Atmospheric Chemistry and Physics
Atmospheric Chemistry and Physics
ACP
HALO-(AC)3 – an airborne campaign to study air mass transformations during warm-air intrusions and cold-air outbreaks (ACP/AMT inter-journal SI)(ACP/AMT inter-journal SI)
Special issues
Special issues
HALO-(AC)3 – an airborne campaign to study air mass transformations during warm-air intrusions and cold-air outbreaks (ACP/AMT inter-journal SI)(ACP/AMT inter-journal SI)
Editor(s): ACP co-editors | Coordinators: Martina Krämer and Paul Zieger | Co-organizers: Manfred Wendisch and Susanne Crewell Special issue jointly organized between Atmospheric Chemistry and Physics and Atmospheric Measurement Techniques

The purpose of the Special Issue is to publish main results from the airborne field campaign HALO-(AC)3 studying warm-air intrusions and cold-air outbreaks and corresponding air mass transformations. HALO-(AC)3 took place in the area around Svalbard in March and April 2022. The campaign is embedded into a Transregional Collaborative Research Centre ( http://www.ac3-tr.de/) that investigates causes and consequences of the currently ongoing dramatic climate changes in the Arctic.

Review process: all papers of this special issue underwent the regular interactive peer-review process of Atmospheric Chemistry and Physics handled by members of the ACP editorial board.

