Articles | Volume 18, issue 4
Atmos. Chem. Phys., 18, 2913–2928, 2018
https://doi.org/10.5194/acp-18-2913-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue: Results of the project "Dynamics–aerosol–chemistry–cloud...
Atmos. Chem. Phys., 18, 2913–2928, 2018
https://doi.org/10.5194/acp-18-2913-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
01 Mar 2018
Research article
| 01 Mar 2018
An overview of the diurnal cycle of the atmospheric boundary layer during the West African monsoon season: results from the 2016 observational campaign
Norbert Kalthoff et al.
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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.
Maurin Zouzoua, Fabienne Lohou, Paul Assamoi, Marie Lothon, Véronique Yoboue, Cheikh Dione, Norbert Kalthoff, Bianca Adler, Karmen Babić, Xabier Pedruzo-Bagazgoitia, and Solène Derrien
Atmos. Chem. Phys., 21, 2027–2051, https://doi.org/10.5194/acp-21-2027-2021, https://doi.org/10.5194/acp-21-2027-2021, 2021
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Based on a field experiment conducted in June and July 2016, we analyzed the daytime breakup of continental low-level stratiform clouds over southern West Africa in order to provide complementary guidance for model evaluation during the monsoon season. Those clouds exhibit weaker temperature and moisture jumps at the top compared to marine stratiform clouds. Their lifetime and the transition towards shallow convective clouds during daytime hours depend on their coupling with the surface.
Barbara Altstädter, Konrad Deetz, Bernhard Vogel, Karmen Babić, Cheikh Dione, Federica Pacifico, Corinne Jambert, Friederike Ebus, Konrad Bärfuss, Falk Pätzold, Astrid Lampert, Bianca Adler, Norbert Kalthoff, and Fabienne Lohou
Atmos. Chem. Phys., 20, 7911–7928, https://doi.org/10.5194/acp-20-7911-2020, https://doi.org/10.5194/acp-20-7911-2020, 2020
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We present the high vertical variability of the black carbon (BC) mass concentration measured with the unmanned aerial system ALADINA during the field experiment of DACCIWA. The COSMO-ART model output was applied for the campaign period and is compared with the observational BC data during a case study on 14–15 July 2016. Enhanced BC concentrations were related to transport processes to the measurement site by maritime inflow and not to local emissions as initially expected.
Philipp Gasch, Andreas Wieser, Julie K. Lundquist, and Norbert Kalthoff
Atmos. Meas. Tech., 13, 1609–1631, https://doi.org/10.5194/amt-13-1609-2020, https://doi.org/10.5194/amt-13-1609-2020, 2020
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We present an airborne Doppler lidar simulator (ADLS) based on high-resolution atmospheric wind fields (LES). The ADLS is used to evaluate the retrieval accuracy of airborne wind profiling under turbulent, inhomogeneous wind field conditions inside the boundary layer. With the ADLS, the error due to the violation of the wind field homogeneity assumption used for retrieval can be revealed. For the conditions considered, flow inhomogeneities exert a dominant influence on wind profiling error.
Xabier Pedruzo-Bagazgoitia, Stephan R. de Roode, Bianca Adler, Karmen Babić, Cheikh Dione, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 20, 2735–2754, https://doi.org/10.5194/acp-20-2735-2020, https://doi.org/10.5194/acp-20-2735-2020, 2020
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Using a high-resolution model we simulate the transition from night to day clouds on southern West Africa using observations from the DACCIWA project. We find that the radiative effects of clouds help mantain a thick cloud layer in the night, while the mixing of cloud air with air above during the day, aided by moisture and heat fluxes at the surface, thins this layer and promotes its transition to other clouds. The effect of changing wind with height accelerates the transition.
Fabienne Lohou, Norbert Kalthoff, Bianca Adler, Karmen Babić, Cheikh Dione, Marie Lothon, Xabier Pedruzo-Bagazgoitia, and Maurin Zouzoua
Atmos. Chem. Phys., 20, 2263–2275, https://doi.org/10.5194/acp-20-2263-2020, https://doi.org/10.5194/acp-20-2263-2020, 2020
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A conceptual model of the low-level stratiform clouds (LLSCs), which develop almost every night in southern West Africa, is built with the dataset acquired during the DACCIWA (Dynamics Aerosol Chemistry Cloud Interactions in West Africa) ground-based field experiment. Several processes occur during the four phases composing this diurnal cycle: the cooling of the air until saturation (stable and jet phases), LLSC and low-level jet interactions (stratus phase), and LLSC breakup (convective phase).
Karmen Babić, Norbert Kalthoff, Bianca Adler, Julian F. Quinting, Fabienne Lohou, Cheikh Dione, and Marie Lothon
Atmos. Chem. Phys., 19, 13489–13506, https://doi.org/10.5194/acp-19-13489-2019, https://doi.org/10.5194/acp-19-13489-2019, 2019
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This study investigates differences in atmospheric conditions between nights with and without low-level stratus clouds (LLCs) over southern West Africa. We use high-quality observations collected during 2016 summer monsoon season and the ERA5 reanalysis data set. Our results show that the formation of LLCs depends on the interplay between the onset time and strength of the nocturnal low-level jet, horizontal cold-air advection, and the overall moisture level in the whole region.
Cheikh Dione, Fabienne Lohou, Marie Lothon, Bianca Adler, Karmen Babić, Norbert Kalthoff, Xabier Pedruzo-Bagazgoitia, Yannick Bezombes, and Omar Gabella
Atmos. Chem. Phys., 19, 8979–8997, https://doi.org/10.5194/acp-19-8979-2019, https://doi.org/10.5194/acp-19-8979-2019, 2019
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Low atmospheric dynamics and low-level cloud (LLC) macrophysical properties are analyzed using in situ and remote sensing data collected from 20 June to 30 July at Savè, Benin, during the DACCIWA field campaign in 2016. We find that the low-level jet (LLJ), LLCs, monsoon flow, and maritime inflow reveal a day-to-day variability. LLCs form at the same level as the jet core height. The cloud base height is stationary at night and remains below the jet. The cloud top height is found above the jet.
Sophie L. Haslett, Jonathan W. Taylor, Konrad Deetz, Bernhard Vogel, Karmen Babić, Norbert Kalthoff, Andreas Wieser, Cheikh Dione, Fabienne Lohou, Joel Brito, Régis Dupuy, Alfons Schwarzenboeck, Paul Zieger, and Hugh Coe
Atmos. Chem. Phys., 19, 1505–1520, https://doi.org/10.5194/acp-19-1505-2019, https://doi.org/10.5194/acp-19-1505-2019, 2019
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As the population in West Africa grows and air pollution increases, it is becoming ever more important to understand the effects of this pollution on the climate and on health. Aerosol particles can grow by absorbing water from the air around them. This paper shows that during the monsoon season, aerosol particles in the region are likely to grow significantly because of the high moisture in the air. This means that climate effects from increasing pollution will be enhanced.
Karmen Babić, Bianca Adler, Norbert Kalthoff, Hendrik Andersen, Cheikh Dione, Fabienne Lohou, Marie Lothon, and Xabier Pedruzo-Bagazgoitia
Atmos. Chem. Phys., 19, 1281–1299, https://doi.org/10.5194/acp-19-1281-2019, https://doi.org/10.5194/acp-19-1281-2019, 2019
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The first detailed observational analysis of the complete diurnal cycle of low-level clouds (LLC) and associated atmospheric processes over southern West Africa is performed using the data gathered within the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud-Interactions in West Africa) ground-based campaign. We find cooling related to the horizontal advection, which occurs in connection with the inflow of cool maritime air mass and a prominent low-level jet, to have the dominant role in LLC formation.
Bianca Adler, Karmen Babić, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, Cheikh Dione, Xabier Pedruzo-Bagazgoitia, and Hendrik Andersen
Atmos. Chem. Phys., 19, 663–681, https://doi.org/10.5194/acp-19-663-2019, https://doi.org/10.5194/acp-19-663-2019, 2019
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This study deals with nocturnal stratiform low-level clouds that frequently form in the atmospheric boundary layer over southern West Africa. We use observational data from 11 nights to characterize the clouds and intranight variability of boundary layer conditions as well as to assess the physical processes relevant for cloud formation. We find that cooling is crucial to reach saturation and a large part of the cooling is related to horizontal advection of cool air from the Gulf of Guinea.
Adrien Deroubaix, Laurent Menut, Cyrille Flamant, Joel Brito, Cyrielle Denjean, Volker Dreiling, Andreas Fink, Corinne Jambert, Norbert Kalthoff, Peter Knippertz, Russ Ladkin, Sylvain Mailler, Marlon Maranan, Federica Pacifico, Bruno Piguet, Guillaume Siour, and Solène Turquety
Atmos. Chem. Phys., 19, 473–497, https://doi.org/10.5194/acp-19-473-2019, https://doi.org/10.5194/acp-19-473-2019, 2019
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This article presents a detailed analysis of anthropogenic and biomass burning pollutants over the Gulf of Guinea coastal region, using observations from the DACCIWA field campaign and modeling. The novelty is that we focus on how these two pollution sources are mixed and transported further inland. We show that during the day pollutants are accumulated along the coastline and transported northward as soon as the daytime convection in the atmospheric boundary layer ceases (16:00 UTC).
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.
Bianca Adler, Norbert Kalthoff, and Leonhard Gantner
Atmos. Chem. Phys., 17, 899–910, https://doi.org/10.5194/acp-17-899-2017, https://doi.org/10.5194/acp-17-899-2017, 2017
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This study deals with the development of nocturnal low-level clouds, which frequently form over southern West Africa during the monsoon season. We performed numerical simulations with the COSMO model and identified processes possibly relevant to cloud formation. The study was made in preparation of a field campaign, which took place in summer 2016 within the DACCIWA project and the results contributed to the optimisation of the measurement strategy during the campaign.
V. Maurer, N. Kalthoff, A. Wieser, M. Kohler, M. Mauder, and L. Gantner
Atmos. Chem. Phys., 16, 1377–1400, https://doi.org/10.5194/acp-16-1377-2016, https://doi.org/10.5194/acp-16-1377-2016, 2016
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The measurement of turbulence in the lowest 1–2 km above the land surface is important for our understanding of boundary-layer processes. We compared turbulence profiles measured at three locations lying about 3 km apart and found that the deployment of the instruments in different crop fields has no direct influence on turbulence statistics on cloud-free days. Nevertheless, spatial differences as well as correlations were found, indicating the existence of organized structures of turbulence.
Bianca Adler, James M. Wilczak, Jaymes Kenyon, Laura Bianco, Irina V. Djalalova, Joseph B. Olson, and David D. Turner
Geosci. Model Dev., 16, 597–619, https://doi.org/10.5194/gmd-16-597-2023, https://doi.org/10.5194/gmd-16-597-2023, 2023
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Rapid changes in wind speed make the integration of wind energy produced during persistent orographic cold-air pools difficult to integrate into the electrical grid. By evaluating three versions of NOAA’s High-Resolution Rapid Refresh model, we demonstrate how model developments targeted during the second Wind Forecast Improvement Project improve the forecast of a persistent cold-air pool event.
Moritz Zemann, Roderick van der Linden, Dan Trinh Cong, Duong Hoang Thai Vu, Nguyet Minh Nguyen, Frank Seidel, Peter Oberle, Franz Nestmann, and Andreas H. Fink
EGUsphere, https://doi.org/10.5194/egusphere-2022-1447, https://doi.org/10.5194/egusphere-2022-1447, 2023
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The study investigates the possibility to predict wave heights close to the coast of the Mekong Delta based on long time climate model wave heights which are only availabe offshore. Due to severe coastal erosion in the Mekong Delta with average land loss rates of up to 10m per year, the coast needs to be protected from wave attacks e.g. by breakwaters. To design a breakwater in the right dimensions for the local conditions, the knowledge of wave heights is essential to the performing engineer.
