Articles | Volume 21, issue 7
https://doi.org/10.5194/acp-21-5477-2021
© Author(s) 2021. 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-21-5477-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Apr 2021
Research article |
| 08 Apr 2021
| 08 Apr 2021
Lagrangian matches between observations from aircraft, lidar and radar in a warm conveyor belt crossing orography
Maxi Boettcher
CORRESPONDING AUTHOR
Institute for Atmospheric and Climate Science, ETH Zurich, Zürich, Switzerland
Andreas Schäfler
Institute of Atmospheric Physics, German Aerospace Center, Oberpfaffenhofen, Germany
Michael Sprenger
Institute for Atmospheric and Climate Science, ETH Zurich, Zürich, Switzerland
Harald Sodemann
Geophysical Institute, University of Bergen, and Bjerknes Centre for Climate Research, Bergen, Norway
Stefan Kaufmann
Institute of Atmospheric Physics, German Aerospace Center, Oberpfaffenhofen, Germany
Christiane Voigt
Institute of Atmospheric Physics, German Aerospace Center, Oberpfaffenhofen, Germany
Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
Hans Schlager
Institute of Atmospheric Physics, German Aerospace Center, Oberpfaffenhofen, Germany
Donato Summa
Consiglio Nazionale delle Ricerche, Istituto di Metodologie per l'Analisi Ambientale (CNR-IMAA), Tito, Italy
Scuola di Ingegneria, Universita degli Studi della Basilicata, Potenza, Italy
Paolo Di Girolamo
Scuola di Ingegneria, Universita degli Studi della Basilicata, Potenza, Italy
Daniele Nerini
Federal Office of Meteorology and Climatology MeteoSwiss, Locarno-Monti, Switzerland
Urs Germann
Federal Office of Meteorology and Climatology MeteoSwiss, Locarno-Monti, Switzerland
Heini Wernli
Institute for Atmospheric and Climate Science, ETH Zurich, Zürich, Switzerland
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Martin Lainer, Killian P. Brennan, Alessandro Hering, Jérôme Kopp, Samuel Monhart, Daniel Wolfensberger, and Urs Germann
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Rebecca Katharina Dischl, Daniel Sauer, Christiane Voigt, Theresa Harlaß, Felicitas Sakellariou, Raphael Satoru Märkl, Ulrich Schumann, Monika Scheibe, Stefan Kaufmann, Anke Roiger, Andreas Dörnbrack, Charles Renard, Maxime Gauthier, Peter Swann, Paul Madden, Darren Luff, Mark Johnson, Denise Ahrens, Reetu Sallinen, Tobias Schripp, Georg Eckel, Uwe Bauder, and Patrick Le Clercq
EGUsphere, https://doi.org/10.5194/egusphere-2024-1224, https://doi.org/10.5194/egusphere-2024-1224, 2024
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Katharina Heitmann, Michael Sprenger, Hanin Binder, Heini Wernli, and Hanna Joos
Weather Clim. Dynam., 5, 537–557, https://doi.org/10.5194/wcd-5-537-2024, https://doi.org/10.5194/wcd-5-537-2024, 2024
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Warm conveyor belts (WCBs) are coherently ascending air streams that occur in extratropical cyclones where they form precipitation and often affect the large-scale flow. We quantified the key characteristics and impacts of WCBs and linked them to different phases in the cyclone life cycle and to different WCB branches. A climatology of these metrics revealed that WCBs are most intense during cyclone intensification and that the cyclonic and anticyclonic WCB branches show distinct differences.
Cassidy Soloff, Taiwo Ajayi, Yonghoon Choi, Ewan C. Crosbie, Joshua P. DiGangi, Glenn S. Diskin, Marta A. Fenn, Richard A. Ferrare, Francesca Gallo, Johnathan W. Hair, Miguel Ricardo A. Hilario, Simon Kirschler, Richard H. Moore, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Christiane Voigt, Edward L. Winstead, Luke D. Ziemba, and Armin Sorooshian
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Using aircraft measurements over the northwest Atlantic between the U.S. East Coast and Bermuda and trajectory modeling of continental outflow, we identify trace gas and particle properties that exhibit gradients with offshore distance and quantify these changes with high resolution measurements of concentrations as well as particle chemistry, size, and scattering properties. This work furthers our understanding of the complex interactions between continental and marine environments.
Konstantin Krüger, Andreas Schäfler, Martin Weissmann, and George C. Craig
Weather Clim. Dynam., 5, 491–509, https://doi.org/10.5194/wcd-5-491-2024, https://doi.org/10.5194/wcd-5-491-2024, 2024
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Initial conditions of current numerical weather prediction models insufficiently represent the sharp vertical gradients across the midlatitude tropopause. Observation-space data assimilation output is used to study the influence of assimilated radiosondes on the tropopause. The radiosondes reduce systematic biases of the model background and sharpen temperature and wind gradients in the analysis. Tropopause sharpness is still underestimated in the analysis, which may impact weather forecasts.
Katharina Hartmuth, Heini Wernli, and Lukas Papritz
EGUsphere, https://doi.org/10.5194/egusphere-2024-878, https://doi.org/10.5194/egusphere-2024-878, 2024
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
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In this study, we use large-ensemble climate model simulations to analyze extreme winters in the Barents Sea in a changing climate. We find that variability in both atmospheric processes and sea ice conditions determines the formation of such seasons in the present-day climate. The reduction in sea ice variability results in a decreasing importance of surface boundary conditions in a warmer climate, while the robust link shown for surface weather systems persists.
Lukas Jansing, Lukas Papritz, and Michael Sprenger
Weather Clim. Dynam., 5, 463–489, https://doi.org/10.5194/wcd-5-463-2024, https://doi.org/10.5194/wcd-5-463-2024, 2024
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Using an innovative approach, the descent of foehn is diagnosed from a Lagrangian perspective based on 15 kilometer-scale simulations combined with online trajectories. The descent is confined to distinct hotspots in the immediate lee of local mountain peaks and chains. Two detailed case studies reveal a varying wave regime to be associated with the descent. Furthermore, additional controlling factors, such as the diurnal cycle, likewise influence the descent activity.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 5, 419–438, https://doi.org/10.5194/wcd-5-419-2024, https://doi.org/10.5194/wcd-5-419-2024, 2024
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We show that the formation of Mediterranean cyclones follows the presence of cyclones over the North Atlantic. The distinct regions of cyclone activity in the Mediterranean in the different seasons can be linked to the atmospheric state, in particular the position of the polar jet over the North Atlantic. With this we now better understand the processes that lead to the formation of Mediterranean cyclones. We used a novel simulation framework in which we directly show and probe this connection.
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
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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.
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 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 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 Schäfer, Vera Schemannn, 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
EGUsphere, https://doi.org/10.5194/egusphere-2024-783, https://doi.org/10.5194/egusphere-2024-783, 2024
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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 the mid-latitude weather. In our article we describe how to observe air mass transformations during CAOs and WAIs using three research aircraft instrumented wit state-of-the-art remote sensing and in-situ measurement devices.
Jérôme Kopp, Alessandro Hering, Urs Germann, and Olivia Martius
EGUsphere, https://doi.org/10.5194/egusphere-2024-729, https://doi.org/10.5194/egusphere-2024-729, 2024
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We present a verification of two products based on weather radars to detect the presence of hail and estimate its size. Radar products are remote detection of hail, so they must be verified with ground-based observations. We use reports from users of the Swiss Weather Services phone app to do the verification. We found that the product estimating the presence of hail provides fair results but that it should be recalibrated, and that estimating the hail size with radar is more challenging.
José Alex Zenteno-Hernández, Adolfo Comerón, Federico Dios, Alejandro Rodríguez-Gómez, Constantino Muñoz-Porcar, Michaël Sicard, Noemi Franco, Andreas Behrendt, and Paolo Di Girolamo
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-32, https://doi.org/10.5194/amt-2024-32, 2024
Revised manuscript accepted for AMT
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We study how the spectral characteristics of a solid-state laser in an atmospheric temperature profiling lidar using the Raman technique impact the temperature retrieval accuracy. We find that the spectral widening, with respect to a seeded laser, has virtually no impact, while crystal-rod temperature variations in the laser must be kept within 1 K for the uncertainty in the atmospheric temperature be kept below 1 K. The study is carried out through spectroscopy simulations.
Adrien Deroubaix, Marco Vountas, Benjamin Gaubert, Maria Dolores Andrés Hernández, Stephan Borrmann, Guy Brasseur, Bruna Holanda, Yugo Kanaya, Katharina Kaiser, Flora Kluge, Ovid Oktavian Krüger, Inga Labuhn, Michael Lichtenstern, Klaus Pfeilsticker, Mira Pöhlker, Hans Schlager, Johannes Schneider, Guillaume Siour, Basudev Swain, Paolo Tuccella, Kameswara S. Vinjamuri, Mihalis Vrekoussis, Benjamin Weyland, and John P. Burrows
EGUsphere, https://doi.org/10.5194/egusphere-2024-516, https://doi.org/10.5194/egusphere-2024-516, 2024
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This study assesses atmospheric composition using air quality models during aircraft campaigns in Europe and Asia, focusing on carbonaceous aerosols and trace gases. While carbon monoxide is well modeled, other pollutants have moderate to weak agreement with observations. Wind speed modeling is reliable for identifying pollution plumes, where models tend to overestimate concentrations. This highlights challenges in accurately modeling aerosol and trace gas composition, particularly in cities.
Alfonso Ferrone, Jérôme Kopp, Martin Lainer, Marco Gabella, Urs Germann, and Alexis Berne
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-2, https://doi.org/10.5194/amt-2024-2, 2024
Preprint under review for AMT
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Estimates of hail size have been collected by a network of hail sensors, installed in three regions of Switzerland, since September 2018. In this study, we use a technique called “double moment normalization” to model the distribution of diameter sizes. The parameters of the method have been defined over 70 % of the dataset, and testes over the remaining 30 %. An independent distribution of hail sizes, collected by a drone, has also been used to evaluate the method.
Adrien Deroubaix, Marco Vountas, Benjamin Gaubert, Maria Dolores Andrés Hernández, Stephan Borrmann, Guy Brasseur, Bruna Holanda, Yugo Kanaya, Katharina Kaiser, Flora Kluge, Ovid Oktavian Krüger, Inga Labuhn, Michael Lichtenstern, Klaus Pfeilsticker, Mira Pöhlker, Hans Schlager, Johannes Schneider, Guillaume Siour, Basudev Swain, Paolo Tuccella, Kameswara S. Vinjamuri, Mihalis Vrekoussis, Benjamin Weyland, and John P. Burrows
EGUsphere, https://doi.org/10.5194/egusphere-2024-521, https://doi.org/10.5194/egusphere-2024-521, 2024
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This study explores the proportional relationships between carbonaceous aerosols (black and organic carbon) and trace gases using airborne measurements from two campaigns in Europe and East Asia. Differences between regions were found, but air quality models struggled to reproduce them accurately. We show that these proportional relationships can help to constrain models and can be used to infer aerosol concentrations from satellite observations of trace gases, especially in urban areas.
Theresa Harlass, Rebecca Dischl, Stefan Kaufmann, Raphael Märkl, Daniel Sauer, Monika Scheibe, Paul Stock, Tiziana Bräuer, Andreas Dörnbrack, Anke Roiger, Hans Schlager, Ulrich Schumann, Tobias Schripp, Tobias Grein, Linda Bondorf, Charles Renard, Maxime Gauthier, Mark Johnson, Darren Luff, Paul Madden, Peter Swann, Denise Ahrens, Reetu Sallinen, and Christiane Voigt
EGUsphere, https://doi.org/10.5194/egusphere-2024-454, https://doi.org/10.5194/egusphere-2024-454, 2024
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Emissions from aircraft have a direct impact on our climate. Here, we present airborne and ground based measurement data of nitrogen oxides which were collected in the exhaust of an Airbus aircraft. We study the impact of burning fossil and sustainable aviation fuel on nitrogen oxide emissions at different engine settings related to combustor temperature, pressure and fuel flow. Further, we compare observations with engine emission models.
Robert Hanfland, Dominik Brunner, Christiane Voigt, Alina Fiehn, Anke Roiger, and Margit Pattantyús-Ábrahám
Atmos. Chem. Phys., 24, 2511–2534, https://doi.org/10.5194/acp-24-2511-2024, https://doi.org/10.5194/acp-24-2511-2024, 2024
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To show that the three-dimensional dispersion of plumes simulated by the Atmospheric Radionuclide Transport Model within the planetary boundary layer agrees with real plumes, we identify the most important input parameters and analyse the turbulence properties of five different turbulence models in very unstable stratification conditions using their deviation from the well-mixed state. Simulations show that one model agrees slightly better in unstable stratification conditions.
Esther S. Breuninger, Julie Tolu, Iris Thurnherr, Franziska Aemisegger, Aryeh Feinberg, Sylvain Bouchet, Jeroen E. Sonke, Véronique Pont, Heini Wernli, and Lenny H. E. Winkel
Atmos. Chem. Phys., 24, 2491–2510, https://doi.org/10.5194/acp-24-2491-2024, https://doi.org/10.5194/acp-24-2491-2024, 2024
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Atmospheric deposition is an important source of selenium (Se) and other health-relevant trace elements in surface environments. We found that the variability in elemental concentrations in atmospheric deposition reflects not only changes in emission sources but also weather conditions during atmospheric removal. Depending on the sources and if Se is derived more locally or from further away, the Se forms can be different, affecting the bioavailability of Se atmospherically supplied to soils.
Johanna Mayer, Bernhard Mayer, Luca Bugliaro, Ralf Meerkötter, and Christiane Voigt
EGUsphere, https://doi.org/10.5194/egusphere-2024-540, https://doi.org/10.5194/egusphere-2024-540, 2024
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This study uses radiative transfer calculations to characterize the relation of two satellite channel combinations (namely infrared window brightness temperature differences (BTDs) of the SEVIRI imager) to the thermodynamic cloud phase. A sensitivity analysis reveals the complex interplay of cloud parameters and their contribution to the observed phase dependence of BTDs. This knowledge helps to design optimal cloud phase retrievals and to understand their potential and limitations.
Hilla Afargan-Gerstman, Dominik Büeler, C. Ole Wulff, Michael Sprenger, and Daniela I. V. Domeisen
Weather Clim. Dynam., 5, 231–249, https://doi.org/10.5194/wcd-5-231-2024, https://doi.org/10.5194/wcd-5-231-2024, 2024
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The stratosphere is a layer of Earth's atmosphere found above the weather systems. Changes in the stratosphere can affect the winds and the storm tracks in the North Atlantic region for a relatively long time, lasting for several weeks and even months. We show that the stratosphere can be important for weather forecasts beyond 1 week, but more work is needed to improve the accuracy of these forecasts for 3–4 weeks.
Yonatan Givon, Or Hess, Emmanouil Flaounas, Jennifer Louise Catto, Michael Sprenger, and Shira Raveh-Rubin
Weather Clim. Dynam., 5, 133–162, https://doi.org/10.5194/wcd-5-133-2024, https://doi.org/10.5194/wcd-5-133-2024, 2024
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A novel classification of Mediterranean cyclones is presented, enabling a separation between storms driven by different atmospheric processes. The surface impact of each cyclone class differs greatly by precipitation, winds, and temperatures, providing an invaluable tool to study the climatology of different types of Mediterranean storms and enhancing the understanding of their predictability, on both weather and climate scales.
Julian F. Quinting, Christian M. Grams, Edmund Kar-Man Chang, Stephan Pfahl, and Heini Wernli
Weather Clim. Dynam., 5, 65–85, https://doi.org/10.5194/wcd-5-65-2024, https://doi.org/10.5194/wcd-5-65-2024, 2024
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Research in the last few decades has revealed that rapidly ascending airstreams in extratropical cyclones have an important effect on the evolution of downstream weather and predictability. In this study, we show that the occurrence of these airstreams over the North Pacific is modulated by tropical convection. Depending on the modulation, known atmospheric circulation patterns evolve quite differently, which may affect extended-range predictions in the Atlantic–European region.
Shuaiqi Tang, Hailong Wang, Xiang-Yu Li, Jingyi Chen, Armin Sorooshian, Xubin Zeng, Ewan Crosbie, Kenneth L. Thornhill, Luke D. Ziemba, and Christiane Voigt
EGUsphere, https://doi.org/10.5194/egusphere-2023-3149, https://doi.org/10.5194/egusphere-2023-3149, 2024
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We examined marine boundary-layer clouds and their interactions with aerosols in the E3SM single-column model (SCM) for a case study. The SCM shows good agreement in simulating the clouds with high-resolution models. It reproduces the relationship between cloud droplet and aerosol particle number concentrations as produced in global models. However, the relationship between cloud liquid water and droplet number concentration are different, which warrants further investigation.
Stefania Gilardoni, Dominic Heslin-Rees, Mauro Mazzola, Vito Vitale, Michael Sprenger, and Radovan Krejci
Atmos. Chem. Phys., 23, 15589–15607, https://doi.org/10.5194/acp-23-15589-2023, https://doi.org/10.5194/acp-23-15589-2023, 2023
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Models still fail in reproducing black carbon (BC) temporal variability in the Arctic. Analysis of equivalent BC concentrations in the European Arctic shows that BC seasonal variability is modulated by the efficiency of removal by precipitation during transport towards high latitudes. Short-term variability is controlled by synoptic-scale circulation patterns. The advection of warm air from lower latitudes is an effective pollution transport pathway during summer.
Marcus Klingebiel, André Ehrlich, Elena Ruiz-Donoso, Nils Risse, Imke Schirmacher, Evelyn Jäkel, Michael Schäfer, Kevin Wolf, Mario Mech, Manuel Moser, Christiane Voigt, and Manfred Wendisch
Atmos. Chem. Phys., 23, 15289–15304, https://doi.org/10.5194/acp-23-15289-2023, https://doi.org/10.5194/acp-23-15289-2023, 2023
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In this study we explain how we use aircraft measurements from two Arctic research campaigns to identify cloud properties (like droplet size) over sea-ice and ice-free ocean. To make sure that our measurements make sense, we compare them with other observations. Our results show, e.g., larger cloud droplets in early summer than in spring. Moreover, the cloud droplets are also larger over ice-free ocean than compared to sea ice. In the future, our data can be used to improve climate models.
Leonie Villiger, Marina Dütsch, Sandrine Bony, Marie Lothon, Stephan Pfahl, Heini Wernli, Pierre-Etienne Brilouet, Patrick Chazette, Pierre Coutris, Julien Delanoë, Cyrille Flamant, Alfons Schwarzenboeck, Martin Werner, and Franziska Aemisegger
Atmos. Chem. Phys., 23, 14643–14672, https://doi.org/10.5194/acp-23-14643-2023, https://doi.org/10.5194/acp-23-14643-2023, 2023
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This study evaluates three numerical simulations performed with an isotope-enabled weather forecast model and investigates the coupling between shallow trade-wind cumulus clouds and atmospheric circulations on different scales. We show that the simulations reproduce key characteristics of shallow trade-wind clouds as observed during the field experiment EUREC4A and that the spatial distribution of stable-water-vapour isotopes is shaped by the overturning circulation associated with these clouds.
Heini Wernli and Suzanne L. Gray
EGUsphere, https://doi.org/10.5194/egusphere-2023-2678, https://doi.org/10.5194/egusphere-2023-2678, 2023
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This review provides a historic overview of research on how diabatic processes influence extratropical weather systems. We highlight that the combination of complementary research approaches – field experiments, diagnostics, numerical model experiments, potential vorticity theory, and consideration of climate change – was essential for reaching a new level of understanding where the interplay of dry dynamics with diabatic processes is considered as central to the field.
Harald Sodemann, Alena Dekhtyareva, Alvaro Fernandez, Andrew Seidl, and Jenny Maccali
Atmos. Meas. Tech., 16, 5181–5203, https://doi.org/10.5194/amt-16-5181-2023, https://doi.org/10.5194/amt-16-5181-2023, 2023
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We describe a device that allows one to produce a continuous stream of water vapour with a specified level of humidity. As a main innovation, we can mix waters with different water isotope composition. Through a series of tests we show that the performance characteristics of the device are in line with specifications. We present two laboratory applications where the device proves useful, first in characterizing instruments, and second for the analysis of water contained in stalagmites.
Thomas Trickl, Martin Adelwart, Dina Khordakova, Ludwig Ries, Christian Rolf, Michael Sprenger, Wolfgang Steinbrecht, and Hannes Vogelmann
Atmos. Meas. Tech., 16, 5145–5165, https://doi.org/10.5194/amt-16-5145-2023, https://doi.org/10.5194/amt-16-5145-2023, 2023
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Tropospheric ozone have been measured for more than a century. Highly quantitative ozone measurements have been made at monitoring stations. However, deficits have been reported for vertical sounding systems. Here, we report a thorough intercomparison effort between a differential-absorption lidar system and two types of balloon-borne ozone sondes, also using ozone sensors at nearby mountain sites as references. The sondes agree very well with the lidar after offset corrections.
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
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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.
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
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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.
Melanie Lauer, Annette Rinke, Irina Gorodetskaya, Michael Sprenger, Mario Mech, and Susanne Crewell
Atmos. Chem. Phys., 23, 8705–8726, https://doi.org/10.5194/acp-23-8705-2023, https://doi.org/10.5194/acp-23-8705-2023, 2023
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We present a new method to analyse the influence of atmospheric rivers (ARs), cyclones, and fronts on the precipitation in the Arctic, based on two campaigns: ACLOUD (early summer 2017) and AFLUX (early spring 2019). There are differences between both campaign periods: in early summer, the precipitation is mostly related to ARs and fronts, especially when they are co-located, while in early spring, cyclones isolated from ARs and fronts contributed most to the precipitation.
