-8-3087-2015, 2015
M. Hummel, C. Hoose, M. Gallagher, D. A. Healy, J. A. Huffman, D. O'Connor, U. Pöschl, C. Pöhlker, N. H. Robinson, M. Schnaiter, J. R. Sodeau, M. Stengel, E. Toprak, and H. Vogel
Atmos. Chem. Phys., 15, 6127–6146, https://doi.org/10.5194/acp-15-6127-2015, https://doi.org/10.5194/acp-15-6127-2015, 2015
G. Mioche, O. Jourdan, M. Ceccaldi, and J. Delanoë
Atmos. Chem. Phys., 15, 2445–2461, https://doi.org/10.5194/acp-15-2445-2015, https://doi.org/10.5194/acp-15-2445-2015, 2015
Short summary
Short summary
The study presents a characterization of the vertical, spatial and seasonal variability of Arctic clouds and mixed-phase clouds (MPCs) over the entire Arctic region. MPC properties in the region of the Svalbard archipelago (78°N, 15°E) are also investigated. The occurrence frequency of clouds and MPCs are determined from CALIPSO/CLOUDSAT measurements processed with the DARDAR retrieval algorithm which allows for a reliable cloud thermodynamic phase classification.
N. Hiranuma, M. Paukert, I. Steinke, K. Zhang, G. Kulkarni, C. Hoose, M. Schnaiter, H. Saathoff, and O. Möhler
Atmos. Chem. Phys., 14, 13145–13158, https://doi.org/10.5194/acp-14-13145-2014, https://doi.org/10.5194/acp-14-13145-2014, 2014
Short summary
Short summary
A new heterogeneous ice nucleation parameterization is developed and implemented in cloud models. The results of our simulations suggest stronger influence of dust particles lifted to the upper troposphere on heterogeneous nucleation and more ice nucleation at temperature and humidity conditions relevant to both mixed-phase and cirrus clouds when compared to the existing parametrical frameworks.
H. Saathoff, S. Henin, K. Stelmaszczyk, M. Petrarca, R. Delagrange, Z. Hao, J. Lüder, O. Möhler, Y. Petit, P. Rohwetter, M. Schnaiter, J. Kasparian, T. Leisner, J.-P. Wolf, and L. Wöste
Atmos. Chem. Phys., 13, 4593–4604, https://doi.org/10.5194/acp-13-4593-2013, https://doi.org/10.5194/acp-13-4593-2013, 2013
J. Skrotzki, P. Connolly, M. Schnaiter, H. Saathoff, O. Möhler, R. Wagner, M. Niemand, V. Ebert, and T. Leisner
Atmos. Chem. Phys., 13, 4451–4466, https://doi.org/10.5194/acp-13-4451-2013, https://doi.org/10.5194/acp-13-4451-2013, 2013
E. Toprak and M. Schnaiter
Atmos. Chem. Phys., 13, 225–243, https://doi.org/10.5194/acp-13-225-2013, https://doi.org/10.5194/acp-13-225-2013, 2013
M. Laborde, M. Schnaiter, C. Linke, H. Saathoff, K.-H. Naumann, O. Möhler, S. Berlenz, U. Wagner, J. W. Taylor, D. Liu, M. Flynn, J. D. Allan, H. Coe, K. Heimerl, F. Dahlkötter, B. Weinzierl, A. G. Wollny, M. Zanatta, J. Cozic, P. Laj, R. Hitzenberger, J. P. Schwarz, and M. Gysel
Atmos. Meas. Tech., 5, 3077–3097, https://doi.org/10.5194/amt-5-3077-2012, https://doi.org/10.5194/amt-5-3077-2012, 2012
Related subject area
Subject: Clouds and Precipitation | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Clouds and precipitation in the initial phase of marine cold-air outbreaks as observed by airborne remote sensing
Estimating the snow density using collocated Parsivel and Micro-Rain Radar measurements: a preliminary study from ICE-POP 2017/2018
Technical note: On the ice microphysics of isolated thunderstorms and non-thunderstorms in southern China – a radar polarimetric perspective
Distinctive aerosol–cloud–precipitation interactions in marine boundary layer clouds from the ACE-ENA and SOCRATES aircraft field campaigns
Theoretical Framework for Measuring Cloud Effective Supersaturation Fluctuations with an Advanced Optical System
Drivers of droplet formation in east Mediterranean orographic clouds
Observability of moisture transport divergence in Arctic atmospheric rivers by dropsondes
Elucidating the boundary layer turbulence dissipation rate using high-resolution measurements from a radar wind profiler network over the Tibetan Plateau
Environmental controls on isolated convection during the Amazonian wet season
Isotopic composition of convective rainfall in the inland tropics of Brazil
Measurement report: Cloud and environmental properties associated with aggregated shallow marine cumulus and cumulus congestus
How does riming influence the observed spatial variability of ice water in mixed-phase clouds?
Lifecycle of updrafts and mass flux in isolated deep convection over the Amazon rainforest: insights from cell tracking
Thermodynamic and cloud evolution in a cold-air outbreak during HALO-(AC)3: quasi-Lagrangian observations compared to the ERA5 and CARRA reanalyses
Powering aircraft with 100 % sustainable aviation fuel reduces ice crystals in contrails
Microphysical view of development and ice production of mid-latitude stratocumulus during an extratropical cyclone
Supercooled liquid water clouds observed over Dome C, Antarctica: temperature sensitivity and cloud radiative forcing
Role of thermodynamic and turbulence processes on the fog life cycle during SOFOG3D experiment
Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements
Investigating the role of typhoon-induced gravity waves and stratospheric hydration in the formation of tropopause cirrus clouds observed during the 2017 Asian monsoon
Differences in microphysical properties of cirrus at high and mid-latitudes
Sub-cloud rain evaporation in the North Atlantic winter trade winds derived by pairing isotopic data with a bin-resolved microphysical model
Overview and statistical analysis of boundary layer clouds and precipitation over the western North Atlantic Ocean
A set of methods to evaluate the below-cloud evaporation effect on local precipitation isotopic composition: a case study for Xi'an, China
Earth-system-model evaluation of cloud and precipitation occurrence for supercooled and warm clouds over the Southern Ocean's Macquarie Island
Pollution slightly enhances atmospheric cooling by low-level clouds in tropical West Africa
Investigating an indirect aviation effect on mid-latitude cirrus clouds – linking lidar-derived optical properties to in situ measurements
Microphysical and thermodynamic phase analyses of Arctic low-level clouds measured above the sea ice and the open ocean in spring and summer
Aircraft observations of gravity wave activity and turbulence in the tropical tropopause layer: prevalence, influence on cirrus clouds, and comparison with global storm-resolving models
Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment
Sensitivity of convectively driven tropical tropopause cirrus properties to ice habits in high-resolution simulations
Upper-tropospheric slightly ice-subsaturated regions: frequency of occurrence and statistical evidence for the appearance of contrail cirrus
Examination of aerosol indirect effects during cirrus cloud evolution
In situ microphysics observations of intense pyroconvection from a large wildfire
Conditions favorable for secondary ice production in Arctic mixed-phase clouds
Interaction between cloud–radiation, atmospheric dynamics and thermodynamics based on observational data from GoAmazon 2014/15 and a cloud-resolving model
Snowfall in Northern Finland derives mostly from ice clouds
Observation of secondary ice production in clouds at low temperatures
In situ and satellite-based estimates of cloud properties and aerosol–cloud interactions over the southeast Atlantic Ocean
Ice fog observed at cirrus temperatures at Dome C, Antarctic Plateau
Life cycle of stratocumulus clouds over 1 year at the coast of the Atacama Desert
Experimental study on the evolution of droplet size distribution during the fog life cycle
Significant continental source of ice-nucleating particles at the tip of Chile's southernmost Patagonia region
Retrieving ice-nucleating particle concentration and ice multiplication factors using active remote sensing validated by in situ observations
Temporal and vertical distributions of the occurrence of cirrus clouds over a coastal station in the Indian monsoon region
Continental thunderstorm ground enhancement observed at an exceptionally low altitude
Ice-nucleating particles from multiple aerosol sources in the urban environment of Beijing under mixed-phase cloud conditions
In situ observation of riming in mixed-phase clouds using the PHIPS probe
Measurement report: Introduction to the HyICE-2018 campaign for measurements of ice-nucleating particles and instrument inter-comparison in the Hyytiälä boreal forest
North Atlantic Ocean SST-gradient-driven variations in aerosol and cloud evolution along Lagrangian cold-air outbreak trajectories
Imke Schirmacher, Sabrina Schnitt, Marcus Klingebiel, Nina Maherndl, Benjamin Kirbus, André Ehrlich, Mario Mech, and Susanne Crewell
Atmos. Chem. Phys., 24, 12823–12842, https://doi.org/10.5194/acp-24-12823-2024, https://doi.org/10.5194/acp-24-12823-2024, 2024
Short summary
Short summary
During Arctic marine cold-air outbreaks, cold air flows from sea ice over open water. Roll circulations evolve, forming cloud streets. We investigate the initial circulation and cloud development using high-resolution airborne measurements. We compute the distance an air mass traveled over water (fetch) from back trajectories. Cloud streets form at 15 km fetch, cloud cover strongly increases at around 20 km, and precipitation forms at around 30 km.
