Articles | Volume 12, issue 4
https://doi.org/10.5194/essd-12-2919-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/essd-12-2919-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Trade-wind clouds and aerosols characterized by airborne horizontal lidar measurements during the EUREC4A field campaign
Patrick Chazette
CORRESPONDING AUTHOR
LSCE/IPSL, CNRS-CEA-UVSQ, Université Paris-Saclay, CEA Saclay, 91191
Gif-sur-Yvette, France
Julien Totems
LSCE/IPSL, CNRS-CEA-UVSQ, Université Paris-Saclay, CEA Saclay, 91191
Gif-sur-Yvette, France
Alexandre Baron
LSCE/IPSL, CNRS-CEA-UVSQ, Université Paris-Saclay, CEA Saclay, 91191
Gif-sur-Yvette, France
Cyrille Flamant
LATMOS/IPSL, CNRS-UPMC-UVSQ, Sorbonne Université, Campus Pierre et
Marie Curie, 75252 Paris, France
Sandrine Bony
LMD/IPSL, CNRS, Sorbonne Université, Campus Pierre et Marie Curie,
UPMC, 4 Place Jussieu, 75252 Paris, France
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Between October 2022 and January 2023, the Water Vapour Lidar Network Assimilation (WaLiNeAs) campaign was conducted on the western Mediterranean by four European countries. To improve the forecasting of heavy precipitation events, eight ground-based stations equipped with water vapour Raman lidars were strategically deployed. They offered a valuable chance to verify the consistency of the water vapour products of both the Infrared Atmospheric Sounding Interferometer (IASI) and ERA5 reanalysis.
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Smoke from Southern African and South American wildfires can travel for thousands of kilometers before reaching the Indian Ocean and Reunion Island. In this study, we use instruments measuring from the ground, from satellites, as well as atmospheric models, to track these smoke plumes and identify their origins and properties. Our findings should help future research focusing on the impact of these plumes on the atmospheric temperature.
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Atmos. Meas. Tech., 18, 7629–7649, https://doi.org/10.5194/amt-18-7629-2025, https://doi.org/10.5194/amt-18-7629-2025, 2025
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This article presents the evolution of aerosol optical properties as derived from a Raman lidar in relation to relative humidity over the Paris area. It examines the influence of aerosol chemical compounds linked to air mass origins, as well as their relationship with the efficiency of aerosol growth. Such a study provides a better understanding of the interactions between aerosols and water vapour, which is important for reducing the uncertainties surrounding the Earth's radiative balance.
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Atmos. Chem. Phys., 25, 17331–17362, https://doi.org/10.5194/acp-25-17331-2025, https://doi.org/10.5194/acp-25-17331-2025, 2025
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Space photographs of the Earth show that clouds form diverse, common but poorly understood cloud patterns. The analysis of observations gathered from research aircraft over the tropical ocean shows that the merging of thermals and clouds in the first kilometer of the atmosphere plays a key role in controlling the size, depth and spacing of clouds. This reveals a fundamental process through which clouds interact with each other and with their environment.
Daniele Zannoni, Hans Christian Steen-Larsen, Harald Sodemann, Iris Thurnherr, Cyrille Flamant, Patrick Chazette, Julien Totems, Martin Werner, and Myriam Raybaut
Atmos. Chem. Phys., 25, 9471–9495, https://doi.org/10.5194/acp-25-9471-2025, https://doi.org/10.5194/acp-25-9471-2025, 2025
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High-resolution airborne observations reveal that mixing between the free troposphere and surface evapotranspiration flux primarily modulates the water vapor isotopic composition in the lower troposphere. Water vapor isotope structure variations occur on the scale of hundreds of meters, underlining the utility of stable isotopes for studying microscale atmospheric dynamics. This study also provides the basis for better validation of water vapor isotope remote sensing retrievals with surface observations.
Patrick Chazette, Julien Totems, and Frédéric Laly
Atmos. Meas. Tech., 18, 2681–2699, https://doi.org/10.5194/amt-18-2681-2025, https://doi.org/10.5194/amt-18-2681-2025, 2025
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The use of active remote sensing instruments to sample the atmospheric environment requires accurate calibration that is stable over time so that measurements are reproducible. This is the case for measurements of atmospheric water vapour using Raman lidar, which are of growing interest in the context of climate risks such as extreme precipitation. This study addresses this issue. It is based on six campaigns spread over a period of 7 years between 2016 and 2022.
Frédéric Laly, Patrick Chazette, Julien Totems, Jérémy Lagarrigue, Laurent Forges, and Cyrille Flamant
Earth Syst. Sci. Data, 16, 5579–5602, https://doi.org/10.5194/essd-16-5579-2024, https://doi.org/10.5194/essd-16-5579-2024, 2024
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We present a dataset of water vapor mixing ratio profiles acquired during the Water Vapor Lidar Network Assimilation campaign in fall and winter 2022 and summer 2023, using three lidar systems deployed on the western Mediterranean coastline. This innovative campaign provides access to lower-tropospheric water vapor variability to constrain meteorological forecasting models. The scientific objective is to improve forecasting of heavy-precipation events that lead to flash floods and landslides.
Maëlie Chazette, Patrick Chazette, Ilja M. Reiter, Xiaoxia Shang, Julien Totems, Jean-Philippe Orts, Irène Xueref-Remy, and Nicolas Montes
Biogeosciences, 21, 3289–3303, https://doi.org/10.5194/bg-21-3289-2024, https://doi.org/10.5194/bg-21-3289-2024, 2024
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The approach presented is original in its coupling between field observations and airborne lidar observations. It has been applied to an instrumented reference forest site in the south of France, which is heavily impacted by climate change. It leads to the evaluation of tree heights and ends with assessments of aerial and root carbon stocks. A detailed assessment of uncertainties is presented to add a level of reliability to the scientific products delivered.
Patrick Chazette and Jean-Christophe Raut
Atmos. Meas. Tech., 16, 5847–5861, https://doi.org/10.5194/amt-16-5847-2023, https://doi.org/10.5194/amt-16-5847-2023, 2023
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The vertical profiles of the effective radii of ice crystals and ice water content in Arctic semi-transparent stratiform clouds were assessed using quantitative ground-based lidar measurements. The field campaign was part of the Pollution in the ARCtic System (PARCS) project which took place from 13 to 26 May 2016 in Hammerfest (70° 39′ 48″ N, 23° 41′ 00″ E). We show that under certain cloud conditions, lidar measurement combined with a dedicated algorithmic approach is an efficient tool.