Armin Sorooshian, Mikhail D. Alexandrov, Adam D. Bell, Ryan Bennett, Grace Betito, Sharon P. Burton, Megan E. Buzanowicz, Brian Cairns, Eduard V. Chemyakin, Gao Chen, Yonghoon Choi, Brian L. Collister, Anthony L. Cook, Andrea F. Corral, Ewan C. Crosbie, Bastiaan van Diedenhoven, Joshua P. DiGangi, Glenn S. Diskin, Sanja Dmitrovic, Eva-Lou Edwards, Marta A. Fenn, Richard A. Ferrare, David van Gilst, Johnathan W. Hair, David B. Harper, Miguel Ricardo A. Hilario, Chris A. Hostetler, Nathan Jester, Michael Jones, Simon Kirschler, Mary M. Kleb, John M. Kusterer, Sean Leavor, Joseph W. Lee, Hongyu Liu, Kayla McCauley, Richard H. Moore, Joseph Nied, Anthony Notari, John B. Nowak, David Painemal, Kasey E. Phillips, Claire E. Robinson, Amy Jo Scarino, Joseph S. Schlosser, Shane T. Seaman, Chellappan Seethala, Taylor J. Shingler, Michael A. Shook, Kenneth A. Sinclair, William L. Smith Jr., Douglas A. Spangenberg, Snorre A. Stamnes, Kenneth L. Thornhill, Christiane Voigt, Holger Vömel, Andrzej P. Wasilewski, Hailong Wang, Edward L. Winstead, Kira Zeider, Xubin Zeng, Bo Zhang, Luke D. Ziemba, and Paquita Zuidema
Earth Syst. Sci. Data, 15, 3419–3472, https://doi.org/10.5194/essd-15-3419-2023, https://doi.org/10.5194/essd-15-3419-2023, 2023
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The NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) produced a unique dataset for research into aerosol–cloud–meteorology interactions. HU-25 Falcon and King Air aircraft conducted systematic and spatially coordinated flights over the northwest Atlantic Ocean. This paper describes the ACTIVATE flight strategy, instrument and complementary dataset products, data access and usage details, and data application notes.
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
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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
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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.
Emmanouil Flaounas, Leonardo Aragão, Lisa Bernini, Stavros Dafis, Benjamin Doiteau, Helena Flocas, Suzanne L. Gray, Alexia Karwat, John Kouroutzoglou, Piero Lionello, Mario Marcello Miglietta, Florian Pantillon, Claudia Pasquero, Platon Patlakas, María Ángeles Picornell, Federico Porcù, Matthew D. K. Priestley, Marco Reale, Malcolm J. Roberts, Hadas Saaroni, Dor Sandler, Enrico Scoccimarro, Michael Sprenger, and Baruch Ziv
Weather Clim. Dynam., 4, 639–661, https://doi.org/10.5194/wcd-4-639-2023, https://doi.org/10.5194/wcd-4-639-2023, 2023
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Cyclone detection and tracking methods (CDTMs) have different approaches in defining and tracking cyclone centers. This leads to disagreements on extratropical cyclone climatologies. We present a new approach that combines tracks from individual CDTMs to produce new composite tracks. These new tracks are shown to correspond to physically meaningful systems with distinctive life stages.
Jérôme Kopp, Agostino Manzato, Alessandro Hering, Urs Germann, and Olivia Martius
Atmos. Meas. Tech., 16, 3487–3503, https://doi.org/10.5194/amt-16-3487-2023, https://doi.org/10.5194/amt-16-3487-2023, 2023
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We present the first study of extended field observations made by a network of 80 automatic hail sensors from Switzerland. The sensors record the exact timing of hailstone impacts, providing valuable information about the local duration of hailfall. We found that the majority of hailfalls lasts just a few minutes and that most hailstones, including the largest, fall during a first phase of high hailstone density, while a few remaining and smaller hailstones fall in a second low-density phase.
Midhun George, Maria Dolores Andrés Hernández, Vladyslav Nenakhov, Yangzhuoran Liu, John Philip Burrows, Birger Bohn, Eric Förster, Florian Obersteiner, Andreas Zahn, Theresa Harlaß, Helmut Ziereis, Hans Schlager, Benjamin Schreiner, Flora Kluge, Katja Bigge, and Klaus Pfeilsticker
Atmos. Chem. Phys., 23, 7799–7822, https://doi.org/10.5194/acp-23-7799-2023, https://doi.org/10.5194/acp-23-7799-2023, 2023
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The applicability of photostationary steady-state (PSS) assumptions to estimate the amount of the sum of peroxy radicals (RO2*) during the EMeRGe airborne observations from the known radical chemistry and onboard measurements of RO2* precursors, photolysis frequencies, and other trace gases such as NOx and O3 was investigated. The comparison of the calculated RO2* with the actual measurements provides an insight into the main processes controlling their concentration in the air masses measured.
Mark J. Rodwell and Heini Wernli
Weather Clim. Dynam., 4, 591–615, https://doi.org/10.5194/wcd-4-591-2023, https://doi.org/10.5194/wcd-4-591-2023, 2023
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Midlatitude storms and their downstream impacts have a major impact on society, yet their prediction is especially prone to uncertainty. While this can never be fully eliminated, we find that the initial rate of growth of uncertainty varies for a range of forecast models. Examination of the model of the European Centre for Medium-Range Weather Forecasts (ECMWF) suggests ways in which uncertainty growth could be reduced, leading to sharper and more reliable forecasts over the first few days.
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
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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.
Astrid Fremme, Paul J. Hezel, Øyvind Seland, and Harald Sodemann
Weather Clim. Dynam., 4, 449–470, https://doi.org/10.5194/wcd-4-449-2023, https://doi.org/10.5194/wcd-4-449-2023, 2023
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We study the atmospheric moisture transport into eastern China for past, present, and future climate. Hence, we use different climate and weather prediction model data with a moisture source identification method. We find that while the moisture to first order originates mostly from similar regions, smaller changes consistently point to differences in the recycling of precipitation over land between different climates. Some differences are larger between models than between different climates.
Mauro Hermann, Matthias Röthlisberger, Arthur Gessler, Andreas Rigling, Cornelius Senf, Thomas Wohlgemuth, and Heini Wernli
Biogeosciences, 20, 1155–1180, https://doi.org/10.5194/bg-20-1155-2023, https://doi.org/10.5194/bg-20-1155-2023, 2023
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This study examines the multi-annual meteorological history of low-forest-greenness events in Europe's temperate and Mediterranean biome in 2002–2022. We systematically identify anomalies in temperature, precipitation, and weather systems as event precursors, with noteworthy differences between the two biomes. We also quantify the impact of the most extensive event in 2022 (37 % coverage), underlining the importance of understanding the forest–meteorology interaction in a changing climate.
Dominik Brunner, Gerrit Kuhlmann, Stephan Henne, Erik Koene, Bastian Kern, Sebastian Wolff, Christiane Voigt, Patrick Jöckel, Christoph Kiemle, Anke Roiger, Alina Fiehn, Sven Krautwurst, Konstantin Gerilowski, Heinrich Bovensmann, Jakob Borchardt, Michal Galkowski, Christoph Gerbig, Julia Marshall, Andrzej Klonecki, Pascal Prunet, Robert Hanfland, Margit Pattantyús-Ábrahám, Andrzej Wyszogrodzki, and Andreas Fix
Atmos. Chem. Phys., 23, 2699–2728, https://doi.org/10.5194/acp-23-2699-2023, https://doi.org/10.5194/acp-23-2699-2023, 2023
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We evaluated six atmospheric transport models for their capability to simulate the CO2 plumes from two of the largest power plants in Europe by comparing the models against aircraft observations collected during the CoMet (Carbon Dioxide and Methane Mission) campaign in 2018. The study analyzed how realistically such plumes can be simulated at different model resolutions and how well the planned European satellite mission CO2M will be able to quantify emissions from power plants.
Chuan-Yao Lin, Wan-Chin Chen, Yi-Yun Chien, Charles C. K. Chou, Chian-Yi Liu, Helmut Ziereis, Hans Schlager, Eric Förster, Florian Obersteiner, Ovid O. Krüger, Bruna A. Holanda, Mira L. Pöhlker, Katharina Kaiser, Johannes Schneider, Birger Bohn, Klaus Pfeilsticker, Benjamin Weyland, Maria Dolores Andrés Hernández, and John P. Burrows
Atmos. Chem. Phys., 23, 2627–2647, https://doi.org/10.5194/acp-23-2627-2023, https://doi.org/10.5194/acp-23-2627-2023, 2023
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During the EMeRGe campaign in Asia, atmospheric pollutants were measured on board the HALO aircraft. The WRF-Chem model was employed to evaluate the biomass burning (BB) plume transported from Indochina and its impact on the downstream areas. The combination of BB aerosol enhancement with cloud water resulted in a reduction in incoming shortwave radiation at the surface in southern China and the East China Sea, which potentially has significant regional climate implications.
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
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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.
Andrew W. Seidl, Harald Sodemann, and Hans Christian Steen-Larsen
Atmos. Meas. Tech., 16, 769–790, https://doi.org/10.5194/amt-16-769-2023, https://doi.org/10.5194/amt-16-769-2023, 2023
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It is challenging to make field measurements of stable water isotopes in the Arctic. To this end, we present a modular stable-water-isotope analyzer profiling system. The system operated for a 2-week field campaign on Svalbard during the Arctic winter. We evaluate the system’s performance and analyze any potential impact that the field conditions might have had on the isotopic measurements and the system's ability to resolve isotope gradients in the lowermost layer of the atmosphere.
Ziming Wang, Luca Bugliaro, Tina Jurkat-Witschas, Romy Heller, Ulrike Burkhardt, Helmut Ziereis, Georgios Dekoutsidis, Martin Wirth, Silke Groß, Simon Kirschler, Stefan Kaufmann, and Christiane Voigt
Atmos. Chem. Phys., 23, 1941–1961, https://doi.org/10.5194/acp-23-1941-2023, https://doi.org/10.5194/acp-23-1941-2023, 2023
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Differences in the microphysical properties of contrail cirrus and natural cirrus in a contrail outbreak situation during the ML-CIRRUS campaign over the North Atlantic flight corridor can be observed from in situ measurements. The cirrus radiative effect in the area of the outbreak, derived from satellite observation-based radiative transfer modeling, is warming in the early morning and cooling during the day.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 4, 157–173, https://doi.org/10.5194/wcd-4-157-2023, https://doi.org/10.5194/wcd-4-157-2023, 2023
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We investigate the dynamical origin of the lower-atmospheric potential vorticity (PV; linked to the intensity of cyclones) in Mediterranean cyclones. We quantify the contribution of the cyclone and the environment by tracing PV backward in time and space and linking it to the track of the cyclone. We find that the lower-tropospheric PV is produced shortly before the cyclone's stage of highest intensity. We investigate the driving processes and use a global dataset and a process-resolving one.
Hanna Joos, Michael Sprenger, Hanin Binder, Urs Beyerle, and Heini Wernli
Weather Clim. Dynam., 4, 133–155, https://doi.org/10.5194/wcd-4-133-2023, https://doi.org/10.5194/wcd-4-133-2023, 2023
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Warm conveyor belts (WCBs) are strongly ascending, cloud- and precipitation-forming airstreams in extratropical cyclones. In this study we assess their representation in a climate simulation and their changes under global warming. They become moister, become more intense, and reach higher altitudes in a future climate, implying that they potentially have an increased impact on the mid-latitude flow.
Andreas Schäfler, Michael Sprenger, Heini Wernli, Andreas Fix, and Martin Wirth
Atmos. Chem. Phys., 23, 999–1018, https://doi.org/10.5194/acp-23-999-2023, https://doi.org/10.5194/acp-23-999-2023, 2023
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In this study, airborne lidar profile measurements of H2O and O3 across a midlatitude jet stream are combined with analyses in tracer–trace space and backward trajectories. We highlight that transport and mixing processes in the history of the observed air masses are governed by interacting tropospheric weather systems on synoptic timescales. We show that these weather systems play a key role in the high variability of the paired H2O and O3 distributions near the tropopause.
Andreas Marsing, Ralf Meerkötter, Romy Heller, Stefan Kaufmann, Tina Jurkat-Witschas, Martina Krämer, Christian Rolf, and Christiane Voigt
Atmos. Chem. Phys., 23, 587–609, https://doi.org/10.5194/acp-23-587-2023, https://doi.org/10.5194/acp-23-587-2023, 2023
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We employ highly resolved aircraft measurements of profiles of the ice water content (IWC) in Arctic cirrus clouds in winter and spring, when solar irradiation is low. Using radiation transfer calculations, we assess the cloud radiative effect over different surfaces like snow or ocean. The variability in the IWC of the clouds affects their overall radiative effect and drives internal processes. This helps understand the role of cirrus in a rapidly changing Arctic environment.
Hanin Binder, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 4, 19–37, https://doi.org/10.5194/wcd-4-19-2023, https://doi.org/10.5194/wcd-4-19-2023, 2023
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Warm conveyor belts (WCBs) are the main cloud- and precipitation-producing airstreams in extratropical cyclones. The latent heat release that occurs during cloud formation often contributes to the intensification of the associated cyclone. Based on the Community Earth System Model Large Ensemble coupled climate simulations, we show that WCBs and associated latent heating will become stronger in a future climate and be even more important for explosive cyclone intensification than in the present.
Johannes Lucke, Tina Jurkat-Witschas, Romy Heller, Valerian Hahn, Matthew Hamman, Wolfgang Breitfuss, Venkateshwar Reddy Bora, Manuel Moser, and Christiane Voigt
Atmos. Meas. Tech., 15, 7375–7394, https://doi.org/10.5194/amt-15-7375-2022, https://doi.org/10.5194/amt-15-7375-2022, 2022
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Flight testing in icing conditions requires instruments that are able to accurately measure the liquid water content of supercooled large droplets (SLDs). This work finds that the 12 mm cone of the Nevzorov hot-wire probe has excellent collection properties for SLDs. We also derive a correction to compensate for the low collision efficiency of small droplets with the cone. The results provide a procedure to evaluate LWC measurements of the 12 mm cone during wind tunnel and airborne experiments.
Konstantin Krüger, Andreas Schäfler, Martin Wirth, Martin Weissmann, and George C. Craig
Atmos. Chem. Phys., 22, 15559–15577, https://doi.org/10.5194/acp-22-15559-2022, https://doi.org/10.5194/acp-22-15559-2022, 2022
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A comprehensive data set of airborne lidar water vapour profiles is compared with ERA5 reanalyses for a robust characterization of the vertical structure of the mid-latitude lower-stratospheric moist bias. We confirm a moist bias of up to 55 % at 1.3 km altitude above the tropopause and uncover a decreasing bias beyond. Collocated O3 and H2O observations reveal a particularly strong bias in the mixing layer, indicating insufficiently modelled transport processes fostering the bias.
Benjamin Witschas, Christian Lemmerz, Alexander Geiß, Oliver Lux, Uwe Marksteiner, Stephan Rahm, Oliver Reitebuch, Andreas Schäfler, and Fabian Weiler
Atmos. Meas. Tech., 15, 7049–7070, https://doi.org/10.5194/amt-15-7049-2022, https://doi.org/10.5194/amt-15-7049-2022, 2022
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In August 2018, the first wind lidar Aeolus was launched into space and has since then been providing data of the global wind field. The primary goal of Aeolus was the improvement of numerical weather prediction. To verify the quality of Aeolus wind data, DLR performed four airborne validation campaigns with two wind lidar systems. In this paper, we report on results from the two later campaigns, performed in Iceland and the tropics.
Laura Tomsche, Andreas Marsing, Tina Jurkat-Witschas, Johannes Lucke, Stefan Kaufmann, Katharina Kaiser, Johannes Schneider, Monika Scheibe, Hans Schlager, Lenard Röder, Horst Fischer, Florian Obersteiner, Andreas Zahn, Martin Zöger, Jos Lelieveld, and Christiane Voigt
Atmos. Chem. Phys., 22, 15135–15151, https://doi.org/10.5194/acp-22-15135-2022, https://doi.org/10.5194/acp-22-15135-2022, 2022
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The detection of sulfur compounds in the upper troposphere (UT) and lower stratosphere (LS) is a challenge. In-flight measurements of SO2 and sulfate aerosol were performed during the BLUESKY mission in spring 2020 under exceptional atmospheric conditions. Reduced sinks in the dry UTLS and lower but still significant air traffic influenced the enhanced SO2 in the UT, and aged volcanic plumes enhanced the LS sulfate aerosol impacting the atmospheric radiation budget and global climate.
Oliver Lux, Benjamin Witschas, Alexander Geiß, Christian Lemmerz, Fabian Weiler, Uwe Marksteiner, Stephan Rahm, Andreas Schäfler, and Oliver Reitebuch
Atmos. Meas. Tech., 15, 6467–6488, https://doi.org/10.5194/amt-15-6467-2022, https://doi.org/10.5194/amt-15-6467-2022, 2022
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We discuss the influence of different quality control schemes on the results of Aeolus wind product validation and present statistical tools for ensuring consistency and comparability among diverse validation studies with regard to the specific error characteristics of the Rayleigh-clear and Mie-cloudy winds. The developed methods are applied for the validation of Aeolus winds against an ECMWF model background and airborne wind lidar data from the Joint Aeolus Tropical Atlantic Campaign.
Michael A. Barnes, Thando Ndarana, Michael Sprenger, and Willem A. Landman
Weather Clim. Dynam., 3, 1291–1309, https://doi.org/10.5194/wcd-3-1291-2022, https://doi.org/10.5194/wcd-3-1291-2022, 2022
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Stratospheric air can intrude into the troposphere and is associated with cyclonic development throughout the atmosphere. Through a highly idealized systematic approach, the effect that different intrusion characteristics have on surface cyclogenetic forcing is investigated. The proximity of stratospheric intrusions to the surface is shown to be the main factor in surface cyclogenetic forcing, whilst its width is an additional contributing factor.
Hossein Dadashazar, Andrea F. Corral, Ewan Crosbie, Sanja Dmitrovic, Simon Kirschler, Kayla McCauley, Richard Moore, Claire Robinson, Joseph S. Schlosser, Michael Shook, K. Lee Thornhill, Christiane Voigt, Edward Winstead, Luke Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 22, 13897–13913, https://doi.org/10.5194/acp-22-13897-2022, https://doi.org/10.5194/acp-22-13897-2022, 2022
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Multi-season airborne data over the northwestern Atlantic show that organic mass fraction and the relative amount of oxygenated organics within that fraction are enhanced in droplet residual particles as compared to particles below and above cloud. In-cloud aqueous processing is shown to be a potential driver of this compositional shift in cloud. This implies that aerosol–cloud interactions in the region reduce aerosol hygroscopicity due to the jump in the organic : sulfate ratio in cloud.
Oliver Appel, Franziska Köllner, Antonis Dragoneas, Andreas Hünig, Sergej Molleker, Hans Schlager, Christoph Mahnke, Ralf Weigel, Max Port, Christiane Schulz, Frank Drewnick, Bärbel Vogel, Fred Stroh, and Stephan Borrmann
Atmos. Chem. Phys., 22, 13607–13630, https://doi.org/10.5194/acp-22-13607-2022, https://doi.org/10.5194/acp-22-13607-2022, 2022
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This paper clarifies the chemical composition of the Asian tropopause aerosol layer (ATAL) by means of airborne in situ aerosol mass spectrometry (AMS). Ammonium nitrate and organics are found to significantly contribute to the particle layer, while sulfate does not show a layered structure. An analysis of the single-particle mass spectra suggests that secondary particle formation and subsequent growth dominate the particle composition, rather than condensation on pre-existing primary particles.
Lukas Jansing, Lukas Papritz, Bruno Dürr, Daniel Gerstgrasser, and Michael Sprenger
Weather Clim. Dynam., 3, 1113–1138, https://doi.org/10.5194/wcd-3-1113-2022, https://doi.org/10.5194/wcd-3-1113-2022, 2022
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This study presents a 5-year climatology of three main foehn types and three deep-foehn subtypes. The main types differ in their large-scale and Alpine-scale weather conditions and the subtypes in terms of the amount and extent of precipitation on the Alpine south side. The different types of foehn are found to strongly affect the local meteorological conditions at Altdorf. The study concludes by setting the new classification into a historic context.
Roger Teoh, Ulrich Schumann, Edward Gryspeerdt, Marc Shapiro, Jarlath Molloy, George Koudis, Christiane Voigt, and Marc E. J. Stettler
Atmos. Chem. Phys., 22, 10919–10935, https://doi.org/10.5194/acp-22-10919-2022, https://doi.org/10.5194/acp-22-10919-2022, 2022
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Aircraft condensation trails (contrails) contribute to over half of the climate forcing attributable to aviation. This study uses historical air traffic and weather data to simulate contrails in the North Atlantic over 5 years, from 2016 to 2021. We found large intra- and inter-year variability in contrail radiative forcing and observed a 66 % reduction due to COVID-19. Most warming contrails predominantly result from night-time flights in winter.
Simon F. Reifenberg, Anna Martin, Matthias Kohl, Sara Bacer, Zaneta Hamryszczak, Ivan Tadic, Lenard Röder, Daniel J. Crowley, Horst Fischer, Katharina Kaiser, Johannes Schneider, Raphael Dörich, John N. Crowley, Laura Tomsche, Andreas Marsing, Christiane Voigt, Andreas Zahn, Christopher Pöhlker, Bruna A. Holanda, Ovid Krüger, Ulrich Pöschl, Mira Pöhlker, Patrick Jöckel, Marcel Dorf, Ulrich Schumann, Jonathan Williams, Birger Bohn, Joachim Curtius, Hardwig Harder, Hans Schlager, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 22, 10901–10917, https://doi.org/10.5194/acp-22-10901-2022, https://doi.org/10.5194/acp-22-10901-2022, 2022
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In this work we use a combination of observational data from an aircraft campaign and model results to investigate the effect of the European lockdown due to COVID-19 in spring 2020. Using model results, we show that the largest relative changes to the atmospheric composition caused by the reduced emissions are located in the upper troposphere around aircraft cruise altitude, while the largest absolute changes are present at the surface.