Wei-Yu Chang, Yung-Chuan Yang, Chen-Yu Hung, Kwonil Kim, Gyuwon Lee, and Ali Tokay
Atmos. Chem. Phys., 24, 11955–11979, https://doi.org/10.5194/acp-24-11955-2024, https://doi.org/10.5194/acp-24-11955-2024, 2024
Short summary
Short summary
Snow density is derived by collocated Micro-Rain Radar (MRR) and Parsivel (ICE-POP 2017/2018). We apply the particle size distribution from Parsivel to a T-matrix backscattering simulation and compare with ZHH from MRR. Bulk density and bulk water fractions are derived from comparing simulated and calculated ZHH. Retrieved bulk density is validated by comparing snowfall rate measurements from Pluvio and the Precipitation Imaging Package. Snowfall rate consistency confirms the algorithm.
Chuanhong Zhao, Yijun Zhang, Dong Zheng, Haoran Li, Sai Du, Xueyan Peng, Xiantong Liu, Pengguo Zhao, Jiafeng Zheng, and Juan Shi
Atmos. Chem. Phys., 24, 11637–11651, https://doi.org/10.5194/acp-24-11637-2024, https://doi.org/10.5194/acp-24-11637-2024, 2024
Short summary
Short summary
Understanding lightning activity is important for meteorology and atmospheric chemistry. However, the occurrence of lightning activity in clouds is uncertain. In this study, we quantified the difference between isolated thunderstorms and non-thunderstorms. We showed that lightning activity was more likely to occur with more graupel volume and/or riming. A deeper ZDR column was associated with lightning occurrence. This information can aid in a deeper understanding of lighting physics.
Xiaojian Zheng, Xiquan Dong, Baike Xi, Timothy Logan, and Yuan Wang
Atmos. Chem. Phys., 24, 10323–10347, https://doi.org/10.5194/acp-24-10323-2024, https://doi.org/10.5194/acp-24-10323-2024, 2024
Short summary
Short summary
The marine boundary layer aerosol–cloud interactions (ACIs) are examined using in situ measurements from two aircraft campaigns over the eastern North Atlantic (ACE-ENA) and Southern Ocean (SOCRATES). The SOCRATES clouds have more and smaller cloud droplets. The ACE-ENA clouds exhibit stronger drizzle formation and growth. Results found distinctive aerosol–cloud interactions for two campaigns. The drizzle processes significantly alter sub-cloud aerosol budgets and impact the ACI assessments.
Ye Kuang, Jiangchuan Tao, Hanbin Xu, Li Liu, Pengfei Liu, Wanyun Xu, Weiqi Xu, Yele Sun, and Chunsheng Zhao
EGUsphere, https://doi.org/10.5194/egusphere-2024-2698, https://doi.org/10.5194/egusphere-2024-2698, 2024
Short summary
Short summary
This study presents a novel optical framework to measure supersaturation, a fundamental parameter in cloud physics, by observing the scattering properties of particles that have or have not grown into cloud droplets. The technique offers high-resolution measurements, capturing essential fluctuations in supersaturation necessary for understanding cloud physics.
Romanos Foskinis, Ghislain Motos, Maria I. Gini, Olga Zografou, Kunfeng Gao, Stergios Vratolis, Konstantinos Granakis, Ville Vakkari, Kalliopi Violaki, Andreas Aktypis, Christos Kaltsonoudis, Zongbo Shi, Mika Komppula, Spyros N. Pandis, Konstantinos Eleftheriadis, Alexandros Papayannis, and Athanasios Nenes
Atmos. Chem. Phys., 24, 9827–9842, https://doi.org/10.5194/acp-24-9827-2024, https://doi.org/10.5194/acp-24-9827-2024, 2024
Short summary
Short summary
Analysis of modeling, in situ, and remote sensing measurements reveals the microphysical state of orographic clouds and their response to aerosol from the boundary layer and free troposphere. We show that cloud response to aerosol is robust, as predicted supersaturation and cloud droplet number levels agree with those determined from in-cloud measurements. The ability to determine if clouds are velocity- or aerosol-limited allows for novel model constraints and remote sensing products.
Henning Dorff, Heike Konow, Vera Schemann, and Felix Ament
Atmos. Chem. Phys., 24, 8771–8795, https://doi.org/10.5194/acp-24-8771-2024, https://doi.org/10.5194/acp-24-8771-2024, 2024
Short summary
Short summary
Using synthetic dropsondes, we assess how discrete spatial sampling and temporal evolution during flight affect the accuracy of real sonde-based moisture transport divergence in Arctic atmospheric rivers (ARs). Non-instantaneous sampling during temporal AR evolution deteriorates the divergence values more than spatial undersampling. Moisture advection is the dominating factor but most sensitive to the sampling method. We suggest a minimum of seven sondes to resolve the AR divergence components.
Deli Meng, Jianping Guo, Xiaoran Guo, Yinjun Wang, Ning Li, Yuping Sun, Zhen Zhang, Na Tang, Haoran Li, Fan Zhang, Bing Tong, Hui Xu, and Tianmeng Chen
Atmos. Chem. Phys., 24, 8703–8720, https://doi.org/10.5194/acp-24-8703-2024, https://doi.org/10.5194/acp-24-8703-2024, 2024
Short summary
Short summary
The turbulence in the planetary boundary layer (PBL) over the Tibetan Plateau (TP) remains unclear. Here we elucidate the vertical profile of and temporal variation in the turbulence dissipation rate in the PBL over the TP based on a radar wind profiler (RWP) network. To the best of our knowledge, this is the first time that the turbulence profile over the whole TP has been revealed. Furthermore, the possible mechanisms of clouds acting on the PBL turbulence structure are investigated.
Leandro Alex Moreira Viscardi, Giuseppe Torri, David K. Adams, and Henrique de Melo Jorge Barbosa
Atmos. Chem. Phys., 24, 8529–8548, https://doi.org/10.5194/acp-24-8529-2024, https://doi.org/10.5194/acp-24-8529-2024, 2024
Short summary
Short summary
We evaluate the environmental conditions that control how clouds grow from fair weather cumulus into severe thunderstorms during the Amazonian wet season. Days with rain clouds begin with more moisture in the air and have strong convergence in the afternoon, while precipitation intensity increases with large-scale vertical velocity, moisture, and low-level wind. These results contribute to understanding how clouds form over the rainforest.
Vinicius dos Santos, Didier Gastmans, Ana María Durán-Quesada, Ricardo Sánchez-Murillo, Kazimierz Rozanski, Oliver Kracht, and Demilson de Assis Quintão
Atmos. Chem. Phys., 24, 6663–6680, https://doi.org/10.5194/acp-24-6663-2024, https://doi.org/10.5194/acp-24-6663-2024, 2024
Short summary
Short summary
We present novel findings on convective rainfall, summer rain in the late afternoon, by coupling water stable isotopes, micro rain radar, and satellite data. We found the tallest clouds in the afternoon and much smaller clouds at night, resulting in differences in day–night ratios in water stable isotopes. We sampled rain and meteorological variables every 5–10 min, allowing us to evaluate the development of convective rainfall, contributing to knowledge of rainfall related to extreme events.
Ewan Crosbie, Luke D. Ziemba, Michael A. Shook, Taylor Shingler, Johnathan W. Hair, Armin Sorooshian, Richard A. Ferrare, Brian Cairns, Yonghoon Choi, Joshua DiGangi, Glenn S. Diskin, Chris Hostetler, Simon Kirschler, Richard H. Moore, David Painemal, Claire Robinson, Shane T. Seaman, K. Lee Thornhill, Christiane Voigt, and Edward Winstead
Atmos. Chem. Phys., 24, 6123–6152, https://doi.org/10.5194/acp-24-6123-2024, https://doi.org/10.5194/acp-24-6123-2024, 2024
Short summary
Short summary
Marine clouds are found to clump together in regions or lines, readily discernible from satellite images of the ocean. While clustering is also a feature of deep storm clouds, we focus on smaller cloud systems associated with fair weather and brief localized showers. Two aircraft sampled the region around these shallow systems: one incorporated measurements taken within, adjacent to, and below the clouds, while the other provided a survey from above using remote sensing techniques.