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.
Cyrille Flamant, Marco Gaetani, Jean-Pierre Chaboureau, Patrick Chazette, Juan Cuesta, Stuart John Piketh, and Paola Formenti
Atmos. Chem. Phys., 22, 5701–5724, https://doi.org/10.5194/acp-22-5701-2022, https://doi.org/10.5194/acp-22-5701-2022, 2022
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Rivers of smoke extend from tropical southern Africa towards the Indian Ocean during the winter fire season, controlled by the interaction of tropical easterly waves, and westerly waves at mid latitudes. During the AEROCLO-sA field campaign in 2017, a river of smoke was directly observed over Namibia. In this paper, the evolution and atmospheric drivers of the river of smoke are described, and the role of a mid-latitude cut-off low in lifting the smoke to the upper troposphere is highlighted.
Sandrine Bony, Marie Lothon, Julien Delanoë, Pierre Coutris, Jean-Claude Etienne, Franziska Aemisegger, Anna Lea Albright, Thierry André, Hubert Bellec, Alexandre Baron, Jean-François Bourdinot, Pierre-Etienne Brilouet, Aurélien Bourdon, Jean-Christophe Canonici, Christophe Caudoux, Patrick Chazette, Michel Cluzeau, Céline Cornet, Jean-Philippe Desbios, Dominique Duchanoy, Cyrille Flamant, Benjamin Fildier, Christophe Gourbeyre, Laurent Guiraud, Tetyana Jiang, Claude Lainard, Christophe Le Gac, Christian Lendroit, Julien Lernould, Thierry Perrin, Frédéric Pouvesle, Pascal Richard, Nicolas Rochetin, Kevin Salaün, Alfons Schwarzenboeck, Guillaume Seurat, Bjorn Stevens, Julien Totems, Ludovic Touzé-Peiffer, Gilles Vergez, Jessica Vial, Leonie Villiger, and Raphaela Vogel
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The French ATR42 research aircraft participated in the EUREC4A international field campaign that took place in 2020 over the tropical Atlantic, east of Barbados. We present the extensive instrumentation of the aircraft, the research flights and the different measurements. We show that the ATR measurements of humidity, wind, aerosols and cloudiness in the lower atmosphere are robust and consistent with each other. They will make it possible to advance understanding of cloud–climate interactions.
Karine Desboeufs, Franck Fu, Matthieu Bressac, Antonio Tovar-Sánchez, Sylvain Triquet, Jean-François Doussin, Chiara Giorio, Patrick Chazette, Julie Disnaquet, Anaïs Feron, Paola Formenti, Franck Maisonneuve, Araceli Rodríguez-Romero, Pascal Zapf, François Dulac, and Cécile Guieu
Atmos. Chem. Phys., 22, 2309–2332, https://doi.org/10.5194/acp-22-2309-2022, https://doi.org/10.5194/acp-22-2309-2022, 2022
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This article reports the first concurrent sampling of wet deposition samples and surface seawater and was performed during the PEACETIME cruise in the remote Mediterranean (May–June 2017). Through the chemical composition of trace metals (TMs) in these samples, it emphasizes the decrease of atmospheric metal pollution in this area during the last few decades and the critical role of wet deposition as source of TMs for Mediterranean surface seawater, especially for intense dust deposition events.
Patrick Chazette, Alexandre Baron, and Cyrille Flamant
Atmos. Chem. Phys., 22, 1271–1292, https://doi.org/10.5194/acp-22-1271-2022, https://doi.org/10.5194/acp-22-1271-2022, 2022
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Within the framework of the international EUREC4A project, horizontal lidar measurements were carried out over Barbados from the French research aircraft ATR-42. These measurements highlighted the strong heterogeneity of the aerosol field (mainly dust and biomass burning aerosols) and therefore of the associated optical properties. This heterogeneity varies according to meteorological conditions and could significantly modulate the climatic impact of aerosols trapped over the tropical Atlantic.
Julien Totems, Patrick Chazette, and Alexandre Baron
Atmos. Meas. Tech., 14, 7525–7544, https://doi.org/10.5194/amt-14-7525-2021, https://doi.org/10.5194/amt-14-7525-2021, 2021
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We describe in detail the design and calibration of the new Raman channels for the WALI system, going over the important sources of bias and uncertainty on retrieved temperature profiles. For the first time, their impact is investigated using horizontal shots in a homogenous atmosphere: the magnitude of the highlighted biases can be much larger than the targeted absolute accuracy of 1° C. Actual measurement errors are quantified using radiosoundings launched close to the lidar site.
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.
Kate Smith, Alexandre Baron, Joshua Schwarz, Elizabeth Asher, Emrys Hall, Patrick Cullis, Alex Fritz, Hagen Telg, Ross Burgener, Bryan Thomas, Matthew Martinsen, David Nardini, Darryl Kuniyuki, Penny Smale, Ben Liley, Richard Querel, Krystian Kopka, Ian Crocker, Skyler Jordan, Michael Doneghey, Luke Longren, Stephanie Evan, Jerome Brioude, Jean-Marc Metzger, David Combemale, Cor Becker, Dwight Samuel, Cheryll Tjon A Ten, Mohammed Amierali, Christopher Wongsowidjojo, Dennis Rodrigues, George Paiman, Ankie Piters, Katrin Müller, and Troy Thornberry
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2026-644, https://doi.org/10.5194/essd-2026-644, 2026
Preprint under review for ESSD
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Direct measurements of stratospheric aerosol are sparse, yet it plays an important role in Earth’s climate by scattering incoming solar radiation. The B2SAP network addresses this gap by regularly launching balloons carrying Portable Optical Particle Spectrometers (POPS) from 8 latitudinally diverse sites. The dataset provides vertical profiles of aerosol abundance and size distributions from the ground to 28 km, helping characterize global stratospheric aerosol abundance and variability.