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. Discuss., https://doi.org/10.5194/acp-2022-795, https://doi.org/10.5194/acp-2022-795, 2022
Preprint under review for ACP
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During the DACCIWA campaign in West Africa we found a 35 % increase of cloud droplet concentration that formed in a polluted, compared to 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 to a less polluted cloud. The corresponding additional decrease in temperature turns out rather small.
Lea Eisenstein, Benedikt Schulz, Ghulam A. Qadir, Joaquim G. Pinto, and Peter Knippertz
Weather Clim. Dynam., 3, 1157–1182, https://doi.org/10.5194/wcd-3-1157-2022, https://doi.org/10.5194/wcd-3-1157-2022, 2022
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Mesoscale high-wind features within extratropical cyclones can cause immense damage. Here, we present RAMEFI, a novel approach to objectively identify the wind features based on a probabilistic random forest. RAMEFI enables a wide range of applications such as probabilistic predictions for the occurrence or a multi-decadal climatology of these features, which will be the focus of Part 2 of the study, with the goal of improving wind and, specifically, wind gust forecasts in the long run.
Patrick Ludwig, Florian Ehmele, Mário J. Franca, Susanna Mohr, Alberto Caldas-Alvarez, James E. Daniell, Uwe Ehret, Hendrik Feldmann, Marie Hundhausen, Peter Knippertz, Katharina Küpfer, Michael Kunz, Bernhard Mühr, Joaquim G. Pinto, Julian Quinting, Andreas M. Schäfer, Frank Seidel, and Christina Wisotzky
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2022-225, https://doi.org/10.5194/nhess-2022-225, 2022
Preprint under review for NHESS
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Heavy precipitation in July 2021 led to widespread floods in western Germany and neighboring countries. The event was among the five heaviest precipitation events of the past 70 years in Germany and the river discharges exceeded by far the statistical 100-year return values. Simulations of the event under future climate conditions revealed a strong and non-linear effect on flood peaks: For +2 K global warming, an 18 % increase in rainfall led to a 39 % increase of the flood peak in the Ahr river.
Efi Rousi, Andreas H. Fink, Lauren S. Andersen, Florian N. Becker, Goratz Beobide-Arsuaga, Marcus Breil, Giacomo Cozzi, Jens Heinke, Lisa Jach, Deborah Niermann, Dragan Petrovic, Andy Richling, Johannes Riebold, Stella Steidl, Laura Suarez-Gutierrez, Jordis Tradowsky, Dim Coumou, André Düsterhus, Florian Ellsäßer, Georgios Fragkoulidis, Daniel Gliksman, Dörthe Handorf, Karsten Haustein, Kai Kornhuber, Harald Kunstmann, Joaquim G. Pinto, Kirsten Warrach-Sagi, and Elena Xoplaki
EGUsphere, https://doi.org/10.5194/egusphere-2022-813, https://doi.org/10.5194/egusphere-2022-813, 2022
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Here, we present a comprehensive, multi-faceted analysis of the 2018 extreme summer in terms of heat and drought in central and northern Europe with a particular focus on Germany. Using different analysis approaches we study (a) the extremeness and attribution to anthropogenic climate change (climate perspective), as well as (b) the synoptic dynamics in concert with the role of slowly varying boundary conditions at the ocean and continental surfaces (seasonal and weather perspective).
Seraphine Hauser, Franziska Teubler, Michael Riemer, Peter Knippertz, and Christian M. Grams
Weather Clim. Dynam. Discuss., https://doi.org/10.5194/wcd-2022-44, https://doi.org/10.5194/wcd-2022-44, 2022
Revised manuscript under review for WCD
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Blocking describes a flow configuration in midlatitudes where stationary high-pressure systems block the propagation of weather systems. This study presents a unified framework to capture blocking dynamics from three different perspectives and quantifies the importance of different processes in the formation of a major blocking in 2016. In future work, this framework will enable a holistic view on the dynamics and the role of moist processes in different life cycle stages of the blocking.
Christoph Fischer, Andreas H. Fink, Elmar Schömer, Roderick van der Linden, Michael Maier-Gerber, Marc Rautenhaus, and Michael Riemer
Geosci. Model Dev., 15, 4447–4468, https://doi.org/10.5194/gmd-15-4447-2022, https://doi.org/10.5194/gmd-15-4447-2022, 2022
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Potential vorticity (PV) analysis plays a central role in studying atmospheric dynamics. For example, anomalies in the PV field near the tropopause are linked to extreme weather events. In this study, an objective strategy to identify these anomalies is presented and evaluated. As a novel concept, it can be applied to three-dimensional (3-D) data sets. Supported by 3-D visualizations, we illustrate advantages of this new analysis over existing studies along a case study.
Susanna Mohr, Uwe Ehret, Michael Kunz, Patrick Ludwig, Alberto Caldas-Alvarez, James E. Daniell, Florian Ehmele, Hendrik Feldmann, Mário J. Franca, Christian Gattke, Marie Hundhausen, Peter Knippertz, Katharina Küpfer, Bernhard Mühr, Joaquim G. Pinto, Julian Quinting, Andreas M. Schäfer, Marc Scheibel, Frank Seidel, and Christina Wisotzky
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2022-137, https://doi.org/10.5194/nhess-2022-137, 2022
Revised manuscript accepted for NHESS
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The flood event in July 2021 was one of the most severe natural disasters in Europe in the last half century. The objective of this two-part study is a multi-disciplinary assessment that examine the complex process interactions in different compartments, from meteorology to hydrological conditions to hydro-morphological processes to impacts on assets and environment. While Part 1 focuses on the description of the event, the second part puts the event in historical and climate change contexts.
Eoghan Keany, Geoffrey Bessardon, and Emily Gleeson
Adv. Sci. Res., 19, 13–27, https://doi.org/10.5194/asr-19-13-2022, https://doi.org/10.5194/asr-19-13-2022, 2022
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This work used machine learning to produce the first open source building height map of Ireland. This map is intended to more accurately determine Local Climate Zones for use in the underlying physiography dataset in the HARMONIE AROME numerical weather prediction model.
Andreas Wieser, Andreas Güntner, Peter Dietrich, Jan Handwerker, Dina Khordakova, Uta Ködel, Martin Kohler, Hannes Mollenhauer, Bernhard Mühr, Erik Nixdorf, Marvin Reich, Christian Rolf, Martin Schrön, Claudia Schütze, and Ute Weber
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2022-131, https://doi.org/10.5194/hess-2022-131, 2022
Revised manuscript not accepted
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We present an event-triggered observation concept which covers the entire process chain from heavy precipitation to flooding at the catchment scale. It combines flexible and mobile observing systems out of the fields of meteorology, hydrology and geophysics with stationary networks to capture atmospheric transport processes, heterogeneous precipitation patterns, land surface and subsurface storage processes, and runoff dynamics.
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.
James B. Duncan Jr., Laura Bianco, Bianca Adler, Tyler Bell, Irina V. Djalalova, Laura Riihimaki, Joseph Sedlar, Elizabeth N. Smith, David D. Turner, Timothy J. Wagner, and James M. Wilczak
Atmos. Meas. Tech., 15, 2479–2502, https://doi.org/10.5194/amt-15-2479-2022, https://doi.org/10.5194/amt-15-2479-2022, 2022
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In this study, several ground-based remote sensing instruments are used to estimate the height of the convective planetary boundary layer, and their performance is compared against independent boundary layer depth estimates obtained from radiosondes launched as part of the CHEESEHEAD19 field campaign. The impact of clouds (particularly boundary layer clouds) on the estimation of the boundary layer depth is also investigated.
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.
Irina V. Djalalova, David D. Turner, Laura Bianco, James M. Wilczak, James Duncan, Bianca Adler, and Daniel Gottas
Atmos. Meas. Tech., 15, 521–537, https://doi.org/10.5194/amt-15-521-2022, https://doi.org/10.5194/amt-15-521-2022, 2022
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In this paper we investigate the synergy obtained by combining active (radio acoustic sounding system – RASS) and passive (microwave radiometer) remote sensing observations to obtain temperature vertical profiles through a radiative transfer model. Inclusion of the RASS observations leads to more accurate temperature profiles from the surface to 5 km above ground, well above the maximum height of the RASS observations themselves (2000 m), when compared to the microwave radiometer used alone.
Dina Khordakova, Christian Rolf, Jens-Uwe Grooß, Rolf Müller, Paul Konopka, Andreas Wieser, Martina Krämer, and Martin Riese
Atmos. Chem. Phys., 22, 1059–1079, https://doi.org/10.5194/acp-22-1059-2022, https://doi.org/10.5194/acp-22-1059-2022, 2022
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Extreme storms transport humidity from the troposphere to the stratosphere. Here it has a strong impact on the climate. With ongoing global warming, we expect more storms and, hence, an enhancement of this effect. A case study was performed in order to measure the impact of the direct injection of water vapor into the lower stratosphere. The measurements displayed a significant transport of water vapor into the lower stratosphere, and this was supported by satellite and reanalysis data.
Christopher J. Diekmann, Matthias Schneider, Benjamin Ertl, Frank Hase, Omaira García, Farahnaz Khosrawi, Eliezer Sepúlveda, Peter Knippertz, and Peter Braesicke
Earth Syst. Sci. Data, 13, 5273–5292, https://doi.org/10.5194/essd-13-5273-2021, https://doi.org/10.5194/essd-13-5273-2021, 2021
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The joint analysis of different stable water isotopes in water vapour is a powerful tool for investigating atmospheric moisture pathways. This paper presents a novel global and multi-annual dataset of H2O and HDO in mid-tropospheric water vapour by using data from the satellite sensor Metop/IASI. Due to its unique combination of coverage and resolution in space and time, this dataset is highly promising for studying the hydrological cycle and its representation in weather and climate models.
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.