Nina Maherndl, Manuel Moser, Imke Schirmacher, Aaron Bansemer, Johannes Lucke, Christiane Voigt, and Maximilian Maahn
EGUsphere, https://doi.org/10.5194/egusphere-2024-1214, https://doi.org/10.5194/egusphere-2024-1214, 2024
Short summary
Short summary
It is not clear, why ice crystals in clouds occur in clusters. Here, airborne measurements of clouds in mid- and high-latitudes are used to study the spatial variability of ice. Further, we investigate the influence of riming, which occurs when liquid droplets freeze onto ice crystals. We find that riming enhances the occurrence of ice clusters. In the Arctic, riming leads to ice clustering at spatial scales of 3–5 km. This is due to updrafts, not necessary higher amounts of liquid water.
Siddhant Gupta, Dié Wang, Scott E. Giangrande, Thiago S. Biscaro, and Michael P. Jensen
Atmos. Chem. Phys., 24, 4487–4510, https://doi.org/10.5194/acp-24-4487-2024, https://doi.org/10.5194/acp-24-4487-2024, 2024
Short summary
Short summary
We examine the lifecycle of isolated deep convective clouds (DCCs) in the Amazon rainforest. Weather radar echoes from the DCCs are tracked to evaluate their lifecycle. The DCC size and intensity increase, reach a peak, and then decrease over the DCC lifetime. Vertical profiles of air motion and mass transport from different seasons are examined to understand the transport of energy and momentum within DCC cores and to address the deficiencies in simulating DCCs using weather and climate models.
Benjamin Kirbus, Imke Schirmacher, Marcus Klingebiel, Michael Schäfer, André Ehrlich, Nils Slättberg, Johannes Lucke, Manuel Moser, Hanno Müller, and Manfred Wendisch
Atmos. Chem. Phys., 24, 3883–3904, https://doi.org/10.5194/acp-24-3883-2024, https://doi.org/10.5194/acp-24-3883-2024, 2024
Short summary
Short summary
A research aircraft is used to track the changes in air temperature, moisture, and cloud properties for air that moves from cold Arctic sea ice onto warmer oceanic waters. The measurements are compared to two reanalysis models named ERA5 and CARRA. The biggest differences are found for air temperature over the sea ice and moisture over the ocean. CARRA data are more accurate than ERA5 because they better simulate the sea ice, the transition from sea ice to open ocean, and the forming clouds.
Raphael Satoru Märkl, Christiane Voigt, Daniel Sauer, Rebecca Katharina Dischl, Stefan Kaufmann, Theresa Harlaß, Valerian Hahn, Anke Roiger, Cornelius Weiß-Rehm, Ulrike Burkhardt, Ulrich Schumann, Andreas Marsing, Monika Scheibe, Andreas Dörnbrack, Charles Renard, Maxime Gauthier, Peter Swann, Paul Madden, Darren Luff, Reetu Sallinen, Tobias Schripp, and Patrick Le Clercq
Atmos. Chem. Phys., 24, 3813–3837, https://doi.org/10.5194/acp-24-3813-2024, https://doi.org/10.5194/acp-24-3813-2024, 2024
Short summary
Short summary
In situ measurements of contrails from a large passenger aircraft burning 100 % sustainable aviation fuel (SAF) show a 56 % reduction in contrail ice crystal numbers compared to conventional Jet A-1. Results from a climate model initialized with the observations suggest a significant decrease in radiative forcing from contrails. Our study confirms that future increased use of low aromatic SAF can reduce the climate impact from aviation.
Yuanmou Du, Dantong Liu, Delong Zhao, Mengyu Huang, Ping Tian, Dian Wen, Wei Xiao, Wei Zhou, Baiwan Pan, Dongfei Zuo, Xiange Liu, Yingying Jing, Rong Zhang, Jiujiang Sheng, Fei Wang, Yu Huang, Yunbo Chen, and Deping Ding
EGUsphere, https://doi.org/10.5194/egusphere-2024-314, https://doi.org/10.5194/egusphere-2024-314, 2024
Short summary
Short summary
By conducting in-situ measurements of the microphysical properties, we investigated the ice production and phase transformation of stratocumulus during an extratropical cyclone over the North China Plain. We find the key factors in controlling secondary ice production, and the microphysical properties of clouds with convective cells under different stages are elucidated, which will improve the understanding of the key processes in controlling the cloud glaciation and precipitation process.
Philippe Ricaud, Massimo Del Guasta, Angelo Lupi, Romain Roehrig, Eric Bazile, Pierre Durand, Jean-Luc Attié, Alessia Nicosia, and Paolo Grigioni
Atmos. Chem. Phys., 24, 613–630, https://doi.org/10.5194/acp-24-613-2024, https://doi.org/10.5194/acp-24-613-2024, 2024
Short summary
Short summary
Clouds affect the Earth's climate in ways that depend on the type of cloud (solid/liquid water). From observations at Concordia (Antarctica), we show that in supercooled liquid water (liquid water for temperatures below 0°C) clouds (SLWCs), temperature and SLWC radiative forcing increase with liquid water (up to 70 W m−2). We extrapolated that the maximum SLWC radiative forcing can reach 40 W m−2 over the Antarctic Peninsula, highlighting the importance of SLWCs for global climate prediction.
Cheikh Dione, Martial Haeffelin, Frédéric Burnet, Christine Lac, Guylaine Canut, Julien Delanoë, Jean-Charles Dupont, Susana Jorquera, Pauline Martinet, Jean-François Ribaud, and Felipe Toledo
Atmos. Chem. Phys., 23, 15711–15731, https://doi.org/10.5194/acp-23-15711-2023, https://doi.org/10.5194/acp-23-15711-2023, 2023
Short summary
Short summary
This paper documents the role of thermodynamics and turbulence in the fog life cycle over southwestern France. It is based on a unique dataset collected during the SOFOG3D field campaign in autumn and winter 2019–2020. The paper gives a threshold for turbulence driving the different phases of the fog life cycle and the role of advection in the night-time dissipation of fog. The results can be operationalised to nowcast fog and improve short-range forecasts in numerical weather prediction models.
Hui Xu, Jianping Guo, Bing Tong, Jinqiang Zhang, Tianmeng Chen, Xiaoran Guo, Jian Zhang, and Wenqing Chen
Atmos. Chem. Phys., 23, 15011–15038, https://doi.org/10.5194/acp-23-15011-2023, https://doi.org/10.5194/acp-23-15011-2023, 2023
Short summary
Short summary
The radiative effect of cloud remains one of the largest uncertain factors in climate change, largely due to the lack of cloud vertical structure (CVS) observations. The study presents the first near-global CVS climatology using high-vertical-resolution soundings. Single-layer cloud mainly occurs over arid regions. As the number of cloud layers increases, clouds tend to have lower bases and thinner layer thicknesses. The occurrence frequency of cloud exhibits a pronounced seasonal diurnal cycle.
Amit Kumar Pandit, Jean-Paul Vernier, Thomas Duncan Fairlie, Kristopher M. Bedka, Melody A. Avery, Harish Gadhavi, Madineni Venkat Ratnam, Sanjeev Dwivedi, Kasimahanthi Amar Jyothi, Frank G. Wienhold, Holger Vömel, Hongyu Liu, Bo Zhang, Buduru Suneel Kumar, Tra Dinh, and Achuthan Jayaraman
EGUsphere, https://doi.org/10.5194/egusphere-2023-2236, https://doi.org/10.5194/egusphere-2023-2236, 2023
Short summary
Short summary
This study investigates the formation mechanism of a tropopause cirrus cloud layer observed at extremely cold temperatures over Hyderabad in India during the 2017 Asian summer monsoon using balloon-borne sensors. Ice crystals smaller than 50 microns were found in this optically thin cirrus cloud layer. Combined analysis of back-trajectories, satellite, and model data revealed that the formation of this layer was influenced by gravity waves and stratospheric hydration induced by typhoon Hato.
Elena De La Torre Castro, Tina Jurkat-Witschas, Armin Afchine, Volker Grewe, Valerian Hahn, Simon Kirschler, Martina Krämer, Johannes Lucke, Nicole Spelten, Heini Wernli, Martin Zöger, and Christiane Voigt
Atmos. Chem. Phys., 23, 13167–13189, https://doi.org/10.5194/acp-23-13167-2023, https://doi.org/10.5194/acp-23-13167-2023, 2023
Short summary
Short summary
In this study, we show the differences in the microphysical properties between high-latitude (HL) cirrus and mid-latitude (ML) cirrus over the Arctic, North Atlantic, and central Europe during summer. The in situ measurements are combined with backward trajectories to investigate the influence of the region on cloud formation. We show that HL cirrus are characterized by a lower concentration of larger ice crystals when compared to ML cirrus.