Patrick Chazette, Andreas Behrendt, Adolfo Comerón, Paolo Di Girolamo, Marco Di Paolantonio, Davide Dionisi, Cyrille Flamant, José Luis Gómez-Amo, Jérémy Lagarrigue, Frédéric Laly, Diego Lange, Constantino Muñoz-Porcar, Alejandro Rodríguez-Gómez, Michaël Sicard, Donato Summa, Julien Totems, María Pilar Utrillas, Pedro C. Valdelomar, and Volker Wulfmeyer
Atmos. Meas. Tech., 19, 5223–5242, https://doi.org/10.5194/amt-19-5223-2026, https://doi.org/10.5194/amt-19-5223-2026, 2026
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Between October 2022 and January 2023, the Water Vapour Lidar Network Assimilation (WaLiNeAs) campaign was conducted on the western Mediterranean by four European countries. To improve the forecasting of heavy precipitation events, eight ground-based stations equipped with water vapour Raman lidars were strategically deployed. They offered a valuable chance to verify the consistency of the water vapour products of both the Infrared Atmospheric Sounding Interferometer (IASI) and ERA5 reanalysis.
Dominique Gantois, Alexandre Baron, Michaël Sicard, Valentin Duflot, Niels Groenen, Nelson Bègue, Sabine Eckhardt, Nikolaos Evangeliou, Martine De Mazière, Corinne Vigouroux, Guillaume Payen, Nicolas Marquestaut, Jean-Marc Metzger, Patrick Chazette, and Cyrille Flamant
EGUsphere, https://doi.org/10.5194/egusphere-2026-3070, https://doi.org/10.5194/egusphere-2026-3070, 2026
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Smoke from Southern African and South American wildfires can travel for thousands of kilometers before reaching the Indian Ocean and Reunion Island. In this study, we use instruments measuring from the ground, from satellites, as well as atmospheric models, to track these smoke plumes and identify their origins and properties. Our findings should help future research focusing on the impact of these plumes on the atmospheric temperature.
Patrick Chazette
Atmos. Meas. Tech., 19, 4293–4311, https://doi.org/10.5194/amt-19-4293-2026, https://doi.org/10.5194/amt-19-4293-2026, 2026
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A novel aerosol classification methodology based on Raman lidar observations is presented and applied to measurements acquired during the FENNEC field campaign. The temporal evolution of aerosol classes and optical properties is then used to perform a quantitative evaluation of numerical simulations from the Copernicus Atmosphere Monitoring Service (CAMS) global reanalysis (EAC4).
Zhen Yang, Bärbel Vogel, Felix Plöger, Zhixuan Bai, Dan Li, Sabine Griessbach, Lars Hoffmann, Frank G. Wienhold, Elizabeth Asher, Alexandre A. Baron, Katie R. Smith, Troy Thornberry, Jianchun Bian, and Michaela I. Hegglin
Atmos. Chem. Phys., 26, 4749–4769, https://doi.org/10.5194/acp-26-4749-2026, https://doi.org/10.5194/acp-26-4749-2026, 2026
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Balloon measurements over Lhasa, China, combined with satellite guided modelling, tracked aerosol from the 2019 Raikoke eruption through the Asian summer monsoon anticyclone. We find two altitude dependent routes into the anticyclone. It partly blocks transport but also allows entry and mixing, explaining the gradual weakening of the layers. Balloon measurements over Boulder, United States, outside the anticyclone, provide an independent check outside the region.
Frédéric Laly, Patrick Chazette, Julien Totems, Vincent Crenn, David Ledur, and Alexandre Marpillat
Atmos. Meas. Tech., 18, 7629–7649, https://doi.org/10.5194/amt-18-7629-2025, https://doi.org/10.5194/amt-18-7629-2025, 2025
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This article presents the evolution of aerosol optical properties as derived from a Raman lidar in relation to relative humidity over the Paris area. It examines the influence of aerosol chemical compounds linked to air mass origins, as well as their relationship with the efficiency of aerosol growth. Such a study provides a better understanding of the interactions between aerosols and water vapour, which is important for reducing the uncertainties surrounding the Earth's radiative balance.
Luis Valero, Konrad Kandler, Sina Jost, Holger Tost, Luca Katarina Eichhorn, Christian von Glahn, Harald Rott, Marilena Flory, Alexandre Baron, Kathie Smith, Troy Thornberry, and Ralf Weigel
EGUsphere, https://doi.org/10.5194/egusphere-2025-5568, https://doi.org/10.5194/egusphere-2025-5568, 2025
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We developed a low-cost, balloon-lifted platform with lightweight instruments to measure particles and collect samples. We tested this platform during two field campaigns in Germany. A case study showed its ability to observe the vertical distribution of particles and how they form cloud droplets. Electronic microscope analysis of the samples identified their chemical composition. This work shows the platform is a capable tool for studying atmospheric processes.
Sandrine Bony, Basile Poujol, Brett McKim, Nicolas Rochetin, Marie Lothon, Julia Windmiller, Nicolas Maury, Clarisse Dufaux, Louis Jaffeux, Patrick Chazette, and Julien Delanoë
Atmos. Chem. Phys., 25, 17331–17362, https://doi.org/10.5194/acp-25-17331-2025, https://doi.org/10.5194/acp-25-17331-2025, 2025
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Space photographs of the Earth show that clouds form diverse, common but poorly understood cloud patterns. The analysis of observations gathered from research aircraft over the tropical ocean shows that the merging of thermals and clouds in the first kilometer of the atmosphere plays a key role in controlling the size, depth and spacing of clouds. This reveals a fundamental process through which clouds interact with each other and with their environment.