Bjorn Stevens, Sandrine Bony, David Farrell, Felix Ament, Alan Blyth, Christopher Fairall, Johannes Karstensen, Patricia K. Quinn, Sabrina Speich, Claudia Acquistapace, Franziska Aemisegger, Anna Lea Albright, Hugo Bellenger, Eberhard Bodenschatz, Kathy-Ann Caesar, Rebecca Chewitt-Lucas, Gijs de Boer, Julien Delanoë, Leif Denby, Florian Ewald, Benjamin Fildier, Marvin Forde, Geet George, Silke Gross, Martin Hagen, Andrea Hausold, Karen J. Heywood, Lutz Hirsch, Marek Jacob, Friedhelm Jansen, Stefan Kinne, Daniel Klocke, Tobias Kölling, Heike Konow, Marie Lothon, Wiebke Mohr, Ann Kristin Naumann, Louise Nuijens, Léa Olivier, Robert Pincus, Mira Pöhlker, Gilles Reverdin, Gregory Roberts, Sabrina Schnitt, Hauke Schulz, A. Pier Siebesma, Claudia Christine Stephan, Peter Sullivan, Ludovic Touzé-Peiffer, Jessica Vial, Raphaela Vogel, Paquita Zuidema, Nicola Alexander, Lyndon Alves, Sophian Arixi, Hamish Asmath, Gholamhossein Bagheri, Katharina Baier, Adriana Bailey, Dariusz Baranowski, Alexandre Baron, Sébastien Barrau, Paul A. Barrett, Frédéric Batier, Andreas Behrendt, Arne Bendinger, Florent Beucher, Sebastien Bigorre, Edmund Blades, Peter Blossey, Olivier Bock, Steven Böing, Pierre Bosser, Denis Bourras, Pascale Bouruet-Aubertot, Keith Bower, Pierre Branellec, Hubert Branger, Michal Brennek, Alan Brewer, Pierre-Etienne Brilouet, Björn Brügmann, Stefan A. Buehler, Elmo Burke, Ralph Burton, Radiance Calmer, Jean-Christophe Canonici, Xavier Carton, Gregory Cato Jr., Jude Andre Charles, Patrick Chazette, Yanxu Chen, Michal T. Chilinski, Thomas Choularton, Patrick Chuang, Shamal Clarke, Hugh Coe, Céline Cornet, Pierre Coutris, Fleur Couvreux, Susanne Crewell, Timothy Cronin, Zhiqiang Cui, Yannis Cuypers, Alton Daley, Gillian M. Damerell, Thibaut Dauhut, Hartwig Deneke, Jean-Philippe Desbios, Steffen Dörner, Sebastian Donner, Vincent Douet, Kyla Drushka, Marina Dütsch, André Ehrlich, Kerry Emanuel, Alexandros Emmanouilidis, Jean-Claude Etienne, Sheryl Etienne-Leblanc, Ghislain Faure, Graham Feingold, Luca Ferrero, Andreas Fix, Cyrille Flamant, Piotr Jacek Flatau, Gregory R. Foltz, Linda Forster, Iulian Furtuna, Alan Gadian, Joseph Galewsky, Martin Gallagher, Peter Gallimore, Cassandra Gaston, Chelle Gentemann, Nicolas Geyskens, Andreas Giez, John Gollop, Isabelle Gouirand, Christophe Gourbeyre, Dörte de Graaf, Geiske E. de Groot, Robert Grosz, Johannes Güttler, Manuel Gutleben, Kashawn Hall, George Harris, Kevin C. Helfer, Dean Henze, Calvert Herbert, Bruna Holanda, Antonio Ibanez-Landeta, Janet Intrieri, Suneil Iyer, Fabrice Julien, Heike Kalesse, Jan Kazil, Alexander Kellman, Abiel T. Kidane, Ulrike Kirchner, Marcus Klingebiel, Mareike Körner, Leslie Ann Kremper, Jan Kretzschmar, Ovid Krüger, Wojciech Kumala, Armin Kurz, Pierre L'Hégaret, Matthieu Labaste, Tom Lachlan-Cope, Arlene Laing, Peter Landschützer, Theresa Lang, Diego Lange, Ingo Lange, Clément Laplace, Gauke Lavik, Rémi Laxenaire, Caroline Le Bihan, Mason Leandro, Nathalie Lefevre, Marius Lena, Donald Lenschow, Qiang Li, Gary Lloyd, Sebastian Los, Niccolò Losi, Oscar Lovell, Christopher Luneau, Przemyslaw Makuch, Szymon Malinowski, Gaston Manta, Eleni Marinou, Nicholas Marsden, Sebastien Masson, Nicolas Maury, Bernhard Mayer, Margarette Mayers-Als, Christophe Mazel, Wayne McGeary, James C. McWilliams, Mario Mech, Melina Mehlmann, Agostino Niyonkuru Meroni, Theresa Mieslinger, Andreas Minikin, Peter Minnett, Gregor Möller, Yanmichel Morfa Avalos, Caroline Muller, Ionela Musat, Anna Napoli, Almuth Neuberger, Christophe Noisel, David Noone, Freja Nordsiek, Jakub L. Nowak, Lothar Oswald, Douglas J. Parker, Carolyn Peck, Renaud Person, Miriam Philippi, Albert Plueddemann, Christopher Pöhlker, Veronika Pörtge, Ulrich Pöschl, Lawrence Pologne, Michał Posyniak, Marc Prange, Estefanía Quiñones Meléndez, Jule Radtke, Karim Ramage, Jens Reimann, Lionel Renault, Klaus Reus, Ashford Reyes, Joachim Ribbe, Maximilian Ringel, Markus Ritschel, Cesar B. Rocha, Nicolas Rochetin, Johannes Röttenbacher, Callum Rollo, Haley Royer, Pauline Sadoulet, Leo Saffin, Sanola Sandiford, Irina Sandu, Michael Schäfer, Vera Schemann, Imke Schirmacher, Oliver Schlenczek, Jerome Schmidt, Marcel Schröder, Alfons Schwarzenboeck, Andrea Sealy, Christoph J. Senff, Ilya Serikov, Samkeyat Shohan, Elizabeth Siddle, Alexander Smirnov, Florian Späth, Branden Spooner, M. Katharina Stolla, Wojciech Szkółka, Simon P. de Szoeke, Stéphane Tarot, Eleni Tetoni, Elizabeth Thompson, Jim Thomson, Lorenzo Tomassini, Julien Totems, Alma Anna Ubele, Leonie Villiger, Jan von Arx, Thomas Wagner, Andi Walther, Ben Webber, Manfred Wendisch, Shanice Whitehall, Anton Wiltshire, Allison A. Wing, Martin Wirth, Jonathan Wiskandt, Kevin Wolf, Ludwig Worbes, Ethan Wright, Volker Wulfmeyer, Shanea Young, Chidong Zhang, Dongxiao Zhang, Florian Ziemen, Tobias Zinner, and Martin Zöger
Earth Syst. Sci. Data, 13, 4067–4119, https://doi.org/10.5194/essd-13-4067-2021, https://doi.org/10.5194/essd-13-4067-2021, 2021
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The EUREC4A field campaign, designed to test hypothesized mechanisms by which clouds respond to warming and benchmark next-generation Earth-system models, is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. It was the first campaign that attempted to characterize the full range of processes and scales influencing trade wind clouds.
Pierre-Etienne Brilouet, Marie Lothon, Jean-Claude Etienne, Pascal Richard, Sandrine Bony, Julien Lernoult, Hubert Bellec, Gilles Vergez, Thierry Perrin, Julien Delanoë, Tetyana Jiang, Frédéric Pouvesle, Claude Lainard, Michel Cluzeau, Laurent Guiraud, Patrice Medina, and Theotime Charoy
Earth Syst. Sci. Data, 13, 3379–3398, https://doi.org/10.5194/essd-13-3379-2021, https://doi.org/10.5194/essd-13-3379-2021, 2021
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During the EUREC4A field experiment that took place over the tropical Atlantic Ocean east of Barbados, the French ATR 42 environment research aircraft of SAFIRE aimed to characterize the shallow cloud properties near cloud base and the turbulent structure of the subcloud layer. The high-frequency measurements of wind, temperature and humidity as well as their translation in terms of turbulent fluctuations, turbulent moments and characteristic length scales of turbulence are presented.
Alberto Caldas-Alvarez, Samiro Khodayar, and Peter Knippertz
Weather Clim. Dynam., 2, 561–580, https://doi.org/10.5194/wcd-2-561-2021, https://doi.org/10.5194/wcd-2-561-2021, 2021
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The prediction capabilities of GPS, operational (low-resolution) and targeted (high-resolution) radiosondes for data assimilation in a Mediterranean heavy precipitation event at different model resolutions are investigated. The results show that even if GPS provides accurate observations, their lack of vertical information hampers the improvement, demonstrating the need for assimilating radiosondes, where the location and timing of release was more determinant than the vertical resolution.
Carlos Román-Cascón, Marie Lothon, Fabienne Lohou, Oscar Hartogensis, Jordi Vila-Guerau de Arellano, David Pino, Carlos Yagüe, and Eric R. Pardyjak
Geosci. Model Dev., 14, 3939–3967, https://doi.org/10.5194/gmd-14-3939-2021, https://doi.org/10.5194/gmd-14-3939-2021, 2021
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The type of vegetation (or land cover) and its status influence the heat and water transfers between the surface and the air, affecting the processes that develop in the atmosphere at different (but connected) spatiotemporal scales. In this work, we investigate how these transfers are affected by the way the surface is represented in a widely used weather model. The results encourage including realistic high-resolution and updated land cover databases in models to improve their predictions.
Eoin Walsh, Geoffrey Bessardon, Emily Gleeson, and Priit Ulmas
Adv. Sci. Res., 18, 65–87, https://doi.org/10.5194/asr-18-65-2021, https://doi.org/10.5194/asr-18-65-2021, 2021
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In this work, machine learning techniques, satellite data and land-cover data were used to produce a land-cover map for Ireland that shows greater accuracy and resolution than an altered version of the standard land-cover map (ECOCLIMAP-SG) used for numerical weather prediction. This method offers a way to universally improve meteorological land-cover maps across jurisdictions, while also offering a method of updating the map regularly to account for seasonal changes in surface land-covers.
Maurin Zouzoua, Fabienne Lohou, Paul Assamoi, Marie Lothon, Véronique Yoboue, Cheikh Dione, Norbert Kalthoff, Bianca Adler, Karmen Babić, Xabier Pedruzo-Bagazgoitia, and Solène Derrien
Atmos. Chem. Phys., 21, 2027–2051, https://doi.org/10.5194/acp-21-2027-2021, https://doi.org/10.5194/acp-21-2027-2021, 2021
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Based on a field experiment conducted in June and July 2016, we analyzed the daytime breakup of continental low-level stratiform clouds over southern West Africa in order to provide complementary guidance for model evaluation during the monsoon season. Those clouds exhibit weaker temperature and moisture jumps at the top compared to marine stratiform clouds. Their lifetime and the transition towards shallow convective clouds during daytime hours depend on their coupling with the surface.
Gregor Pante, Peter Knippertz, Andreas H. Fink, and Anke Kniffka
Atmos. Chem. Phys., 21, 35–55, https://doi.org/10.5194/acp-21-35-2021, https://doi.org/10.5194/acp-21-35-2021, 2021
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Seasonal rainfall amounts along the densely populated West African Guinea coast have been decreasing during the past 35 years, with recently accelerating trends. We find strong indications that this is in part related to increasing human air pollution in the region. Given the fast increase in emissions, the political implications of this work are significant. Reducing air pollution locally and regionally would mitigate an imminent health crisis and socio-economic damage from reduced rainfall.
Barbara Altstädter, Konrad Deetz, Bernhard Vogel, Karmen Babić, Cheikh Dione, Federica Pacifico, Corinne Jambert, Friederike Ebus, Konrad Bärfuss, Falk Pätzold, Astrid Lampert, Bianca Adler, Norbert Kalthoff, and Fabienne Lohou
Atmos. Chem. Phys., 20, 7911–7928, https://doi.org/10.5194/acp-20-7911-2020, https://doi.org/10.5194/acp-20-7911-2020, 2020
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We present the high vertical variability of the black carbon (BC) mass concentration measured with the unmanned aerial system ALADINA during the field experiment of DACCIWA. The COSMO-ART model output was applied for the campaign period and is compared with the observational BC data during a case study on 14–15 July 2016. Enhanced BC concentrations were related to transport processes to the measurement site by maritime inflow and not to local emissions as initially expected.
Zvjezdana B. Klaić, Karmen Babić, and Mirko Orlić
Hydrol. Earth Syst. Sci., 24, 3399–3416, https://doi.org/10.5194/hess-24-3399-2020, https://doi.org/10.5194/hess-24-3399-2020, 2020
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Fine-resolution lake temperature measurements (2 min, 15 depths) show different lake responses to atmospheric forcings: (1) continuous diurnal oscillations in the temperature in the first 5 m of the lake, (2) occasional diurnal oscillations in the temperature at depths from 7 to 20 m, and (3) occasional surface and internal seiches. Due to the sloped lake bottom, surface seiches produced the high-frequency oscillations in the lake temperatures with periods of 9 min at depths from 9 to 17 m.
Andreas Behrendt, Volker Wulfmeyer, Christoph Senff, Shravan Kumar Muppa, Florian Späth, Diego Lange, Norbert Kalthoff, and Andreas Wieser
Atmos. Meas. Tech., 13, 3221–3233, https://doi.org/10.5194/amt-13-3221-2020, https://doi.org/10.5194/amt-13-3221-2020, 2020
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In order to understand how solar radiation energy hitting the ground is distributed into the atmosphere, we use a new combination of laser-based remote-sensing techniques to quantify these energy fluxes up to heights of more than 1 km above ground. Before, similar techniques had already been presented for determining the energy flux component regarding the exchange of humidity but not the warm air itself. Now, we show that this can also be measured by remote sensing with low uncertainties.
Christoph P. Gatzen, Andreas H. Fink, David M. Schultz, and Joaquim G. Pinto
Nat. Hazards Earth Syst. Sci., 20, 1335–1351, https://doi.org/10.5194/nhess-20-1335-2020, https://doi.org/10.5194/nhess-20-1335-2020, 2020
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Derechos are widespread, convectively induced severe wind events. A climatology of derechos in Germany is presented. It shows that derechos are not uncommon across the country. Two seasonal peaks indicate a comparable derecho risk in summer and winter. At the same time, we found two different derecho types, a warm- and a cold-season type. We present characteristics of both derecho types that can help forecasters to estimate the potential derecho threat in a given weather situation.