Donato Summa, Fabio Madonna, Noemi Franco, Benedetto De Rosa, and Paolo Di Girolamo
Atmos. Meas. Tech., 15, 4153–4170, https://doi.org/10.5194/amt-15-4153-2022, https://doi.org/10.5194/amt-15-4153-2022, 2022
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The evolution of the atmospheric boundary layer height (ABLH) has an important impact on meteorology. However, the complexity of the phenomena occurring within the ABL and the influence of advection and local accumulation processes often prevent an unambiguous determination of the ABLH. The paper reports results from an inter-comparison effort involving different sensors and techniques to measure the ABLH. Correlations between the ABLH and other atmospheric variables are also assessed.
Andries Jan de Vries, Franziska Aemisegger, Stephan Pfahl, and Heini Wernli
Atmos. Chem. Phys., 22, 8863–8895, https://doi.org/10.5194/acp-22-8863-2022, https://doi.org/10.5194/acp-22-8863-2022, 2022
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The Earth's water cycle contains the common H2O molecule but also the less abundant, heavier HDO. We use their different physical properties to study tropical ice clouds in model simulations of the West African monsoon. Isotope signals reveal different processes through which ice clouds form and decay in deep-convective and widespread cirrus. Previously observed variations in upper-tropospheric vapour isotopes are explained by microphysical processes in convective updraughts and downdraughts.
Ovid O. Krüger, Bruna A. Holanda, Sourangsu Chowdhury, Andrea Pozzer, David Walter, Christopher Pöhlker, Maria Dolores Andrés Hernández, John P. Burrows, Christiane Voigt, Jos Lelieveld, Johannes Quaas, Ulrich Pöschl, and Mira L. Pöhlker
Atmos. Chem. Phys., 22, 8683–8699, https://doi.org/10.5194/acp-22-8683-2022, https://doi.org/10.5194/acp-22-8683-2022, 2022
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The abrupt reduction in human activities during the first COVID-19 lockdown created unprecedented atmospheric conditions. We took the opportunity to quantify changes in black carbon (BC) as a major anthropogenic air pollutant. Therefore, we measured BC on board a research aircraft over Europe during the lockdown and compared the results to measurements from 2017. With model simulations we account for different weather conditions and find a lockdown-related decrease in BC of 41 %.
Simon Kirschler, Christiane Voigt, Bruce Anderson, Ramon Campos Braga, Gao Chen, Andrea F. Corral, Ewan Crosbie, Hossein Dadashazar, Richard A. Ferrare, Valerian Hahn, Johannes Hendricks, Stefan Kaufmann, Richard Moore, Mira L. Pöhlker, Claire Robinson, Amy J. Scarino, Dominik Schollmayer, Michael A. Shook, K. Lee Thornhill, Edward Winstead, Luke D. Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 22, 8299–8319, https://doi.org/10.5194/acp-22-8299-2022, https://doi.org/10.5194/acp-22-8299-2022, 2022
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In this study we show that the vertical velocity dominantly impacts the cloud droplet number concentration (NC) of low-level clouds over the western North Atlantic in the winter and summer season, while the cloud condensation nuclei concentration, aerosol size distribution and chemical composition impact NC within a season. The observational data presented in this study can evaluate and improve the representation of aerosol–cloud interactions for a wide range of conditions.
M. Dolores Andrés Hernández, Andreas Hilboll, Helmut Ziereis, Eric Förster, Ovid O. Krüger, Katharina Kaiser, Johannes Schneider, Francesca Barnaba, Mihalis Vrekoussis, Jörg Schmidt, Heidi Huntrieser, Anne-Marlene Blechschmidt, Midhun George, Vladyslav Nenakhov, Theresa Harlass, Bruna A. Holanda, Jennifer Wolf, Lisa Eirenschmalz, Marc Krebsbach, Mira L. Pöhlker, Anna B. Kalisz Hedegaard, Linlu Mei, Klaus Pfeilsticker, Yangzhuoran Liu, Ralf Koppmann, Hans Schlager, Birger Bohn, Ulrich Schumann, Andreas Richter, Benjamin Schreiner, Daniel Sauer, Robert Baumann, Mariano Mertens, Patrick Jöckel, Markus Kilian, Greta Stratmann, Christopher Pöhlker, Monica Campanelli, Marco Pandolfi, Michael Sicard, José L. Gómez-Amo, Manuel Pujadas, Katja Bigge, Flora Kluge, Anja Schwarz, Nikos Daskalakis, David Walter, Andreas Zahn, Ulrich Pöschl, Harald Bönisch, Stephan Borrmann, Ulrich Platt, and John P. Burrows
Atmos. Chem. Phys., 22, 5877–5924, https://doi.org/10.5194/acp-22-5877-2022, https://doi.org/10.5194/acp-22-5877-2022, 2022
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EMeRGe provides a unique set of in situ and remote sensing airborne measurements of trace gases and aerosol particles along selected flight routes in the lower troposphere over Europe. The interpretation uses also complementary collocated ground-based and satellite measurements. The collected data help to improve the current understanding of the complex spatial distribution of trace gases and aerosol particles resulting from mixing, transport, and transformation of pollution plumes over Europe.
Mireia Papke Chica, Valerian Hahn, Tiziana Braeuer, Elena de la Torre Castro, Florian Ewald, Mathias Gergely, Simon Kirschler, Luca Bugliaro Goggia, Stefanie Knobloch, Martina Kraemer, Johannes Lucke, Johanna Mayer, Raphael Maerkl, Manuel Moser, Laura Tomsche, Tina Jurkat-Witschas, Martin Zoeger, Christian von Savigny, and Christiane Voigt
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-255, https://doi.org/10.5194/acp-2022-255, 2022
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The mixed-phase temperature regime in convective clouds challenges our understanding of microphysical and radiative cloud properties. We provide a rare and unique dataset of aircraft in situ measurements in a strong mid-latitude convective system. We find that mechanisms initiating ice nucleation and growth strongly depend on temperature, relative humidity, and vertical velocity and variate within the measured system, resulting in altitude dependent changes of the cloud liquid and ice fraction.
Philipp Zschenderlein and Heini Wernli
Weather Clim. Dynam., 3, 391–411, https://doi.org/10.5194/wcd-3-391-2022, https://doi.org/10.5194/wcd-3-391-2022, 2022
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Precipitation and temperature are two of the most important variables describing our weather and climate. The relationship between these variables has been studied extensively; however, the role of specific weather systems in shaping this relationship has not been analysed yet. We therefore analyse whether intense precipitation occurs on warmer or on colder days and identify the relevant weather systems. In general, weather systems strongly influence this relationship, especially in winter.
Jan Clemens, Felix Ploeger, Paul Konopka, Raphael Portmann, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 22, 3841–3860, https://doi.org/10.5194/acp-22-3841-2022, https://doi.org/10.5194/acp-22-3841-2022, 2022
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Highly polluted air flows from the surface to higher levels of the atmosphere during the Asian summer monsoon. At high levels, the air is trapped within eddies. Here, we study how air masses can leave the eddy within its cutoff, how they distribute, and how their chemical composition changes. We found evidence for transport from the eddy to higher latitudes over the North Pacific and even Alaska. During transport, trace gas concentrations within cutoffs changed gradually, showing steady mixing.
Helmut Ziereis, Peter Hoor, Jens-Uwe Grooß, Andreas Zahn, Greta Stratmann, Paul Stock, Michael Lichtenstern, Jens Krause, Vera Bense, Armin Afchine, Christian Rolf, Wolfgang Woiwode, Marleen Braun, Jörn Ungermann, Andreas Marsing, Christiane Voigt, Andreas Engel, Björn-Martin Sinnhuber, and Hermann Oelhaf
Atmos. Chem. Phys., 22, 3631–3654, https://doi.org/10.5194/acp-22-3631-2022, https://doi.org/10.5194/acp-22-3631-2022, 2022
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Airborne observations were conducted in the lowermost Arctic stratosphere during the winter of 2015/2016. The observed distribution of reactive nitrogen shows clear indications of nitrification in mid-winter and denitrification in late winter. This was caused by the formation of polar stratospheric cloud particles, which were observed during several flights. The sedimentation and evaporation of these particles and the descent of air masses cause a redistribution of reactive nitrogen.
Adrien Deroubaix, Laurent Menut, Cyrille Flamant, Peter Knippertz, Andreas H. Fink, Anneke Batenburg, Joel Brito, Cyrielle Denjean, Cheikh Dione, Régis Dupuy, Valerian Hahn, Norbert Kalthoff, Fabienne Lohou, Alfons Schwarzenboeck, Guillaume Siour, Paolo Tuccella, and Christiane Voigt
Atmos. Chem. Phys., 22, 3251–3273, https://doi.org/10.5194/acp-22-3251-2022, https://doi.org/10.5194/acp-22-3251-2022, 2022
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During the summer monsoon in West Africa, pollutants emitted in urbanized areas modify cloud cover and precipitation patterns. We analyze these patterns with the WRF-CHIMERE model, integrating the effects of aerosols on meteorology, based on the numerous observations provided by the Dynamics-Aerosol-Climate-Interactions campaign. This study adds evidence to recent findings that increased pollution levels in West Africa delay the breakup time of low-level clouds and reduce precipitation.
Oliver Lux, Christian Lemmerz, Fabian Weiler, Uwe Marksteiner, Benjamin Witschas, Stephan Rahm, Alexander Geiß, Andreas Schäfler, and Oliver Reitebuch
Atmos. Meas. Tech., 15, 1303–1331, https://doi.org/10.5194/amt-15-1303-2022, https://doi.org/10.5194/amt-15-1303-2022, 2022
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The article discusses modifications in the wind retrieval of the ALADIN Airborne Demonstrator (A2D) – one of the key instruments for the validation of Aeolus. Thanks to the retrieval refinements, which are demonstrated in the context of two airborne campaigns in 2019, the systematic and random wind errors of the A2D were significantly reduced, thereby enhancing its validation capabilities. Finally, wind comparisons between A2D and Aeolus for the validation of the satellite data are presented.
Jörg Wieder, Claudia Mignani, Mario Schär, Lucie Roth, Michael Sprenger, Jan Henneberger, Ulrike Lohmann, Cyril Brunner, and Zamin A. Kanji
Atmos. Chem. Phys., 22, 3111–3130, https://doi.org/10.5194/acp-22-3111-2022, https://doi.org/10.5194/acp-22-3111-2022, 2022
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We investigate the variation in ice-nucleating particles (INPs) relevant for primary ice formation in mixed-phased clouds over the Alps based on simultaneous in situ observations at a mountaintop and a nearby high valley (1060 m height difference). In most cases, advection from the surrounding lower regions was responsible for changes in INP concentration, causing a diurnal cycle at the mountaintop. Our study underlines the importance of the planetary boundary layer as an INP reserve.
Jussi Leinonen, Ulrich Hamann, Urs Germann, and John R. Mecikalski
Nat. Hazards Earth Syst. Sci., 22, 577–597, https://doi.org/10.5194/nhess-22-577-2022, https://doi.org/10.5194/nhess-22-577-2022, 2022
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We evaluate the usefulness of different data sources and variables to the short-term prediction (
nowcasting) of severe thunderstorms using machine learning. Machine-learning models are trained with data from weather radars, satellite images, lightning detection and weather forecasts and with terrain elevation data. We analyze the benefits provided by each of the data sources to predicting hazards (heavy precipitation, lightning and hail) caused by the thunderstorms.
Lukas Bösiger, Michael Sprenger, Maxi Boettcher, Hanna Joos, and Tobias Günther
Geosci. Model Dev., 15, 1079–1096, https://doi.org/10.5194/gmd-15-1079-2022, https://doi.org/10.5194/gmd-15-1079-2022, 2022
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Jet streams are coherent air flows that interact with atmospheric structures such as warm conveyor belts (WCBs) and the tropopause. Individually, these structures have a significant impact on the weather evolution. A first step towards a deeper understanding of the meteorological processes is to extract jet stream core lines, for which we develop a novel feature extraction algorithm. Based on the line geometry, we automatically detect and visualize potential interactions between WCBs and jets.
Katharina Hartmuth, Maxi Boettcher, Heini Wernli, and Lukas Papritz
Weather Clim. Dynam., 3, 89–111, https://doi.org/10.5194/wcd-3-89-2022, https://doi.org/10.5194/wcd-3-89-2022, 2022
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In this study, we introduce a novel method to objectively define and identify extreme Arctic seasons based on different surface variables. We find that such seasons are resulting from various combinations of unusual seasonal conditions. The occurrence or absence of different atmospheric processes strongly affects the character of extreme Arctic seasons. Further, changes in sea ice and sea surface temperature can strongly influence the formation of such a season in distinct regions.
Leonie Villiger, Heini Wernli, Maxi Boettcher, Martin Hagen, and Franziska Aemisegger
Weather Clim. Dynam., 3, 59–88, https://doi.org/10.5194/wcd-3-59-2022, https://doi.org/10.5194/wcd-3-59-2022, 2022
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The coupling between the large-scale atmospheric circulation and the clouds in the trade-wind region is complex and not yet fully understood. In this study, the formation pathway of two anomalous cloud layers over Barbados during the field campaign EUREC4A is described. The two case studies highlight the influence of remote weather systems on the local environmental conditions in Barbados.
Philipp Zschenderlein and Heini Wernli
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2021-396, https://doi.org/10.5194/nhess-2021-396, 2022
Preprint withdrawn
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In early January 2021, Spain was affected by two extreme events – an unusually long cold spell and a heavy snowfall event associated with extratropical cyclone Filomena. In the study, we analyse the synoptic-dynamic development of the two extreme events. Cold air from the north was advected towards Spain and between 07 and 10 January, cyclone Filomena was responsible for major parts of the snowfall event. During this event, temperature and moisture contrasts accross Spain were very high.
Monika Feldmann, Urs Germann, Marco Gabella, and Alexis Berne
Weather Clim. Dynam., 2, 1225–1244, https://doi.org/10.5194/wcd-2-1225-2021, https://doi.org/10.5194/wcd-2-1225-2021, 2021
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Mesocyclones are the rotating updraught of supercell thunderstorms that present a particularly hazardous subset of thunderstorms. A first-time characterisation of the spatiotemporal occurrence of mesocyclones in the Alpine region is presented, using 5 years of Swiss operational radar data. We investigate parallels to hailstorms, particularly the influence of large-scale flow, daily cycles and terrain. Improving understanding of mesocyclones is valuable for risk assessment and warning purposes.
Hélène Barras, Olivia Martius, Luca Nisi, Katharina Schroeer, Alessandro Hering, and Urs Germann
Weather Clim. Dynam., 2, 1167–1185, https://doi.org/10.5194/wcd-2-1167-2021, https://doi.org/10.5194/wcd-2-1167-2021, 2021
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In Switzerland hail may occur several days in a row. Such multi-day hail events may cause significant damage, and understanding and forecasting these events is important. Using reanalysis data we show that weather systems over Europe move slower before and during multi-day hail events compared to single hail days. Surface temperatures are typically warmer and the air more humid over Switzerland and winds are slower on multi-day hail clusters. These results may be used for hail forecasting.
Ramon Campos Braga, Barbara Ervens, Daniel Rosenfeld, Meinrat O. Andreae, Jan-David Förster, Daniel Fütterer, Lianet Hernández Pardo, Bruna A. Holanda, Tina Jurkat-Witschas, Ovid O. Krüger, Oliver Lauer, Luiz A. T. Machado, Christopher Pöhlker, Daniel Sauer, Christiane Voigt, Adrian Walser, Manfred Wendisch, Ulrich Pöschl, and Mira L. Pöhlker
Atmos. Chem. Phys., 21, 17513–17528, https://doi.org/10.5194/acp-21-17513-2021, https://doi.org/10.5194/acp-21-17513-2021, 2021
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Interactions of aerosol particles with clouds represent a large uncertainty in estimates of climate change. Properties of aerosol particles control their ability to act as cloud condensation nuclei. Using aerosol measurements in the Amazon, we performed model studies to compare predicted and measured cloud droplet number concentrations at cloud bases. Our results confirm previous estimates of particle hygroscopicity in this region.
Silke Trömel, Clemens Simmer, Ulrich Blahak, Armin Blanke, Sabine Doktorowski, Florian Ewald, Michael Frech, Mathias Gergely, Martin Hagen, Tijana Janjic, Heike Kalesse-Los, Stefan Kneifel, Christoph Knote, Jana Mendrok, Manuel Moser, Gregor Köcher, Kai Mühlbauer, Alexander Myagkov, Velibor Pejcic, Patric Seifert, Prabhakar Shrestha, Audrey Teisseire, Leonie von Terzi, Eleni Tetoni, Teresa Vogl, Christiane Voigt, Yuefei Zeng, Tobias Zinner, and Johannes Quaas
Atmos. Chem. Phys., 21, 17291–17314, https://doi.org/10.5194/acp-21-17291-2021, https://doi.org/10.5194/acp-21-17291-2021, 2021
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The article introduces the ACP readership to ongoing research in Germany on cloud- and precipitation-related process information inherent in polarimetric radar measurements, outlines pathways to inform atmospheric models with radar-based information, and points to remaining challenges towards an improved fusion of radar polarimetry and atmospheric modelling.
Samira Khodayar, Silvio Davolio, Paolo Di Girolamo, Cindy Lebeaupin Brossier, Emmanouil Flaounas, Nadia Fourrie, Keun-Ok Lee, Didier Ricard, Benoit Vie, Francois Bouttier, Alberto Caldas-Alvarez, and Veronique Ducrocq
Atmos. Chem. Phys., 21, 17051–17078, https://doi.org/10.5194/acp-21-17051-2021, https://doi.org/10.5194/acp-21-17051-2021, 2021
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Heavy precipitation (HP) constitutes a major meteorological threat in the western Mediterranean. Every year, recurrent events affect the area with fatal consequences. Despite this being a well-known issue, open questions still remain. The understanding of the underlying mechanisms and the modeling representation of the events must be improved. In this article we present the most recent lessons learned from the Hydrological Cycle in the Mediterranean Experiment (HyMeX).
Paul D. Hamer, Virginie Marécal, Ryan Hossaini, Michel Pirre, Gisèle Krysztofiak, Franziska Ziska, Andreas Engel, Stephan Sala, Timo Keber, Harald Bönisch, Elliot Atlas, Kirstin Krüger, Martyn Chipperfield, Valery Catoire, Azizan A. Samah, Marcel Dorf, Phang Siew Moi, Hans Schlager, and Klaus Pfeilsticker
Atmos. Chem. Phys., 21, 16955–16984, https://doi.org/10.5194/acp-21-16955-2021, https://doi.org/10.5194/acp-21-16955-2021, 2021
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Bromoform is a stratospheric ozone-depleting gas released by seaweed and plankton transported to the stratosphere via convection in the tropics. We study the chemical interactions of bromoform and its derivatives within convective clouds using a cloud-scale model and observations. Our findings are that soluble bromine gases are efficiently washed out and removed within the convective clouds and that most bromine is transported vertically to the upper troposphere in the form of bromoform.
Tiziana Bräuer, Christiane Voigt, Daniel Sauer, Stefan Kaufmann, Valerian Hahn, Monika Scheibe, Hans Schlager, Felix Huber, Patrick Le Clercq, Richard H. Moore, and Bruce E. Anderson
Atmos. Chem. Phys., 21, 16817–16826, https://doi.org/10.5194/acp-21-16817-2021, https://doi.org/10.5194/acp-21-16817-2021, 2021
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Over half of aviation climate impact is caused by contrails. Biofuels can reduce the ice crystal numbers in contrails and mitigate the climate impact. The experiment ECLIF II/NDMAX in 2018 assessed the effects of biofuels on contrails and aviation emissions. The NASA DC-8 aircraft performed measurements inside the contrail of the DLR A320. One reference fuel and two blends of the biofuel HEFA and kerosene are analysed. We find a max reduction of contrail ice numbers through biofuel use of 40 %.
Roman Attinger, Elisa Spreitzer, Maxi Boettcher, Heini Wernli, and Hanna Joos
Weather Clim. Dynam., 2, 1073–1091, https://doi.org/10.5194/wcd-2-1073-2021, https://doi.org/10.5194/wcd-2-1073-2021, 2021
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Diabatic processes affect the development of extratropical cyclones. This work provides a systematic assessment of the diabatic processes that modify potential vorticity (PV) in model simulations. PV is primarily produced by condensation and convection. Given favorable environmental conditions, long-wave radiative cooling and turbulence become the primary process at the cold and warm fronts, respectively. Turbulence and long-wave radiative heating produce negative PV anomalies at the fronts.
Fabienne Dahinden, Franziska Aemisegger, Heini Wernli, Matthias Schneider, Christopher J. Diekmann, Benjamin Ertl, Peter Knippertz, Martin Werner, and Stephan Pfahl
Atmos. Chem. Phys., 21, 16319–16347, https://doi.org/10.5194/acp-21-16319-2021, https://doi.org/10.5194/acp-21-16319-2021, 2021
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We use high-resolution numerical isotope modelling and Lagrangian backward trajectories to identify moisture transport pathways and governing physical and dynamical processes that affect the free-tropospheric humidity and isotopic variability over the eastern subtropical North Atlantic. Furthermore, we conduct a thorough isotope modelling validation with aircraft and remote-sensing observations of water vapour isotopes.
Hossein Dadashazar, Majid Alipanah, Miguel Ricardo A. Hilario, Ewan Crosbie, Simon Kirschler, Hongyu Liu, Richard H. Moore, Andrew J. Peters, Amy Jo Scarino, Michael Shook, K. Lee Thornhill, Christiane Voigt, Hailong Wang, Edward Winstead, Bo Zhang, Luke Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 21, 16121–16141, https://doi.org/10.5194/acp-21-16121-2021, https://doi.org/10.5194/acp-21-16121-2021, 2021
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This study investigates precipitation impacts on long-range transport of North American outflow over the western North Atlantic Ocean (WNAO). Results demonstrate that precipitation scavenging plays a significant role in modifying surface aerosol concentrations over the WNAO, especially in winter and spring due to large-scale scavenging processes. This study highlights how precipitation impacts surface aerosol properties with relevance for other marine regions vulnerable to continental outflow.