Hans Segura, Xabier Pedruzo-Bagazgoitia, Philipp Weiss, Sebastian K. Müller, Thomas Rackow, Junhong Lee, Edgar Dolores-Tesillos, Imme Benedict, Matthias Aengenheyster, Razvan Aguridan, Gabriele Arduini, Alexander J. Baker, Jiawei Bao, Swantje Bastin, Eulàlia Baulenas, Tobias Becker, Sebastian Beyer, Hendryk Bockelmann, Nils Brüggemann, Lukas Brunner, Suvarchal K. Cheedela, Sushant Das, Jasper Denissen, Ian Dragaud, Piotr Dziekan, Madeleine Ekblom, Jan Frederik Engels, Monika Esch, Richard Forbes, Claudia Frauen, Lilli Freischem, Diego García-Maroto, Philipp Geier, Paul Gierz, Álvaro González-Cervera, Katherine Grayson, Matthew Griffith, Oliver Gutjahr, Helmuth Haak, Ioan Hadade, Kerstin Haslehner, Shabeh ul Hasson, Jan Hegewald, Lukas Kluft, Aleksei Koldunov, Nikolay Koldunov, Tobias Kölling, Shunya Koseki, Sergey Kosukhin, Josh Kousal, Peter Kuma, Arjun U. Kumar, Rumeng Li, Nicolas Maury, Maximilian Meindl, Sebastian Milinski, Kristian Mogensen, Bimochan Niraula, Jakub Nowak, Divya Sri Praturi, Ulrike Proske, Dian Putrasahan, René Redler, David Santuy, Domokos Sármány, Reiner Schnur, Patrick Scholz, Dmitry Sidorenko, Dorian Spät, Birgit Sützl, Daisuke Takasuka, Adrian Tompkins, Alejandro Uribe, Mirco Valentini, Menno Veerman, Aiko Voigt, Sarah Warnau, Fabian Wachsmann, Marta Wacławczyk, Nils Wedi, Karl-Hermann Wieners, Jonathan Wille, Marius Winkler, Yuting Wu, Florian Ziemen, Janos Zimmermann, Frida A.-M. Bender, Dragana Bojovic, Sandrine Bony, Simona Bordoni, Patrice Brehmer, Marcus Dengler, Emanuel Dutra, Saliou Faye, Erich Fischer, Chiel van Heerwaarden, Cathy Hohenegger, Heikki Järvinen, Markus Jochum, Thomas Jung, Johann H. Jungclaus, Noel S. Keenlyside, Daniel Klocke, Heike Konow, Martina Klose, Szymon Malinowski, Olivia Martius, Thorsten Mauritsen, Juan Pedro Mellado, Theresa Mieslinger, Elsa Mohino, Hanna Pawłowska, Karsten Peters-von Gehlen, Abdoulaye Sarré, Pajam Sobhani, Philip Stier, Lauri Tuppi, Pier Luigi Vidale, Irina Sandu, and Bjorn Stevens
Geosci. Model Dev., 18, 7735–7761, https://doi.org/10.5194/gmd-18-7735-2025, https://doi.org/10.5194/gmd-18-7735-2025, 2025
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The Next Generation of Earth Modeling Systems project (nextGEMS) developed two Earth system models that use horizontal grid spacing of 10 km and finer, giving more fidelity to the representation of local phenomena, globally. In its fourth cycle, nextGEMS simulated the Earth System climate over the 2020–2049 period under the SSP3-7.0 scenario. Here, we provide an overview of nextGEMS, insights into the model development, and the realism of multi-decadal, kilometer-scale simulations.
Tristan Millet, Hassan Bencherif, Thierry Portafaix, Nelson Bègue, Alexandre Baron, Valentin Duflot, Cathy Clerbaux, Pierre-François Coheur, Andrea Pazmiño, Michaël Sicard, Anne Boynard, Jean-Marc Metzger, Guillaume Payen, Nicolas Marquestaut, and Sophie Godin-Beekmann
Atmos. Chem. Phys., 25, 10887–10905, https://doi.org/10.5194/acp-25-10887-2025, https://doi.org/10.5194/acp-25-10887-2025, 2025
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On 15 January 2022, the Hunga volcano erupted, releasing sulfur dioxide and water vapor into the stratosphere, impacting ozone levels over the Indian Ocean. Satellite data show the presence of a transient ozone depletion event related to the water vapor anomalies and sulfate aerosol clouds. Ozone reduction was confined to two distinct layers. On 21 January, the fifth percentile of total and stratospheric column ozone anomalies reached −18.6 and −14.5 DU, respectively.
Tanguy Jonville, Maurus Borne, Cyrille Flamant, Juan Cuesta, Olivier Bock, Pierre Bosser, Christophe Lavaysse, Andreas Fink, and Peter Knippertz
Atmos. Chem. Phys., 25, 9765–9786, https://doi.org/10.5194/acp-25-9765-2025, https://doi.org/10.5194/acp-25-9765-2025, 2025
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Tropical waves structure the atmosphere. Four types of tropical waves (equatorial Rossby – ER, Kelvin, MRG-TD1, and MRG-TD2 – mixed Rossby gravity–tropical depressions) are studied using filters, satellite measurements, and in situ data from the Clouds–Atmosphere Dynamics–Dust Interaction in West Africa (CADDIWA) campaign held in September 2021 in Cabo Verde. ER waves impact temperature and humidity above 2500 m, MRG-TD1 around 3500 m, and MRG-TD2 around 2000 m. Interactions between these waves favor tropical cyclone formation.
Daniele Zannoni, Hans Christian Steen-Larsen, Harald Sodemann, Iris Thurnherr, Cyrille Flamant, Patrick Chazette, Julien Totems, Martin Werner, and Myriam Raybaut
Atmos. Chem. Phys., 25, 9471–9495, https://doi.org/10.5194/acp-25-9471-2025, https://doi.org/10.5194/acp-25-9471-2025, 2025
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High-resolution airborne observations reveal that mixing between the free troposphere and surface evapotranspiration flux primarily modulates the water vapor isotopic composition in the lower troposphere. Water vapor isotope structure variations occur on the scale of hundreds of meters, underlining the utility of stable isotopes for studying microscale atmospheric dynamics. This study also provides the basis for better validation of water vapor isotope remote sensing retrievals with surface observations.
Mégane Ventura, Fabien Waquet, Isabelle Chiapello, Gérard Brogniez, Frédéric Parol, Frédérique Auriol, Rodrigue Loisil, Cyril Delegove, Luc Blarel, Oleg Dubovik, Marc Mallet, Cyrille Flamant, and Paola Formenti
Atmos. Meas. Tech., 18, 4005–4024, https://doi.org/10.5194/amt-18-4005-2025, https://doi.org/10.5194/amt-18-4005-2025, 2025
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Biomass-burning aerosols (BBAs) from Central Africa are transported above stratocumulus clouds. The absorption of solar energy by aerosols induces warming, altering the cloud dynamics. We developed an approach that combines polarimeter and lidar to quantify this. This methodology is assessed during the AEROCLO-sA (AErosol RadiatiOn and CLOud in Southern Africa) campaign. To validate it, we used irradiance measurements acquired during aircraft spiral descents. A major perspective is the generalization of this method to the global level.
Patrick Chazette, Julien Totems, and Frédéric Laly
Atmos. Meas. Tech., 18, 2681–2699, https://doi.org/10.5194/amt-18-2681-2025, https://doi.org/10.5194/amt-18-2681-2025, 2025
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The use of active remote sensing instruments to sample the atmospheric environment requires accurate calibration that is stable over time so that measurements are reproducible. This is the case for measurements of atmospheric water vapour using Raman lidar, which are of growing interest in the context of climate risks such as extreme precipitation. This study addresses this issue. It is based on six campaigns spread over a period of 7 years between 2016 and 2022.