Benjamin Fersch, Alfonso Senatore, Bianca Adler, Joël Arnault, Matthias Mauder, Katrin Schneider, Ingo Völksch, and Harald Kunstmann
Hydrol. Earth Syst. Sci., 24, 2457–2481, https://doi.org/10.5194/hess-24-2457-2020, https://doi.org/10.5194/hess-24-2457-2020, 2020
Alima Dajuma, Kehinde O. Ogunjobi, Heike Vogel, Peter Knippertz, Siélé Silué, Evelyne Touré N'Datchoh, Véronique Yoboué, and Bernhard Vogel
Atmos. Chem. Phys., 20, 5373–5390, https://doi.org/10.5194/acp-20-5373-2020, https://doi.org/10.5194/acp-20-5373-2020, 2020
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A modeling study through COSMO-ART was used to investigate the implication of downward mixing induced by clouds in transporting biomass burning aerosols from central and southern Africa located between 2 and 4 km into the PBL over southern West Africa. Results showed that individual mixing events south of the coast of Côte d’Ivoire due to mid-level convective clouds injects part of the biomass burning plume into the PBL. 15 % of CO mass from the 2–4 km layer is mixed below 1 km.
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.
Cyrielle Denjean, Thierry Bourrianne, Frederic Burnet, Marc Mallet, Nicolas Maury, Aurélie Colomb, Pamela Dominutti, Joel Brito, Régis Dupuy, Karine Sellegri, Alfons Schwarzenboeck, Cyrille Flamant, and Peter Knippertz
Atmos. Chem. Phys., 20, 4735–4756, https://doi.org/10.5194/acp-20-4735-2020, https://doi.org/10.5194/acp-20-4735-2020, 2020
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This paper presents aircraft measurements of aerosol optical properties over southern West Africa. We show that aerosol optical properties in the boundary layer were dominated by a persistent biomass burning loading from the Southern Hemisphere. Biomass burning aerosols were more light absorbing that those previously measured in other areas (Amazonia, North America). Our study suggests that lens-coated black carbon particles were the dominant absorber for these biomass burning aerosols.
Philipp Gasch, Andreas Wieser, Julie K. Lundquist, and Norbert Kalthoff
Atmos. Meas. Tech., 13, 1609–1631, https://doi.org/10.5194/amt-13-1609-2020, https://doi.org/10.5194/amt-13-1609-2020, 2020
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We present an airborne Doppler lidar simulator (ADLS) based on high-resolution atmospheric wind fields (LES). The ADLS is used to evaluate the retrieval accuracy of airborne wind profiling under turbulent, inhomogeneous wind field conditions inside the boundary layer. With the ADLS, the error due to the violation of the wind field homogeneity assumption used for retrieval can be revealed. For the conditions considered, flow inhomogeneities exert a dominant influence on wind profiling error.
Hendrik Andersen, Jan Cermak, Julia Fuchs, Peter Knippertz, Marco Gaetani, Julian Quinting, Sebastian Sippel, and Roland Vogt
Atmos. Chem. Phys., 20, 3415–3438, https://doi.org/10.5194/acp-20-3415-2020, https://doi.org/10.5194/acp-20-3415-2020, 2020
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Fog and low clouds (FLCs) are an essential but poorly understood element of Namib regional climate. Here, a satellite-based data set of FLCs in central Namib, reanalysis data, and back trajectories are used to systematically analyze conditions when FLCs occur. Synoptic-scale mechanisms are identified that influence the formation of FLCs and the onshore advection of marine boundary-layer air masses. The findings lead to a new conceptual model of mechanisms that drive FLC variability in the Namib.
Xabier Pedruzo-Bagazgoitia, Stephan R. de Roode, Bianca Adler, Karmen Babić, Cheikh Dione, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 20, 2735–2754, https://doi.org/10.5194/acp-20-2735-2020, https://doi.org/10.5194/acp-20-2735-2020, 2020
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Using a high-resolution model we simulate the transition from night to day clouds on southern West Africa using observations from the DACCIWA project. We find that the radiative effects of clouds help mantain a thick cloud layer in the night, while the mixing of cloud air with air above during the day, aided by moisture and heat fluxes at the surface, thins this layer and promotes its transition to other clouds. The effect of changing wind with height accelerates the transition.
Fabienne Lohou, Norbert Kalthoff, Bianca Adler, Karmen Babić, Cheikh Dione, Marie Lothon, Xabier Pedruzo-Bagazgoitia, and Maurin Zouzoua
Atmos. Chem. Phys., 20, 2263–2275, https://doi.org/10.5194/acp-20-2263-2020, https://doi.org/10.5194/acp-20-2263-2020, 2020
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A conceptual model of the low-level stratiform clouds (LLSCs), which develop almost every night in southern West Africa, is built with the dataset acquired during the DACCIWA (Dynamics Aerosol Chemistry Cloud Interactions in West Africa) ground-based field experiment. Several processes occur during the four phases composing this diurnal cycle: the cooling of the air until saturation (stable and jet phases), LLSC and low-level jet interactions (stratus phase), and LLSC breakup (convective phase).
Sophie L. Haslett, Jonathan W. Taylor, Mathew Evans, Eleanor Morris, Bernhard Vogel, Alima Dajuma, Joel Brito, Anneke M. Batenburg, Stephan Borrmann, Johannes Schneider, Christiane Schulz, Cyrielle Denjean, Thierry Bourrianne, Peter Knippertz, Régis Dupuy, Alfons Schwarzenböck, Daniel Sauer, Cyrille Flamant, James Dorsey, Ian Crawford, and Hugh Coe
Atmos. Chem. Phys., 19, 15217–15234, https://doi.org/10.5194/acp-19-15217-2019, https://doi.org/10.5194/acp-19-15217-2019, 2019
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Three aircraft datasets from the DACCIWA campaign in summer 2016 are used here to show there is a background mass of pollution present in the lower atmosphere in southern West Africa. We suggest that this likely comes from biomass burning in central and southern Africa, which has been carried into the region over the Atlantic Ocean. This would have a negative health impact on populations living near the coast and may alter the impact of growing city emissions on cloud formation and the monsoon.
Helen R. Smith, Zbigniew Ulanowski, Paul H. Kaye, Edwin Hirst, Warren Stanley, Richard Kaye, Andreas Wieser, Chris Stopford, Maria Kezoudi, Joseph Girdwood, Richard Greenaway, and Robert Mackenzie
Atmos. Meas. Tech., 12, 6579–6599, https://doi.org/10.5194/amt-12-6579-2019, https://doi.org/10.5194/amt-12-6579-2019, 2019
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The Universal Cloud and Aerosol Sounding System (UCASS) is a low-cost miniature optical particle counter (OPC) capable of sizing particles in the size range 0.4–40 μm. The open-geometry design makes the instrument suitable for deployment on balloon-borne sounding systems, dropsonde systems or as part of an unmanned aerial vehicle (UAV). Laboratory and field experiments show good agreement with reference instruments in a range of cloudy and dusty environments.
Karmen Babić, Norbert Kalthoff, Bianca Adler, Julian F. Quinting, Fabienne Lohou, Cheikh Dione, and Marie Lothon
Atmos. Chem. Phys., 19, 13489–13506, https://doi.org/10.5194/acp-19-13489-2019, https://doi.org/10.5194/acp-19-13489-2019, 2019
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This study investigates differences in atmospheric conditions between nights with and without low-level stratus clouds (LLCs) over southern West Africa. We use high-quality observations collected during 2016 summer monsoon season and the ERA5 reanalysis data set. Our results show that the formation of LLCs depends on the interplay between the onset time and strength of the nocturnal low-level jet, horizontal cold-air advection, and the overall moisture level in the whole region.
Marie Lothon, Paul Barnéoud, Omar Gabella, Fabienne Lohou, Solène Derrien, Sylvain Rondi, Marjolaine Chiriaco, Sophie Bastin, Jean-Charles Dupont, Martial Haeffelin, Jordi Badosa, Nicolas Pascal, and Nadège Montoux
Atmos. Meas. Tech., 12, 5519–5534, https://doi.org/10.5194/amt-12-5519-2019, https://doi.org/10.5194/amt-12-5519-2019, 2019
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In the context of an atmospheric network of instrumented sites equipped with sky cameras for cloud monitoring, we present an algorithm named ELIFAN, which aims to estimate the cloud cover amount from full-sky visible daytime images. ELIFAN is based on red-to-blue ratio thresholding applied on the image pixels and on the use of a blue-sky library. We present its principle and its performance and highlight the interest of combining several complementary instruments.
Jesús Yus-Díez, Mireia Udina, Maria Rosa Soler, Marie Lothon, Erik Nilsson, Joan Bech, and Jielun Sun
Atmos. Chem. Phys., 19, 9495–9514, https://doi.org/10.5194/acp-19-9495-2019, https://doi.org/10.5194/acp-19-9495-2019, 2019
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This study helps improve the understanding of the turbulence description and the interactions occurring in the lower part of the boundary layer. It is carried out at an orographically influenced site close to the Pyrenees to explore the hockey-stick transition (HOST) theory. HOST is seen to be strongly dependent on both the meteorological conditions and the orographic features. Examples of intermittent turbulence events that lead to transitions between the turbulence regimes are also identified.
Cheikh Dione, Fabienne Lohou, Marie Lothon, Bianca Adler, Karmen Babić, Norbert Kalthoff, Xabier Pedruzo-Bagazgoitia, Yannick Bezombes, and Omar Gabella
Atmos. Chem. Phys., 19, 8979–8997, https://doi.org/10.5194/acp-19-8979-2019, https://doi.org/10.5194/acp-19-8979-2019, 2019
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Low atmospheric dynamics and low-level cloud (LLC) macrophysical properties are analyzed using in situ and remote sensing data collected from 20 June to 30 July at Savè, Benin, during the DACCIWA field campaign in 2016. We find that the low-level jet (LLJ), LLCs, monsoon flow, and maritime inflow reveal a day-to-day variability. LLCs form at the same level as the jet core height. The cloud base height is stationary at night and remains below the jet. The cloud top height is found above the jet.
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.
José Dias Neto, Stefan Kneifel, Davide Ori, Silke Trömel, Jan Handwerker, Birger Bohn, Normen Hermes, Kai Mühlbauer, Martin Lenefer, and Clemens Simmer
Earth Syst. Sci. Data, 11, 845–863, https://doi.org/10.5194/essd-11-845-2019, https://doi.org/10.5194/essd-11-845-2019, 2019
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This study describes a 2-month dataset of ground-based, vertically pointing triple-frequency cloud radar observations recorded during the winter season 2015/2016 in Jülich, Germany. Intensive quality control has been applied to the unique long-term dataset, which allows the multifrequency signatures of ice and snow particles to be statistically analyzed for the first time. The analysis includes, for example, aggregation and its dependence on cloud temperature, riming, and onset of melting.
Geoffrey Elie Quentin Bessardon, Kwabena Fosu-Amankwah, Anders Petersson, and Barbara Jane Brooks
Atmos. Meas. Tech., 12, 1311–1324, https://doi.org/10.5194/amt-12-1311-2019, https://doi.org/10.5194/amt-12-1311-2019, 2019
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This paper presents the first performance assessment during a field campaign of a new reusable radiosonde: the Windsond S1H2. The reuse feature of the S1H2 requires evaluation of the data alteration due to sonde reuse in addition to performance and reproducibility assessments. A comparison with the Vaisala RS41-SG, a well-proven system, shows the potential of the S1H2, with no major performance degradation arising from S1H2 sonde reuse but shows the need for improving the S1H2 GPS system.