Philippe Besson, Luise J. Fischer, Sebastian Schemm, and Michael Sprenger
Weather Clim. Dynam., 2, 991–1009, https://doi.org/10.5194/wcd-2-991-2021, https://doi.org/10.5194/wcd-2-991-2021, 2021
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The strongest cyclone intensification is associated with a strong dry-dynamical forcing. Moreover, strong forcing and strong intensification correspond to a tendency for poleward cyclone propagation, which occurs in distinct regions in the Northern Hemisphere. There is a clear spatial pattern in the occurrence of certain forcing combinations. This implies a fundamental relationship between dry-dynamical processes and the intensification as well as the propagation of extratropical cyclones.
Yu-Wen Chen, Yi-Chun Chen, Charles C.-K. Chou, Hui-Ming Hung, Shih-Yu Chang, Lisa Eirenschmalz, Michael Lichtenstern, Helmut Ziereis, Hans Schlager, Greta Stratmann, Katharina Kaiser, Johannes Schneider, Stephan Borrmann, Florian Obersteiner, Eric Förster, Andreas Zahn, Wei-Nai Chen, Po-Hsiung Lin, Shuenn-Chin Chang, Maria Dolores Andrés Hernández, Pao-Kuan Wang, and John P. Burrows
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-788, https://doi.org/10.5194/acp-2021-788, 2021
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By presenting an approach using EMeRGe-Asia airborne field measurements and surface observations, this study shows that the fraction of OH reactivity due to SO2-OH reaction has a significant correlation with the sulfate concentration. Approximately 30 % of sulfate is produced by SO2-OH reaction. Our results underline the importance of SO2-OH gas-phase oxidation in sulfate formation, and demonstrate that the method can be applied to other regions and under different meteorological conditions.
Jonas Hamperl, Clément Capitaine, Jean-Baptiste Dherbecourt, Myriam Raybaut, Patrick Chazette, Julien Totems, Bruno Grouiez, Laurence Régalia, Rosa Santagata, Corinne Evesque, Jean-Michel Melkonian, Antoine Godard, Andrew Seidl, Harald Sodemann, and Cyrille Flamant
Atmos. Meas. Tech., 14, 6675–6693, https://doi.org/10.5194/amt-14-6675-2021, https://doi.org/10.5194/amt-14-6675-2021, 2021
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Laser active remote sensing of tropospheric water vapor is a promising technology for enhancing our understanding of processes governing the global hydrological cycle. We investigate the potential of a ground-based lidar to monitor the main water vapor isotopes at high spatio-temporal resolutions in the lower troposphere. Using a realistic end-to-end simulator, we show that high-precision measurements can be achieved within a range of 1.5 km, in mid-latitude or tropical environments.
Ramon Campos Braga, Daniel Rosenfeld, Ovid O. Krüger, Barbara Ervens, Bruna A. Holanda, Manfred Wendisch, Trismono Krisna, Ulrich Pöschl, Meinrat O. Andreae, Christiane Voigt, and Mira L. Pöhlker
Atmos. Chem. Phys., 21, 14079–14088, https://doi.org/10.5194/acp-21-14079-2021, https://doi.org/10.5194/acp-21-14079-2021, 2021
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Quantifying the precipitation within clouds is crucial for our understanding of the Earth's hydrological cycle. Using in situ measurements of cloud and rain properties over the Amazon Basin and Atlantic Ocean, we show here a linear relationship between the effective radius (re) and precipitation water content near the tops of convective clouds for different pollution states and temperature levels. Our results emphasize the role of re to determine both initiation and amount of precipitation.
Yongbiao Weng, Aina Johannessen, and Harald Sodemann
Weather Clim. Dynam., 2, 713–737, https://doi.org/10.5194/wcd-2-713-2021, https://doi.org/10.5194/wcd-2-713-2021, 2021
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High-resolution measurements of stable isotopes in near-surface vapour and precipitation show a
W-shaped evolution during a 24 h land-falling atmospheric river event in southern Norway. We distinguish contributions from below-cloud processes, weather system characteristics, and moisture source conditions during different stages of the event. Rayleigh distillation models need to be expanded by additional processes to accurately predict isotopes in surface precipitation from stratiform clouds.
Patrick Chazette, Cyrille Flamant, Harald Sodemann, Julien Totems, Anne Monod, Elsa Dieudonné, Alexandre Baron, Andrew Seidl, Hans Christian Steen-Larsen, Pascal Doira, Amandine Durand, and Sylvain Ravier
Atmos. Chem. Phys., 21, 10911–10937, https://doi.org/10.5194/acp-21-10911-2021, https://doi.org/10.5194/acp-21-10911-2021, 2021
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To gain understanding on the vertical structure of atmospheric water vapour above mountain lakes and to assess its link to the isotopic composition of the lake water and small-scale dynamics, the L-WAIVE field campaign was conducted in the Annecy valley in the French Alps in June 2019. Based on a synergy between ground-based, boat-borne, and airborne measuring platforms, significant gradients of isotopic content have been revealed at the transitions to the lake and to the free troposphere.
Hossein Dadashazar, David Painemal, Majid Alipanah, Michael Brunke, Seethala Chellappan, Andrea F. Corral, Ewan Crosbie, Simon Kirschler, Hongyu Liu, Richard H. Moore, Claire Robinson, Amy Jo Scarino, Michael Shook, Kenneth Sinclair, K. Lee Thornhill, Christiane Voigt, Hailong Wang, Edward Winstead, Xubin Zeng, Luke Ziemba, Paquita Zuidema, and Armin Sorooshian
Atmos. Chem. Phys., 21, 10499–10526, https://doi.org/10.5194/acp-21-10499-2021, https://doi.org/10.5194/acp-21-10499-2021, 2021
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This study investigates the seasonal cycle of cloud drop number concentration (Nd) over the western North Atlantic Ocean (WNAO) using multiple datasets. Reasons for the puzzling discrepancy between the seasonal cycles of Nd and aerosol concentration were identified. Results indicate that Nd is highest in winter (when aerosol proxy values are often lowest) due to conditions both linked to cold-air outbreaks and that promote greater droplet activation.
Raphael Portmann, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 2, 507–534, https://doi.org/10.5194/wcd-2-507-2021, https://doi.org/10.5194/wcd-2-507-2021, 2021
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We explore the three-dimensional life cycle of cyclonic structures
(so-called PV cutoffs) near the tropopause. PV cutoffs are frequent weather systems in the extratropics that lead to high-impact weather. However, many unknowns exist regarding their evolution. We present a new method to track PV cutoffs as 3D objects in reanalysis data by following air parcels along the flow. We study the climatological life cycles of PV cutoffs in detail and propose a classification into three types.
Ulrich Schumann, Ian Poll, Roger Teoh, Rainer Koelle, Enrico Spinielli, Jarlath Molloy, George S. Koudis, Robert Baumann, Luca Bugliaro, Marc Stettler, and Christiane Voigt
Atmos. Chem. Phys., 21, 7429–7450, https://doi.org/10.5194/acp-21-7429-2021, https://doi.org/10.5194/acp-21-7429-2021, 2021
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The roughly 70 % reduction of air traffic during the COVID-19 pandemic from March–August 2020 compared to 2019 provides a test case for the relationship between air traffic density, contrails, and their radiative forcing of climate change. This paper investigates the induced traffic and contrail changes in a model study. Besides strong weather changes, the model results indicate aviation-induced cirrus and top-of-the-atmosphere irradiance changes, which can be tested with observations.
Daniel Wolfensberger, Marco Gabella, Marco Boscacci, Urs Germann, and Alexis Berne
Atmos. Meas. Tech., 14, 3169–3193, https://doi.org/10.5194/amt-14-3169-2021, https://doi.org/10.5194/amt-14-3169-2021, 2021
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In this work, we present a novel quantitative precipitation estimation method for Switzerland that uses random forests, an ensemble-based machine learning technique. The estimator has been trained with a database of 4 years of ground and radar observations. The results of an in-depth evaluation indicate that, compared with the more classical method in use at MeteoSwiss, this novel estimator is able to reduce both the average error and bias of the predictions.
Iris Thurnherr, Katharina Hartmuth, Lukas Jansing, Josué Gehring, Maxi Boettcher, Irina Gorodetskaya, Martin Werner, Heini Wernli, and Franziska Aemisegger
Weather Clim. Dynam., 2, 331–357, https://doi.org/10.5194/wcd-2-331-2021, https://doi.org/10.5194/wcd-2-331-2021, 2021
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Extratropical cyclones are important for the transport of moisture from low to high latitudes. In this study, we investigate how the isotopic composition of water vapour is affected by horizontal temperature advection associated with extratropical cyclones using measurements and modelling. It is shown that air–sea moisture fluxes induced by this horizontal temperature advection lead to the strong variability observed in the isotopic composition of water vapour in the marine boundary layer.
Andreas Schäfler, Andreas Fix, and Martin Wirth
Atmos. Chem. Phys., 21, 5217–5234, https://doi.org/10.5194/acp-21-5217-2021, https://doi.org/10.5194/acp-21-5217-2021, 2021
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First-ever, collocated ozone and water vapor lidar observations across the tropopause are applied to investigate the extratropical transition layer (ExTL). The combined view of a quasi-instantaneous cross section and its tracer–tracer depiction allows us to analyze the ExTL shape and composition and the formation of mixing lines in relation to the dynamic situation. Such lidar data are relevant for future upper-tropospheric and lower-stratospheric investigations and model validations.
Franziska Aemisegger, Raphaela Vogel, Pascal Graf, Fabienne Dahinden, Leonie Villiger, Friedhelm Jansen, Sandrine Bony, Bjorn Stevens, and Heini Wernli
Weather Clim. Dynam., 2, 281–309, https://doi.org/10.5194/wcd-2-281-2021, https://doi.org/10.5194/wcd-2-281-2021, 2021
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The interaction of clouds in the trade wind region with the atmospheric flow is complex and at the heart of uncertainties associated with climate projections. In this study, a natural tracer of atmospheric circulation is used to establish a link between air originating from dry regions of the midlatitudes and the occurrence of specific cloud patterns. Two pathways involving transport within midlatitude weather systems are identified, by which air is brought into the trades within 5–10 d.
Gemine Vivone, Giuseppe D'Amico, Donato Summa, Simone Lolli, Aldo Amodeo, Daniele Bortoli, and Gelsomina Pappalardo
Atmos. Chem. Phys., 21, 4249–4265, https://doi.org/10.5194/acp-21-4249-2021, https://doi.org/10.5194/acp-21-4249-2021, 2021
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We developed a methodology to retrieve the atmospheric boundary layer height from elastic and multi-wavelength lidar observations that uses a new approach based on morphological image processing techniques. The intercomparison with other state-of-the-art algorithms shows on average 30 % improved performance. The algorithm also shows excellent performance with respect to the running time, i.e., just few seconds to execute the whole signal processing chain over 72 h of continuous measurements.
Inken Knop, Stephan E. Bansmer, Valerian Hahn, and Christiane Voigt
Atmos. Meas. Tech., 14, 1761–1781, https://doi.org/10.5194/amt-14-1761-2021, https://doi.org/10.5194/amt-14-1761-2021, 2021
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Knowledge on droplet size and concentration is essential for several applications of atomizers. After having developed a new spray system for our icing wind tunnel, we did intercomparison tests of different droplet measurement techniques including two commercial probes. The probes proved the good repeatability of the spray conditions and showed good overall agreement in measuring size and concentration. Furthermore, we could identify limitations and error sources of the measuring techniques.
Melissa L. Breeden, Amy H. Butler, John R. Albers, Michael Sprenger, and Andrew O'Neil Langford
Atmos. Chem. Phys., 21, 2781–2794, https://doi.org/10.5194/acp-21-2781-2021, https://doi.org/10.5194/acp-21-2781-2021, 2021
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Prior research has found a maximum in deep stratosphere-to-troposphere mass/ozone transport over the western United States in boreal spring, which can enhance surface ozone concentrations, reducing air quality. We find that the winter-to-summer evolution of the north Pacific jet increases the frequency of stratospheric intrusions that drive transport, helping explain the observed maximum. The El Niño–Southern Oscillation affects the timing of the spring jet transition and therefore transport.
Joan Stude, Heinfried Aufmhoff, Hans Schlager, Markus Rapp, Frank Arnold, and Boris Strelnikov
Atmos. Meas. Tech., 14, 983–993, https://doi.org/10.5194/amt-14-983-2021, https://doi.org/10.5194/amt-14-983-2021, 2021
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In this paper we describe the instrument ROMARA and show data from the first flight on a research rocket.
On the way through the atmosphere, the instrument detects positive and negative, natural occurring ions before returning back to ground.
ROMARA was successfully launched together with other instruments into a special radar echo.
We detected typical, light ions of positive and negative charge and heavy negative ions, but no heavy positive ions.
Annika Oertel, Michael Sprenger, Hanna Joos, Maxi Boettcher, Heike Konow, Martin Hagen, and Heini Wernli
Weather Clim. Dynam., 2, 89–110, https://doi.org/10.5194/wcd-2-89-2021, https://doi.org/10.5194/wcd-2-89-2021, 2021
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Convection embedded in the stratiform cloud band of strongly ascending airstreams in extratropical cyclones (so-called warm conveyor belts) can influence not only surface precipitation but also the
upper-tropospheric potential vorticity (PV) and waveguide. The comparison of intense vs. moderate embedded convection shows that its strength alone is not a reliable measure for upper-tropospheric PV modification. Instead, characteristics of the ambient flow co-determine its dynamical significance.
Emmanouil Flaounas, Matthias Röthlisberger, Maxi Boettcher, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 2, 71–88, https://doi.org/10.5194/wcd-2-71-2021, https://doi.org/10.5194/wcd-2-71-2021, 2021
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In this study we identify the wettest seasons globally and address their meteorological characteristics. We show that in different regions the wettest seasons occur in different times of the year and result from either unusually high frequencies of wet days and/or daily extremes. These high frequencies can be largely attributed to four specific weather systems, especially cyclones. Our analysis uses a thoroughly explained, novel methodology that could also be applied to climate models.
Johannes Schneider, Ralf Weigel, Thomas Klimach, Antonis Dragoneas, Oliver Appel, Andreas Hünig, Sergej Molleker, Franziska Köllner, Hans-Christian Clemen, Oliver Eppers, Peter Hoppe, Peter Hoor, Christoph Mahnke, Martina Krämer, Christian Rolf, Jens-Uwe Grooß, Andreas Zahn, Florian Obersteiner, Fabrizio Ravegnani, Alexey Ulanovsky, Hans Schlager, Monika Scheibe, Glenn S. Diskin, Joshua P. DiGangi, John B. Nowak, Martin Zöger, and Stephan Borrmann
Atmos. Chem. Phys., 21, 989–1013, https://doi.org/10.5194/acp-21-989-2021, https://doi.org/10.5194/acp-21-989-2021, 2021
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During five aircraft missions, we detected aerosol particles containing meteoric material in the lower stratosphere. The stratospheric measurements span a latitude range from 15 to 68° N, and we find that at potential temperature levels of more than 40 K above the tropopause; particles containing meteoric material occur at similar abundance fractions across latitudes and seasons. We conclude that meteoric material is efficiently distributed between high and low latitudes by isentropic mixing.
Sebastian Schemm, Heini Wernli, and Hanin Binder
Weather Clim. Dynam., 2, 55–69, https://doi.org/10.5194/wcd-2-55-2021, https://doi.org/10.5194/wcd-2-55-2021, 2021
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North Pacific cyclone intensities are reduced in winter, which is in contrast to North Atlantic cyclones and unexpected from the high available growth potential in winter. We investigate this intensity suppression from a cyclone life-cycle perspective and show that in winter Kuroshio cyclones propagate away from the region where they can grow more quickly, East China Sea cyclones are not relevant before spring, and Kamchatka cyclones grow in a region of reduced growth potential.
Claudia Mignani, Jörg Wieder, Michael A. Sprenger, Zamin A. Kanji, Jan Henneberger, Christine Alewell, and Franz Conen
Atmos. Chem. Phys., 21, 657–664, https://doi.org/10.5194/acp-21-657-2021, https://doi.org/10.5194/acp-21-657-2021, 2021
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Most precipitation above land starts with ice in clouds. It is promoted by extremely rare particles. Some ice-nucleating particles (INPs) cause cloud droplets to already freeze above −15°C, a temperature at which many clouds begin to snow. We found that the abundance of such INPs among other particles of similar size is highest in precipitating air masses and lowest when air carries desert dust. This brings us closer to understanding the interactions between land, clouds, and precipitation.
Flora Kluge, Tilman Hüneke, Matthias Knecht, Michael Lichtenstern, Meike Rotermund, Hans Schlager, Benjamin Schreiner, and Klaus Pfeilsticker
Atmos. Chem. Phys., 20, 12363–12389, https://doi.org/10.5194/acp-20-12363-2020, https://doi.org/10.5194/acp-20-12363-2020, 2020
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The presented study reports on airborne measurements of formaldehyde, glyoxal, methylglyoxal, and CO over the Amazon basin and lays a special focus on the influence of biomass burning emissions on the atmospheric profiles of these carbonyl compounds within the planetary boundary layer as well as in the free and upper troposphere.
Stefan Rüdisühli, Michael Sprenger, David Leutwyler, Christoph Schär, and Heini Wernli
Weather Clim. Dynam., 1, 675–699, https://doi.org/10.5194/wcd-1-675-2020, https://doi.org/10.5194/wcd-1-675-2020, 2020
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Most precipitation over Europe is linked to low-pressure systems, cold fronts, warm fronts, or high-pressure systems. Based on a massive computer simulation able to resolve thunderstorms, we quantify in detail how much precipitation these weather systems produced during 2000–2008. We find distinct seasonal and regional differences, such as fronts precipitating a lot in fall and winter over the North Atlantic but high-pressure systems mostly in summer over the continent by way of thunderstorms.
Raphael Portmann, Juan Jesús González-Alemán, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 597–615, https://doi.org/10.5194/wcd-1-597-2020, https://doi.org/10.5194/wcd-1-597-2020, 2020
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In September 2018 an intense Mediterranean cyclone with structural similarities to a hurricane, a so-called medicane, caused severe damage in Greece. Its development was uncertain, even just a few days in advance. The reason for this was uncertainties in the jet stream over the North Atlantic 3 d prior to cyclogenesis that propagated into the Mediterranean. They led to an uncertain position of the upper-level disturbance and, as a result, of the position and thermal structure of the cyclone.
Hanin Binder, Maxi Boettcher, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 577–595, https://doi.org/10.5194/wcd-1-577-2020, https://doi.org/10.5194/wcd-1-577-2020, 2020
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Warm conveyor belts (WCBs) are important cloud- and
precipitation-producing airstreams in extratropical cyclones. By combining satellite observations with model data from a new reanalysis dataset, this study provides detailed observational insight into the vertical cloud structure of WCBs. We find that the reanalyses essentially capture the observed cloud pattern, but the observations reveal mesoscale structures not resolved by the temporally and spatially much coarser-resolution model data.
Hirofumi Ohyama, Isamu Morino, Voltaire A. Velazco, Theresa Klausner, Gerry Bagtasa, Matthäus Kiel, Matthias Frey, Akihiro Hori, Osamu Uchino, Tsuneo Matsunaga, Nicholas M. Deutscher, Joshua P. DiGangi, Yonghoon Choi, Glenn S. Diskin, Sally E. Pusede, Alina Fiehn, Anke Roiger, Michael Lichtenstern, Hans Schlager, Pao K. Wang, Charles C.-K. Chou, Maria Dolores Andrés-Hernández, and John P. Burrows
Atmos. Meas. Tech., 13, 5149–5163, https://doi.org/10.5194/amt-13-5149-2020, https://doi.org/10.5194/amt-13-5149-2020, 2020
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Column-averaged dry-air mole fractions of CO2 and CH4 measured by a solar viewing portable Fourier transform spectrometer (EM27/SUN) were validated with in situ profile data obtained during the transfer flights of two aircraft campaigns. Atmospheric dynamical properties based on ERA5 and WRF-Chem were used as criteria for selecting the best aircraft profiles for the validation. The resulting air-mass-independent correction factors for the EM27/SUN data were 0.9878 for CO2 and 0.9829 for CH4.
Mauro Hermann, Lukas Papritz, and Heini Wernli
Weather Clim. Dynam., 1, 497–518, https://doi.org/10.5194/wcd-1-497-2020, https://doi.org/10.5194/wcd-1-497-2020, 2020
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We find, by tracing backward in time, that air masses causing extensive melt of the Greenland Ice Sheet originate from further south and lower altitudes than usual. Their exceptional warmth further arises due to ascent and cloud formation, which is special compared to near-surface heat waves in the midlatitudes or the central Arctic. The atmospheric systems and transport pathways identified here are crucial in understanding and simulating the atmospheric control of the ice sheet in the future.
Sebastian Schemm, Stefan Rüdisühli, and Michael Sprenger
Weather Clim. Dynam., 1, 459–479, https://doi.org/10.5194/wcd-1-459-2020, https://doi.org/10.5194/wcd-1-459-2020, 2020
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Troughs and ridges are ubiquitous flow features in the upper troposphere and are centerpiece elements of weather and climate research. A novel method is introduced to identify and track the life cycle of troughs and ridges and their orientation. The aim is to close the existing gap between methods that detect the initiation phase and methods that detect the decaying phase of Rossby wave development. Global climatologies, the influence of ENSO and Lagrangian characteristics are discussed.
Daniel Steinfeld, Maxi Boettcher, Richard Forbes, and Stephan Pfahl
Weather Clim. Dynam., 1, 405–426, https://doi.org/10.5194/wcd-1-405-2020, https://doi.org/10.5194/wcd-1-405-2020, 2020
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The effect of latent heating on atmospheric blocking is investigated using numerical sensitivity experiments. The modification of latent heating in the upstream cyclone has substantial effects on the upper-tropospheric circulation, demonstrating that some blocking systems do not develop at all without upstream latent heating. The results highlight the importance of moist-diabatic processes for the dynamics of prolonged anticyclonic circulation anomalies.