Mampi Sarkar, Adriana Bailey, Peter Blossey, Simon P. de Szoeke, David Noone, Estefanía Quiñones Meléndez, Mason D. Leandro, and Patrick Y. Chuang
Atmos. Chem. Phys., 23, 12671–12690, https://doi.org/10.5194/acp-23-12671-2023, https://doi.org/10.5194/acp-23-12671-2023, 2023
Short summary
Short summary
We study rain evaporation characteristics below shallow cumulus clouds over the North Atlantic Ocean by pairing isotope observations with a microphysical model. The modeled fraction of rain mass that evaporates below the cloud strongly depends on the raindrop size and distribution width. Moreover, the higher the rain mass fraction evaporated, the greater the change in deuterium excess. In this way, rain evaporation could be studied independently using only isotope and microphysical observations.
Simon Kirschler, Christiane Voigt, Bruce E. Anderson, Gao Chen, Ewan C. Crosbie, Richard A. Ferrare, Valerian Hahn, Johnathan W. Hair, Stefan Kaufmann, Richard H. Moore, David Painemal, Claire E. Robinson, Kevin J. Sanchez, Amy J. Scarino, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Edward L. Winstead, Luke D. Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 23, 10731–10750, https://doi.org/10.5194/acp-23-10731-2023, https://doi.org/10.5194/acp-23-10731-2023, 2023
Short summary
Short summary
In this study we present an overview of liquid and mixed-phase clouds and precipitation in the marine boundary layer over the western North Atlantic Ocean. We compare microphysical properties of pure liquid clouds to mixed-phase clouds and show that the initiation of the ice phase in mixed-phase clouds promotes precipitation. The observational data presented in this study are well suited for investigating the processes that give rise to liquid and mixed-phase clouds, ice, and precipitation.
Meng Xing, Weiguo Liu, Jing Hu, and Zheng Wang
Atmos. Chem. Phys., 23, 9123–9136, https://doi.org/10.5194/acp-23-9123-2023, https://doi.org/10.5194/acp-23-9123-2023, 2023
Short summary
Short summary
The below-cloud evaporation effect (BCE) on precipitation largely impacts the final isotopic composition. However, determining the BCE effect remains poorly constrained. Our work used a ΔdΔδ diagram to differentiate the below-cloud processes. Moreover, by comparing two different computing methods, we considered that both methods are suitable for evaluation the BCE, except for snowfall events. Overall, our work compiled a set of effective methods to evaluate the BCE effect.
McKenna W. Stanford, Ann M. Fridlind, Israel Silber, Andrew S. Ackerman, Greg Cesana, Johannes Mülmenstädt, Alain Protat, Simon Alexander, and Adrian McDonald
Atmos. Chem. Phys., 23, 9037–9069, https://doi.org/10.5194/acp-23-9037-2023, https://doi.org/10.5194/acp-23-9037-2023, 2023
Short summary
Short summary
Clouds play an important role in the Earth’s climate system as they modulate the amount of radiation that either reaches the surface or is reflected back to space. This study demonstrates an approach to robustly evaluate surface-based observations against a large-scale model. We find that the large-scale model precipitates too infrequently relative to observations, contrary to literature documentation suggesting otherwise based on satellite measurements.
Valerian Hahn, Ralf Meerkötter, Christiane Voigt, Sonja Gisinger, Daniel Sauer, Valéry Catoire, Volker Dreiling, Hugh Coe, Cyrille Flamant, Stefan Kaufmann, Jonas Kleine, Peter Knippertz, Manuel Moser, Philip Rosenberg, Hans Schlager, Alfons Schwarzenboeck, and Jonathan Taylor
Atmos. Chem. Phys., 23, 8515–8530, https://doi.org/10.5194/acp-23-8515-2023, https://doi.org/10.5194/acp-23-8515-2023, 2023
Short summary
Short summary
During the DACCIWA campaign in West Africa, we found a 35 % increase in the cloud droplet concentration that formed in a polluted compared with a less polluted environment and a decrease of 17 % in effective droplet diameter. Radiative transfer simulations, based on the measured cloud properties, reveal that these low-level polluted clouds radiate only 2.6 % more energy back to space, compared with a less polluted cloud. The corresponding additional decrease in temperature is rather small.
Silke Groß, Tina Jurkat-Witschas, Qiang Li, Martin Wirth, Benedikt Urbanek, Martina Krämer, Ralf Weigel, and Christiane Voigt
Atmos. Chem. Phys., 23, 8369–8381, https://doi.org/10.5194/acp-23-8369-2023, https://doi.org/10.5194/acp-23-8369-2023, 2023
Short summary
Short summary
Aviation-emitted aerosol can have an impact on cirrus clouds. We present optical and microphysical properties of mid-latitude cirrus clouds which were formed under the influence of aviation-emitted aerosol or which were formed under rather pristine conditions. We find that cirrus clouds affected by aviation-emitted aerosol show larger values of the particle linear depolarization ratio, larger mean effective ice particle diameters and decreased ice particle number concentrations.
Manuel Moser, Christiane Voigt, Tina Jurkat-Witschas, Valerian Hahn, Guillaume Mioche, Olivier Jourdan, Régis Dupuy, Christophe Gourbeyre, Alfons Schwarzenboeck, Johannes Lucke, Yvonne Boose, Mario Mech, Stephan Borrmann, André Ehrlich, Andreas Herber, Christof Lüpkes, and Manfred Wendisch
Atmos. Chem. Phys., 23, 7257–7280, https://doi.org/10.5194/acp-23-7257-2023, https://doi.org/10.5194/acp-23-7257-2023, 2023
Short summary
Short summary
This study provides a comprehensive microphysical and thermodynamic phase analysis of low-level clouds in the northern Fram Strait, above the sea ice and the open ocean, during spring and summer. Using airborne in situ cloud data, we show that the properties of Arctic low-level clouds vary significantly with seasonal meteorological situations and surface conditions. The observations presented in this study can help one to assess the role of clouds in the Arctic climate system.
Rachel Atlas and Christopher S. Bretherton
Atmos. Chem. Phys., 23, 4009–4030, https://doi.org/10.5194/acp-23-4009-2023, https://doi.org/10.5194/acp-23-4009-2023, 2023
Short summary
Short summary
The tropical tropopause layer exists between the troposphere and the stratosphere in the tropics. Very thin cirrus clouds cool Earth's surface by scrubbing water vapor (a greenhouse gas) out of air parcels as they ascend through the tropical tropopause layer on their way to the stratosphere. We show observational evidence from aircraft that small-scale (< 100 km) gravity waves and turbulence increase the amount of ice in these clouds and may allow them to remove more water vapor from the air.
Konstantinos Matthaios Doulgeris, Ville Vakkari, Ewan J. O'Connor, Veli-Matti Kerminen, Heikki Lihavainen, and David Brus
Atmos. Chem. Phys., 23, 2483–2498, https://doi.org/10.5194/acp-23-2483-2023, https://doi.org/10.5194/acp-23-2483-2023, 2023
Short summary
Short summary
We investigated how different long-range-transported air masses can affect the microphysical properties of low-level clouds in a clean subarctic environment. A connection was revealed. Higher values of cloud droplet number concentrations were related to continental air masses, whereas the lowest values of number concentrations were related to marine air masses. These were characterized by larger cloud droplets. Clouds in all regions were sensitive to increases in cloud number concentration.
Fayçal Lamraoui, Martina Krämer, Armin Afchine, Adam B. Sokol, Sergey Khaykin, Apoorva Pandey, and Zhiming Kuang
Atmos. Chem. Phys., 23, 2393–2419, https://doi.org/10.5194/acp-23-2393-2023, https://doi.org/10.5194/acp-23-2393-2023, 2023
Short summary
Short summary
Cirrus in the tropical tropopause layer (TTL) can play a key role in vertical transport. We investigate the role of different cloud regimes and the associated ice habits in regulating the properties of the TTL. We use high-resolution numerical experiments at the scales of large-eddy simulations (LESs) and aircraft measurements. We found that LES-scale parameterizations that predict ice shape are crucial for an accurate representation of TTL cirrus and thus the associated (de)hydration process.
Yun Li, Christoph Mahnke, Susanne Rohs, Ulrich Bundke, Nicole Spelten, Georgios Dekoutsidis, Silke Groß, Christiane Voigt, Ulrich Schumann, Andreas Petzold, and Martina Krämer
Atmos. Chem. Phys., 23, 2251–2271, https://doi.org/10.5194/acp-23-2251-2023, https://doi.org/10.5194/acp-23-2251-2023, 2023
Short summary
Short summary
The radiative effect of aviation-induced cirrus is closely related to ambient conditions and its microphysical properties. Our study investigated the occurrence of contrail and natural cirrus measured above central Europe in spring 2014. It finds that contrail cirrus appears frequently in the pressure range 200 to 245 hPa and occurs more often in slightly ice-subsaturated environments than expected. Avoiding slightly ice-subsaturated regions by aviation might help mitigate contrail cirrus.