Federica Pacifico, Claire Delon, Corinne Jambert, Pierre Durand, Eleanor Morris, Mat J. Evans, Fabienne Lohou, Solène Derrien, Venance H. E. Donnou, Arnaud V. Houeto, Irene Reinares Martínez, and Pierre-Etienne Brilouet
Atmos. Chem. Phys., 19, 2299–2325, https://doi.org/10.5194/acp-19-2299-2019, https://doi.org/10.5194/acp-19-2299-2019, 2019
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Biogenic fluxes from soil at a local and regional scale are crucial to study air pollution and climate. Here we present field measurements of soil fluxes of nitric oxide (NO) and ammonia (NH3) observed over four different land cover types, i.e. bare soil, grassland, maize field, and forest, at an inland rural site in Benin, West Africa, during the DACCIWA field campaign in
June and July 2016.
Anke Kniffka, Peter Knippertz, and Andreas H. Fink
Atmos. Chem. Phys., 19, 1623–1647, https://doi.org/10.5194/acp-19-1623-2019, https://doi.org/10.5194/acp-19-1623-2019, 2019
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The role of low-level clouds in the southern West Africa (SWA) energy balance and the West African monsoon system is assessed via targeted sensitivity studies with the NWP model ICON. We show for the first time that rainfall over SWA depends logarithmically on the optical thickness of low clouds, as these control the diurnal evolution of the planetary boundary layer, vertical stability and finally convection. Small variations in clouds or aerosol have a substantial impact on precipitation.
Sophie L. Haslett, Jonathan W. Taylor, Konrad Deetz, Bernhard Vogel, Karmen Babić, Norbert Kalthoff, Andreas Wieser, Cheikh Dione, Fabienne Lohou, Joel Brito, Régis Dupuy, Alfons Schwarzenboeck, Paul Zieger, and Hugh Coe
Atmos. Chem. Phys., 19, 1505–1520, https://doi.org/10.5194/acp-19-1505-2019, https://doi.org/10.5194/acp-19-1505-2019, 2019
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As the population in West Africa grows and air pollution increases, it is becoming ever more important to understand the effects of this pollution on the climate and on health. Aerosol particles can grow by absorbing water from the air around them. This paper shows that during the monsoon season, aerosol particles in the region are likely to grow significantly because of the high moisture in the air. This means that climate effects from increasing pollution will be enhanced.
Karmen Babić, Bianca Adler, Norbert Kalthoff, Hendrik Andersen, Cheikh Dione, Fabienne Lohou, Marie Lothon, and Xabier Pedruzo-Bagazgoitia
Atmos. Chem. Phys., 19, 1281–1299, https://doi.org/10.5194/acp-19-1281-2019, https://doi.org/10.5194/acp-19-1281-2019, 2019
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The first detailed observational analysis of the complete diurnal cycle of low-level clouds (LLC) and associated atmospheric processes over southern West Africa is performed using the data gathered within the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud-Interactions in West Africa) ground-based campaign. We find cooling related to the horizontal advection, which occurs in connection with the inflow of cool maritime air mass and a prominent low-level jet, to have the dominant role in LLC formation.
Bianca Adler, Karmen Babić, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, Cheikh Dione, Xabier Pedruzo-Bagazgoitia, and Hendrik Andersen
Atmos. Chem. Phys., 19, 663–681, https://doi.org/10.5194/acp-19-663-2019, https://doi.org/10.5194/acp-19-663-2019, 2019
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This study deals with nocturnal stratiform low-level clouds that frequently form in the atmospheric boundary layer over southern West Africa. We use observational data from 11 nights to characterize the clouds and intranight variability of boundary layer conditions as well as to assess the physical processes relevant for cloud formation. We find that cooling is crucial to reach saturation and a large part of the cooling is related to horizontal advection of cool air from the Gulf of Guinea.
Adrien Deroubaix, Laurent Menut, Cyrille Flamant, Joel Brito, Cyrielle Denjean, Volker Dreiling, Andreas Fink, Corinne Jambert, Norbert Kalthoff, Peter Knippertz, Russ Ladkin, Sylvain Mailler, Marlon Maranan, Federica Pacifico, Bruno Piguet, Guillaume Siour, and Solène Turquety
Atmos. Chem. Phys., 19, 473–497, https://doi.org/10.5194/acp-19-473-2019, https://doi.org/10.5194/acp-19-473-2019, 2019
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This article presents a detailed analysis of anthropogenic and biomass burning pollutants over the Gulf of Guinea coastal region, using observations from the DACCIWA field campaign and modeling. The novelty is that we focus on how these two pollution sources are mixed and transported further inland. We show that during the day pollutants are accumulated along the coastline and transported northward as soon as the daytime convection in the atmospheric boundary layer ceases (16:00 UTC).
Ryan R. Neely III, Lindsay Bennett, Alan Blyth, Chris Collier, David Dufton, James Groves, Daniel Walker, Chris Walden, John Bradford, Barbara Brooks, Freya I. Addison, John Nicol, and Ben Pickering
Atmos. Meas. Tech., 11, 6481–6494, https://doi.org/10.5194/amt-11-6481-2018, https://doi.org/10.5194/amt-11-6481-2018, 2018
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Mobile X-band radars are widely used by atmospheric scientists to observe clouds and make estimates of rainfall. Here we describe the National Centre for Atmospheric Science's mobile X-band dual-polarisation Doppler radar (NXPol). NXPol is the first radar of its kind in the UK. To demonstrate the radar’s capabilities, we present examples of its use in three field campaigns as well as an example from ongoing observations at the National Facility for Atmospheric and Radio Research.
Konrad Deetz, Heike Vogel, Sophie Haslett, Peter Knippertz, Hugh Coe, and Bernhard Vogel
Atmos. Chem. Phys., 18, 14271–14295, https://doi.org/10.5194/acp-18-14271-2018, https://doi.org/10.5194/acp-18-14271-2018, 2018
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Water uptake can significantly increase the size and therefore alters the optical properties of aerosols. Our model study reveals that the high moisture and aerosol burden in the southern West African monsoon
layer makes it favorable to quantify properties that determine the aerosol liquid water content and its impact on the aerosol optical depth and radiative transfer. Especially in moist tropical environments the relative humidity impact on AOD has to be considered in atmospheric models.
Cyrille Flamant, Adrien Deroubaix, Patrick Chazette, Joel Brito, Marco Gaetani, Peter Knippertz, Andreas H. Fink, Gaëlle de Coetlogon, Laurent Menut, Aurélie Colomb, Cyrielle Denjean, Rémi Meynadier, Philip Rosenberg, Regis Dupuy, Pamela Dominutti, Jonathan Duplissy, Thierry Bourrianne, Alfons Schwarzenboeck, Michel Ramonet, and Julien Totems
Atmos. Chem. Phys., 18, 12363–12389, https://doi.org/10.5194/acp-18-12363-2018, https://doi.org/10.5194/acp-18-12363-2018, 2018
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This work sheds light on the complex mechanisms by which coastal shallow circulations distribute atmospheric pollutants over the densely populated southern West African region. Pollutants of concern are anthropogenic emissions from coastal cities, as well as biomass burning aerosol and dust associated with long-range transport. The complex vertical distribution of aerosols over coastal southern West Africa is investigated using airborne observations and numerical simulations.
Angela Benedetti, Jeffrey S. Reid, Peter Knippertz, John H. Marsham, Francesca Di Giuseppe, Samuel Rémy, Sara Basart, Olivier Boucher, Ian M. Brooks, Laurent Menut, Lucia Mona, Paolo Laj, Gelsomina Pappalardo, Alfred Wiedensohler, Alexander Baklanov, Malcolm Brooks, Peter R. Colarco, Emilio Cuevas, Arlindo da Silva, Jeronimo Escribano, Johannes Flemming, Nicolas Huneeus, Oriol Jorba, Stelios Kazadzis, Stefan Kinne, Thomas Popp, Patricia K. Quinn, Thomas T. Sekiyama, Taichu Tanaka, and Enric Terradellas
Atmos. Chem. Phys., 18, 10615–10643, https://doi.org/10.5194/acp-18-10615-2018, https://doi.org/10.5194/acp-18-10615-2018, 2018
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Numerical prediction of aerosol particle properties has become an important activity at many research and operational weather centers. This development is due to growing interest from a diverse set of stakeholders, such as air quality regulatory bodies, aviation authorities, solar energy plant managers, climate service providers, and health professionals. This paper describes the advances in the field and sets out requirements for observations for the sustainability of these activities.
Konrad Deetz, Heike Vogel, Peter Knippertz, Bianca Adler, Jonathan Taylor, Hugh Coe, Keith Bower, Sophie Haslett, Michael Flynn, James Dorsey, Ian Crawford, Christoph Kottmeier, and Bernhard Vogel
Atmos. Chem. Phys., 18, 9767–9788, https://doi.org/10.5194/acp-18-9767-2018, https://doi.org/10.5194/acp-18-9767-2018, 2018
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Highly resolved process study simulations for 2–3 July are conducted with COSMO-ART to assess the aerosol direct and indirect effect on meteorological conditions over southern West Africa. The meteorological phenomena of Atlantic inflow and stratus-to-cumulus transition are identified as highly susceptible to the aerosol direct effect, leading to a spatial shift of the Atlantic inflow front and a temporal shift of the stratus-to-cumulus transition with changes in the aerosol amount.
Hervé Petetin, Bastien Sauvage, Herman G. J. Smit, François Gheusi, Fabienne Lohou, Romain Blot, Hannah Clark, Gilles Athier, Damien Boulanger, Jean-Marc Cousin, Philippe Nedelec, Patrick Neis, Susanne Rohs, and Valérie Thouret
Atmos. Chem. Phys., 18, 9561–9581, https://doi.org/10.5194/acp-18-9561-2018, https://doi.org/10.5194/acp-18-9561-2018, 2018
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Based on the numerous profiles available since 1994, this paper investigates the vertical stratification of ozone, carbon monoxide and relative humidity in the lower part of the troposphere (planetary boundary layer, lower free troposphere). Such a characterization of the vertical distribution of pollution is notably important for better understanding vertical exchanges and evaluating models on the vertical dimension.
Florian Pantillon, Andreas Wieser, Bianca Adler, Ulrich Corsmeier, and Peter Knippertz
Adv. Sci. Res., 15, 91–97, https://doi.org/10.5194/asr-15-91-2018, https://doi.org/10.5194/asr-15-91-2018, 2018
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The Wind and Storms Experiment (WASTEX) was conducted during the winter 2016–2017 in the Upper Rhine Valley to better understand the formation of wind gusts during the passage of storms. The key instrument of the field campaign was a scanning Doppler lidar, which provides accurate wind observations along its beam with high spatial and temporal resolutions and within a range of several km. Results from WASTEX should help improving the representation of wind gusts in weather and climate models.
Joel Brito, Evelyn Freney, Pamela Dominutti, Agnes Borbon, Sophie L. Haslett, Anneke M. Batenburg, Aurelie Colomb, Regis Dupuy, Cyrielle Denjean, Frederic Burnet, Thierry Bourriane, Adrien Deroubaix, Karine Sellegri, Stephan Borrmann, Hugh Coe, Cyrille Flamant, Peter Knippertz, and Alfons Schwarzenboeck
Atmos. Chem. Phys., 18, 757–772, https://doi.org/10.5194/acp-18-757-2018, https://doi.org/10.5194/acp-18-757-2018, 2018
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This work focuses on sources of submicron aerosol particles over southern West Africa (SWA). Results have shown that isoprene, a gas-phase compound of biogenic origin, is responsible for roughly 25 % of the organic aerosol (OA) loading, under most background or urban plumes alike. This fraction represents a lower estimate from the biogenic contribution in this fairly polluted region. This work sheds light upon the role of anthropogenic and biogenic emissions on the pollution burden over SWA.
Marian Amoakowaah Osei, Leonard Kofitse Amekudzi, David Dotse Wemegah, Kwasi Preko, Emmanuella Serwaa Gyawu, and Kwasi Obiri-Danso
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-729, https://doi.org/10.5194/hess-2017-729, 2018
Revised manuscript not accepted
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The study focussed on the negative implication of anthropogenic invasion at the Owabi catchment. Results from modelling the hydro-climate showed the main pathway of water loss were evapotranspiration and surface runoff. Streamflow generation is projected to increase slightly under two landuse scenarios. This, if properly harnessed will boost water production and supply to meet rising demands for the Kumasi metropolis.