Yongbiao Weng, Alexandra Touzeau, and Harald Sodemann
Atmos. Meas. Tech., 13, 3167–3190, https://doi.org/10.5194/amt-13-3167-2020, https://doi.org/10.5194/amt-13-3167-2020, 2020
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We find that the known mixing ratio dependence of laser spectrometers for water vapour isotope measurements varies with isotope composition. We have developed a scheme to correct for this isotope-composition-dependent bias. The correction is most substantial at low mixing ratios. Stability tests indicate that the first-order dependency is a constant instrument characteristic. Water vapour isotope measurements at low mixing ratios can now be corrected by following our proposed procedure.
Nicolas Jullien, Étienne Vignon, Michael Sprenger, Franziska Aemisegger, and Alexis Berne
The Cryosphere, 14, 1685–1702, https://doi.org/10.5194/tc-14-1685-2020, https://doi.org/10.5194/tc-14-1685-2020, 2020
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Although snowfall is the main input of water to the Antarctic ice sheet, snowflakes are often evaporated by dry and fierce winds near the surface of the continent. The amount of snow that actually reaches the ground is therefore considerably reduced. By analyzing the position of cyclones and fronts as well as by back-tracing the atmospheric moisture pathway towards Antarctica, this study explains in which meteorological conditions snowfall is either completely evaporated or reaches the ground.
Floor van den Heuvel, Loris Foresti, Marco Gabella, Urs Germann, and Alexis Berne
Atmos. Meas. Tech., 13, 2481–2500, https://doi.org/10.5194/amt-13-2481-2020, https://doi.org/10.5194/amt-13-2481-2020, 2020
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In areas with reduced visibility at the ground level, radar precipitation measurements higher up in the atmosphere need to be extrapolated to the ground and be corrected for the vertical change (i.e. growth and transformation) of precipitation. This study proposes a method based on hydrometeor proportions and machine learning (ML) to apply these corrections at smaller spatiotemporal scales. In comparison with existing techniques, the ML methods can make predictions from higher altitudes.
Iris Thurnherr, Anna Kozachek, Pascal Graf, Yongbiao Weng, Dimitri Bolshiyanov, Sebastian Landwehr, Stephan Pfahl, Julia Schmale, Harald Sodemann, Hans Christian Steen-Larsen, Alessandro Toffoli, Heini Wernli, and Franziska Aemisegger
Atmos. Chem. Phys., 20, 5811–5835, https://doi.org/10.5194/acp-20-5811-2020, https://doi.org/10.5194/acp-20-5811-2020, 2020
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Stable water isotopes (SWIs) are tracers of moist atmospheric processes. We analyse the impact of large- to small-scale atmospheric processes and various environmental conditions on the variability of SWIs using ship-based SWI measurement in water vapour from the Atlantic and Southern Ocean. Furthermore, simultaneous measurements of SWIs at two altitudes are used to illustrate the potential of such measurements for future research to estimate sea spray evaporation and turbulent moisture fluxes.
Philipp Zschenderlein, Stephan Pfahl, Heini Wernli, and Andreas H. Fink
Weather Clim. Dynam., 1, 191–206, https://doi.org/10.5194/wcd-1-191-2020, https://doi.org/10.5194/wcd-1-191-2020, 2020
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We analyse the formation of upper-tropospheric anticyclones connected to European surface heat waves. Tracing air masses backwards from these anticyclones, we found that trajectories are diabatically heated in two branches, either by North Atlantic cyclones or by convection closer to the heat wave anticyclone. The first branch primarily affects the onset of the anticyclone, while the second branch is more relevant for the maintenance. Our results are relevant for heat wave predictions.
Bruna A. Holanda, Mira L. Pöhlker, David Walter, Jorge Saturno, Matthias Sörgel, Jeannine Ditas, Florian Ditas, Christiane Schulz, Marco Aurélio Franco, Qiaoqiao Wang, Tobias Donth, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Ramon Braga, Joel Brito, Yafang Cheng, Maximilian Dollner, Johannes W. Kaiser, Thomas Klimach, Christoph Knote, Ovid O. Krüger, Daniel Fütterer, Jošt V. Lavrič, Nan Ma, Luiz A. T. Machado, Jing Ming, Fernando G. Morais, Hauke Paulsen, Daniel Sauer, Hans Schlager, Johannes Schneider, Hang Su, Bernadett Weinzierl, Adrian Walser, Manfred Wendisch, Helmut Ziereis, Martin Zöger, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Chem. Phys., 20, 4757–4785, https://doi.org/10.5194/acp-20-4757-2020, https://doi.org/10.5194/acp-20-4757-2020, 2020
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Biomass burning smoke from African savanna and grassland is transported across the South Atlantic Ocean in defined layers within the free troposphere. The combination of in situ aircraft and ground-based measurements aided by satellite observations showed that these layers are transported into the Amazon Basin during the early dry season. The influx of aged smoke, enriched in black carbon and cloud condensation nuclei, has important implications for the Amazonian aerosol and cloud cycling.
Annika Oertel, Maxi Boettcher, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 127–153, https://doi.org/10.5194/wcd-1-127-2020, https://doi.org/10.5194/wcd-1-127-2020, 2020
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Warm conveyor belts (WCBs) are important, mainly stratiform cloud forming airstreams in extratropical cyclones that can include embedded convection. This WCB case study systematically compares the characteristics of convective vs. slantwise ascent of the WCB. We find that embedded convection leads to regions of significantly stronger precipitation. Moreover, it strongly modifies the potential vorticity distribution in the lower and upper troposphere, where its also influences the waveguide.
Mattia Righi, Johannes Hendricks, Ulrike Lohmann, Christof Gerhard Beer, Valerian Hahn, Bernd Heinold, Romy Heller, Martina Krämer, Michael Ponater, Christian Rolf, Ina Tegen, and Christiane Voigt
Geosci. Model Dev., 13, 1635–1661, https://doi.org/10.5194/gmd-13-1635-2020, https://doi.org/10.5194/gmd-13-1635-2020, 2020
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A new cloud microphysical scheme is implemented in the global EMAC-MADE3 aerosol model and evaluated. The new scheme features a detailed parameterization for aerosol-driven ice formation in cirrus clouds, accounting for the competition between homogeneous and heterogeneous ice formation processes. The comparison against satellite data and in situ measurements shows that the model performance is in line with similar global coupled models featuring ice cloud parameterizations.
Matthias Röthlisberger, Michael Sprenger, Emmanouil Flaounas, Urs Beyerle, and Heini Wernli
Weather Clim. Dynam., 1, 45–62, https://doi.org/10.5194/wcd-1-45-2020, https://doi.org/10.5194/wcd-1-45-2020, 2020
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In this study we quantify how much the coldest, middle and hottest third of all days during extremely hot summers contribute to their respective seasonal mean anomaly. This
extreme-summer substructurevaries substantially across the Northern Hemisphere and is directly related to the local physical drivers of extreme summers. Furthermore, comparing re-analysis (i.e. measurement-based) and climate model extreme-summer substructures reveals a remarkable level of agreement.
Fan Mei, Jian Wang, Jennifer M. Comstock, Ralf Weigel, Martina Krämer, Christoph Mahnke, John E. Shilling, Johannes Schneider, Christiane Schulz, Charles N. Long, Manfred Wendisch, Luiz A. T. Machado, Beat Schmid, Trismono Krisna, Mikhail Pekour, John Hubbe, Andreas Giez, Bernadett Weinzierl, Martin Zoeger, Mira L. Pöhlker, Hans Schlager, Micael A. Cecchini, Meinrat O. Andreae, Scot T. Martin, Suzane S. de Sá, Jiwen Fan, Jason Tomlinson, Stephen Springston, Ulrich Pöschl, Paulo Artaxo, Christopher Pöhlker, Thomas Klimach, Andreas Minikin, Armin Afchine, and Stephan Borrmann
Atmos. Meas. Tech., 13, 661–684, https://doi.org/10.5194/amt-13-661-2020, https://doi.org/10.5194/amt-13-661-2020, 2020
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In 2014, the US DOE G1 aircraft and the German HALO aircraft overflew the Amazon basin to study how aerosols influence cloud cycles under a clean condition and around a tropical megacity. This paper describes how to meaningfully compare similar measurements from two research aircraft and identify the potential measurement issue. We also discuss the uncertainty range for each measurement for further usage in model evaluation and satellite data validation.
Pascal Polonik, Christoph Knote, Tobias Zinner, Florian Ewald, Tobias Kölling, Bernhard Mayer, Meinrat O. Andreae, Tina Jurkat-Witschas, Thomas Klimach, Christoph Mahnke, Sergej Molleker, Christopher Pöhlker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, Christiane Voigt, Ralf Weigel, and Manfred Wendisch
Atmos. Chem. Phys., 20, 1591–1605, https://doi.org/10.5194/acp-20-1591-2020, https://doi.org/10.5194/acp-20-1591-2020, 2020
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A realistic representation of cloud–aerosol interactions is central to accurate climate projections. Here we combine observations collected during the ACRIDICON-CHUVA campaign with chemistry-transport simulations to evaluate the model’s ability to represent the indirect effects of biomass burning aerosol on cloud microphysics. We find an upper limit for the model sensitivity on cloud condensation nuclei concentrations well below the levels reached during the burning season in the Amazon Basin.
Benedetto De Rosa, Paolo Di Girolamo, and Donato Summa
Atmos. Meas. Tech., 13, 405–427, https://doi.org/10.5194/amt-13-405-2020, https://doi.org/10.5194/amt-13-405-2020, 2020
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Temperature and water vapour profiles measured by the BASIL lidar are compared with profiles from several sensors/models, namely radiosondes, the IASI and AIRS satellite sensors and model reanalyses data (ECMWF & ECMWF-ERA). The comparison effort allows for the performance of all of the sensors and models to be assessed in terms of bias and RMS deviation. BASIL measurement quality is confirmed to be high enough for long-term monitoring of atmospheric composition and thermal structure changes.
Thomas Trickl, Hannes Vogelmann, Ludwig Ries, and Michael Sprenger
Atmos. Chem. Phys., 20, 243–266, https://doi.org/10.5194/acp-20-243-2020, https://doi.org/10.5194/acp-20-243-2020, 2020
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Ozone transfer from the stratosphere to the troposphere seems to to have grown over the past decade, parallel to global warming. Lidar measurements, carried out in Garmisch-Partenkirchen, Germany, between 2007 and 2016 show a considerable stratospheric influence in the free troposphere over these sites, with observations of stratospheric layers in the troposphere on 84 % of the measurement days. This high fraction is almost reached also in North America, but frequently not throughout the year.
Ignacio Pisso, Espen Sollum, Henrik Grythe, Nina I. Kristiansen, Massimo Cassiani, Sabine Eckhardt, Delia Arnold, Don Morton, Rona L. Thompson, Christine D. Groot Zwaaftink, Nikolaos Evangeliou, Harald Sodemann, Leopold Haimberger, Stephan Henne, Dominik Brunner, John F. Burkhart, Anne Fouilloux, Jerome Brioude, Anne Philipp, Petra Seibert, and Andreas Stohl
Geosci. Model Dev., 12, 4955–4997, https://doi.org/10.5194/gmd-12-4955-2019, https://doi.org/10.5194/gmd-12-4955-2019, 2019
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We present the latest release of the Lagrangian transport model FLEXPART, which simulates the transport, diffusion, dry and wet deposition, radioactive decay, and 1st-order chemical reactions of atmospheric tracers. The model has been recently updated both technically and in the representation of physicochemical processes. We describe the changes, document the most recent input and output files, provide working examples, and introduce testing capabilities.
Jordi Figueras i Ventura, Nicolau Pineda, Nikola Besic, Jacopo Grazioli, Alessandro Hering, Oscar A. van der Velde, David Romero, Antonio Sunjerga, Amirhossein Mostajabi, Mohammad Azadifar, Marcos Rubinstein, Joan Montanyà, Urs Germann, and Farhad Rachidi
Atmos. Meas. Tech., 12, 5573–5591, https://doi.org/10.5194/amt-12-5573-2019, https://doi.org/10.5194/amt-12-5573-2019, 2019
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This paper presents an analysis of the lightning production of convective cells. Polarimetric weather radar data were used to identify and characterize the convective cells while lightning was detected using the EUCLID network and a lightning mapping array deployed during the summer of 2017 in the northeastern part of Switzerland. In it we show that there is a good correlation between the height of the rimed-particle column and the intensity of the lightning activity in the convective cell.
Seppo Pulkkinen, Daniele Nerini, Andrés A. Pérez Hortal, Carlos Velasco-Forero, Alan Seed, Urs Germann, and Loris Foresti
Geosci. Model Dev., 12, 4185–4219, https://doi.org/10.5194/gmd-12-4185-2019, https://doi.org/10.5194/gmd-12-4185-2019, 2019
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Reliable precipitation forecasts are vital for the society, as water-related hazards can cause economic losses and loss of lives. Pysteps is an open-source Python library for radar-based precipitation forecasting. It aims to be a well-documented platform for development of new methods as well as an easy-to-use tool for practitioners. The potential of the library is demonstrated by case studies and scientific experiments using radar data from Finland, Switzerland, the United States and Australia.
Vanessa Brocchi, Gisèle Krysztofiak, Adrien Deroubaix, Greta Stratmann, Daniel Sauer, Hans Schlager, Konrad Deetz, Guillaume Dayma, Claude Robert, Stéphane Chevrier, and Valéry Catoire
Atmos. Chem. Phys., 19, 11401–11411, https://doi.org/10.5194/acp-19-11401-2019, https://doi.org/10.5194/acp-19-11401-2019, 2019
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This study reports the first flaring in situ measurements in southern West Africa. According to the measurements, oil rig flaring plumes in Ghana lead to increases in NO2 and aerosols but not always in CO and not in SO2. Flaring measurements can be reproduced using FLEXPART model, adjusting both the emission flux and the injection height. The DACCIWA satellite flaring inventory provides a reasonable estimate of flaring emission.
Andreas Marsing, Tina Jurkat-Witschas, Jens-Uwe Grooß, Stefan Kaufmann, Romy Heller, Andreas Engel, Peter Hoor, Jens Krause, and Christiane Voigt
Atmos. Chem. Phys., 19, 10757–10772, https://doi.org/10.5194/acp-19-10757-2019, https://doi.org/10.5194/acp-19-10757-2019, 2019
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We study the partitioning of inorganic chlorine into active (ozone-depleting) and reservoir species in the lowermost stratosphere of the Arctic polar vortex, using novel in situ aircraft measurements in winter 2015/2016. We observe a change in recovery pathways of the reservoirs HCl and ClONO2 with increasing potential temperature. A comparison with the CLaMS model relates the observations to the vortex-wide evolution and confirms unresolved discrepancies in the mid-winter HCl distribution.
Nadia Fourrié, Mathieu Nuret, Pierre Brousseau, Olivier Caumont, Alexis Doerenbecher, Eric Wattrelot, Patrick Moll, Hervé Bénichou, Dominique Puech, Olivier Bock, Pierre Bosser, Patrick Chazette, Cyrille Flamant, Paolo Di Girolamo, Evelyne Richard, and Frédérique Saïd
Geosci. Model Dev., 12, 2657–2678, https://doi.org/10.5194/gmd-12-2657-2019, https://doi.org/10.5194/gmd-12-2657-2019, 2019
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The AROME-WMED (western Mediterranean) model is a dedicated version of the mesoscale Numerical Weather Prediction AROME-France model that ran in real time during the first special observation period of HyMeX. Two reanalyses were performed after the campaign. This paper depicts the main differences between the real-time version and the benefits brought by both HyMeX reanalyses. The second reanalysis is found to be closer to observations than the previous AROME-WMED analyses.
Jonathan W. Taylor, Sophie L. Haslett, Keith Bower, Michael Flynn, Ian Crawford, James Dorsey, Tom Choularton, Paul J. Connolly, Valerian Hahn, Christiane Voigt, Daniel Sauer, Régis Dupuy, Joel Brito, Alfons Schwarzenboeck, Thierry Bourriane, Cyrielle Denjean, Phil Rosenberg, Cyrille Flamant, James D. Lee, Adam R. Vaughan, Peter G. Hill, Barbara Brooks, Valéry Catoire, Peter Knippertz, and Hugh Coe
Atmos. Chem. Phys., 19, 8503–8522, https://doi.org/10.5194/acp-19-8503-2019, https://doi.org/10.5194/acp-19-8503-2019, 2019
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Low-level clouds cover a wide area of southern West Africa (SWA) and play an important role in the region's climate, reflecting sunlight away from the surface. We performed aircraft measurements of aerosols and clouds over SWA during the 2016 summer monsoon and found pollution, and polluted clouds, across the whole region. Smoke from biomass burning in Central Africa is transported to West Africa, causing a polluted background which limits the effect of local pollution on cloud properties.
Astrid Fremme and Harald Sodemann
Hydrol. Earth Syst. Sci., 23, 2525–2540, https://doi.org/10.5194/hess-23-2525-2019, https://doi.org/10.5194/hess-23-2525-2019, 2019
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This study examines the evaporation sources of precipitation falling over the Yangtze River valley on China's east coast. The summer monsoon rainfall causes large seasonal and interannual variations which affect a large population. We found that evaporation from surrounding land regions is important, supplying more than half of the summertime precipitation. Extreme dry and wet summers are connected to contributions from specific land and ocean regions.
Jordi Figueras i Ventura, Nicolau Pineda, Nikola Besic, Jacopo Grazioli, Alessandro Hering, Oscar A. van der Velde, David Romero, Antonio Sunjerga, Amirhossein Mostajabi, Mohammad Azadifar, Marcos Rubinstein, Joan Montanyà, Urs Germann, and Farhad Rachidi
Atmos. Meas. Tech., 12, 2881–2911, https://doi.org/10.5194/amt-12-2881-2019, https://doi.org/10.5194/amt-12-2881-2019, 2019
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This paper presents an analysis of a large dataset of lightning and polarimetric weather radar data collected over the course of a lightning measurement campaign that took place in the summer of 2017 in the area surrounding Säntis in northeastern Switzerland. We show that polarimetric weather radar data can be helpful in determining regions where lightning is more likely to occur, which is a first step towards a lightning nowcasting system.
Bojan Škerlak, Stephan Pfahl, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 19, 6535–6549, https://doi.org/10.5194/acp-19-6535-2019, https://doi.org/10.5194/acp-19-6535-2019, 2019
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Upper-level fronts are often associated with the rapid transport of stratospheric air to the lower troposphere, leading to significantly enhanced ozone concentrations. This paper considers the multi-scale nature that is needed to bring stratospheric air down to the surface. The final transport step to the surface can be related to frontal zones and the associated vertical winds or to near-horizontal tracer transport followed by entrainment into a growing planetary boundary layer.
Dario Stelitano, Paolo Di Girolamo, Andrea Scoccione, Donato Summa, and Marco Cacciani
Atmos. Meas. Tech., 12, 2183–2199, https://doi.org/10.5194/amt-12-2183-2019, https://doi.org/10.5194/amt-12-2183-2019, 2019
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Vertical profiles of the particle backscattering coefficient at 355, 532 and 1064 nm measured by the Raman lidar system BASIL are compared with simulated particle backscatter profiles obtained through the application of a Mie scattering code and the use of simultaneous and co-located measurements by an optical particle counter on board the French research aircraft ATR42 operated by SAFIRE in the framework of the Hydrological Cycle in the Mediterranean Experiment – Special Observation Period 1.
Pascal Graf, Heini Wernli, Stephan Pfahl, and Harald Sodemann
Atmos. Chem. Phys., 19, 747–765, https://doi.org/10.5194/acp-19-747-2019, https://doi.org/10.5194/acp-19-747-2019, 2019
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This article studies the interaction between falling rain and vapour with stable water isotopes. In particular, rain evaporation is relevant for several atmospheric processes, but remains difficult to quantify. A novel framework is introduced to facilitate the interpretation of stable water isotope observations in near-surface vapour and rain. The usefulness of this concept is demonstrated using observations at high time resolution from a cold front. Sensitivities are tested with a simple model.
Michael Weger, Bernd Heinold, Christa Engler, Ulrich Schumann, Axel Seifert, Romy Fößig, Christiane Voigt, Holger Baars, Ulrich Blahak, Stephan Borrmann, Corinna Hoose, Stefan Kaufmann, Martina Krämer, Patric Seifert, Fabian Senf, Johannes Schneider, and Ina Tegen
Atmos. Chem. Phys., 18, 17545–17572, https://doi.org/10.5194/acp-18-17545-2018, https://doi.org/10.5194/acp-18-17545-2018, 2018
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The impact of desert dust on cloud formation is investigated for a major Saharan dust event over Europe by interactive regional dust modeling. Dust particles are very efficient ice-nucleating particles promoting the formation of ice crystals in clouds. The simulations show that the observed extensive cirrus development was likely related to the above-average dust load. The interactive dust–cloud feedback in the model significantly improves the agreement with aircraft and satellite observations.
Stefan Kaufmann, Christiane Voigt, Romy Heller, Tina Jurkat-Witschas, Martina Krämer, Christian Rolf, Martin Zöger, Andreas Giez, Bernhard Buchholz, Volker Ebert, Troy Thornberry, and Ulrich Schumann
Atmos. Chem. Phys., 18, 16729–16745, https://doi.org/10.5194/acp-18-16729-2018, https://doi.org/10.5194/acp-18-16729-2018, 2018
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We present an intercomparison of the airborne water vapor measurements during the ML-CIRRUS mission. Although the agreement of the hygrometers significantly improved compared to studies from recent decades, systematic differences remain under specific meteorological conditions. We compare the measurements to model data, where we observe a model wet bias in the lower stratosphere close to the tropopause, likely caused by a blurred humidity gradient in the model tropopause.