Michaël Sicard, Alexandre Baron, Marion Ranaivombola, Dominique Gantois, Tristan Millet, Pasquale Sellitto, Nelson Bègue, Hassan Bencherif, Guillaume Payen, Nicolas Marquestaut, and Valentin Duflot
Atmos. Chem. Phys., 25, 367–381, https://doi.org/10.5194/acp-25-367-2025, https://doi.org/10.5194/acp-25-367-2025, 2025
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This study quantifies the radiative impact over Réunion Island (21° S, 55° E) of the aerosols and water vapor injected into the stratosphere by the Hunga volcano in the South Pacific. The overall aerosol and water vapor impact on the Earth’s radiation budget for the whole period is negative (cooling, -0.82 ± 0.35 W m-2) and dominated by the aerosols. At the Earth’s surface, aerosols are the main drivers and produce a negative (cooling, -1.04 ± 0.36 W m-2) radiative impact.
Cedric G. Ngoungue Langue, Christophe Lavaysse, and Cyrille Flamant
Nat. Hazards Earth Syst. Sci., 25, 147–168, https://doi.org/10.5194/nhess-25-147-2025, https://doi.org/10.5194/nhess-25-147-2025, 2025
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The present study addresses the predictability of heat waves at subseasonal timescales in West African cities over the period 2001–2020. Two models, the European Centre for Medium-Range Weather Forecasts (ECMWF) and the UK Met Office models, were evaluated using two reanalyses: ERA5 and MERRA. The results suggest that at subseasonal timescales, the forecast models provide a better forecast than climatology, but the hit rate and false alarm rate are sub-optimal.
Frédéric Laly, Patrick Chazette, Julien Totems, Jérémy Lagarrigue, Laurent Forges, and Cyrille Flamant
Earth Syst. Sci. Data, 16, 5579–5602, https://doi.org/10.5194/essd-16-5579-2024, https://doi.org/10.5194/essd-16-5579-2024, 2024
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We present a dataset of water vapor mixing ratio profiles acquired during the Water Vapor Lidar Network Assimilation campaign in fall and winter 2022 and summer 2023, using three lidar systems deployed on the western Mediterranean coastline. This innovative campaign provides access to lower-tropospheric water vapor variability to constrain meteorological forecasting models. The scientific objective is to improve forecasting of heavy-precipation events that lead to flash floods and landslides.
Maëlie Chazette, Patrick Chazette, Ilja M. Reiter, Xiaoxia Shang, Julien Totems, Jean-Philippe Orts, Irène Xueref-Remy, and Nicolas Montes
Biogeosciences, 21, 3289–3303, https://doi.org/10.5194/bg-21-3289-2024, https://doi.org/10.5194/bg-21-3289-2024, 2024
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The approach presented is original in its coupling between field observations and airborne lidar observations. It has been applied to an instrumented reference forest site in the south of France, which is heavily impacted by climate change. It leads to the evaluation of tree heights and ends with assessments of aerial and root carbon stocks. A detailed assessment of uncertainties is presented to add a level of reliability to the scientific products delivered.
Nelson Bègue, Alexandre Baron, Gisèle Krysztofiak, Gwenaël Berthet, Corinna Kloss, Fabrice Jégou, Sergey Khaykin, Marion Ranaivombola, Tristan Millet, Thierry Portafaix, Valentin Duflot, Philippe Keckhut, Hélène Vérèmes, Guillaume Payen, Mahesh Kumar Sha, Pierre-François Coheur, Cathy Clerbaux, Michaël Sicard, Tetsu Sakai, Richard Querel, Ben Liley, Dan Smale, Isamu Morino, Osamu Uchino, Tomohiro Nagai, Penny Smale, John Robinson, and Hassan Bencherif
Atmos. Chem. Phys., 24, 8031–8048, https://doi.org/10.5194/acp-24-8031-2024, https://doi.org/10.5194/acp-24-8031-2024, 2024
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During the 2020 austral summer, the pristine atmosphere of the southwest Indian Ocean basin experienced significant perturbations. Numerical models indicated that the lower-stratospheric aerosol content was influenced by the intense and persistent stratospheric aerosol layer generated during the 2019–2020 extreme Australian bushfire events. Ground-based observations at Réunion confirmed the simultaneous presence of African and Australian aerosol layers.
Bjorn Stevens, Stefan Adami, Tariq Ali, Hartwig Anzt, Zafer Aslan, Sabine Attinger, Jaana Bäck, Johanna Baehr, Peter Bauer, Natacha Bernier, Bob Bishop, Hendryk Bockelmann, Sandrine Bony, Guy Brasseur, David N. Bresch, Sean Breyer, Gilbert Brunet, Pier Luigi Buttigieg, Junji Cao, Christelle Castet, Yafang Cheng, Ayantika Dey Choudhury, Deborah Coen, Susanne Crewell, Atish Dabholkar, Qing Dai, Francisco Doblas-Reyes, Dale Durran, Ayoub El Gaidi, Charlie Ewen, Eleftheria Exarchou, Veronika Eyring, Florencia Falkinhoff, David Farrell, Piers M. Forster, Ariane Frassoni, Claudia Frauen, Oliver Fuhrer, Shahzad Gani, Edwin Gerber, Debra Goldfarb, Jens Grieger, Nicolas Gruber, Wilco Hazeleger, Rolf Herken, Chris Hewitt, Torsten Hoefler, Huang-Hsiung Hsu, Daniela Jacob, Alexandra Jahn, Christian Jakob, Thomas Jung, Christopher Kadow, In-Sik Kang, Sarah Kang, Karthik Kashinath, Katharina Kleinen-von Königslöw, Daniel Klocke, Uta Kloenne, Milan Klöwer, Chihiro Kodama, Stefan Kollet, Tobias Kölling, Jenni Kontkanen, Steve Kopp, Michal Koran, Markku Kulmala, Hanna Lappalainen, Fakhria Latifi, Bryan Lawrence, June Yi Lee, Quentin Lejeun, Christian Lessig, Chao Li, Thomas Lippert, Jürg Luterbacher, Pekka Manninen, Jochem Marotzke, Satoshi Matsouoka, Charlotte Merchant, Peter Messmer, Gero Michel, Kristel Michielsen, Tomoki Miyakawa, Jens Müller, Ramsha Munir, Sandeep Narayanasetti, Ousmane Ndiaye, Carlos Nobre, Achim Oberg, Riko Oki, Tuba Özkan-Haller, Tim Palmer, Stan Posey, Andreas Prein, Odessa Primus, Mike Pritchard, Julie Pullen, Dian Putrasahan, Johannes Quaas, Krishnan Raghavan, Venkatachalam Ramaswamy, Markus Rapp, Florian Rauser, Markus Reichstein, Aromar Revi, Sonakshi Saluja, Masaki Satoh, Vera Schemann, Sebastian Schemm, Christina Schnadt Poberaj, Thomas Schulthess, Cath Senior, Jagadish Shukla, Manmeet Singh, Julia Slingo, Adam Sobel, Silvina Solman, Jenna Spitzer, Philip Stier, Thomas Stocker, Sarah Strock, Hang Su, Petteri Taalas, John Taylor, Susann Tegtmeier, Georg Teutsch, Adrian Tompkins, Uwe Ulbrich, Pier-Luigi Vidale, Chien-Ming Wu, Hao Xu, Najibullah Zaki, Laure Zanna, Tianjun Zhou, and Florian Ziemen
Earth Syst. Sci. Data, 16, 2113–2122, https://doi.org/10.5194/essd-16-2113-2024, https://doi.org/10.5194/essd-16-2113-2024, 2024
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To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines is proposed as an international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.