Philipp Gasch, Daniel Rieger, Carolin Walter, Pavel Khain, Yoav Levi, Peter Knippertz, and Bernhard Vogel
Atmos. Chem. Phys., 17, 13573–13604, https://doi.org/10.5194/acp-17-13573-2017, https://doi.org/10.5194/acp-17-13573-2017, 2017
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This paper presents simulations of a severe dust event in the Eastern Mediterranean with a weather prediction model using very high spatial resolution. Due to the high resolution, the small-scale features of the event are captured in great detail. Consequently, the previously erroneous forecast of the event is improved drastically. In addition, the interaction of mineral dust with radiation inside the model has been included as a part of this work and is presented here.
Florian Pantillon, Peter Knippertz, and Ulrich Corsmeier
Nat. Hazards Earth Syst. Sci., 17, 1795–1810, https://doi.org/10.5194/nhess-17-1795-2017, https://doi.org/10.5194/nhess-17-1795-2017, 2017
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The predictability of 25 historical winter storms over Europe is revisited by taking advantage of a homogeneous dataset of retrospective forecasts for the 1995–2015 period. The forecasts well predict the storms up to 2–4 days ahead only but also show clear potential for the early warning of storms up to 10 days ahead. However, the predictability of individual storms exhibits large variability and physical characteristics are identified for outliers with a poor predictability.
Peter Knippertz, Andreas H. Fink, Adrien Deroubaix, Eleanor Morris, Flore Tocquer, Mat J. Evans, Cyrille Flamant, Marco Gaetani, Christophe Lavaysse, Celine Mari, John H. Marsham, Rémi Meynadier, Abalo Affo-Dogo, Titike Bahaga, Fabien Brosse, Konrad Deetz, Ridha Guebsi, Issaou Latifou, Marlon Maranan, Philip D. Rosenberg, and Andreas Schlueter
Atmos. Chem. Phys., 17, 10893–10918, https://doi.org/10.5194/acp-17-10893-2017, https://doi.org/10.5194/acp-17-10893-2017, 2017
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In June–July 2016 DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa), a large, EU-funded European–African project, organised an international field campaign in densely populated southern West Africa, including measurements from ground sites, research aircraft, weather balloons and urban sites. This paper gives an overview of the atmospheric evolution during this period focusing on meteorological (precipitation, cloudiness, winds) and composition (gases, particles) aspects.
Marian Amoakowaah Osei, Leonard Kofitse Amekudzi, David Dotse Wemegah, Kwasi Preko, Emmanuella Serwaa Gyawu, and Kwasi Obiri-Danso
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-421, https://doi.org/10.5194/hess-2017-421, 2017
Manuscript not accepted for further review
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The study used the SWAT model to simulate baseline (1985–2015) and projection (2020–2050) streamflow and water balance at the Owabi catchment. The simulated streamflow was compared with an observed to test the efficiency of model prediction. The main water loss at the catchment was by evapotranspiration. The comparison results were satisfactory on a monthly timescale. For projection, water loss shifted to surface runoff which could have a positive effect by increasing water yield and streamflow.
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.
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.
Emanuel Christner, Martin Kohler, and Matthias Schneider
Atmos. Chem. Phys., 17, 1207–1225, https://doi.org/10.5194/acp-17-1207-2017, https://doi.org/10.5194/acp-17-1207-2017, 2017
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Post-depositional fractionation of stable water isotopes due to fractioning surface evaporation introduces uncertainty to isotope applications such as the reconstruction of paleotemperatures, paleoaltimetry, and the investigation of ground water formation. In this paper we combine measurements of stable water isotopes in near-surface water vapor with a Lagrangian isotope model to investigate isotope fractionation during the evaporation of surface-layer snow in central Europe.
Bianca Adler, Norbert Kalthoff, and Leonhard Gantner
Atmos. Chem. Phys., 17, 899–910, https://doi.org/10.5194/acp-17-899-2017, https://doi.org/10.5194/acp-17-899-2017, 2017
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This study deals with the development of nocturnal low-level clouds, which frequently form over southern West Africa during the monsoon season. We performed numerical simulations with the COSMO model and identified processes possibly relevant to cloud formation. The study was made in preparation of a field campaign, which took place in summer 2016 within the DACCIWA project and the results contributed to the optimisation of the measurement strategy during the campaign.
Line Båserud, Joachim Reuder, Marius O. Jonassen, Stephan T. Kral, Mostafa B. Paskyabi, and Marie Lothon
Atmos. Meas. Tech., 9, 4901–4913, https://doi.org/10.5194/amt-9-4901-2016, https://doi.org/10.5194/amt-9-4901-2016, 2016
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The micro-RPAS SUMO (Small Unmanned Meteorological Observer) equipped with a five-hole-probe (5HP) system for turbulent flow measurements was operated in 49 flight missions during the BLLAST (Boundary-Layer Late Afternoon and Sunset Turbulence) field campaign in 2011. Based on data sets from these flights, we investigate the potential and limitations of airborne velocity variance and TKE (turbulent kinetic energy) estimations by an RPAS with a take-off weight below 1 kg.
Guylaine Canut, Fleur Couvreux, Marie Lothon, Dominique Legain, Bruno Piguet, Astrid Lampert, William Maurel, and Eric Moulin
Atmos. Meas. Tech., 9, 4375–4386, https://doi.org/10.5194/amt-9-4375-2016, https://doi.org/10.5194/amt-9-4375-2016, 2016
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Turbulent processes of the atmospheric boundary layer contribute the most to transfers between the surface and the atmosphere. Typically, turbulent boundary layer parameters are measured by sonic anemometers on masts and by research aircraft. This is to measure in situ turbulent parameters in the planetary boundary layer (PBL) at altitudes above 50 m. For this purpose, our team have developed a system under a tethered balloon which has been in use since 2010.
Joan Cuxart, Burkhard Wrenger, Daniel Martínez-Villagrasa, Joachim Reuder, Marius O. Jonassen, Maria A. Jiménez, Marie Lothon, Fabienne Lohou, Oscar Hartogensis, Jens Dünnermann, Laura Conangla, and Anirban Garai
Atmos. Chem. Phys., 16, 9489–9504, https://doi.org/10.5194/acp-16-9489-2016, https://doi.org/10.5194/acp-16-9489-2016, 2016
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Estimations of the effect of thermal advection in the surface energy budget are provided. Data from the experimental campaign BLLAST, held in Southern France in summer 2011, are used, including airborne data by drones and surface-based instrumentation. Model data outputs and satellite information are also inspected. Surface heterogeneities of the order of the kilometer or larger seem to have little effect on the budget, whereas hectometer-scale structures may contribute significantly to it.
Fleur Couvreux, Eric Bazile, Guylaine Canut, Yann Seity, Marie Lothon, Fabienne Lohou, Françoise Guichard, and Erik Nilsson
Atmos. Chem. Phys., 16, 8983–9002, https://doi.org/10.5194/acp-16-8983-2016, https://doi.org/10.5194/acp-16-8983-2016, 2016
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This study evaluates the ability of operational models to predict the boundary-layer turbulent processes and mesoscale variability observed during the Boundary Layer Late-Afternoon and Sunset Turbulence field campaign. The models succeed in reproducing the variability from one day to another in terms of cloud cover, temperature and boundary-layer depth. However, they exhibit some systematic biases. The high-resolution model reproduces the vertical structures better.
Erik Nilsson, Fabienne Lohou, Marie Lothon, Eric Pardyjak, Larry Mahrt, and Clara Darbieu
Atmos. Chem. Phys., 16, 8849–8872, https://doi.org/10.5194/acp-16-8849-2016, https://doi.org/10.5194/acp-16-8849-2016, 2016
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The evolution of near-surface turbulence kinetic energy (TKE) and its budget in the afternoon transition has been studied based on field measurements. The study shows that TKE transport is an important budget term that needs to be taken into account in modeling of TKE. A non-local parametrization of dissipation using a TKE–length scale model which takes into account of boundary layer depth also gave improved results compared to a local parametrization.
Erik Nilsson, Marie Lothon, Fabienne Lohou, Eric Pardyjak, Oscar Hartogensis, and Clara Darbieu
Atmos. Chem. Phys., 16, 8873–8898, https://doi.org/10.5194/acp-16-8873-2016, https://doi.org/10.5194/acp-16-8873-2016, 2016
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A new simple model for turbulence kinetic energy (TKE) and its budget is presented for the sheared convective atmospheric boundary layer. It is used to study effects of buoyancy and shear on TKE evolution during the afternoon transition, especially near the surface. We also find a region of weak turbulence during unstable afternoon conditions below the inversion top, which we refer to as a "pre-residual layer".
Xinxin Xie, Raquel Evaristo, Clemens Simmer, Jan Handwerker, and Silke Trömel
Atmos. Chem. Phys., 16, 7105–7116, https://doi.org/10.5194/acp-16-7105-2016, https://doi.org/10.5194/acp-16-7105-2016, 2016
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This study provides a first analysis of rainfall observations and related microphysical processes during the HOPE campaign, which will benefit future studies on the evaluation and improvement of climate models within the HD(CP)2 framework. The results conveyed in this study confirm that polarimetric radars have the capability to validate weather and climate models with respect to rainfall estimation and the ongoing microphysical processes.
V. Maurer, N. Kalthoff, A. Wieser, M. Kohler, M. Mauder, and L. Gantner
Atmos. Chem. Phys., 16, 1377–1400, https://doi.org/10.5194/acp-16-1377-2016, https://doi.org/10.5194/acp-16-1377-2016, 2016
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The measurement of turbulence in the lowest 1–2 km above the land surface is important for our understanding of boundary-layer processes. We compared turbulence profiles measured at three locations lying about 3 km apart and found that the deployment of the instruments in different crop fields has no direct influence on turbulence statistics on cloud-free days. Nevertheless, spatial differences as well as correlations were found, indicating the existence of organized structures of turbulence.
P. Achtert, I. M. Brooks, B. J. Brooks, B. I. Moat, J. Prytherch, P. O. G. Persson, and M. Tjernström
Atmos. Meas. Tech., 8, 4993–5007, https://doi.org/10.5194/amt-8-4993-2015, https://doi.org/10.5194/amt-8-4993-2015, 2015
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Doppler lidar wind measurements were obtained during a 3-month Arctic cruise in summer 2014. Ship-motion effects were compensated by combining a commercial Doppler lidar with a custom-made motion-stabilisation platform. This enables the retrieval of wind profiles in the Arctic boundary layer with uncertainties comparable to land-based lidar measurements and standard radiosondes. The presented set-up has the potential to facilitate continuous ship-based wind profile measurements over the oceans.
C. Darbieu, F. Lohou, M. Lothon, J. Vilà-Guerau de Arellano, F. Couvreux, P. Durand, D. Pino, E. G. Patton, E. Nilsson, E. Blay-Carreras, and B. Gioli
Atmos. Chem. Phys., 15, 10071–10086, https://doi.org/10.5194/acp-15-10071-2015, https://doi.org/10.5194/acp-15-10071-2015, 2015
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A case study of the BLLAST experiment is considered to explore the decay of turbulence that occurs in the convective boundary layer over land during the afternoon. Based on observations and on a large-eddy simulation, the analysis reveals two phases in the afternoon: a first quasi-stationary phase when the turbulent kinetic energy slowly decays without significant change in the turbulence structure and a second phase of more rapid decay with a change in spectral turbulence characteristics.