Simone Brunamonti, Teresa Jorge, Peter Oelsner, Sreeharsha Hanumanthu, Bhupendra B. Singh, K. Ravi Kumar, Sunil Sonbawne, Susanne Meier, Deepak Singh, Frank G. Wienhold, Bei Ping Luo, Maxi Boettcher, Yann Poltera, Hannu Jauhiainen, Rijan Kayastha, Jagadishwor Karmacharya, Ruud Dirksen, Manish Naja, Markus Rex, Suvarna Fadnavis, and Thomas Peter
Atmos. Chem. Phys., 18, 15937–15957, https://doi.org/10.5194/acp-18-15937-2018, https://doi.org/10.5194/acp-18-15937-2018, 2018
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Based on balloon-borne measurements performed in India and Nepal in 2016–2017, we infer the vertical distributions of water vapor, ozone and aerosols in the atmosphere, from the surface to 30 km altitude. Our measurements show that the atmospheric dynamics of the Asian summer monsoon system over the polluted Indian subcontinent lead to increased concentrations of water vapor and aerosols in the high atmosphere (approximately 14–20 km altitude), which can have an important effect on climate.
Christiane Voigt, Andreas Dörnbrack, Martin Wirth, Silke M. Groß, Michael C. Pitts, Lamont R. Poole, Robert Baumann, Benedikt Ehard, Björn-Martin Sinnhuber, Wolfgang Woiwode, and Hermann Oelhaf
Atmos. Chem. Phys., 18, 15623–15641, https://doi.org/10.5194/acp-18-15623-2018, https://doi.org/10.5194/acp-18-15623-2018, 2018
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The 2015–2016 stratospheric winter was the coldest in the 36-year climatological data record. The extreme conditions promoted the formation of persistent Arctic polar stratospheric ice clouds. An extended ice PSC detected by airborne lidar in January 2016 shows a second mode with higher particle depolarization ratios. Back-trajectories from the high-depol ice matched to CALIOP PSC curtains provide evidence for ice nucleation on NAT. The novel data consolidate our understanding of PSC formation.
Christiane Schulz, Johannes Schneider, Bruna Amorim Holanda, Oliver Appel, Anja Costa, Suzane S. de Sá, Volker Dreiling, Daniel Fütterer, Tina Jurkat-Witschas, Thomas Klimach, Christoph Knote, Martina Krämer, Scot T. Martin, Stephan Mertes, Mira L. Pöhlker, Daniel Sauer, Christiane Voigt, Adrian Walser, Bernadett Weinzierl, Helmut Ziereis, Martin Zöger, Meinrat O. Andreae, Paulo Artaxo, Luiz A. T. Machado, Ulrich Pöschl, Manfred Wendisch, and Stephan Borrmann
Atmos. Chem. Phys., 18, 14979–15001, https://doi.org/10.5194/acp-18-14979-2018, https://doi.org/10.5194/acp-18-14979-2018, 2018
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Aerosol chemical composition measurements in the tropical upper troposphere over the Amazon region show that 78 % of the aerosol in the upper troposphere consists of organic matter. Up to 20 % of the organic aerosol can be attributed to isoprene epoxydiol secondary organic aerosol (IEPOX-SOA). Furthermore, organic nitrates were identified, suggesting a connection to the IEPOX-SOA formation.
Franziska Gerber, Nikola Besic, Varun Sharma, Rebecca Mott, Megan Daniels, Marco Gabella, Alexis Berne, Urs Germann, and Michael Lehning
The Cryosphere, 12, 3137–3160, https://doi.org/10.5194/tc-12-3137-2018, https://doi.org/10.5194/tc-12-3137-2018, 2018
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A comparison of winter precipitation variability in operational radar measurements and high-resolution simulations reveals that large-scale variability is well captured by the model, depending on the event. Precipitation variability is driven by topography and wind. A good portion of small-scale variability is captured at the highest resolution. This is essential to address small-scale precipitation processes forming the alpine snow seasonal snow cover – an important source of water.
Floor van den Heuvel, Marco Gabella, Urs Germann, and Alexis Berne
Atmos. Meas. Tech., 11, 5181–5198, https://doi.org/10.5194/amt-11-5181-2018, https://doi.org/10.5194/amt-11-5181-2018, 2018
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The paper aims at characterising and quantifying the spatio-temporal variability of the melting layer (ML; transition zone from solid to liquid precipitation). A method based on the Fourier transform is found to accurately describe different ML signatures. Hence, it is applied to characterise the ML variability in a relatively flat area and in an inner Alpine valley in Switzerland, where the variability at smaller spatial scales is found to be relatively more important.
Nikola Besic, Josué Gehring, Christophe Praz, Jordi Figueras i Ventura, Jacopo Grazioli, Marco Gabella, Urs Germann, and Alexis Berne
Atmos. Meas. Tech., 11, 4847–4866, https://doi.org/10.5194/amt-11-4847-2018, https://doi.org/10.5194/amt-11-4847-2018, 2018
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In this paper we propose an innovative approach for hydrometeor de-mixing, i.e., to identify and quantify the presence of mixtures of different hydrometeor types in a radar sampling volume. It is a bin-based approach, inspired by conventional decomposition methods and evaluated using C- and X-band radar measurements compared with synchronous ground observations. The paper also investigates the potential influence of incoherency in the backscattering from hydrometeor mixtures in a radar volume.
Sören Johansson, Wolfgang Woiwode, Michael Höpfner, Felix Friedl-Vallon, Anne Kleinert, Erik Kretschmer, Thomas Latzko, Johannes Orphal, Peter Preusse, Jörn Ungermann, Michelle L. Santee, Tina Jurkat-Witschas, Andreas Marsing, Christiane Voigt, Andreas Giez, Martina Krämer, Christian Rolf, Andreas Zahn, Andreas Engel, Björn-Martin Sinnhuber, and Hermann Oelhaf
Atmos. Meas. Tech., 11, 4737–4756, https://doi.org/10.5194/amt-11-4737-2018, https://doi.org/10.5194/amt-11-4737-2018, 2018
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We present two-dimensional cross sections of temperature, HNO3, O3, ClONO2, H2O and CFC-12 from measurements of the GLORIA infrared limb imager during the POLSTRACC/GW-LCYCLE/SALSA aircraft campaigns in the Arctic winter 2015/2016. GLORIA sounded the atmosphere between 5 and 14 km with vertical resolutions of 0.4–1 km. Estimated errors are in the range of 1–2 K (temperature) and 10 %–20 % (trace gases). Comparisons to in situ instruments onboard the aircraft and to Aura/MLS are shown.
Aurélien Chauvigné, Olivier Jourdan, Alfons Schwarzenboeck, Christophe Gourbeyre, Jean François Gayet, Christiane Voigt, Hans Schlager, Stefan Kaufmann, Stephan Borrmann, Sergej Molleker, Andreas Minikin, Tina Jurkat, and Ulrich Schumann
Atmos. Chem. Phys., 18, 9803–9822, https://doi.org/10.5194/acp-18-9803-2018, https://doi.org/10.5194/acp-18-9803-2018, 2018
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This paper demonstrates a new form of statistical analysis of contrail to cirrus evolution. The authors show well-separated analyses of the different stages of the contrail's evolution, which allows us to study their optical, microphysical, and chemical properties. These results could be used to develop representative parameterizations of the scattering and geometrical properties of the ice crystals’ shapes and sizes, observed in the visible wavelength range.
Armin Afchine, Christian Rolf, Anja Costa, Nicole Spelten, Martin Riese, Bernhard Buchholz, Volker Ebert, Romy Heller, Stefan Kaufmann, Andreas Minikin, Christiane Voigt, Martin Zöger, Jessica Smith, Paul Lawson, Alexey Lykov, Sergey Khaykin, and Martina Krämer
Atmos. Meas. Tech., 11, 4015–4031, https://doi.org/10.5194/amt-11-4015-2018, https://doi.org/10.5194/amt-11-4015-2018, 2018
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The ice water content (IWC) of cirrus clouds is an essential parameter that determines their radiative properties and is thus important for climate simulations. Experimental investigations of IWCs measured on board research aircraft reveal that their accuracy is influenced by the sampling position. IWCs detected at the aircraft roof deviate significantly from wing, side or bottom IWCs. The reasons are deflections of the gas streamlines and ice particle trajectories behind the aircraft cockpit.
Oliver Lux, Christian Lemmerz, Fabian Weiler, Uwe Marksteiner, Benjamin Witschas, Stephan Rahm, Andreas Schäfler, and Oliver Reitebuch
Atmos. Meas. Tech., 11, 3297–3322, https://doi.org/10.5194/amt-11-3297-2018, https://doi.org/10.5194/amt-11-3297-2018, 2018
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This work reports airborne wind lidar observations performed in a recent field campaign. The deployed lidar system serves as a demonstrator for the satellite instrument ALADIN on board Aeolus, which is scheduled for launch in 2018 and will become the first wind lidar in space. After presenting the measurement principle, operation procedures and wind retrieval algorithm, the obtained wind results are validated and discussed, providing valuable information in preparation for the satellite mission.
Stephan E. Bansmer, Arne Baumert, Stephan Sattler, Inken Knop, Delphine Leroy, Alfons Schwarzenboeck, Tina Jurkat-Witschas, Christiane Voigt, Hugo Pervier, and Biagio Esposito
Atmos. Meas. Tech., 11, 3221–3249, https://doi.org/10.5194/amt-11-3221-2018, https://doi.org/10.5194/amt-11-3221-2018, 2018
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Snow, frost formation and ice cubes in our drinks are part of our daily life. But what about our technical innovations like aviation, electrical power transmission and wind-energy production, can they cope with icing? Icing Wind Tunnels are an ideal laboratory environment to answer that question. In this paper, we show how the icing wind tunnel in Braunschweig (Germany) was built and how we can use it for engineering and climate research.
Klaus-Dirk Gottschaldt, Hans Schlager, Robert Baumann, Duy Sinh Cai, Veronika Eyring, Phoebe Graf, Volker Grewe, Patrick Jöckel, Tina Jurkat-Witschas, Christiane Voigt, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 18, 5655–5675, https://doi.org/10.5194/acp-18-5655-2018, https://doi.org/10.5194/acp-18-5655-2018, 2018
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This study places aircraft trace gas measurements from within the Asian summer monsoon anticyclone into the context of regional, intra- and interannual variability. We find that the processes reflected in the measurements are present throughout multiple simulated monsoon seasons. Dynamical instabilities, photochemical ozone production, lightning and entrainments from the lower troposphere and from the tropopause region determine the distinct composition of the anticyclone and its outflow.
Paolo Di Girolamo, Andrea Scoccione, Marco Cacciani, Donato Summa, Benedetto De Rosa, and Jan H. Schween
Atmos. Chem. Phys., 18, 4885–4896, https://doi.org/10.5194/acp-18-4885-2018, https://doi.org/10.5194/acp-18-4885-2018, 2018
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The paper illustrates what we believe are the first measurements of a phenomenon taking place in upper portion of the convective boundary layer in clear-air conditions leading to the appearance of a persistent minimum in lidar backscatter echoes, with alternating intensifications and attenuations. The paper gives experimental evidence of the phenomenon and provides possible interpretations for its occurrence referring to both hygroscopic and scattering properties of sounded aerosol particles.
Trismono C. Krisna, Manfred Wendisch, André Ehrlich, Evelyn Jäkel, Frank Werner, Ralf Weigel, Stephan Borrmann, Christoph Mahnke, Ulrich Pöschl, Meinrat O. Andreae, Christiane Voigt, and Luiz A. T. Machado
Atmos. Chem. Phys., 18, 4439–4462, https://doi.org/10.5194/acp-18-4439-2018, https://doi.org/10.5194/acp-18-4439-2018, 2018
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The optical thickness and particle effective radius of a cirrus above liquid water clouds and a DCC topped by an anvil cirrus are retrieved based on SMART and MODIS radiance measurements. For the cirrus, retrieved particle effective radius are validated with corresponding in situ data using a vertical weighting method. This approach allows to assess the measurements, retrieval algorithms, and derived cloud products.
Frédérique Saïd, Bernard Campistron, and Paolo Di Girolamo
Atmos. Meas. Tech., 11, 1669–1688, https://doi.org/10.5194/amt-11-1669-2018, https://doi.org/10.5194/amt-11-1669-2018, 2018
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Vertical profiles of the atmospheric water vapor mixing ratio are retrieved with an algorithm based on the combination of measurements from a wind profiler radar and radiosoundings at a coarser time resolution. The major advance with respect to previous works is the use of the radar capacity to detect transition levels, such as the top level of the boundary layer, marked by a maximum in the radar reflectivity.
Yulan Zhang, Shichang Kang, Michael Sprenger, Zhiyuan Cong, Tanguang Gao, Chaoliu Li, Shu Tao, Xiaofei Li, Xinyue Zhong, Min Xu, Wenjun Meng, Bigyan Neupane, Xiang Qin, and Mika Sillanpää
The Cryosphere, 12, 413–431, https://doi.org/10.5194/tc-12-413-2018, https://doi.org/10.5194/tc-12-413-2018, 2018
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Light-absorbing impurities deposited on snow can reduce surface albedo and contribute to the near-worldwide melting of snowpack and ice. This study focused on the black carbon and mineral dust in snow cover on the Tibetan Plateau. We discussed their concentrations, distributions, possible sources, and albedo reduction and radiative forcing. Findings indicated that the impacts of black carbon and mineral dust need to be properly accounted for in future regional climate projections.
Marina Dütsch, Stephan Pfahl, Miro Meyer, and Heini Wernli
Atmos. Chem. Phys., 18, 1653–1669, https://doi.org/10.5194/acp-18-1653-2018, https://doi.org/10.5194/acp-18-1653-2018, 2018
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Atmospheric processes are imprinted in the concentrations of stable water isotopes. Therefore, isotopes can be used to gain insight into these processes and improve our understanding of the water cycle. In this study, we present a new method that quantitatively shows which atmospheric processes influence isotope concentrations in near-surface water vapour over Europe. We found that the most important processes are evaporation from the ocean, evapotranspiration from land, and turbulent mixing.
Thomas Trickl, Hannes Vogelmann, Ludwig Ries, Hans-Eckhart Scheel, and Michael Sprenger
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-1192, https://doi.org/10.5194/acp-2017-1192, 2018
Revised manuscript not accepted
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
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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.
Romy Heller, Christiane Voigt, Stuart Beaton, Andreas Dörnbrack, Andreas Giez, Stefan Kaufmann, Christian Mallaun, Hans Schlager, Johannes Wagner, Kate Young, and Markus Rapp
Atmos. Chem. Phys., 17, 14853–14869, https://doi.org/10.5194/acp-17-14853-2017, https://doi.org/10.5194/acp-17-14853-2017, 2017
Ramon Campos Braga, Daniel Rosenfeld, Ralf Weigel, Tina Jurkat, Meinrat O. Andreae, Manfred Wendisch, Ulrich Pöschl, Christiane Voigt, Christoph Mahnke, Stephan Borrmann, Rachel I. Albrecht, Sergej Molleker, Daniel A. Vila, Luiz A. T. Machado, and Lucas Grulich
Atmos. Chem. Phys., 17, 14433–14456, https://doi.org/10.5194/acp-17-14433-2017, https://doi.org/10.5194/acp-17-14433-2017, 2017
Jean-Christophe Raut, Louis Marelle, Jerome D. Fast, Jennie L. Thomas, Bernadett Weinzierl, Katharine S. Law, Larry K. Berg, Anke Roiger, Richard C. Easter, Katharina Heimerl, Tatsuo Onishi, Julien Delanoë, and Hans Schlager
Atmos. Chem. Phys., 17, 10969–10995, https://doi.org/10.5194/acp-17-10969-2017, https://doi.org/10.5194/acp-17-10969-2017, 2017
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We study the cross-polar transport of plumes from Siberian fires to the Arctic in summer, both in terms of transport pathways and efficiency of deposition processes. Those plumes containing soot may originate from anthropogenic and biomass burning sources in mid-latitude regions and may impact the Arctic climate by depositing on snow and ice surfaces. We evaluate the role of the respective source contributions, investigate the transport of plumes and treat pathway-dependent removal of particles.
Micael A. Cecchini, Luiz A. T. Machado, Meinrat O. Andreae, Scot T. Martin, Rachel I. Albrecht, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Daniel Fütterer, Tina Jurkat, Christoph Mahnke, Andreas Minikin, Sergej Molleker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, Christiane Voigt, Bernadett Weinzierl, and Manfred Wendisch
Atmos. Chem. Phys., 17, 10037–10050, https://doi.org/10.5194/acp-17-10037-2017, https://doi.org/10.5194/acp-17-10037-2017, 2017
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We study the effects of aerosol particles and updraft speed on the warm phase of Amazonian clouds. We expand the sensitivity analysis usually found in the literature by concomitantly considering cloud evolution and the effects on droplet size distribution (DSD) shape. The quantitative results show that particle concentration is the primary driver for the vertical profiles of effective diameter and droplet concentration in the warm phase of Amazonian convective clouds.
Evelyn Jäkel, Manfred Wendisch, Trismono C. Krisna, Florian Ewald, Tobias Kölling, Tina Jurkat, Christiane Voigt, Micael A. Cecchini, Luiz A. T. Machado, Armin Afchine, Anja Costa, Martina Krämer, Meinrat O. Andreae, Ulrich Pöschl, Daniel Rosenfeld, and Tianle Yuan
Atmos. Chem. Phys., 17, 9049–9066, https://doi.org/10.5194/acp-17-9049-2017, https://doi.org/10.5194/acp-17-9049-2017, 2017
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Vertical profiles of the cloud particle phase state in tropical deep convective clouds (DCCs) were investigated using airborne imaging spectrometer measurements during the ACRIDICON-CHUVA campaign, which was conducted over the Brazilian rainforest in September 2014. A phase discrimination retrieval was applied to observations of clouds formed in different aerosol conditions. The profiles were compared to in situ and satellite measurements.
Ramon Campos Braga, Daniel Rosenfeld, Ralf Weigel, Tina Jurkat, Meinrat O. Andreae, Manfred Wendisch, Mira L. Pöhlker, Thomas Klimach, Ulrich Pöschl, Christopher Pöhlker, Christiane Voigt, Christoph Mahnke, Stephan Borrmann, Rachel I. Albrecht, Sergej Molleker, Daniel A. Vila, Luiz A. T. Machado, and Paulo Artaxo
Atmos. Chem. Phys., 17, 7365–7386, https://doi.org/10.5194/acp-17-7365-2017, https://doi.org/10.5194/acp-17-7365-2017, 2017
Daniele Nerini, Nikola Besic, Ioannis Sideris, Urs Germann, and Loris Foresti
Hydrol. Earth Syst. Sci., 21, 2777–2797, https://doi.org/10.5194/hess-21-2777-2017, https://doi.org/10.5194/hess-21-2777-2017, 2017
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Stochastic generators are effective tools for the quantification of uncertainty in a number of applications with weather radar data, including quantitative precipitation estimation and very short-term forecasting. However, most of the current stochastic rainfall field generators cannot handle spatial non-stationarity. We propose an approach based on the short-space Fourier transform, which aims to reproduce the local spatial structure of the observed rainfall fields.
Hanna Joos, Erica Madonna, Kasja Witlox, Sylvaine Ferrachat, Heini Wernli, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 6243–6255, https://doi.org/10.5194/acp-17-6243-2017, https://doi.org/10.5194/acp-17-6243-2017, 2017
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The influence of pollution on the precipitation formation in warm conveyor belts (WCBs), the most rising air streams in low-pressure systems is investigated. We investigate in detail the cloud properties and resulting precipitation along these rising airstreams which are simulated with a global climate model. Overall, no big impact of aerosols on precipitation can be seen, however, when comparing the most polluted/cleanest WCBs, a suppression of precipitation by aerosols is observed.
Harald Sodemann, Franziska Aemisegger, Stephan Pfahl, Mark Bitter, Ulrich Corsmeier, Thomas Feuerle, Pascal Graf, Rolf Hankers, Gregor Hsiao, Helmut Schulz, Andreas Wieser, and Heini Wernli
Atmos. Chem. Phys., 17, 6125–6151, https://doi.org/10.5194/acp-17-6125-2017, https://doi.org/10.5194/acp-17-6125-2017, 2017
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We report here the first survey of stable water isotope composition over the Mediterranean sea made from aircraft. The stable isotope composition of the atmospheric water vapour changed in response to evaporation conditions at the sea surface, elevation, and airmass transport history. Our data set will be valuable for testing how water is transported in weather prediction and climate models and for understanding processes in the Mediterranean water cycle.
Klaus-D. Gottschaldt, Hans Schlager, Robert Baumann, Heiko Bozem, Veronika Eyring, Peter Hoor, Patrick Jöckel, Tina Jurkat, Christiane Voigt, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 17, 6091–6111, https://doi.org/10.5194/acp-17-6091-2017, https://doi.org/10.5194/acp-17-6091-2017, 2017
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We present upper-tropospheric trace gas measurements in the Asian summer monsoon anticyclone, obtained with the HALO research aircraft in September 2012. The anticyclone is one of the largest atmospheric features on Earth, but many aspects of it are not well understood. With the help of model simulations we find that entrainments from the tropopause region and the lower troposphere, combined with photochemistry and dynamical instabilities, can explain the observations.
Benedikt Urbanek, Silke Groß, Andreas Schäfler, and Martin Wirth
Atmos. Meas. Tech., 10, 1653–1664, https://doi.org/10.5194/amt-10-1653-2017, https://doi.org/10.5194/amt-10-1653-2017, 2017
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Cirrus evolution from nucleation to cloud breakup can be investigated with a novel classification scheme based on airborne lidar data. Applying it to a case study from the ML-CIRRUS campaign, we investigate the impact of large-scale dynamics and small-scale gravity lee waves on the detailed spatial distribution of evolution stages in individual clouds. Our scheme may help to gain more insights in optical and radiative properties of cirrus under various formation and life cycle conditions.