Flor Vanessa Maciel, Minghui Diao, and Ryan Patnaude
Atmos. Chem. Phys., 23, 1103–1129, https://doi.org/10.5194/acp-23-1103-2023, https://doi.org/10.5194/acp-23-1103-2023, 2023
Short summary
Short summary
Aerosol indirect effects on cirrus clouds are investigated during cirrus evolution, using global-scale in situ observations and climate model simulations. As cirrus evolves, the mechanisms to form ice crystals also change with time. Both small and large aerosols are found to affect cirrus properties. Southern Hemisphere cirrus appears to be more sensitive to additional aerosols. The climate model underestimates ice crystal mass, likely due to biases of relative humidity and vertical velocity.
David E. Kingsmill, Jeffrey R. French, and Neil P. Lareau
Atmos. Chem. Phys., 23, 1–21, https://doi.org/10.5194/acp-23-1-2023, https://doi.org/10.5194/acp-23-1-2023, 2023
Short summary
Short summary
This study uses in situ aircraft measurements to characterize the size and shape distributions of 10 µm to 6 mm diameter particles observed during six penetrations of wildfire-induced pyroconvection. Particles sampled in one penetration of a smoke plume are most likely pyrometeors composed of ash. The other penetrations are through pyrocumulus clouds where particle composition is most likely a combination of hydrometeors (ice particles) and pyrometeors (ash).
Julie Thérèse Pasquier, Jan Henneberger, Fabiola Ramelli, Annika Lauber, Robert Oscar David, Jörg Wieder, Tim Carlsen, Rosa Gierens, Marion Maturilli, and Ulrike Lohmann
Atmos. Chem. Phys., 22, 15579–15601, https://doi.org/10.5194/acp-22-15579-2022, https://doi.org/10.5194/acp-22-15579-2022, 2022
Short summary
Short summary
It is important to understand how ice crystals and cloud droplets form in clouds, as their concentrations and sizes determine the exact radiative properties of the clouds. Normally, ice crystals form from aerosols, but we found evidence for the formation of additional ice crystals from the original ones over a large temperature range within Arctic clouds. In particular, additional ice crystals were formed during collisions of several ice crystals or during the freezing of large cloud droplets.
Layrson J. M. Gonçalves, Simone M. S. C. Coelho, Paulo Y. Kubota, and Dayana C. Souza
Atmos. Chem. Phys., 22, 15509–15526, https://doi.org/10.5194/acp-22-15509-2022, https://doi.org/10.5194/acp-22-15509-2022, 2022
Short summary
Short summary
This research aims to study the environmental conditions that are favorable and not favorable to cloud formation, in this case specifically for the Amazon region. The results found in this research will be used to improve the representation of clouds in numerical models that are used in weather and climate prediction. In general, it is expected that with better knowledge regarding the cloud–radiation interaction, it is possible to make a better forecast of weather and climate.
Claudia Mignani, Lukas Zimmermann, Rigel Kivi, Alexis Berne, and Franz Conen
Atmos. Chem. Phys., 22, 13551–13568, https://doi.org/10.5194/acp-22-13551-2022, https://doi.org/10.5194/acp-22-13551-2022, 2022
Short summary
Short summary
We determined over the course of 8 winter months the phase of clouds associated with snowfall in Northern Finland using radiosondes and observations of ice particle habits at ground level. We found that precipitating clouds were extending from near ground to at least 2.7 km altitude and approximately three-quarters of them were likely glaciated. Possible moisture sources and ice formation processes are discussed.
Alexei Korolev, Paul J. DeMott, Ivan Heckman, Mengistu Wolde, Earle Williams, David J. Smalley, and Michael F. Donovan
Atmos. Chem. Phys., 22, 13103–13113, https://doi.org/10.5194/acp-22-13103-2022, https://doi.org/10.5194/acp-22-13103-2022, 2022
Short summary
Short summary
The present study provides the first explicit in situ observation of secondary ice production at temperatures as low as −27 °C, which is well outside the range of the Hallett–Mossop process (−3 to −8 °C). This observation expands our knowledge of the temperature range of initiation of secondary ice in clouds. The obtained results are intended to stimulate laboratory and theoretical studies to develop physically based parameterizations for weather prediction and climate models.
Siddhant Gupta, Greg M. McFarquhar, Joseph R. O'Brien, Michael R. Poellot, David J. Delene, Ian Chang, Lan Gao, Feng Xu, and Jens Redemann
Atmos. Chem. Phys., 22, 12923–12943, https://doi.org/10.5194/acp-22-12923-2022, https://doi.org/10.5194/acp-22-12923-2022, 2022
Short summary
Short summary
The ability of NASA’s Terra and Aqua satellites to retrieve cloud properties and estimate the changes in cloud properties due to aerosol–cloud interactions (ACI) was examined. There was good agreement between satellite retrievals and in situ measurements over the southeast Atlantic Ocean. This suggests that, combined with information on aerosol properties, satellite retrievals of cloud properties can be used to study ACI over larger domains and longer timescales in the absence of in situ data.
Étienne Vignon, Lea Raillard, Christophe Genthon, Massimo Del Guasta, Andrew J. Heymsfield, Jean-Baptiste Madeleine, and Alexis Berne
Atmos. Chem. Phys., 22, 12857–12872, https://doi.org/10.5194/acp-22-12857-2022, https://doi.org/10.5194/acp-22-12857-2022, 2022
Short summary
Short summary
The near-surface atmosphere over the Antarctic Plateau is cold and pristine and resembles to a certain extent the high troposphere where cirrus clouds form. In this study, we use innovative humidity measurements at Concordia Station to study the formation of ice fogs at temperatures <−40°C. We provide observational evidence that ice fogs can form through the homogeneous freezing of solution aerosols, a common nucleation pathway for cirrus clouds.
Jan H. Schween, Camilo del Rio, Juan-Luis García, Pablo Osses, Sarah Westbrook, and Ulrich Löhnert
Atmos. Chem. Phys., 22, 12241–12267, https://doi.org/10.5194/acp-22-12241-2022, https://doi.org/10.5194/acp-22-12241-2022, 2022
Short summary
Short summary
Marine stratocumulus clouds of the eastern Pacific play an essential role in the Earth's climate. These clouds form the major source of water to parts of the extreme dry Atacama Desert at the northern coast of Chile. For the first time these clouds are observed over a whole year with three remote sensing instruments. It is shown how these clouds are influenced by the land–sea wind system and the distribution of ocean temperatures.
Marie Mazoyer, Frédéric Burnet, and Cyrielle Denjean
Atmos. Chem. Phys., 22, 11305–11321, https://doi.org/10.5194/acp-22-11305-2022, https://doi.org/10.5194/acp-22-11305-2022, 2022
Short summary
Short summary
The evolution of the droplet size distribution during the fog life cycle remains poorly understood and progress is required to reduce the uncertainty of fog forecasts. To gain insights into the physical processes driving the microphysics, intensive field campaigns were conducted during three winters at the SIRTA site in the south of Paris. This study analyzed the variations in fog microphysical properties and their potential interactions at the different evolutionary stages of the fog events.
Xianda Gong, Martin Radenz, Heike Wex, Patric Seifert, Farnoush Ataei, Silvia Henning, Holger Baars, Boris Barja, Albert Ansmann, and Frank Stratmann
Atmos. Chem. Phys., 22, 10505–10525, https://doi.org/10.5194/acp-22-10505-2022, https://doi.org/10.5194/acp-22-10505-2022, 2022
Short summary
Short summary
The sources of ice-nucleating particles (INPs) are poorly understood in the Southern Hemisphere (SH). We studied INPs in the boundary layer in the southern Patagonia region. No seasonal cycle of INP concentrations was observed. The majority of INPs are biogenic particles, likely from local continental sources. The INP concentrations are higher when strong precipitation occurs. While previous studies focused on marine INP sources in SH, we point out the importance of continental sources of INPs.
Jörg Wieder, Nikola Ihn, Claudia Mignani, Moritz Haarig, Johannes Bühl, Patric Seifert, Ronny Engelmann, Fabiola Ramelli, Zamin A. Kanji, Ulrike Lohmann, and Jan Henneberger
Atmos. Chem. Phys., 22, 9767–9797, https://doi.org/10.5194/acp-22-9767-2022, https://doi.org/10.5194/acp-22-9767-2022, 2022
Short summary
Short summary
Ice formation and its evolution in mixed-phase clouds are still uncertain. We evaluate the lidar retrieval of ice-nucleating particle concentration in dust-dominated and continental air masses over the Swiss Alps with in situ observations. A calibration factor to improve the retrieval from continental air masses is proposed. Ice multiplication factors are obtained with a new method utilizing remote sensing. Our results indicate that secondary ice production occurs at temperatures down to −30 °C.