Cyrille Flamant, Jean-Pierre Chaboureau, Marco Gaetani, Kerstin Schepanski, and Paola Formenti
Atmos. Chem. Phys., 24, 4265–4288, https://doi.org/10.5194/acp-24-4265-2024, https://doi.org/10.5194/acp-24-4265-2024, 2024
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In the austral dry season, the atmospheric composition over southern Africa is dominated by biomass burning aerosols and terrigenous aerosols (so-called mineral dust). This study suggests that the radiative effect of biomass burning aerosols needs to be taken into account to properly forecast dust emissions in Namibia.
Maurus Borne, Peter Knippertz, Martin Weissmann, Benjamin Witschas, Cyrille Flamant, Rosimar Rios-Berrios, and Peter Veals
Atmos. Meas. Tech., 17, 561–581, https://doi.org/10.5194/amt-17-561-2024, https://doi.org/10.5194/amt-17-561-2024, 2024
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This study assesses the quality of Aeolus wind measurements over the tropical Atlantic. The results identified the accuracy and precision of the Aeolus wind measurements and the potential source of errors. For instance, the study revealed atmospheric conditions that can deteriorate the measurement quality, such as weaker laser signal in cloudy or dusty conditions, and confirmed the presence of an orbital-dependant bias. These results can help to improve the Aeolus wind measurement algorithm.
Gaëlle de Coëtlogon, Adrien Deroubaix, Cyrille Flamant, Laurent Menut, and Marco Gaetani
Atmos. Chem. Phys., 23, 15507–15521, https://doi.org/10.5194/acp-23-15507-2023, https://doi.org/10.5194/acp-23-15507-2023, 2023
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Using a numerical atmospheric model, we found that cooling sea surface temperatures along the southern coast of West Africa in July cause the “little dry season”. This effect reduces humidity and pollutant transport inland, potentially enhancing West Africa's synoptic and seasonal forecasting.
Patrick Chazette and Jean-Christophe Raut
Atmos. Meas. Tech., 16, 5847–5861, https://doi.org/10.5194/amt-16-5847-2023, https://doi.org/10.5194/amt-16-5847-2023, 2023
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The vertical profiles of the effective radii of ice crystals and ice water content in Arctic semi-transparent stratiform clouds were assessed using quantitative ground-based lidar measurements. The field campaign was part of the Pollution in the ARCtic System (PARCS) project which took place from 13 to 26 May 2016 in Hammerfest (70° 39′ 48″ N, 23° 41′ 00″ E). We show that under certain cloud conditions, lidar measurement combined with a dedicated algorithmic approach is an efficient tool.
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.
Tristan Millet, Hassan Bencherif, Thierry Portafaix, Nelson Bègue, Alexandre Baron, Valentin Duflot, Michaël Sicard, Jean-Marc Metzger, Guillaume Payen, Nicolas Marquestaut, and Sophie Godin-Beekmann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2645, https://doi.org/10.5194/egusphere-2023-2645, 2023
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The eruption of the Hunga Tonga volcano in January 2022 released substantial amounts of aerosols, sulfur dioxide, and water vapor into the stratosphere. Satellite and ground instruments followed the displacement of the volcanic aerosol plume and its impact on ozone levels over the Indian Ocean. Ozone data reveal the presence of a persistent ozone mini-hole structure from 17 January to 22 January, with most ozone depletion occurring within the ozone layer at the location of the aerosol plume.
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.
Cedric Gacial Ngoungue Langue, Christophe Lavaysse, Mathieu Vrac, and Cyrille Flamant
Nat. Hazards Earth Syst. Sci., 23, 1313–1333, https://doi.org/10.5194/nhess-23-1313-2023, https://doi.org/10.5194/nhess-23-1313-2023, 2023
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Heat waves (HWs) are climatic hazards that affect the planet. We assess here uncertainties encountered in the process of HW detection and analyse their recent trends in West Africa using reanalysis data. Three types of uncertainty have been investigated. We identified 6 years with higher frequency of HWs, possibly due to higher sea surface temperatures in the equatorial Atlantic. We noticed an increase in HW characteristics during the last decade, which could be a consequence of climate change.
Jean-Pierre Chaboureau, Laurent Labbouz, Cyrille Flamant, and Alma Hodzic
Atmos. Chem. Phys., 22, 8639–8658, https://doi.org/10.5194/acp-22-8639-2022, https://doi.org/10.5194/acp-22-8639-2022, 2022
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Ground-based, spaceborne and rare airborne observations of biomass burning aerosols (BBAs) during the AEROCLO-sA field campaign in 2017 are complemented with convection-permitting simulations with online trajectories. The results show that the radiative effect of the BBA accelerates the southern African easterly jet and generates upward motions that transport the BBAs to higher altitudes and farther southwest.