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13 Aug 2024
| Overview paper
Overview: quasi-Lagrangian observations of Arctic air mass transformations – introduction and initial results of the HALO–(𝒜 𝒞)3 aircraft campaign
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
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27 Oct 2025
Parameterization of 3D cloud geometry and a neural-network-based fast forward operator for polarized radiative transfer
Anna Weber, Gregor Köcher, and Bernhard Mayer
Atmos. Meas. Tech., 18, 5805–5821, https://doi.org/10.5194/amt-18-5805-2025,https://doi.org/10.5194/amt-18-5805-2025, 2025
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21 Oct 2025
Lagrangian single-column modeling of Arctic air mass transformation during HALO-(𝒜 𝒞)3
Michail Karalis, Gunilla Svensson, Manfred Wendisch, and Michael Tjernström
Atmos. Chem. Phys., 25, 13177–13198, https://doi.org/10.5194/acp-25-13177-2025,https://doi.org/10.5194/acp-25-13177-2025, 2025
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25 Sep 2025
Retrieval of cloud thermodynamic phase partitioning from multi-angle polarimetric imaging of Arctic mixed-phase clouds
Anna Weber, Veronika Pörtge, Claudia Emde, and Bernhard Mayer
EGUsphere, https://doi.org/10.5194/egusphere-2025-3595,https://doi.org/10.5194/egusphere-2025-3595, 2025
Preprint under review for AMT (discussion: open, 2 comments)
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24 Sep 2025
High-resolution maps of Arctic surface skin temperature and type retrieved from airborne thermal infrared imagery collected during the HALO–(𝒜 𝒞)3 campaign
Joshua J. Müller, Michael Schäfer, Sophie Rosenburg, André Ehrlich, and Manfred Wendisch
Atmos. Meas. Tech., 18, 4695–4708, https://doi.org/10.5194/amt-18-4695-2025,https://doi.org/10.5194/amt-18-4695-2025, 2025
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11 Sep 2025
Cloud liquid water path detectability and retrieval accuracy from airborne passive microwave observations over Arctic sea ice
Nils Risse, Mario Mech, Catherine Prigent, Joshua Jeremias Müller, and Susanne Crewell
EGUsphere, https://doi.org/10.5194/egusphere-2025-3311,https://doi.org/10.5194/egusphere-2025-3311, 2025
Preprint under review for AMT (discussion: final response, 5 comments)
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04 Sep 2025
Airborne observations of cloud properties during their evolution from organized streets to isotropic cloud structures along an Arctic cold-air outbreak
Marcus Klingebiel, André Ehrlich, Micha Gryschka, Nils Risse, Nina Maherndl, Imke Schirmacher, Sophie Rosenburg, Sabine Hörnig, Manuel Moser, Evelyn Jäkel, Michael Schäfer, Hartwig Deneke, Mario Mech, Christiane Voigt, and Manfred Wendisch
Atmos. Chem. Phys., 25, 9787–9801, https://doi.org/10.5194/acp-25-9787-2025,https://doi.org/10.5194/acp-25-9787-2025, 2025
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19 Aug 2025
The Arctic Low-Level Mixed-Phase Haze Regime and its Microphysical Differences to Mixed-Phase Clouds
Manuel Moser, Christiane Voigt, Oliver Eppers, Johannes Lucke, Elena De La Torre Castro, Johanna Mayer, Regis Dupuy, Guillaume Mioche, Olivier Jourdan, Hans-Christian Clemen, Johannes Schneider, Philipp Joppe, Stephan Mertes, Bruno Wetzel, Stephan Borrmann, Marcus Klingebiel, Mario Mech, Christof Lüpkes, Susanne Crewell, André Ehrlich, Andreas Herber, and Manfred Wendisch
EGUsphere, https://doi.org/10.5194/egusphere-2025-3876,https://doi.org/10.5194/egusphere-2025-3876, 2025
Preprint under review for ACP (discussion: final response, 3 comments)
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31 Jul 2025
Moisture budget estimates derived from airborne observations in an Arctic atmospheric river during its dissipation
Henning Dorff, Florian Ewald, Heike Konow, Mario Mech, Davide Ori, Vera Schemann, Andreas Walbröl, Manfred Wendisch, and Felix Ament
Atmos. Chem. Phys., 25, 8329–8354, https://doi.org/10.5194/acp-25-8329-2025,https://doi.org/10.5194/acp-25-8329-2025, 2025
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20 May 2025
Observed and modeled Arctic airmass transformations during warm air intrusions and cold air outbreaks
Manfred Wendisch, Benjamin Kirbus, Davide Ori, Matthew D. Shupe, Susanne Crewell, Harald Sodemann, and Vera Schemann
EGUsphere, https://doi.org/10.5194/egusphere-2025-2062,https://doi.org/10.5194/egusphere-2025-2062, 2025
Revised manuscript accepted for ACP (discussion: final response, 4 comments)
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16 Dec 2024
How does riming influence the observed spatial variability of ice water in mixed-phase clouds?
Nina Maherndl, Manuel Moser, Imke Schirmacher, Aaron Bansemer, Johannes Lucke, Christiane Voigt, and Maximilian Maahn
Atmos. Chem. Phys., 24, 13935–13960, https://doi.org/10.5194/acp-24-13935-2024,https://doi.org/10.5194/acp-24-13935-2024, 2024
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19 Nov 2024
Clouds and precipitation in the initial phase of marine cold-air outbreaks as observed by airborne remote sensing
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
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17 Jul 2024
Evaluating the representation of Arctic cirrus solar radiative effects in the Integrated Forecasting System with airborne measurements
Johannes Röttenbacher, André Ehrlich, Hanno Müller, Florian Ewald, Anna E. Luebke, Benjamin Kirbus, Robin J. Hogan, and Manfred Wendisch
Atmos. Chem. Phys., 24, 8085–8104, https://doi.org/10.5194/acp-24-8085-2024,https://doi.org/10.5194/acp-24-8085-2024, 2024
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15 Jul 2024
Contrasting extremely warm and long-lasting cold air anomalies in the North Atlantic sector of the Arctic during the HALO-(𝒜 𝒞)3 campaign
Andreas Walbröl, Janosch Michaelis, Sebastian Becker, Henning Dorff, Kerstin Ebell, Irina Gorodetskaya, Bernd Heinold, Benjamin Kirbus, Melanie Lauer, Nina Maherndl, Marion Maturilli, Johanna Mayer, Hanno Müller, Roel A. J. Neggers, Fiona M. Paulus, Johannes Röttenbacher, Janna E. Rückert, Imke Schirmacher, Nils Slättberg, André Ehrlich, Manfred Wendisch, and Susanne Crewell
Atmos. Chem. Phys., 24, 8007–8029, https://doi.org/10.5194/acp-24-8007-2024,https://doi.org/10.5194/acp-24-8007-2024, 2024
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24 May 2024
The effects of warm-air intrusions in the high Arctic on cirrus clouds
Georgios Dekoutsidis, Martin Wirth, and Silke Groß
Atmos. Chem. Phys., 24, 5971–5987, https://doi.org/10.5194/acp-24-5971-2024,https://doi.org/10.5194/acp-24-5971-2024, 2024
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02 Apr 2024
Thermodynamic and cloud evolution in a cold-air outbreak during HALO-(AC)3: quasi-Lagrangian observations compared to the ERA5 and CARRA reanalyses
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
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14 Feb 2024
Tethered balloon-borne observations of thermal-infrared irradiance and cooling rate profiles in the Arctic atmospheric boundary layer
Michael Lonardi, Elisa F. Akansu, André Ehrlich, Mauro Mazzola, Christian Pilz, Matthew D. Shupe, Holger Siebert, and Manfred Wendisch
Atmos. Chem. Phys., 24, 1961–1978, https://doi.org/10.5194/acp-24-1961-2024,https://doi.org/10.5194/acp-24-1961-2024, 2024
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11 Sep 2023
Assessing Arctic low-level clouds and precipitation from above – a radar perspective
Imke Schirmacher, Pavlos Kollias, Katia Lamer, Mario Mech, Lukas Pfitzenmaier, Manfred Wendisch, and Susanne Crewell
Atmos. Meas. Tech., 16, 4081–4100, https://doi.org/10.5194/amt-16-4081-2023,https://doi.org/10.5194/amt-16-4081-2023, 2023
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11 Mar 2024
Quantifying riming from airborne data during the HALO-(AC)3 campaign
Nina Maherndl, Manuel Moser, Johannes Lucke, Mario Mech, Nils Risse, Imke Schirmacher, and Maximilian Maahn
Atmos. Meas. Tech., 17, 1475–1495, https://doi.org/10.5194/amt-17-1475-2024,https://doi.org/10.5194/amt-17-1475-2024, 2024
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