Saleem Ali, Sanjay Kumar Mehta, Aravindhavel Ananthavel, and Tondapu Venkata Ramesh Reddy
Atmos. Chem. Phys., 22, 8321–8342, https://doi.org/10.5194/acp-22-8321-2022, https://doi.org/10.5194/acp-22-8321-2022, 2022
Short summary
Short summary
Multiple cirrus clouds frequently occur over regions of deep convection in the tropics. Tropical convection has a strong diurnal pattern, with peaks in the afternoon to early evening, over the continents. Continuous micropulse lidar observations over a coastal station in the Indian monsoon region enable us, for the first time, to demonstrate a robust diurnal pattern of single and multiple cirrus occurrences, with peaks during the late afternoon and early morning hours, respectively.
Ivana Kolmašová, Ondřej Santolík, Jakub Šlegl, Jana Popová, Zbyněk Sokol, Petr Zacharov, Ondřej Ploc, Gerhard Diendorfer, Ronald Langer, Radek Lán, and Igor Strhárský
Atmos. Chem. Phys., 22, 7959–7973, https://doi.org/10.5194/acp-22-7959-2022, https://doi.org/10.5194/acp-22-7959-2022, 2022
Short summary
Short summary
Gamma ray radiation related to thunderstorms was previously observed at the high-altitude mountain observatories or on the western coast of Japan, usually being terminated by lightning discharges. We show unusual observations of gamma rays at an altitude below 1000 m, coinciding with peculiar rapid variations in the vertical electric field, which are linked to inverted intracloud lightning discharges. This indicates that a strong, lower positive-charge region was present inside the thundercloud.
Cuiqi Zhang, Zhijun Wu, Jingchuan Chen, Jie Chen, Lizi Tang, Wenfei Zhu, Xiangyu Pei, Shiyi Chen, Ping Tian, Song Guo, Limin Zeng, Min Hu, and Zamin A. Kanji
Atmos. Chem. Phys., 22, 7539–7556, https://doi.org/10.5194/acp-22-7539-2022, https://doi.org/10.5194/acp-22-7539-2022, 2022
Short summary
Short summary
The immersion ice nucleation effectiveness of aerosols from multiple sources in the urban environment remains elusive. In this study, we demonstrate that the immersion ice-nucleating particle (INP) concentration increased dramatically during a dust event in an urban atmosphere. Pollutant aerosols, including inorganic salts formed through secondary transformation (SIA) and black carbon (BC), might not act as effective INPs under mixed-phase cloud conditions.
Fritz Waitz, Martin Schnaiter, Thomas Leisner, and Emma Järvinen
Atmos. Chem. Phys., 22, 7087–7103, https://doi.org/10.5194/acp-22-7087-2022, https://doi.org/10.5194/acp-22-7087-2022, 2022
Short summary
Short summary
Riming, i.e., the accretion of small droplets on the surface of ice particles via collision, is one of the major uncertainties in model prediction of mixed-phase clouds. We discuss the occurrence (up to 50% of particles) and aging of rimed ice particles and show correlations of the occurrence and the degree of riming with ambient meteorological parameters using data gathered by the Particle Habit Imaging and Polar Scattering (PHIPS) probe during three airborne in situ field campaigns.
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
Atmos. Chem. Phys., 22, 5117–5145, https://doi.org/10.5194/acp-22-5117-2022, https://doi.org/10.5194/acp-22-5117-2022, 2022
Short summary
Short summary
The present measurement report introduces the ice nucleation campaign organized in Hyytiälä, Finland, in 2018 (HyICE-2018). We provide an overview of the campaign settings, and we describe the measurement infrastructure and operating procedures used. In addition, we use results from ice nucleation instrument inter-comparison to show that the suite of these instruments deployed during the campaign reports consistent results.
Kevin J. Sanchez, Bo Zhang, Hongyu Liu, Matthew D. Brown, Ewan C. Crosbie, Francesca Gallo, Johnathan W. Hair, Chris A. Hostetler, Carolyn E. Jordan, Claire E. Robinson, Amy Jo Scarino, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Elizabeth B. Wiggins, Edward L. Winstead, Luke D. Ziemba, Georges Saliba, Savannah L. Lewis, Lynn M. Russell, Patricia K. Quinn, Timothy S. Bates, Jack Porter, Thomas G. Bell, Peter Gaube, Eric S. Saltzman, Michael J. Behrenfeld, and Richard H. Moore
Atmos. Chem. Phys., 22, 2795–2815, https://doi.org/10.5194/acp-22-2795-2022, https://doi.org/10.5194/acp-22-2795-2022, 2022
Short summary
Short summary
Atmospheric particle concentrations impact clouds, which strongly impact the amount of sunlight reflected back into space and the overall climate. Measurements of particles over the ocean are rare and expensive to collect, so models are necessary to fill in the gaps by simulating both particle and clouds. However, some measurements are needed to test the accuracy of the models. Here, we measure changes in particles in different weather conditions, which are ideal for comparison with models.
Cited articles
Abdelmonem, A., Järvinen, E., Duft, D., Hirst, E., Vogt, S., Leisner, T., and Schnaiter, M.: PHIPS–HALO: the airborne Particle Habit Imaging and Polar Scattering probe – Part 1: Design and operation, Atmos. Meas. Tech., 9, 3131–3144, https://doi.org/10.5194/amt-9-3131-2016, 2016. a
Bailey, M. P. and Hallett, J.: A Comprehensive Habit Diagram for Atmospheric
Ice Crystals: Confirmation from the Laboratory, AIRS II, and Other Field
Studies, J. Atmos. Sci., 66, 2888–2899,
https://doi.org/10.1175/2009JAS2883.1, 2009. a, b
Baumgardner, D., Jonsson, H., Dawson, W., O'Connor, D., and Newton, R.: The
cloud, aerosol and precipitation spectrometer: a new instrument for cloud
investigations, Atmos. Res., 59-60, 251–264,
https://doi.org/10.1016/S0169-8095(01)00119-3, 2001. a
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,
https://doi.org/10.1175/amsmonographs-d-16-0011.1, 2017. a
Brown, P. R. A. and Francis, P. N.: Improved Measurements of the Ice Water
Content in Cirrus Using a Total-Water Probe, J. Atmos. Ocean. Tech., 12, 410–414, https://doi.org/10.1175/1520-0426(1995)012<0410:IMOTIW>2.0.CO;2, 1995. a, b
Cai, Y., Montague, D. C., Mooiweer-Bryan, W., and Deshler, T.: Performance
characteristics of the ultra high sensitivity aerosol spectrometer for
particles between 55 and 800 nm: Laboratory and field studies, J.