H. P. Pietersen, J. Vilà-Guerau de Arellano, P. Augustin, A. van de Boer, O. de Coster, H. Delbarre, P. Durand, M. Fourmentin, B. Gioli, O. Hartogensis, F. Lohou, M. Lothon, H. G. Ouwersloot, D. Pino, and J. Reuder
Atmos. Chem. Phys., 15, 4241–4257, https://doi.org/10.5194/acp-15-4241-2015, https://doi.org/10.5194/acp-15-4241-2015, 2015
M. Lothon, F. Lohou, D. Pino, F. Couvreux, E. R. Pardyjak, J. Reuder, J. Vilà-Guerau de Arellano, P Durand, O. Hartogensis, D. Legain, P. Augustin, B. Gioli, D. H. Lenschow, I. Faloona, C. Yagüe, D. C. Alexander, W. M. Angevine, E Bargain, J. Barrié, E. Bazile, Y. Bezombes, E. Blay-Carreras, A. van de Boer, J. L. Boichard, A. Bourdon, A. Butet, B. Campistron, O. de Coster, J. Cuxart, A. Dabas, C. Darbieu, K. Deboudt, H. Delbarre, S. Derrien, P. Flament, M. Fourmentin, A. Garai, F. Gibert, A. Graf, J. Groebner, F. Guichard, M. A. Jiménez, M. Jonassen, A. van den Kroonenberg, V. Magliulo, S. Martin, D. Martinez, L. Mastrorillo, A. F. Moene, F. Molinos, E. Moulin, H. P. Pietersen, B. Piguet, E. Pique, C. Román-Cascón, C. Rufin-Soler, F. Saïd, M. Sastre-Marugán, Y. Seity, G. J. Steeneveld, P. Toscano, O. Traullé, D. Tzanos, S. Wacker, N. Wildmann, and A. Zaldei
Atmos. Chem. Phys., 14, 10931–10960, https://doi.org/10.5194/acp-14-10931-2014, https://doi.org/10.5194/acp-14-10931-2014, 2014
E. Blay-Carreras, E. R. Pardyjak, D. Pino, D. C. Alexander, F. Lohou, and M. Lothon
Atmos. Chem. Phys., 14, 9077–9085, https://doi.org/10.5194/acp-14-9077-2014, https://doi.org/10.5194/acp-14-9077-2014, 2014
S. Fiedler, K. Schepanski, P. Knippertz, B. Heinold, and I. Tegen
Atmos. Chem. Phys., 14, 8983–9000, https://doi.org/10.5194/acp-14-8983-2014, https://doi.org/10.5194/acp-14-8983-2014, 2014
S. M. Cowie, P. Knippertz, and J. H. Marsham
Atmos. Chem. Phys., 14, 8579–8597, https://doi.org/10.5194/acp-14-8579-2014, https://doi.org/10.5194/acp-14-8579-2014, 2014
E. Blay-Carreras, D. Pino, J. Vilà-Guerau de Arellano, A. van de Boer, O. De Coster, C. Darbieu, O. Hartogensis, F. Lohou, M. Lothon, and H. Pietersen
Atmos. Chem. Phys., 14, 4515–4530, https://doi.org/10.5194/acp-14-4515-2014, https://doi.org/10.5194/acp-14-4515-2014, 2014
F. Lohou, L. Kergoat, F. Guichard, A. Boone, B. Cappelaere, J.-M. Cohard, J. Demarty, S. Galle, M. Grippa, C. Peugeot, D. Ramier, C. M. Taylor, and F. Timouk
Atmos. Chem. Phys., 14, 3883–3898, https://doi.org/10.5194/acp-14-3883-2014, https://doi.org/10.5194/acp-14-3883-2014, 2014
G. Poljak, M. T. Prtenjak, M. Kvakić, N. Strelec Mahović, and K. Babić
Ann. Geophys., 32, 401–420, https://doi.org/10.5194/angeo-32-401-2014, https://doi.org/10.5194/angeo-32-401-2014, 2014
Related subject area
Subject: Clouds and Precipitation | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
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
Upper tropospheric slightly ice-subsaturated regions: Frequency of occurrence and statistical evidence for the appearance of contrail cirrus
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
Annual exposure to polycyclic aromatic hydrocarbons in urban environments linked to wintertime wood-burning episodes
Reduced ice number concentrations in contrails from low-aromatic biofuel blends
Distinct impacts on precipitation by aerosol radiative effect over three different megacity regions of eastern China
Estimation of the terms acting on local 1 h surface temperature variations in Paris region: the specific contribution of clouds
Contrasting characteristics of open- and closed-cellular stratocumulus cloud in the eastern North Atlantic
Mass and density of individual frozen hydrometeors
Linear relationship between effective radius and precipitation water content near the top of convective clouds: measurement results from ACRIDICON–CHUVA campaign
Supercooled liquid water and secondary ice production in Kelvin–Helmholtz instability as revealed by radar Doppler spectra observations
Morning boundary layer conditions for shallow to deep convective cloud evolution during the dry season in the central Amazon
Analysis of aerosol–cloud interactions and their implications for precipitation formation using aircraft observations over the United Arab Emirates
Impact of wind pattern and complex topography on snow microphysics during International Collaborative Experiment for PyeongChang 2018 Olympic and Paralympic winter games (ICE-POP 2018)
Evaluation of simulated cloud liquid water in low clouds over the Beaufort Sea in the Arctic System Reanalysis using ARISE airborne in situ observations
Comprehensive quantification of height dependence of entrainment mixing between stratiform cloud top and environment
Sunlight-absorbing aerosol amplifies the seasonal cycle in low-cloud fraction over the southeast Atlantic
Coupled and decoupled stratocumulus-topped boundary layers: turbulence properties
Shape dependence of snow crystal fall speed
Captured cirrus ice particles in high definition
What drives daily precipitation over the central Amazon? Differences observed between wet and dry seasons
Microphysical investigation of the seeder and feeder region of an Alpine mixed-phase cloud
Case study of a humidity layer above Arctic stratocumulus and potential turbulent coupling with the cloud top
Joint cloud water path and rainwater path retrievals from airborne ORACLES observations
Lagrangian matches between observations from aircraft, lidar and radar in a warm conveyor belt crossing orography
Influence of low-level blocking and turbulence on the microphysics of a mixed-phase cloud in an inner-Alpine valley
Observed trends in clouds and precipitation (1983–2009): implications for their cause(s)
Statistical characteristics of raindrop size distribution over the Western Ghats of India: wet versus dry spells of the Indian summer monsoon
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.
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. Discuss., https://doi.org/10.5194/acp-2022-632, https://doi.org/10.5194/acp-2022-632, 2022
Revised manuscript accepted for ACP
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The radiative effect of aviation-induced cirrus is closely related to ambient conditions and their microphysical properties. Our study investigated the occurrence of contrail and natural cirrus measured above Central Europe in 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. The avoidance of slightly ice-subsaturated regions by aviation might thus mitigate contrail cirrus.
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.
Irini Tsiodra, Georgios Grivas, Kalliopi Tavernaraki, Aikaterini Bougiatioti, Maria Apostolaki, Despina Paraskevopoulou, Alexandra Gogou, Constantine Parinos, Konstantina Oikonomou, Maria Tsagkaraki, Pavlos Zarmpas, Athanasios Nenes, and Nikolaos Mihalopoulos
Atmos. Chem. Phys., 21, 17865–17883, https://doi.org/10.5194/acp-21-17865-2021, https://doi.org/10.5194/acp-21-17865-2021, 2021
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We analyze observations from year-long measurements at Athens, Greece. Nighttime wintertime PAH levels are 4 times higher than daytime, and wintertime values are 15 times higher than summertime. Biomass burning aerosol during wintertime pollution events is responsible for these significant wintertime enhancements and accounts for 43 % of the population exposure to PAH carcinogenic risk. Biomass burning poses additional health risks beyond those associated with the high PM levels that develop.
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 %.
Yue Sun and Chuanfeng Zhao
Atmos. Chem. Phys., 21, 16555–16574, https://doi.org/10.5194/acp-21-16555-2021, https://doi.org/10.5194/acp-21-16555-2021, 2021
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Using high-resolution multi-year warm season data, the influence of aerosol on precipitation time over the North China Plain (NCP), Yangtze River Delta (YRD), and Pearl River Delta (PRD) is investigated. Aerosol amount and type have significant influence on precipitation time: precipitation start time is advanced by 3 h in the NCP, delayed 2 h in the PRD, and negligibly changed in the YRD. Aerosol impact on precipitation is also influenced by precipitation type and meteorological conditions.
Oscar Javier Rojas Muñoz, Marjolaine Chiriaco, Sophie Bastin, and Justine Ringard
Atmos. Chem. Phys., 21, 15699–15723, https://doi.org/10.5194/acp-21-15699-2021, https://doi.org/10.5194/acp-21-15699-2021, 2021
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A method is developed and evaluated to quantify each process that affects hourly 2 m temperature variations on a local scale, based almost exclusively on observations retrieved from an observatory near the Paris region. Each term involved in surface temperature variations is estimated, and its contribution and importance are also assessed. It is found that clouds are the main modulator on hourly temperature variations for most hours of the day, and thus their characterization is addressed.
Michael P. Jensen, Virendra P. Ghate, Dié Wang, Diana K. Apoznanski, Mary J. Bartholomew, Scott E. Giangrande, Karen L. Johnson, and Mandana M. Thieman
Atmos. Chem. Phys., 21, 14557–14571, https://doi.org/10.5194/acp-21-14557-2021, https://doi.org/10.5194/acp-21-14557-2021, 2021
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This work compares the large-scale meteorology, cloud, aerosol, precipitation, and thermodynamics of closed- and open-cell cloud organizations using long-term observations from the astern North Atlantic. Open-cell cases are associated with cold-air outbreaks and occur in deeper boundary layers, with stronger winds and higher rain rates compared to closed-cell cases. These results offer important benchmarks for model representation of boundary layer clouds in this climatically important region.
Karlie N. Rees, Dhiraj K. Singh, Eric R. Pardyjak, and Timothy J. Garrett
Atmos. Chem. Phys., 21, 14235–14250, https://doi.org/10.5194/acp-21-14235-2021, https://doi.org/10.5194/acp-21-14235-2021, 2021
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Accurate predictions of weather and climate require descriptions of the mass and density of snowflakes as a function of their size. Few measurements have been obtained to date because snowflakes are so small and fragile. This article describes results from a new instrument that automatically measures individual snowflake size, mass, and density. Key findings are that small snowflakes have much lower densities than is often assumed and that snowflake density increases with temperature.
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.
Haoran Li, Alexei Korolev, and Dmitri Moisseev
Atmos. Chem. Phys., 21, 13593–13608, https://doi.org/10.5194/acp-21-13593-2021, https://doi.org/10.5194/acp-21-13593-2021, 2021
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Kelvin–Helmholtz (K–H) clouds embedded in a stratiform precipitation event were uncovered via radar Doppler spectral analysis. Given the unprecedented detail of the observations, we show that multiple populations of secondary ice columns were generated in the pockets where larger cloud droplets are formed and not at some constant level within the cloud. Our results highlight that the K–H instability is favorable for liquid droplet growth and secondary ice formation.
Alice Henkes, Gilberto Fisch, Luiz A. T. Machado, and Jean-Pierre Chaboureau
Atmos. Chem. Phys., 21, 13207–13225, https://doi.org/10.5194/acp-21-13207-2021, https://doi.org/10.5194/acp-21-13207-2021, 2021
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The Amazonian boundary layer is investigated during the dry season in order to better understand the processes that occur between night and day until the stage where shallow cumulus clouds become deep. Observations show that shallow to deep clouds are characterized by a shorter morning transition stage (e.g., the time needed to eliminate the stable boundary layer inversion), while higher humidity above the boundary layer favors the evolution from shallow to deep cumulus clouds.
Youssef Wehbe, Sarah A. Tessendorf, Courtney Weeks, Roelof Bruintjes, Lulin Xue, Roy Rasmussen, Paul Lawson, Sarah Woods, and Marouane Temimi
Atmos. Chem. Phys., 21, 12543–12560, https://doi.org/10.5194/acp-21-12543-2021, https://doi.org/10.5194/acp-21-12543-2021, 2021
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The role of dust aerosols as ice-nucleating particles is well established in the literature, whereas their role as cloud condensation nuclei is less understood, particularly in polluted desert environments. We analyze coincident aerosol size distributions and cloud particle imagery collected over the UAE with a research aircraft. Despite the presence of ultra-giant aerosol sizes associated with dust, an active collision–coalescence process is not observed within the limited depths of warm cloud.