Andreas Macke, Patric Seifert, Holger Baars, Christian Barthlott, Christoph Beekmans, Andreas Behrendt, Birger Bohn, Matthias Brueck, Johannes Bühl, Susanne Crewell, Thomas Damian, Hartwig Deneke, Sebastian Düsing, Andreas Foth, Paolo Di Girolamo, Eva Hammann, Rieke Heinze, Anne Hirsikko, John Kalisch, Norbert Kalthoff, Stefan Kinne, Martin Kohler, Ulrich Löhnert, Bomidi Lakshmi Madhavan, Vera Maurer, Shravan Kumar Muppa, Jan Schween, Ilya Serikov, Holger Siebert, Clemens Simmer, Florian Späth, Sandra Steinke, Katja Träumner, Silke Trömel, Birgit Wehner, Andreas Wieser, Volker Wulfmeyer, and Xinxin Xie
Atmos. Chem. Phys., 17, 4887–4914, https://doi.org/10.5194/acp-17-4887-2017, https://doi.org/10.5194/acp-17-4887-2017, 2017
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This article provides an overview of the instrumental setup and the main results obtained during the two HD(CP)2 Observational Prototype Experiments HOPE-Jülich and HOPE-Melpitz conducted in Germany in April–May and Sept 2013, respectively. Goal of the field experiments was to provide high-resolution observational datasets for both, improving the understaning of boundary layer and cloud processes, as well as for the evaluation of the new ICON model that is run at 156 m horizontal resolution.
Ulrich Schumann, Christoph Kiemle, Hans Schlager, Ralf Weigel, Stephan Borrmann, Francesco D'Amato, Martina Krämer, Renaud Matthey, Alain Protat, Christiane Voigt, and C. Michael Volk
Atmos. Chem. Phys., 17, 2311–2346, https://doi.org/10.5194/acp-17-2311-2017, https://doi.org/10.5194/acp-17-2311-2017, 2017
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A long-lived (1 h) contrail and overshooting convection were observed in the tropics, near Darwin, Australia. The data are used to study the contrail life cycle at low temperatures and cirrus from deep overturning convection in the lower tropical stratosphere. Airborne in situ, lidar, profiler, radar, and satellite data, as well as a photo, are used to distinguish contrail cirrus from convective cirrus and to study the origin of the observed ice and aerosol, up to 2.3 km above the tropopause.
Paolo Di Girolamo, Marco Cacciani, Donato Summa, Andrea Scoccione, Benedetto De Rosa, Andreas Behrendt, and Volker Wulfmeyer
Atmos. Chem. Phys., 17, 745–767, https://doi.org/10.5194/acp-17-745-2017, https://doi.org/10.5194/acp-17-745-2017, 2017
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This paper reports what we believe are the first measurements throughout the atmospheric convective boundary layer of higher-order moments (up to the fourth) of the turbulent fluctuations of water vapour mixing ratio and temperature performed by a single lidar system, i.e. the Raman lidar system BASIL. These measurements, in combination with measurements from other lidar systems, are fundamental to verify and possibly improve turbulence parametrisation in weather and climate models.
Ulrich Schumann, Robert Baumann, Darrel Baumgardner, Sarah T. Bedka, David P. Duda, Volker Freudenthaler, Jean-Francois Gayet, Andrew J. Heymsfield, Patrick Minnis, Markus Quante, Ehrhard Raschke, Hans Schlager, Margarita Vázquez-Navarro, Christiane Voigt, and Zhien Wang
Atmos. Chem. Phys., 17, 403–438, https://doi.org/10.5194/acp-17-403-2017, https://doi.org/10.5194/acp-17-403-2017, 2017
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The initially linear clouds often seen behind aircraft are known as contrails. Contrails are prototype cirrus clouds forming under well-known conditions, but with less certain life cycle and climate effects. This paper collects contrail data from a large set of measurements and compares them among each other and with models. The observations show consistent contrail properties over a wide range of aircraft and atmosphere conditions. The dataset is available for further research.
Christiane Voigt, Andreas Dörnbrack, Martin Wirth, Silke M. Groß, Robert Baumann, Benedikt Ehard, Michael C. Pitts, Lamont R. Poole, Björn-Martin Sinnhuber, and Hermann Oelhaf
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2016-1082, https://doi.org/10.5194/acp-2016-1082, 2016
Revised manuscript not accepted
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The letter describes unprecedented observations of widespread and persistent polar stratospheric ice clouds (ice PSCs) in the exceptionally cold Arctic stratospheric winter 2015/16. The unique observations are of global relevance because trends in Arctic ozone loss and in polar temperatures are highly uncertain. The new observations at cold conditions serve to enhance our knowledge on ice PSC formation, Arctic ozone loss and polar stratrospheric temperatures in a changing climate.
Davide Putero, Paolo Cristofanelli, Michael Sprenger, Bojan Škerlak, Laura Tositti, and Paolo Bonasoni
Atmos. Chem. Phys., 16, 14203–14217, https://doi.org/10.5194/acp-16-14203-2016, https://doi.org/10.5194/acp-16-14203-2016, 2016
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The aim of this paper is to present STEFLUX, a tool to obtain a fast-computing identification of the stratospheric intrusion (SI) events occurring at a specific location and during a specified time window. STEFLUX results are compared to the SI observations at two high-mountain WMO/GAW global stations in Nepal and Italy, representative of two hot spots for climate change. Furthermore, the climatology of SI at the two stations is assessed, and the impact of several climate factors investigated.
Dimitris Akritidis, Andrea Pozzer, Prodromos Zanis, Evangelos Tyrlis, Bojan Škerlak, Michael Sprenger, and Jos Lelieveld
Atmos. Chem. Phys., 16, 14025–14039, https://doi.org/10.5194/acp-16-14025-2016, https://doi.org/10.5194/acp-16-14025-2016, 2016
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We investigate the contribution of tropopause folds in the summertime tropospheric ozone pool over the eastern Mediterranean and the Middle East. For this purpose we use the EMAC atmospheric chemistry–climate model and a fold identification algorithm. A clear increase of ozone is found in the middle troposphere due to fold activity. The interannual variability of near-surface ozone over the eastern Mediterranean is related to that of both tropopause folds and ozone in the free troposphere.
Gerard Ancellet, Nikos Daskalakis, Jean Christophe Raut, David Tarasick, Jonathan Hair, Boris Quennehen, François Ravetta, Hans Schlager, Andrew J. Weinheimer, Anne M. Thompson, Bryan Johnson, Jennie L. Thomas, and Katharine S. Law
Atmos. Chem. Phys., 16, 13341–13358, https://doi.org/10.5194/acp-16-13341-2016, https://doi.org/10.5194/acp-16-13341-2016, 2016
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An integrated analysis of all the ozone observations (lidar, sondes, and airborne in situ measurements) conducted during the 2008 IPY campaigns is performed and the processes that determine summer ozone concentrations over Greenland and Canada are discussed. Combined with a regional model simulation (WRFChem), the analysis of ozone, CO, and PV latitudinal and vertical variability allows the determination of the influence of stratospheric sources and biomass burning and anthropogenic emissions.
Manuel Gutleben, Silke Gross, Martin Wirth, and Andreas Schäfler
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2016-333, https://doi.org/10.5194/amt-2016-333, 2016
Revised manuscript not accepted
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Shallow marine cumulus convection over the Atlantic ocean is studied with observations by airborne and spaceborne lidar instruments. Cloud top height as well as cloud length and cloud gap length distributions are calculated by use of a newly developed algorithm. The distribution of cloud top heights during wintertime measurements shows a two-layer structure. However, significant differences in cloud top height distributions compared to summertime measurements are found.
Valery Shcherbakov, Olivier Jourdan, Christiane Voigt, Jean-Francois Gayet, Aurélien Chauvigne, Alfons Schwarzenboeck, Andreas Minikin, Marcus Klingebiel, Ralf Weigel, Stephan Borrmann, Tina Jurkat, Stefan Kaufmann, Romy Schlage, Christophe Gourbeyre, Guy Febvre, Tatyana Lapyonok, Wiebke Frey, Sergej Molleker, and Bernadett Weinzierl
Atmos. Chem. Phys., 16, 11883–11897, https://doi.org/10.5194/acp-16-11883-2016, https://doi.org/10.5194/acp-16-11883-2016, 2016
Nikola Besic, Jordi Figueras i Ventura, Jacopo Grazioli, Marco Gabella, Urs Germann, and Alexis Berne
Atmos. Meas. Tech., 9, 4425–4445, https://doi.org/10.5194/amt-9-4425-2016, https://doi.org/10.5194/amt-9-4425-2016, 2016
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In this paper we propose a novel semi-supervised method for hydrometeor classification, which takes into account both the specificities of acquired polarimetric radar measurements and the presumed electromagnetic behavior of different hydrometeor types. The method has been applied on three datasets, each acquired by different C-band radar from the Swiss network, and on two X-band research radar datasets. The obtained classification is found to be of high quality.
Stefan Müller, Peter Hoor, Heiko Bozem, Ellen Gute, Bärbel Vogel, Andreas Zahn, Harald Bönisch, Timo Keber, Martina Krämer, Christian Rolf, Martin Riese, Hans Schlager, and Andreas Engel
Atmos. Chem. Phys., 16, 10573–10589, https://doi.org/10.5194/acp-16-10573-2016, https://doi.org/10.5194/acp-16-10573-2016, 2016
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In situ airborne measurements performed during TACTS/ESMVal 2012 were analysed to investigate the chemical compostion of the upper troposphere and lower stratosphere. N2O, CO and O3 data show an increase in tropospherically affected air masses within the extratropical stratosphere from August to September 2012, which originate from the Asian monsoon region. Thus, the Asian monsoon anticyclone significantly affected the chemical composition of the extratropical stratosphere during summer 2012.
María Barrera-Verdejo, Susanne Crewell, Ulrich Löhnert, Emiliano Orlandi, and Paolo Di Girolamo
Atmos. Meas. Tech., 9, 4013–4028, https://doi.org/10.5194/amt-9-4013-2016, https://doi.org/10.5194/amt-9-4013-2016, 2016
Thomas Trickl, Hannes Vogelmann, Andreas Fix, Andreas Schäfler, Martin Wirth, Bertrand Calpini, Gilbert Levrat, Gonzague Romanens, Arnoud Apituley, Keith M. Wilson, Robert Begbie, Jens Reichardt, Holger Vömel, and Michael Sprenger
Atmos. Chem. Phys., 16, 8791–8815, https://doi.org/10.5194/acp-16-8791-2016, https://doi.org/10.5194/acp-16-8791-2016, 2016
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A rather homogeneous deep stratospheric intrusion event was mapped by vertical sounding over central Europe and by model calculations along the transport path. The very low minimum H2O mixing ratios demonstrate almost negligible mixing with tropospheric air during the downward transport. The vertical distributions of O3 and aerosol were transferred from the source region to Europe without major change. A rather shallow outflow from the stratosphere was found.
Luca Panziera, Marco Gabella, Stefano Zanini, Alessandro Hering, Urs Germann, and Alexis Berne
Hydrol. Earth Syst. Sci., 20, 2317–2332, https://doi.org/10.5194/hess-20-2317-2016, https://doi.org/10.5194/hess-20-2317-2016, 2016
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This paper presents a novel system to issue heavy rainfall alerts for predefined geographical regions by evaluating the sum of precipitation fallen in the immediate past and expected in the near future. In order to objectively define the thresholds for the alerts, an extreme rainfall analysis for the 159 regions used for official warnings in Switzerland was developed. It is shown that the system has additional lead time with respect to thunderstorm tracking tools targeted for convective storms.
Florian Berkes, Peter Hoor, Heiko Bozem, Daniel Kunkel, Michael Sprenger, and Stephan Henne
Atmos. Chem. Phys., 16, 6011–6025, https://doi.org/10.5194/acp-16-6011-2016, https://doi.org/10.5194/acp-16-6011-2016, 2016
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We presented airborne measurements of CO2 and O3 across the entrainment zone over a semi-remote environment in southwestern Germany in late summer 2011 .
For the first time CO2 and O3 were used as tracer to identify mixing through this transport barrier. We demonstrated that the tracer--tracer correlation of CO2 and O3 is a powerful tool to identify entrainment and mixing.
Tina Jurkat, Stefan Kaufmann, Christiane Voigt, Dominik Schäuble, Philipp Jeßberger, and Helmut Ziereis
Atmos. Meas. Tech., 9, 1907–1923, https://doi.org/10.5194/amt-9-1907-2016, https://doi.org/10.5194/amt-9-1907-2016, 2016
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The paper details novel mass spectrometric measurements with AIMS-TG aboard the new German research aircraft HALO. The measurements comprise a wide range of tracers with characteristic source regions. Using these tracers, stratospheric and tropospheric air in the UTLS is tagged. The instrument is equipped with a new discharge ionization source, an in-flight calibration and improved transmission of adhesive gases like HNO3 and HCl. AIMS was built to characterize transport and mixing in the UTLS.
Stefan Kaufmann, Christiane Voigt, Tina Jurkat, Troy Thornberry, David W. Fahey, Ru-Shan Gao, Romy Schlage, Dominik Schäuble, and Martin Zöger
Atmos. Meas. Tech., 9, 939–953, https://doi.org/10.5194/amt-9-939-2016, https://doi.org/10.5194/amt-9-939-2016, 2016
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We present the development of a new airborne mass spectrometer AIMS-H2O for the fast and accurate measurement of water vapor in the upper troposphere and lower stratosphere. The high accuracy needed for e.g. quantification of atmospheric water vapor transport processes or cloud formation is achieved by an in-flight calibration of the instrument. AIMS-H2O is deployed on the DLR research aircraft HALO and Falcon where it covers a range of water vapor mixing ratios from 1 to 500 ppmv.
Louis Marelle, Jennie L. Thomas, Jean-Christophe Raut, Kathy S. Law, Jukka-Pekka Jalkanen, Lasse Johansson, Anke Roiger, Hans Schlager, Jin Kim, Anja Reiter, and Bernadett Weinzierl
Atmos. Chem. Phys., 16, 2359–2379, https://doi.org/10.5194/acp-16-2359-2016, https://doi.org/10.5194/acp-16-2359-2016, 2016
C. Flamant, J.-P. Chaboureau, P. Chazette, P. Di Girolamo, T. Bourrianne, J. Totems, and M. Cacciani
Atmos. Chem. Phys., 15, 12231–12249, https://doi.org/10.5194/acp-15-12231-2015, https://doi.org/10.5194/acp-15-12231-2015, 2015
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We analyze the direct radiative impact of an intense African dust plume on orographic precipitation in the western Mediterranean in the fall of 2012 using high-resolution simulations from a convection permitting mesoscale model validated against measurements acquired during the first special observation period of HyMeX. We show that the dust's direct radiative effect in such a dynamical environment is not sufficient to impact 24h of accumulated rainfall over the Cevennes in the dust simulation.
S. Groß, V. Freudenthaler, K. Schepanski, C. Toledano, A. Schäfler, A. Ansmann, and B. Weinzierl
Atmos. Chem. Phys., 15, 11067–11080, https://doi.org/10.5194/acp-15-11067-2015, https://doi.org/10.5194/acp-15-11067-2015, 2015
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In June and July 2013 dual-wavelength lidar measurements were performed in Barbados to study long-range transported Saharan dust across the Atlantic Ocean and investigate transport-induced changes. The focus of our measurements is the intensive optical properties, the lidar ratio and the particle linear depolarization ratio. While the lidar ratio shows no differences compared to the values of fresh Saharan dust, the particle linear depolarization ratio shows slight differences.
P. Reutter, B. Škerlak, M. Sprenger, and H. Wernli
Atmos. Chem. Phys., 15, 10939–10953, https://doi.org/10.5194/acp-15-10939-2015, https://doi.org/10.5194/acp-15-10939-2015, 2015
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In this manuscript, we investigate the exchange of air masses across the dynamical tropopause (stratosphere-troposphere exchange, STE) in the vicinity of North Atlantic cyclones. By using two 6-hourly resolved ERA-Interim climatologies of STE and cyclones from 1979 to 2011, we are able to directly compute the amount of STE in the vicinity of every individual cyclone in this time period. This enables us to provide a robust and consistent quantification of STE near North Atlantic cyclones.
C. Rolf, A. Afchine, H. Bozem, B. Buchholz, V. Ebert, T. Guggenmoser, P. Hoor, P. Konopka, E. Kretschmer, S. Müller, H. Schlager, N. Spelten, O. Sumińska-Ebersoldt, J. Ungermann, A. Zahn, and M. Krämer
Atmos. Chem. Phys., 15, 9143–9158, https://doi.org/10.5194/acp-15-9143-2015, https://doi.org/10.5194/acp-15-9143-2015, 2015
M. Sprenger and H. Wernli
Geosci. Model Dev., 8, 2569–2586, https://doi.org/10.5194/gmd-8-2569-2015, https://doi.org/10.5194/gmd-8-2569-2015, 2015
M. Rautenhaus, M. Kern, A. Schäfler, and R. Westermann
Geosci. Model Dev., 8, 2329–2353, https://doi.org/10.5194/gmd-8-2329-2015, https://doi.org/10.5194/gmd-8-2329-2015, 2015
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This article presents "Met.3D", a new open-source tool for the interactive 3D visualization of numerical ensemble weather predictions. Met.3D builds a bridge from proven 2D visualization methods commonly used in meteorology to 3D visualization and implements approaches to using the ensemble to allow the user to assess forecast uncertainty. The article is the first part of a two-paper study discussing how 3D and ensemble visualization can be used in a meaningful way suited to weather forecasting.
M. Rautenhaus, C. M. Grams, A. Schäfler, and R. Westermann
Geosci. Model Dev., 8, 2355–2377, https://doi.org/10.5194/gmd-8-2355-2015, https://doi.org/10.5194/gmd-8-2355-2015, 2015
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This article presents the application of interactive 3D visualization of ensemble
weather predictions to forecasting warm conveyor belt situations during aircraft-based atmospheric research campaigns. A method to predict 3D probabilities of the spatial occurrence of WCBs is developed and integrated into the 3D visualization tool "Met.3D", introduced in the first part of this two-paper study. A case study demonstrates the use of 3D and uncertainty visualization for weather forecasting.
C. L. Ryder, J. B. McQuaid, C. Flamant, P. D. Rosenberg, R. Washington, H. E. Brindley, E. J. Highwood, J. H. Marsham, D. J. Parker, M. C. Todd, J. R. Banks, J. K. Brooke, S. Engelstaedter, V. Estelles, P. Formenti, L. Garcia-Carreras, C. Kocha, F. Marenco, H. Sodemann, C. J. T. Allen, A. Bourdon, M. Bart, C. Cavazos-Guerra, S. Chevaillier, J. Crosier, E. Darbyshire, A. R. Dean, J. R. Dorsey, J. Kent, D. O'Sullivan, K. Schepanski, K. Szpek, J. Trembath, and A. Woolley
Atmos. Chem. Phys., 15, 8479–8520, https://doi.org/10.5194/acp-15-8479-2015, https://doi.org/10.5194/acp-15-8479-2015, 2015
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Measurements of the Saharan atmosphere and of atmospheric mineral dust are lacking but are vital to our understanding of the climate of this region and their impacts further afield. Novel observations were made by the Fennec climate programme during June 2011 and 2012 using ground-based, remote sensing and airborne platforms. Here we describe the airborne observations and the contributions they have made to furthering our understanding of the Saharan climate system.
A. Foth, H. Baars, P. Di Girolamo, and B. Pospichal
Atmos. Chem. Phys., 15, 7753–7763, https://doi.org/10.5194/acp-15-7753-2015, https://doi.org/10.5194/acp-15-7753-2015, 2015
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We present a method to derive water vapour profiles from Raman lidar measurements calibrated by the integrated water vapour from a collocated microwave radiometer. These simultaneous observations provide an operational and continuous measurement of water vapour profiles. The stability of the calibration factor allows for the calibration of the lidar even in the presence of clouds. Based on this approach, water vapour profiles can be retrieved during all non-precipitating conditions.
M. Höpfner, C. D. Boone, B. Funke, N. Glatthor, U. Grabowski, A. Günther, S. Kellmann, M. Kiefer, A. Linden, S. Lossow, H. C. Pumphrey, W. G. Read, A. Roiger, G. Stiller, H. Schlager, T. von Clarmann, and K. Wissmüller
Atmos. Chem. Phys., 15, 7017–7037, https://doi.org/10.5194/acp-15-7017-2015, https://doi.org/10.5194/acp-15-7017-2015, 2015
J. Ungermann, J. Blank, M. Dick, A. Ebersoldt, F. Friedl-Vallon, A. Giez, T. Guggenmoser, M. Höpfner, T. Jurkat, M. Kaufmann, S. Kaufmann, A. Kleinert, M. Krämer, T. Latzko, H. Oelhaf, F. Olchewski, P. Preusse, C. Rolf, J. Schillings, O. Suminska-Ebersoldt, V. Tan, N. Thomas, C. Voigt, A. Zahn, M. Zöger, and M. Riese
Atmos. Meas. Tech., 8, 2473–2489, https://doi.org/10.5194/amt-8-2473-2015, https://doi.org/10.5194/amt-8-2473-2015, 2015
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The GLORIA sounder is an airborne infrared limb-imager combining a two-dimensional infrared detector with a Fourier transform spectrometer. It was operated aboard the new German Gulfstream G550 research aircraft HALO during the TACTS and ESMVAL campaigns in summer 2012. This paper describes the retrieval of temperature, as well as H2O, HNO3, and O3 cross sections from GLORIA dynamics mode spectra. A high correlation is achieved between the remote sensing and the in situ trace gas measurements.