Aerosol Sci., 39, 759–769, https://doi.org/10.1016/j.jaerosci.2008.04.007, 2008. a
Crosier, J., Bower, K. N., Choularton, T. W., Westbrook, C. D., Connolly, P. J., Cui, Z. Q., Crawford, I. P., Capes, G. L., Coe, H., Dorsey, J. R., Williams, P. I., Illingworth, A. J., Gallagher, M. W., and Blyth, A. M.: Observations of ice multiplication in a weakly convective cell embedded in supercooled mid-level stratus, Atmos. Chem. Phys., 11, 257–273, https://doi.org/10.5194/acp-11-257-2011, 2011. a
Curry, J. A. and Ebert, E. E.: Annual cycle of radiation fluxes over the Arctic Ocean: Sensitivity to cloud optical properties, J. Climate, 5,
1267–1280, 1992. a
Curry, J. A., Schramm, J. L., Rossow, W. B., and Randall, D.: Overview of
Arctic cloud and radiation characteristics, J. Climate, 9,
1731–1764, 1996. a
Dupuy, R., Jourdan, O., Mioche, G., Ehrlich, A., Waitz, F., Gourbeyre, C., Järvinen, E., Schnaiter, M., and Schwarzenböck, A.: Cloud Microphysical Properties Of Summertime Arctic Stratocumulus During The Acloud CamPaign: Comparison With Previous Results In The European Arctic, Vancouver, Canada, hal-01932907, https://hal.science/hal-01932907 (last access: 9 November 2022), 2018. a
Dupuy, R., Jourdan, O., Mioche, G., Gourbeyre, C., Leroy, D., and Schwarzenböck, A.: CDP, CIP and PIP In-situ arctic cloud microphysical properties observed during ACLOUD-AC3 campaign in June 2017, LAMP/CNRS/UCA/OPGC, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.899074, 2019. a, b
Fridlind, A. M., Ackerman, A., McFarquhar, G., Zhang, G., Poellot, M., DeMott, P., Prenni, A., and Heymsfield, A.: Ice properties of single-layer
stratocumulus during the Mixed-Phase Arctic Cloud Experiment: 2. Model
results, J. Geophys. Res.-Atmos., 112, D24202, https://doi.org/10.1029/2007JD008646, 2007. a, b
Fu, Q.: A new parameterization of an asymmetry factor of cirrus clouds for
climate models, J. Atmos. Sci., 64, 4140–4150, 2007. a
Gultepe, I., Isaac, G., Hudak, D., Nissen, R., and Strapp, J. W.: Dynamical and Microphysical Characteristics of Arctic Clouds during BASE, J. Climate, 13, 1225–1254, https://doi.org/10.1175/1520-0442(2000)013<1225:DAMCOA>2.0.CO;2, 2000. a, b
Gultepe, I., Isaac, G., and Cober, S.: Ice crystal number concentration versus temperature for climate studies, Int. J. Climatol., 21,
1281–1302, https://doi.org/10.1002/joc.642, 2001. a, b, c
Gultepe, I., Heymsfield, A. J., Field, P. R., and Axisa, D.: Ice-Phase
Precipitation, Meteor. Mon., 58, 6.1–6.36,
https://doi.org/10.1175/AMSMONOGRAPHS-D-16-0013.1, 2017. a
Hartmann, J., Gehrmann, M., Kohnert, K., Metzger, S., and Sachs, T.: New calibration procedures for airborne turbulence measurements and accuracy of the methane fluxes during the AirMeth campaigns, Atmos. Meas. Tech., 11, 4567–4581, https://doi.org/10.5194/amt-11-4567-2018, 2018. a, b
Hartmann, J., Lüpkes, C., and Chechin, D.: 1Hz resolution aircraft measurements of wind and temperature during the ACLOUD campaign in 2017, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.902849, 2019. a, b
Hirst, E., Kaye, P., Greenaway, R., Field, P., and Johnson, D.: Discrimination of micrometre-sized ice and super-cooled droplets in mixed-phase cloud, Atmos. Environ., 35, 33–47,
https://doi.org/10.1016/S1352-2310(00)00377-0, 2001. a
Jackson, R. C., McFarquhar, G. M., Korolev, A. V., Earle, M. E., Liu, P. S. K., Lawson, R. P., Brooks, S., Wolde, M., Laskin, A., and Freer, M.: The dependence of ice microphysics on aerosol concentration in arctic mixed-phase
stratus clouds during ISDAC and M-PACE, J. Geophys. Res.-Atmos., 117, D15207, https://doi.org/10.1029/2012JD017668, 2012. a, b, c, d, e
Järvinen, E., Jourdan, O., Neubauer, D., Yao, B., Liu, C., Andreae, M. O., Lohmann, U., Wendisch, M., McFarquhar, G. M., Leisner, T., and Schnaiter, M.: Additional global climate cooling by clouds due to ice crystal complexity, Atmos. Chem. Phys., 18, 15767–15781, https://doi.org/10.5194/acp-18-15767-2018, 2018. a
Järvinen, E., McCluskey, C. S., Waitz, F., Schnaiter, M., Bansemer, A.,
Bardeen, C. G., Gettelman, A., Heymsfield, A., Stith, J. L., Wu, W.,
D’Alessandro, J. J., McFarquhar, G. M., Diao, M., Finlon, J. A., Hill, T.
C. J., Levin, E. J. T., Moore, K. A., and DeMott, P. J.: Evidence for
Secondary Ice Production in Southern Ocean Maritime Boundary Layer Clouds,
J. Geophys. Res.-Atmos., 127, e2021JD036411,
https://doi.org/10.1029/2021JD036411, 2022. a
Järvinen, E. and Schnaiter, M.: SID-3 Liquid and Ice Phase Particle Size Distributions measured during ACLOUD, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.960269, 2023. a, b
Jourdan, O., Mioche, G., Garrett, T. J., Schwarzenböck, A., Vidot, J.,
Xie, Y., Shcherbakov, V., Yang, P., and Gayet, J. F.: Coupling of the
microphysical and optical properties of an Arctic nimbostratus cloud during
the ASTAR 2004 experiment: Implications for light-scattering modeling,
J. Geophys. Res.-Atmos., 115, 1–16, https://doi.org/10.1029/2010JD014016, 2010. a
Kahl, J. D.: Characteristics of the low-level temperature inversion along the
Alaskan Arctic coast, Int. J. Climatol., 10, 537–548, 1990. a
Kahl, J. D., Serreze, M. C., and Schnell, R. C.: Tropospheric low-level
temperature inversions in the Canadian Arctic, Atmos.-Ocean, 30,
511–529, 1992. a
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, https://doi.org/10.1175/AMSMONOGRAPHS-D-16-0006.1, 2017. a, b, c
Knudsen, E. M., Heinold, B., Dahlke, S., Bozem, H., Crewell, S., Gorodetskaya, I. V., Heygster, G., Kunkel, D., Maturilli, M., Mech, M., Viceto, C., Rinke, A., Schmithüsen, H., Ehrlich, A., Macke, A., Lüpkes, C., and Wendisch, M.: Meteorological conditions during the ACLOUD/PASCAL field campaign near Svalbard in early summer 2017, Atmos. Chem. Phys., 18, 17995–18022, https://doi.org/10.5194/acp-18-17995-2018, 2018. a, b
Korolev, A. V., Isaac, G. A., and Hallett, J.: Ice particle habits in Arctic
clouds, Geophys. Res. Lett., 26, 1299–1302,
https://doi.org/10.1029/1999GL900232, 1999. a
Lasher-Trapp, S., Scott, E. L., Järvinen, E., Schnaiter, M., Waitz, F., DeMott, P. J., McCluskey, C. S., and Hill, T. C.: Observations and Modeling of Rime Splintering in Southern Ocean Cumuli, J. Geophys. Res.-Atmos., 126, 1–18, https://doi.org/10.1029/2021JD035479, 2021. 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, https://doi.org/10.1029/2000JD900789, 2001. a, b, c
Li, G., Wieder, J., Pasquier, J. T., Henneberger, J., and Kanji, Z. A.: Predicting atmospheric background number concentration of ice-nucleating particles in the Arctic, Atmos. Chem. Phys., 22, 14441–14454, https://doi.org/10.5194/acp-22-14441-2022, 2022. a, b
Lloyd, G., Choularton, T. W., Bower, K. N., Crosier, J., Jones, H., Dorsey, J. R., Gallagher, M. W., Connolly, P., Kirchgaessner, A. C. R., and Lachlan-Cope, T.: Observations and comparisons of cloud microphysical properties in spring and summertime Arctic stratocumulus clouds during the ACCACIA campaign, Atmos. Chem. Phys., 15, 3719–3737, https://doi.org/10.5194/acp-15-3719-2015, 2015. a, b, c, d
Mages, Z., Kollias, P., Zhu, Z., and Luke, E. P.: Surface-based observations of cold-air outbreak clouds during the COMBLE field campaign, Atmos. Chem. Phys., 23, 3561–3574, https://doi.org/10.5194/acp-23-3561-2023, 2023. a
McFarquhar, G. M. and Heymsfield, A. J.: The definition and significance of an effective radius for ice clouds, J. Atmos. Sci., 55, 2039–2052, 1998. a
McFarquhar, G. M., Zhang, G., Poellot, M. R., Kok, G. L., McCoy, R., Tooman,
T., Fridlind, A., and Heymsfield, A. J.: Ice properties of single-layer
stratocumulus during the Mixed-Phase Arctic Cloud Experiment: 1.