Cyrille Flamant, Marco Gaetani, Jean-Pierre Chaboureau, Patrick Chazette, Juan Cuesta, Stuart John Piketh, and Paola Formenti
Atmos. Chem. Phys., 22, 5701–5724, https://doi.org/10.5194/acp-22-5701-2022, https://doi.org/10.5194/acp-22-5701-2022, 2022
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Rivers of smoke extend from tropical southern Africa towards the Indian Ocean during the winter fire season, controlled by the interaction of tropical easterly waves, and westerly waves at mid latitudes. During the AEROCLO-sA field campaign in 2017, a river of smoke was directly observed over Namibia. In this paper, the evolution and atmospheric drivers of the river of smoke are described, and the role of a mid-latitude cut-off low in lifting the smoke to the upper troposphere is highlighted.
Sandrine Bony, Marie Lothon, Julien Delanoë, Pierre Coutris, Jean-Claude Etienne, Franziska Aemisegger, Anna Lea Albright, Thierry André, Hubert Bellec, Alexandre Baron, Jean-François Bourdinot, Pierre-Etienne Brilouet, Aurélien Bourdon, Jean-Christophe Canonici, Christophe Caudoux, Patrick Chazette, Michel Cluzeau, Céline Cornet, Jean-Philippe Desbios, Dominique Duchanoy, Cyrille Flamant, Benjamin Fildier, Christophe Gourbeyre, Laurent Guiraud, Tetyana Jiang, Claude Lainard, Christophe Le Gac, Christian Lendroit, Julien Lernould, Thierry Perrin, Frédéric Pouvesle, Pascal Richard, Nicolas Rochetin, Kevin Salaün, Alfons Schwarzenboeck, Guillaume Seurat, Bjorn Stevens, Julien Totems, Ludovic Touzé-Peiffer, Gilles Vergez, Jessica Vial, Leonie Villiger, and Raphaela Vogel
Earth Syst. Sci. Data, 14, 2021–2064, https://doi.org/10.5194/essd-14-2021-2022, https://doi.org/10.5194/essd-14-2021-2022, 2022
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The French ATR42 research aircraft participated in the EUREC4A international field campaign that took place in 2020 over the tropical Atlantic, east of Barbados. We present the extensive instrumentation of the aircraft, the research flights and the different measurements. We show that the ATR measurements of humidity, wind, aerosols and cloudiness in the lower atmosphere are robust and consistent with each other. They will make it possible to advance understanding of cloud–climate interactions.
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.
Karine Desboeufs, Franck Fu, Matthieu Bressac, Antonio Tovar-Sánchez, Sylvain Triquet, Jean-François Doussin, Chiara Giorio, Patrick Chazette, Julie Disnaquet, Anaïs Feron, Paola Formenti, Franck Maisonneuve, Araceli Rodríguez-Romero, Pascal Zapf, François Dulac, and Cécile Guieu
Atmos. Chem. Phys., 22, 2309–2332, https://doi.org/10.5194/acp-22-2309-2022, https://doi.org/10.5194/acp-22-2309-2022, 2022
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This article reports the first concurrent sampling of wet deposition samples and surface seawater and was performed during the PEACETIME cruise in the remote Mediterranean (May–June 2017). Through the chemical composition of trace metals (TMs) in these samples, it emphasizes the decrease of atmospheric metal pollution in this area during the last few decades and the critical role of wet deposition as source of TMs for Mediterranean surface seawater, especially for intense dust deposition events.
Patrick Chazette, Alexandre Baron, and Cyrille Flamant
Atmos. Chem. Phys., 22, 1271–1292, https://doi.org/10.5194/acp-22-1271-2022, https://doi.org/10.5194/acp-22-1271-2022, 2022
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Within the framework of the international EUREC4A project, horizontal lidar measurements were carried out over Barbados from the French research aircraft ATR-42. These measurements highlighted the strong heterogeneity of the aerosol field (mainly dust and biomass burning aerosols) and therefore of the associated optical properties. This heterogeneity varies according to meteorological conditions and could significantly modulate the climatic impact of aerosols trapped over the tropical Atlantic.
Julien Totems, Patrick Chazette, and Alexandre Baron
Atmos. Meas. Tech., 14, 7525–7544, https://doi.org/10.5194/amt-14-7525-2021, https://doi.org/10.5194/amt-14-7525-2021, 2021
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We describe in detail the design and calibration of the new Raman channels for the WALI system, going over the important sources of bias and uncertainty on retrieved temperature profiles. For the first time, their impact is investigated using horizontal shots in a homogenous atmosphere: the magnitude of the highlighted biases can be much larger than the targeted absolute accuracy of 1° C. Actual measurement errors are quantified using radiosoundings launched close to the lidar site.
Marco Gaetani, Benjamin Pohl, Maria del Carmen Alvarez Castro, Cyrille Flamant, and Paola Formenti
Atmos. Chem. Phys., 21, 16575–16591, https://doi.org/10.5194/acp-21-16575-2021, https://doi.org/10.5194/acp-21-16575-2021, 2021
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During the dry austral winter, biomass fires in tropical Africa emit large amounts of smoke in the atmosphere, with large impacts on climate and air quality. The study of the relationship between atmospheric circulation and smoke transport shows that midlatitude atmospheric disturbances may deflect the smoke from tropical Africa towards southern Africa. Understanding the distribution of the smoke in the region is crucial for climate modelling and air quality monitoring.
Geet George, Bjorn Stevens, Sandrine Bony, Robert Pincus, Chris Fairall, Hauke Schulz, Tobias Kölling, Quinn T. Kalen, Marcus Klingebiel, Heike Konow, Ashley Lundry, Marc Prange, and Jule Radtke
Earth Syst. Sci. Data, 13, 5253–5272, https://doi.org/10.5194/essd-13-5253-2021, https://doi.org/10.5194/essd-13-5253-2021, 2021
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Dropsondes measure atmospheric parameters such as temperature, pressure, humidity and horizontal winds. The EUREC4A field campaign deployed 1215 dropsondes during January–February 2020 in the north Atlantic trade-wind region in order to characterize the thermodynamic and the dynamic structure of the atmosphere, primarily at horizontal scales of ~ 200 km. We present JOANNE, the dataset that provides these dropsonde measurements and thereby a rich characterization of the trade-wind atmosphere.
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.
Cedric G. Ngoungue Langue, Christophe Lavaysse, Mathieu Vrac, Philippe Peyrillé, and Cyrille Flamant
Weather Clim. Dynam., 2, 893–912, https://doi.org/10.5194/wcd-2-893-2021, https://doi.org/10.5194/wcd-2-893-2021, 2021
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This work assesses the forecast of the temperature over the Sahara, a key driver of the West African Monsoon, at a seasonal timescale. The seasonal models are able to reproduce the climatological state and some characteristics of the temperature during the rainy season in the Sahel. But, because of errors in the timing, the forecast skill scores are significant only for the first 4 weeks.