M. Barrera-Verdejo, S. Crewell, U. Löhnert, E. Orlandi, and P. Di Girolamo
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amtd-8-5467-2015, https://doi.org/10.5194/amtd-8-5467-2015, 2015
Revised manuscript not accepted
S. A. Monks, S. R. Arnold, L. K. Emmons, K. S. Law, S. Turquety, B. N. Duncan, J. Flemming, V. Huijnen, S. Tilmes, J. Langner, J. Mao, Y. Long, J. L. Thomas, S. D. Steenrod, J. C. Raut, C. Wilson, M. P. Chipperfield, G. S. Diskin, A. Weinheimer, H. Schlager, and G. Ancellet
Atmos. Chem. Phys., 15, 3575–3603, https://doi.org/10.5194/acp-15-3575-2015, https://doi.org/10.5194/acp-15-3575-2015, 2015
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Multi-model simulations of Arctic CO, O3 and OH are evaluated using observations. Models show highly variable concentrations but the relative importance of emission regions and types is robust across the models, demonstrating the importance of biomass burning as a source. Idealised tracer experiments suggest that some of the model spread is due to variations in simulated transport from Europe in winter and from Asia throughout the year.
S. Steinke, S. Eikenberg, U. Löhnert, G. Dick, D. Klocke, P. Di Girolamo, and S. Crewell
Atmos. Chem. Phys., 15, 2675–2692, https://doi.org/10.5194/acp-15-2675-2015, https://doi.org/10.5194/acp-15-2675-2015, 2015
M. Kaufmann, J. Blank, T. Guggenmoser, J. Ungermann, A. Engel, M. Ern, F. Friedl-Vallon, D. Gerber, J. U. Grooß, G. Guenther, M. Höpfner, A. Kleinert, E. Kretschmer, Th. Latzko, G. Maucher, T. Neubert, H. Nordmeyer, H. Oelhaf, F. Olschewski, J. Orphal, P. Preusse, H. Schlager, H. Schneider, D. Schuettemeyer, F. Stroh, O. Suminska-Ebersoldt, B. Vogel, C. M. Volk, W. Woiwode, and M. Riese
Atmos. Meas. Tech., 8, 81–95, https://doi.org/10.5194/amt-8-81-2015, https://doi.org/10.5194/amt-8-81-2015, 2015
Y. Ren, R. Baumann, and H. Schlager
Atmos. Meas. Tech., 8, 69–80, https://doi.org/10.5194/amt-8-69-2015, https://doi.org/10.5194/amt-8-69-2015, 2015
R. Pommrich, R. Müller, J.-U. Grooß, P. Konopka, F. Ploeger, B. Vogel, M. Tao, C. M. Hoppe, G. Günther, N. Spelten, L. Hoffmann, H.-C. Pumphrey, S. Viciani, F. D'Amato, C. M. Volk, P. Hoor, H. Schlager, and M. Riese
Geosci. Model Dev., 7, 2895–2916, https://doi.org/10.5194/gmd-7-2895-2014, https://doi.org/10.5194/gmd-7-2895-2014, 2014
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A version of the chemical transport model CLaMS is presented, which features a simplified (numerically inexpensive) chemistry scheme. The model results using this version of CLaMS show a good representation of anomaly fields of CO, CH4, N2O, and CFC-11 in the lower stratosphere. CO measurements of three instruments (COLD, HAGAR, and Falcon-CO) in the lower tropical stratosphere (during the campaign TROCCINOX in 2005) have been compared and show a good agreement within the error bars.
A. Kunz, N. Spelten, P. Konopka, R. Müller, R. M. Forbes, and H. Wernli
Atmos. Chem. Phys., 14, 10803–10822, https://doi.org/10.5194/acp-14-10803-2014, https://doi.org/10.5194/acp-14-10803-2014, 2014
S. Molleker, S. Borrmann, H. Schlager, B. Luo, W. Frey, M. Klingebiel, R. Weigel, M. Ebert, V. Mitev, R. Matthey, W. Woiwode, H. Oelhaf, A. Dörnbrack, G. Stratmann, J.-U. Grooß, G. Günther, B. Vogel, R. Müller, M. Krämer, J. Meyer, and F. Cairo
Atmos. Chem. Phys., 14, 10785–10801, https://doi.org/10.5194/acp-14-10785-2014, https://doi.org/10.5194/acp-14-10785-2014, 2014
T. Trickl, H. Vogelmann, H. Giehl, H.-E. Scheel, M. Sprenger, and A. Stohl
Atmos. Chem. Phys., 14, 9941–9961, https://doi.org/10.5194/acp-14-9941-2014, https://doi.org/10.5194/acp-14-9941-2014, 2014
S. Groß, M. Wirth, A. Schäfler, A. Fix, S. Kaufmann, and C. Voigt
Atmos. Meas. Tech., 7, 2745–2755, https://doi.org/10.5194/amt-7-2745-2014, https://doi.org/10.5194/amt-7-2745-2014, 2014
P. Reutter, J. Trentmann, A. Seifert, P. Neis, H. Su, D. Chang, M. Herzog, H. Wernli, M. O. Andreae, and U. Pöschl
Atmos. Chem. Phys., 14, 7573–7583, https://doi.org/10.5194/acp-14-7573-2014, https://doi.org/10.5194/acp-14-7573-2014, 2014
C. M. Grams, H. Binder, S. Pfahl, N. Piaget, and H. Wernli
Nat. Hazards Earth Syst. Sci., 14, 1691–1702, https://doi.org/10.5194/nhess-14-1691-2014, https://doi.org/10.5194/nhess-14-1691-2014, 2014
A. Winschall, S. Pfahl, H. Sodemann, and H. Wernli
Atmos. Chem. Phys., 14, 6605–6619, https://doi.org/10.5194/acp-14-6605-2014, https://doi.org/10.5194/acp-14-6605-2014, 2014
F. Dahlkötter, M. Gysel, D. Sauer, A. Minikin, R. Baumann, P. Seifert, A. Ansmann, M. Fromm, C. Voigt, and B. Weinzierl
Atmos. Chem. Phys., 14, 6111–6137, https://doi.org/10.5194/acp-14-6111-2014, https://doi.org/10.5194/acp-14-6111-2014, 2014
J. Tian, N. Riemer, M. West, L. Pfaffenberger, H. Schlager, and A. Petzold
Atmos. Chem. Phys., 14, 5327–5347, https://doi.org/10.5194/acp-14-5327-2014, https://doi.org/10.5194/acp-14-5327-2014, 2014
J.-L. Bonne, V. Masson-Delmotte, O. Cattani, M. Delmotte, C. Risi, H. Sodemann, and H. C. Steen-Larsen
Atmos. Chem. Phys., 14, 4419–4439, https://doi.org/10.5194/acp-14-4419-2014, https://doi.org/10.5194/acp-14-4419-2014, 2014
F. Aemisegger, S. Pfahl, H. Sodemann, I. Lehner, S. I. Seneviratne, and H. Wernli
Atmos. Chem. Phys., 14, 4029–4054, https://doi.org/10.5194/acp-14-4029-2014, https://doi.org/10.5194/acp-14-4029-2014, 2014
S. Pfahl and H. Sodemann
Clim. Past, 10, 771–781, https://doi.org/10.5194/cp-10-771-2014, https://doi.org/10.5194/cp-10-771-2014, 2014
J.-U. Grooß, I. Engel, S. Borrmann, W. Frey, G. Günther, C. R. Hoyle, R. Kivi, B. P. Luo, S. Molleker, T. Peter, M. C. Pitts, H. Schlager, G. Stiller, H. Vömel, K. A. Walker, and R. Müller
Atmos. Chem. Phys., 14, 1055–1073, https://doi.org/10.5194/acp-14-1055-2014, https://doi.org/10.5194/acp-14-1055-2014, 2014
B. Škerlak, M. Sprenger, and H. Wernli
Atmos. Chem. Phys., 14, 913–937, https://doi.org/10.5194/acp-14-913-2014, https://doi.org/10.5194/acp-14-913-2014, 2014
P. Jeßberger, C. Voigt, U. Schumann, I. Sölch, H. Schlager, S. Kaufmann, A. Petzold, D. Schäuble, and J.-F. Gayet
Atmos. Chem. Phys., 13, 11965–11984, https://doi.org/10.5194/acp-13-11965-2013, https://doi.org/10.5194/acp-13-11965-2013, 2013
D. Summa, P. Di Girolamo, D. Stelitano, and M. Cacciani
Atmos. Meas. Tech., 6, 3515–3525, https://doi.org/10.5194/amt-6-3515-2013, https://doi.org/10.5194/amt-6-3515-2013, 2013
A. K. Miltenberger, S. Pfahl, and H. Wernli
Geosci. Model Dev., 6, 1989–2004, https://doi.org/10.5194/gmd-6-1989-2013, https://doi.org/10.5194/gmd-6-1989-2013, 2013
C. Frick, A. Seifert, and H. Wernli
Geosci. Model Dev., 6, 1925–1939, https://doi.org/10.5194/gmd-6-1925-2013, https://doi.org/10.5194/gmd-6-1925-2013, 2013
K. Liechti, L. Panziera, U. Germann, and M. Zappa
Hydrol. Earth Syst. Sci., 17, 3853–3869, https://doi.org/10.5194/hess-17-3853-2013, https://doi.org/10.5194/hess-17-3853-2013, 2013
M. von Hobe, S. Bekki, S. Borrmann, F. Cairo, F. D'Amato, G. Di Donfrancesco, A. Dörnbrack, A. Ebersoldt, M. Ebert, C. Emde, I. Engel, M. Ern, W. Frey, S. Genco, S. Griessbach, J.-U. Grooß, T. Gulde, G. Günther, E. Hösen, L. Hoffmann, V. Homonnai, C. R. Hoyle, I. S. A. Isaksen, D. R. Jackson, I. M. Jánosi, R. L. Jones, K. Kandler, C. Kalicinsky, A. Keil, S. M. Khaykin, F. Khosrawi, R. Kivi, J. Kuttippurath, J. C. Laube, F. Lefèvre, R. Lehmann, S. Ludmann, B. P. Luo, M. Marchand, J. Meyer, V. Mitev, S. Molleker, R. Müller, H. Oelhaf, F. Olschewski, Y. Orsolini, T. Peter, K. Pfeilsticker, C. Piesch, M. C. Pitts, L. R. Poole, F. D. Pope, F. Ravegnani, M. Rex, M. Riese, T. Röckmann, B. Rognerud, A. Roiger, C. Rolf, M. L. Santee, M. Scheibe, C. Schiller, H. Schlager, M. Siciliani de Cumis, N. Sitnikov, O. A. Søvde, R. Spang, N. Spelten, F. Stordal, O. Sumińska-Ebersoldt, A. Ulanovski, J. Ungermann, S. Viciani, C. M. Volk, M. vom Scheidt, P. von der Gathen, K. Walker, T. Wegner, R. Weigel, S. Weinbruch, G. Wetzel, F. G. Wienhold, I. Wohltmann, W. Woiwode, I. A. K. Young, V. Yushkov, B. Zobrist, and F. Stroh
Atmos. Chem. Phys., 13, 9233–9268, https://doi.org/10.5194/acp-13-9233-2013, https://doi.org/10.5194/acp-13-9233-2013, 2013
P. D. Hamer, V. Marécal, R. Hossaini, M. Pirre, N. Warwick, M. Chipperfield, A. A. Samah, N. Harris, A. Robinson, B. Quack, A. Engel, K. Krüger, E. Atlas, K. Subramaniam, D. Oram, Emma C. Leedham Elvidge, G. Mills, K. Pfeilsticker, S. Sala, T. Keber, H. Bönisch, L. K. Peng, M. S. M. Nadzir, P. T. Lim, A. Mujahid, A. Anton, H. Schlager, V. Catoire, G. Krysztofiak, S. Fühlbrügge, M. Dorf, and W. T. Sturges
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-13-20611-2013, https://doi.org/10.5194/acpd-13-20611-2013, 2013
Revised manuscript not accepted
T. D. Thornberry, A. W. Rollins, R. S. Gao, L. A. Watts, S. J. Ciciora, R. J. McLaughlin, C. Voigt, B. Hall, and D. W. Fahey
Atmos. Meas. Tech., 6, 1461–1475, https://doi.org/10.5194/amt-6-1461-2013, https://doi.org/10.5194/amt-6-1461-2013, 2013
H. C. Steen-Larsen, S. J. Johnsen, V. Masson-Delmotte, B. Stenni, C. Risi, H. Sodemann, D. Balslev-Clausen, T. Blunier, D. Dahl-Jensen, M. D. Ellehøj, S. Falourd, A. Grindsted, V. Gkinis, J. Jouzel, T. Popp, S. Sheldon, S. B. Simonsen, J. Sjolte, J. P. Steffensen, P. Sperlich, A. E. Sveinbjörnsdóttir, B. M. Vinther, and J. W. C. White
Atmos. Chem. Phys., 13, 4815–4828, https://doi.org/10.5194/acp-13-4815-2013, https://doi.org/10.5194/acp-13-4815-2013, 2013
J. L. Thomas, J.-C. Raut, K. S. Law, L. Marelle, G. Ancellet, F. Ravetta, J. D. Fast, G. Pfister, L. K. Emmons, G. S. Diskin, A. Weinheimer, A. Roiger, and H. Schlager
Atmos. Chem. Phys., 13, 3825–3848, https://doi.org/10.5194/acp-13-3825-2013, https://doi.org/10.5194/acp-13-3825-2013, 2013
K. Gottschaldt, C. Voigt, P. Jöckel, M. Righi, R. Deckert, and S. Dietmüller
Atmos. Chem. Phys., 13, 3003–3025, https://doi.org/10.5194/acp-13-3003-2013, https://doi.org/10.5194/acp-13-3003-2013, 2013
K. A. Cummings, T. L. Huntemann, K. E. Pickering, M. C. Barth, W. C. Skamarock, H. Höller, H.-D. Betz, A. Volz-Thomas, and H. Schlager
Atmos. Chem. Phys., 13, 2757–2777, https://doi.org/10.5194/acp-13-2757-2013, https://doi.org/10.5194/acp-13-2757-2013, 2013
C. L. Ryder, E. J. Highwood, P. D. Rosenberg, J. Trembath, J. K. Brooke, M. Bart, A. Dean, J. Crosier, J. Dorsey, H. Brindley, J. Banks, J. H. Marsham, J. B. McQuaid, H. Sodemann, and R. Washington
Atmos. Chem. Phys., 13, 303–325, https://doi.org/10.5194/acp-13-303-2013, https://doi.org/10.5194/acp-13-303-2013, 2013
Related subject area
Subject: Clouds and Precipitation | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
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
Lifecycle of updrafts and mass flux in isolated deep convection over the Amazon rainforest: insights from cell tracking
Elucidating the boundary layer turbulence dissipation rate using high-resolution measurements from a radar wind profiler network over the Tibetan Plateau
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
Drivers of Droplet Formation in East Mediterranean Orographic Clouds
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
Environmental Controls on Isolated Convection during the Amazonian Wet Season
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
Observability of Moisture Transport Divergence in Arctic Atmospheric Rivers by Dropsondes
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
Investigating the vertical extent and short-wave radiative effects of the ice phase in Arctic summertime low-level clouds
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
Factors affecting precipitation formation and precipitation susceptibility of marine stratocumulus with variable above- and below-cloud aerosol concentrations over the Southeast Atlantic
An assessment of macrophysical and microphysical cloud properties driving radiative forcing of shallow trade-wind clouds
High concentrations of ice crystals in upper-tropospheric tropical clouds: is there a link to biomass and fossil fuel combustion?
Atmospheric rivers and associated precipitation patterns during the ACLOUD and PASCAL campaigns near Svalbard (May–June 2017): case studies using observations, reanalyses, and a regional climate model
Mass of different snow crystal shapes derived from fall speed measurements
Measurement report: Impact of African aerosol particles on cloud evolution in a tropical montane cloud forest in the Caribbean
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
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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
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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.
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
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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.
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
EGUsphere, https://doi.org/10.5194/egusphere-2024-860, https://doi.org/10.5194/egusphere-2024-860, 2024
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The turbulence in the planetary boundary layer (PBL) over the Tibetan Plateau (TP) remains unclear. Here we elucidate the vertical profile and temporal variation of the turbulence dissipation rate in the PBL over the TP based on the radar wind profiler (RWP) network. To the best of our knowledge, this is the first time that the turbulence profile over the whole TP is revealed. Furthermore, the possible mechanisms of clouds on the PBL turbulence structure are investigated.
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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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
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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.
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
EGUsphere, https://doi.org/10.5194/egusphere-2024-490, https://doi.org/10.5194/egusphere-2024-490, 2024
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Analysis of modeling, in-situ & remote sensing reveal the microphysical state of orographic clouds & their response to aerosol from the boundary layer & free troposphere. We should that this cloud responses 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 allow for novel model constraints and remote sensing products.
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
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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
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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.
Leandro Alex Moreira Viscardi, Giuseppe Torri, David Kenton Adams, and Henrique de Melo Jorge Barbosa
EGUsphere, https://doi.org/10.5194/egusphere-2023-2697, https://doi.org/10.5194/egusphere-2023-2697, 2023
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We evaluate the environmental conditions that control how clouds grow from fair weather cumulus to 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.
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
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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
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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
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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
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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
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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
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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
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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.
Henning Dorff, Heike Konow, Vera Schemann, and Felix Ament
EGUsphere, https://doi.org/10.5194/egusphere-2023-1570, https://doi.org/10.5194/egusphere-2023-1570, 2023
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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.
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
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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
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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.
Emma Järvinen, Franziska Nehlert, Guanglang Xu, Fritz Waitz, Guillaume Mioche, Regis Dupuy, Olivier Jourdan, and Martin Schnaiter
Atmos. Chem. Phys., 23, 7611–7633, https://doi.org/10.5194/acp-23-7611-2023, https://doi.org/10.5194/acp-23-7611-2023, 2023
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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.
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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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.
Siddhant Gupta, Greg M. McFarquhar, Joseph R. O'Brien, Michael R. Poellot, David J. Delene, Rose M. Miller, and Jennifer D. Small Griswold
Atmos. Chem. Phys., 22, 2769–2793, https://doi.org/10.5194/acp-22-2769-2022, https://doi.org/10.5194/acp-22-2769-2022, 2022
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This study evaluates the impact of biomass burning aerosols on precipitation in marine stratocumulus clouds using observations from the NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign over the Southeast Atlantic. Instances of contact and separation between aerosol and cloud layers show polluted clouds have a lower precipitation rate and a lower precipitation susceptibility. This information will help improve cloud representation in Earth system models.
Anna E. Luebke, André Ehrlich, Michael Schäfer, Kevin Wolf, and Manfred Wendisch
Atmos. Chem. Phys., 22, 2727–2744, https://doi.org/10.5194/acp-22-2727-2022, https://doi.org/10.5194/acp-22-2727-2022, 2022
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A combination of aircraft and satellite observations is used to show how the characteristics of tropical shallow clouds interact with incoming and outgoing energy. A complete depiction of these clouds is challenging to obtain, but such data are useful for understanding how models can correctly represent them. The amount of cloud is found to be the most important factor, while other cloud characteristics become increasingly impactful when more cloud is present.
Graciela B. Raga, Darrel Baumgardner, Blanca Rios, Yanet Díaz-Esteban, Alejandro Jaramillo, Martin Gallagher, Bastien Sauvage, Pawel Wolff, and Gary Lloyd
Atmos. Chem. Phys., 22, 2269–2292, https://doi.org/10.5194/acp-22-2269-2022, https://doi.org/10.5194/acp-22-2269-2022, 2022
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The In-Service Aircraft for a Global Observing System (IAGOS) is a small fleet of commercial aircraft that carry a suite of meteorological, gas, aerosol, and cloud sensors and have been measuring worldwide for almost 9 years, since late 2011. Extreme ice events (EIEs) have been identified from the IAGOS cloud measurements and linked to surface emissions for biomass and fossil fuel consumption. The results reported here are highly relevant for climate change and flight operations forecasting.
Carolina Viceto, Irina V. Gorodetskaya, Annette Rinke, Marion Maturilli, Alfredo Rocha, and Susanne Crewell
Atmos. Chem. Phys., 22, 441–463, https://doi.org/10.5194/acp-22-441-2022, https://doi.org/10.5194/acp-22-441-2022, 2022
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We focus on anomalous moisture transport events known as atmospheric rivers (ARs). During ACLOUD and PASCAL, three AR events were identified: 30 May, 6 June, and 9 June 2017. We explore their spatio-temporal evolution and precipitation patterns using measurements, reanalyses, and a model. We show the importance of the following: Atlantic and Siberian pathways during spring–summer in the Arctic, AR-associated heat/moisture increase, precipitation phase transition, and high-resolution datasets.
Sandra Vázquez-Martín, Thomas Kuhn, and Salomon Eliasson
Atmos. Chem. Phys., 21, 18669–18688, https://doi.org/10.5194/acp-21-18669-2021, https://doi.org/10.5194/acp-21-18669-2021, 2021
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High-resolution top- and side-view images of snow ice particles taken by the D-ICI instrument are used to determine the shape; size; cross-sectional area; fall speed; and, based upon these properties, the mass of the individual snow particles. The study analyses the relationships between these fundamental properties as a function of particle shape and highlights that the choice of size parameter, maximum dimension or another characteristic length, is crucial when relating fall speed to mass.
Elvis Torres-Delgado, Darrel Baumgardner, and Olga L. Mayol-Bracero
Atmos. Chem. Phys., 21, 18011–18027, https://doi.org/10.5194/acp-21-18011-2021, https://doi.org/10.5194/acp-21-18011-2021, 2021
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African dust aerosols can travel thousands of kilometers and reach the Caribbean and other places, where they can serve as ice and cloud condensation nuclei and alter precipitation patterns. Cloud microphysical properties (droplet number and size) were measured in a Caribbean tropical montane cloud forest along with models and satellite products. The results of the study suggest that meteorology and air mass history are more important for cloud processes than aerosols transported from Africa.
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Short summary
Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation. We present a case study that involves aircraft, lidar and radar observations of water and clouds in a WCB ascending from western Europe across the Alps towards the Baltic Sea during the field campaigns HyMeX and T-NAWDEX-Falcon in October 2012. A probabilistic trajectory measure and an airborne tracer experiment were used to confirm the long pathway of the WCB.
Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to...
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