Observations, J. Geophys. Res.-Atmos., 112, 1–19,
https://doi.org/10.1029/2007JD008633, 2007. a, b, c, d, e, f, g, h, i, j
Mertes, S., Kästner, U., and Macke, A.: Airborne in-situ measurements of the aerosol absorption coefficient, aerosol particle number concentration and size distribution of cloud particle residuals and ambient aerosol particles during the ACLOUD campaign in May and June 2017, Leibniz-Institut für Troposphärenforschung e.V., Leipzig, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.900403, 2019. a, b
Meyers, M. P., DeMott, P. J., and Cotton, W. R.: New Primary Ice-Nucleation Parameterizations in an Explicit Cloud Model, J. Appl. Meteorol. Clim., 31, 708–721, https://doi.org/10.1175/1520-0450(1992)031<0708:NPINPI>2.0.CO;2, 1992. a
Mioche, G., Jourdan, O., Ceccaldi, M., and Delanoë, J.: Variability of mixed-phase clouds in the Arctic with a focus on the Svalbard region: a study based on spaceborne active remote sensing, Atmos. Chem. Phys., 15, 2445–2461, https://doi.org/10.5194/acp-15-2445-2015, 2015. a
Mioche, G., Jourdan, O., Delanoë, J., Gourbeyre, C., Febvre, G., Dupuy, R., Monier, M., Szczap, F., Schwarzenboeck, A., and Gayet, J.-F.: Vertical distribution of microphysical properties of Arctic springtime low-level mixed-phase clouds over the Greenland and Norwegian seas, Atmos. Chem. Phys., 17, 12845–12869, https://doi.org/10.5194/acp-17-12845-2017, 2017. a, b, c, d, e, f, g, h, i, j
Mitchell, D. L., Zhang, R., and Pitter, R. L.: Mass-Dimensional Relationships for Ice Particles and the Influence of Riming on Snowfall Rates, J. Appl. Meteorol. Clim., 29, 153–163, https://doi.org/10.1175/1520-0450(1990)029<0153:MDRFIP>2.0.CO;2, 1990. a
Morrison, H., de Boer, G., Feingold, G., Harrington, J., Shupe, M. D., and Sulia, K.: Resilience of persistent Arctic mixed-phase clouds, Nat. Geosci., 5, 11–17, https://doi.org/10.1038/ngeo1332, 2012. a, b
Mossop, S.: Microphysical properties of supercooled cumulus clouds in which an ice particle multiplication process operated, Q. J. Roy. Meteor. Soc., 111, 183–198, 1985. a
Pasquier, J. T., Henneberger, J., Ramelli, F., Lauber, A., David, R. O., Wieder, J., Carlsen, T., Gierens, R., Maturilli, M., and Lohmann, U.: Conditions favorable for secondary ice production in Arctic mixed-phase clouds, Atmos. Chem. Phys., 22, 15579–15601, https://doi.org/10.5194/acp-22-15579-2022, 2022. a, b, c
Payne, R. E.: Albedo of the sea surface, J. Atmos. Sci., 29, 959–970, 1972. a
Phillips, V. T. J., Demott, P. J., Andronache, C., Pratt, K. A., Prather,
K. A., Subramanian, R., and Twohy, C.: Improvements to an Empirical
Parameterization of Heterogeneous Ice Nucleation and Its Comparison with
Observations, J. Atmos. Sci., 70, 378–409,
https://doi.org/10.1175/JAS-D-12-080.1, 2013. a
Previdi, M., Smith, K. L., and Polvani, L. M.: Arctic amplification of climate change: a review of underlying mechanisms, Environ. Res. Lett.,
16, 093003, https://doi.org/10.1088/1748-9326/ac1c29, 2021. a
Rangno, A. L. and Hobbs, P. V.: Ice particles in stratiform clouds in the
Arctic and possible mechanisms for the production of high ice
concentrations, J. Geophys. Res.-Atmos., 106, 15065–15075, https://doi.org/10.1029/2000JD900286, 2001. a, b, c
Rigor, I. G., Colony, R. L., and Martin, S.: Variations in surface air
temperature observations in the Arctic, 1979–97, J. Climate, 13,
896–914, 2000. a
Schnaiter, M. and Järvinen, E.: SID-3 analysis results for 2D scattering patterns during the ACLOUD campaign in 2017, Karlsruher Institut für Technologie, Institut für Meteorologie und Klimaforschung, Karlsruhe, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.900380, 2019a. a
Schnaiter, M. and Järvinen, E.: PHIPS particle-by-particle data for the
ACLOUD campaign in 2017, Karlsruher Institut für Technologie, Institut
für Meteorologie und Klimaforschung, Karlsruhe, PANGAEA [data set],
https://doi.org/10.1594/PANGAEA.902611, 2019b. a, b
Schnaiter, M., Järvinen, E., Abdelmonem, A., and Leisner, T.: PHIPS-HALO: the airborne particle habit imaging and polar scattering probe – Part 2: Characterization and first results, Atmos. Meas. Tech., 11, 341–357, https://doi.org/10.5194/amt-11-341-2018, 2018. a
Serreze, M. C., Kahl, J. D., and Schnell, R. C.: Low-level temperature
inversions of the Eurasian Arctic and comparisons with Soviet drifting
station data, J. Climate, 5, 615–629, 1992. a
Serreze, M. C., Barrett, A. P., Stroeve, J. C., Kindig, D. N., and Holland, M. M.: The emergence of surface-based Arctic amplification, The Cryosphere, 3, 11–19, https://doi.org/10.5194/tc-3-11-2009, 2009. a
Shupe, M. D. and Intrieri, J. M.: Cloud Radiative Forcing of the Arctic Surface: The Influence of Cloud Properties, Surface Albedo, and Solar Zenith
Angle, J. Climate, 17, 616–628,
https://doi.org/10.1175/1520-0442(2004)017<0616:CRFOTA>2.0.CO;2, 2004. a
Sotiropoulou, G., Sullivan, S., Savre, J., Lloyd, G., Lachlan-Cope, T., Ekman, A. M. L., and Nenes, A.: The impact of secondary ice production on Arctic stratocumulus, Atmos. Chem. Phys., 20, 1301–1316, https://doi.org/10.5194/acp-20-1301-2020, 2020. a, b
Spreen, G., Kaleschke, L., and Heygster, G.: Sea ice remote sensing using
AMSR-E 89-GHz channels, J. Geophys. Res.-Oceans, 113, C02S03,
https://doi.org/10.1029/2005JC003384, 2008. a
Stapf, J., Ehrlich, A., Jäkel, E., Lüpkes, C., and Wendisch, M.: Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions, Atmos. Chem. Phys., 20, 9895–9914, https://doi.org/10.5194/acp-20-9895-2020, 2020. a
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, c, d
Waitz, F., Schnaiter, M., Leisner, T., and Järvinen, E.: PHIPS-HALO: the airborne Particle Habit Imaging and Polar Scattering probe – Part 3: Single-particle phase discrimination and particle size distribution based on the angular-scattering function, Atmos. Meas. Tech., 14, 3049–3070, https://doi.org/10.5194/amt-14-3049-2021, 2021. a, b
Wendisch, M., Macke, A., Ehrlich, A., Lüpkes, C., Mech, M., Chechin, D., Dethloff, K., Velasco, C. B., Bozem, H., Brückner, M., Clemen, H. C., Crewell, S., Donth, T., Dupuy, R., Ebell, K., Egerer, U., Engelmann, R., Engler, C., Eppers, O., Gehrmann, M., Gong, X., Gottschalk, M., Gourbeyre, C., Griesche, H., Hartmann, J., Hartmann, M., Heinold, B., Herber, A., Herrmann, H., Heygster, G., Hoor, P., Jafariserajehlou, S., Jäkel, E., Järvinen, E., Jourdan, O., Kästner, U., Kecorius, S., Knudsen, E. M., Köllner, F., Kretzschmar, J., Lelli, L., Leroy, D., Maturilli, M., Mei, L., Mertes, S., Mioche, G., Neuber, R., Nicolaus, M., Nomokonova, T., Notholt, J., Palm, M., Van Pinxteren, M., Quaas, J., Richter, P., Ruiz-Donoso, E., Schäfer, M., Schmieder, K., Schnaiter, M., Schneider, J., Schwarzenböck, A., Seifert, P., Shupe, M. D., Siebert, H., Spreen, G., Stapf, J., Stratmann, F., Vogl, T., Welti, A., Wex, H., Wiedensohler, A., Zanatta, M., and Zeppenfeld, S.: The arctic cloud puzzle using acloud/pascal multiplatform observations to unravel the role of clouds and aerosol particles in arctic amplification, B. Am.
Meteorol. Soc., 100, 841–871, https://doi.org/10.1175/BAMS-D-18-0072.1, 2019. a, b
Xu, G., Schnaiter, M., and Järvinen, E.: Accurate Retrieval of Asymmetry Parameter for Large and Complex Ice Crystals From In‐Situ Polar
Nephelometer Measurements, J. Geophys. Res.-Atmos.,
127, 1–19, https://doi.org/10.1029/2021jd036071, 2022. a, b
Zhao, X., Liu, X., Phillips, V. T. J., and Patade, S.: Impacts of secondary ice production on Arctic mixed-phase clouds based on ARM observations and CAM6 single-column model simulations, Atmos. Chem. Phys., 21, 5685–5703, https://doi.org/10.5194/acp-21-5685-2021, 2021. a, b
Short summary
The Arctic is warming faster than other regions. Arctic low-level mixed-phase clouds, where ice crystals and liquid droplets co-exist, are thought to have an important role in Arctic warming. Here we show airborne measurements of vertical distribution of liquid and ice particles and their relative abundance. Ice particles are found in relative warm clouds, which can be explained by multiplication of existing ice crystals. However, the role of ice particles in redistributing sun light is minimal.
The Arctic is warming faster than other regions. Arctic low-level mixed-phase clouds, where ice...
Altmetrics
Final-revised paper
Preprint