Cited articles
Berthier, S., Chazette, P., Pelon, J., and Baum, B.: Comparison of cloud statistics from spaceborne lidar systems, Atmos. Chem. Phys., 8, 6965–6977, https://doi.org/10.5194/acp-8-6965-2008, 2008.
Bony, S. and Dufresne, J. L.: Marine boundary layer clouds at the heart of
tropical cloud feedback uncertainties in climate models, Geophys. Res.
Lett., 32, 1–4, https://doi.org/10.1029/2005GL023851, 2005.
Bony, S., Stevens, B., Ament, F., Bigorre, S., Chazette, P., Crewell, S.,
Delanoë, J., Emanuel, K., Farrell, D., Flamant, C., Gross, S., Hirsch,
L., Karstensen, J., Mayer, B., Nuijens, L., Ruppert, J. H., Sandu, I.,
Siebesma, P., Speich, S., Szczap, F., Totems, J., Vogel, R., Wendisch, M.,
and Wirth, M.: EUREC4A: A Field Campaign to Elucidate the Couplings
Between Clouds, Convection and Circulation, Surv. Geophys., 38, 1529–1568,
https://doi.org/10.1007/s10712-017-9428-0, 2017.
Bony, S., Schulz, H., Vial, J., and Stevens, B.: Sugar, Gravel, Fish, and
Flowers: Dependence of Mesoscale Patterns of Trade-Wind Clouds on
Environmental Conditions, Geophys. Res. Lett., 47, 1–12,
https://doi.org/10.1029/2019GL085988, 2020.
Brient, F., Schneider, T., Tan, Z., Bony, S., Qu, X., and Hall, A.:
Shallowness of tropical low clouds as a predictor of climate models'
response to warming, Clim. Dynam., 47, 433–449,
https://doi.org/10.1007/s00382-015-2846-0, 2016.
Chazette, P.: Aerosol optical properties as observed from an ultralight aircraft over the Strait of Gibraltar, Atmos. Meas. Tech., 13, 4461–4477, https://doi.org/10.5194/amt-13-4461-2020, 2020.
Chazette, P., Pelon, J., and Mégie, G.: Determination by spaceborne
backscatter lidar of the structural parameters of atmospheric scattering
layers., Appl. Optic, 40, 3428–3440, https://doi.org/10.1364/AO.40.003428, 2001.
Chazette, P., Sanak, J., and Dulac, F.: New approach for aerosol profiling
with a lidar onboard an ultralight aircraft: application to the African
Monsoon Multidisciplinary Analysis., Environ. Sci. Technol., 41,
8335–8341, https://doi.org/10.1021/es070343y, 2007.
Chazette, P., Bocquet, M., Royer, P., Winiarek, V., Raut, J. C., Labazuy,
P., Gouhier, M., Lardier, M., and Cariou, J. P.: Eyjafjallajökull ash
concentrations derived from both lidar and modeling, J. Geophys. Res.-Atmos., 117, D00U14, https://doi.org/10.1029/2011JD015755, 2012a.
Chazette, P., Dabas, A., Sanak, J., Lardier, M., and Royer, P.: French airborne lidar measurements for Eyjafjallajökull ash plume survey, Atmos. Chem. Phys., 12, 7059–7072, https://doi.org/10.5194/acp-12-7059-2012, 2012b.
Chazette, P., Raut, J.-C., and Totems, J.: Springtime aerosol load as observed from ground-based and airborne lidars over northern Norway, Atmos. Chem. Phys., 18, 13075–13095, https://doi.org/10.5194/acp-18-13075-2018, 2018.
Chazette, P., Totems, J., Baron, A., Flamant, C., and Bony, S.: EUREC4A –
ATR-42 – Lidar ALiAS – Level 2 & 3 aerosol products, AERIS data Cent.,
https://doi.org/10.25326/59, 2020a.
Chazette, P., Totems, J., Baron, A., Flamant, C., and Bony, S.: EUREC4A
ATR-42 Lidar ALiAS – Level 2 & 3 cloud products, AERIS data Cent.,
https://doi.org/10.25326/58, 2020b.
Chazette, P., Totems, J., Baron, A., Flamant, C., and Bony, S.: EUREC4A
ATR-42 Lidar ALiAS – Levels 1 & 1.5, AERIS data Cent., https://doi.org/10.25326/57,
2020c.
Collis, R. T. H. and Russel, P. B.: Laser Monitoring of the Atmosphere,
edited by: Hinkley, E. D., Springer Berlin Heidelberg, Berlin, Heidelberg.,
1976.
Flamant, C., Deroubaix, A., Chazette, P., Brito, J., Gaetani, M., Knippertz, P., Fink, A. H., de Coetlogon, G., Menut, L., Colomb, A., Denjean, C., Meynadier, R., Rosenberg, P., Dupuy, R., Dominutti, P., Duplissy, J., Bourrianne, T., Schwarzenboeck, A., Ramonet, M., and Totems, J.: Aerosol distribution in the northern Gulf of Guinea: local anthropogenic sources, long-range transport, and the role of coastal shallow circulations, Atmos. Chem. Phys., 18, 12363–12389, https://doi.org/10.5194/acp-18-12363-2018, 2018.
Haarig, M., Ansmann, A., Althausen, D., Klepel, A., Groß, S., Freudenthaler, V., Toledano, C., Mamouri, R.-E., Farrell, D. A., Prescod, D. A., Marinou, E., Burton, S. P., Gasteiger, J., Engelmann, R., and Baars, H.: Triple-wavelength depolarization-ratio profiling of Saharan dust over Barbados during SALTRACE in 2013 and 2014, Atmos. Chem. Phys., 17, 10767–10794, https://doi.org/10.5194/acp-17-10767-2017, 2017.
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Short summary
To characterize the trade-wind cumuli for climate change purposes, 20 ATR-42 flights were conducted over the tropical Atlantic, off the coast of Barbados from 23 January to 13 February 2020. These flights were conducted as part of the international EUREC4A (Elucidating the role of cloud–circulation coupling in climate) field campaign. A new sampling approach was applied, consisting in using a sidewards-staring lidar. The data are now made available to the international scientific community.
To characterize the trade-wind cumuli for climate change purposes, 20 ATR-42 flights were...
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