Kwonil Kim, Wonbae Bang, Eun-Chul Chang, Francisco J. Tapiador, Chia-Lun Tsai, Eunsil Jung, and Gyuwon Lee
Atmos. Chem. Phys., 21, 11955–11978, https://doi.org/10.5194/acp-21-11955-2021, https://doi.org/10.5194/acp-21-11955-2021, 2021
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This study analyzes the microphysical characteristics of snow in complex terrain and the nearby ocean according to topography and wind pattern during the ICE-POP 2018 campaign. The observations from collocated vertically pointing radars and disdrometers indicate that the riming in the mountainous region is likely caused by a strong shear and turbulence. The different behaviors of aggregation and riming were found by three different synoptic patterns (air–sea interaction, cold low, and warm low).
J. Brant Dodson, Patrick C. Taylor, Richard H. Moore, David H. Bromwich, Keith M. Hines, Kenneth L. Thornhill, Chelsea A. Corr, Bruce E. Anderson, Edward L. Winstead, and Joseph R. Bennett
Atmos. Chem. Phys., 21, 11563–11580, https://doi.org/10.5194/acp-21-11563-2021, https://doi.org/10.5194/acp-21-11563-2021, 2021
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Aircraft in situ observations of low-level Beaufort Sea cloud properties and thermodynamics from the ARISE campaign are compared with the Arctic System Reanalysis (ASR) to better understand deficiencies in simulated clouds. ASR produces too little cloud water, which coincides with being too warm and dry. In addition, ASR struggles to produce cloud water even in favorable thermodynamic conditions. A random sampling experiment also shows the effects of the limited aircraft sampling on the results.
Sinan Gao, Chunsong Lu, Yangang Liu, Seong Soo Yum, Jiashan Zhu, Lei Zhu, Neel Desai, Yongfeng Ma, and Shang Wu
Atmos. Chem. Phys., 21, 11225–11241, https://doi.org/10.5194/acp-21-11225-2021, https://doi.org/10.5194/acp-21-11225-2021, 2021
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Only a few studies have been focused on the vertical variation of entrainment mixing with low resolutions which are crucial to cloud-related processes. A sawtooth pattern allows for an examination of mixing with high vertical resolution. A new measure is introduced to estimate entrainment mixing to overcome difficulties in existing measures, where vertical profile indicates that entrainment mixing becomes more homogeneous with decreasing altitudes, consistent with the dynamical measures.
Jianhao Zhang and Paquita Zuidema
Atmos. Chem. Phys., 21, 11179–11199, https://doi.org/10.5194/acp-21-11179-2021, https://doi.org/10.5194/acp-21-11179-2021, 2021
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The subtropical Atlantic hosts one of the planet's largest marine low cloud decks and interacts with biomass burning aerosol from approximately July through October. This study clarifies how the monthly evolution in meteorology and the biomass burning aerosol vertical structure affects the seasonal cycle in its low cloud fraction, such that the July–October evolution in low cloud cover and morphology are reinforced, when compared to scenarios with less aerosol present.
Jakub L. Nowak, Holger Siebert, Kai-Erik Szodry, and Szymon P. Malinowski
Atmos. Chem. Phys., 21, 10965–10991, https://doi.org/10.5194/acp-21-10965-2021, https://doi.org/10.5194/acp-21-10965-2021, 2021
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Turbulence properties in two cases of a marine stratocumulus-topped boundary layer have been compared using high-resolution helicopter-borne in situ measurements. In the coupled one, small-scale turbulence was close to isotropic and reasonably followed inertial range scaling according to Kolmogorov theory. In the decoupled one, turbulence was more anisotropic and the scaling deviated from theory. This was more pronounced in the cloud and subcloud layers in comparison to the surface mixed layer.
Sandra Vázquez-Martín, Thomas Kuhn, and Salomon Eliasson
Atmos. Chem. Phys., 21, 7545–7565, https://doi.org/10.5194/acp-21-7545-2021, https://doi.org/10.5194/acp-21-7545-2021, 2021
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In this work, we present new fall speed measurements of natural snow particles and ice crystals. We study the particle fall speed relationships and how they depend on particle shape. We analyze these relationships as a function of particle size, cross-sectional area, and area ratio for different particle shape groups. We also investigate the dependence of the particle fall speed on the orientation, as it has a large impact on the cross-sectional area.
Nathan Magee, Katie Boaggio, Samantha Staskiewicz, Aaron Lynn, Xuanyi Zhao, Nicholas Tusay, Terance Schuh, Manisha Bandamede, Lucas Bancroft, David Connelly, Kevin Hurler, Bryan Miner, and Elissa Khoudary
Atmos. Chem. Phys., 21, 7171–7185, https://doi.org/10.5194/acp-21-7171-2021, https://doi.org/10.5194/acp-21-7171-2021, 2021
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The cryo-electron microscopy images and analysis in this paper result from the first balloon-borne capture, preservation, and high-resolution imaging of ice particles from cirrus clouds. The images show cirrus particle complexity in unprecedented detail, revealing unexpected morphology, a mixture of surface roughness scales and patterns, embedded aerosols, and a large variety of habits within a single cloud. The results should inform ongoing efforts to refine modeling of cirrus radiative impact.
Thiago S. Biscaro, Luiz A. T. Machado, Scott E. Giangrande, and Michael P. Jensen
Atmos. Chem. Phys., 21, 6735–6754, https://doi.org/10.5194/acp-21-6735-2021, https://doi.org/10.5194/acp-21-6735-2021, 2021
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This study suggests that there are two distinct modes driving diurnal precipitating convective clouds over the central Amazon. In the wet season, local factors such as turbulence and nighttime cloud coverage are the main controls of daily precipitation, while dry-season daily precipitation is modulated primarily by the mesoscale convective pattern. The results imply that models and parameterizations must consider different formulations based on the seasonal cycle to correctly resolve convection.
Fabiola Ramelli, Jan Henneberger, Robert O. David, Johannes Bühl, Martin Radenz, Patric Seifert, Jörg Wieder, Annika Lauber, Julie T. Pasquier, Ronny Engelmann, Claudia Mignani, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys., 21, 6681–6706, https://doi.org/10.5194/acp-21-6681-2021, https://doi.org/10.5194/acp-21-6681-2021, 2021
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Orographic mixed-phase clouds are an important source of precipitation, but the ice formation processes within them remain uncertain. Here we investigate the origin of ice crystals in a mixed-phase cloud in the Swiss Alps using aerosol and cloud data from in situ and remote sensing observations. We found that ice formation primarily occurs in cloud top generating cells. Our results indicate that secondary ice processes are active in the feeder region, which can enhance orographic precipitation.
Ulrike Egerer, André Ehrlich, Matthias Gottschalk, Hannes Griesche, Roel A. J. Neggers, Holger Siebert, and Manfred Wendisch
Atmos. Chem. Phys., 21, 6347–6364, https://doi.org/10.5194/acp-21-6347-2021, https://doi.org/10.5194/acp-21-6347-2021, 2021
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This paper describes a case study of a three-day period with a persistent humidity inversion above a mixed-phase cloud layer in the Arctic. It is based on measurements with a tethered balloon, complemented with results from a dedicated high-resolution large-eddy simulation. Both methods show that the humidity layer acts to provide moisture to the cloud layer through downward turbulent transport. This supply of additional moisture can contribute to the persistence of Arctic clouds.
Andrew M. Dzambo, Tristan L'Ecuyer, Kenneth Sinclair, Bastiaan van Diedenhoven, Siddhant Gupta, Greg McFarquhar, Joseph R. O'Brien, Brian Cairns, Andrzej P. Wasilewski, and Mikhail Alexandrov
Atmos. Chem. Phys., 21, 5513–5532, https://doi.org/10.5194/acp-21-5513-2021, https://doi.org/10.5194/acp-21-5513-2021, 2021
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This work highlights a new algorithm using data collected from the 2016–2018 NASA ORACLES field campaign. This algorithm synthesizes cloud and rain measurements to attain estimates of cloud and precipitation properties over the southeast Atlantic Ocean. Estimates produced by this algorithm compare well against in situ estimates. Increased rain fractions and rain rates are found in regions of atmospheric instability. This dataset can be used to explore aerosol–cloud–precipitation interactions.
Maxi Boettcher, Andreas Schäfler, Michael Sprenger, Harald Sodemann, Stefan Kaufmann, Christiane Voigt, Hans Schlager, Donato Summa, Paolo Di Girolamo, Daniele Nerini, Urs Germann, and Heini Wernli
Atmos. Chem. Phys., 21, 5477–5498, https://doi.org/10.5194/acp-21-5477-2021, https://doi.org/10.5194/acp-21-5477-2021, 2021
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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.
Fabiola Ramelli, Jan Henneberger, Robert O. David, Annika Lauber, Julie T. Pasquier, Jörg Wieder, Johannes Bühl, Patric Seifert, Ronny Engelmann, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys., 21, 5151–5172, https://doi.org/10.5194/acp-21-5151-2021, https://doi.org/10.5194/acp-21-5151-2021, 2021
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Interactions between dynamics, microphysics and orography can enhance precipitation. Yet the exact role of these interactions is still uncertain. Here we investigate the role of low-level blocking and turbulence for precipitation by combining remote sensing and in situ observations. The observations show that blocked flow can induce the formation of feeder clouds and that turbulence can enhance hydrometeor growth, demonstrating the importance of local flow effects for orographic precipitation.
Xiang Zhong, Shaw Chen Liu, Run Liu, Xinlu Wang, Jiajia Mo, and Yanzi Li
Atmos. Chem. Phys., 21, 4899–4913, https://doi.org/10.5194/acp-21-4899-2021, https://doi.org/10.5194/acp-21-4899-2021, 2021
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The distributions of linear trends in total cloud cover and precipitation in 1983–2009 are both characterized by a broadening of the major ascending zone of Hadley circulation around the Maritime Continent. The broadening is driven primarily by the moisture–convection–latent-heat feedback cycle under global warming conditions. Contribution by other climate oscillations is secondary. The reduction of total cloud cover in China in 1957–2005 is driven by the same mechanism.
Uriya Veerendra Murali Krishna, Subrata Kumar Das, Ezhilarasi Govindaraj Sulochana, Utsav Bhowmik, Sachin Madhukar Deshpande, and Govindan Pandithurai
Atmos. Chem. Phys., 21, 4741–4757, https://doi.org/10.5194/acp-21-4741-2021, https://doi.org/10.5194/acp-21-4741-2021, 2021
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Indian summer monsoon (ISM) rainfall exhibits sub-seasonal variability as active spells with good rainfall (wet spell) and weak spells or breaks with little to no rainfall (dry spell). Studies have shown that during the wet and dry periods of the ISM, there are contrasting behaviors in the formation of weather systems and large-scale instability. Thus, it is worth investigating how the raindrop size distribution varies during intra-seasonal timescale variations of the ISM in the Western Ghats.
Cited articles
Abdou, K., Parker, D. J., Brooks, B., Kalthoff, N., and Lebel, T.: The
diurnal cycle of lower boundary-layer wind in the West African monsoon,
Q. J. Roy. Meteor. Soc., 136, 66–76, https://doi.org/10.1002/qj.536, 2010.
Adler, B., Kalthoff, N., and Gantner, L.: Nocturnal low-level clouds over
southern West Africa analysed using high-resolution simulations, Atmos. Chem.
Phys., 17, 899–910, https://doi.org/10.5194/acp-17-899-2017, 2017.
Aubinet, M., Vesala, T., and Papale, D. (Eds.): Eddy covariance. A practical
guide to measurement and data analysis, Springer, Dordrecht, the Netherlands,
https://doi.org/10.1007/978-94-007-2351-1, 2012.
Banta, R. M., Pichugina, Y. L., and Brewer, W. A.: Turbulent
velocity-variance profiles in the stable boundary layer generated by a
nocturnal low-level jet, J. Atmos. Sci., 63, 2700–2719, 2006.
Bessardon, G., Brooks, B., Abiye, O., Adler, B., Ajao, A., Ajileye, O.,
Altstätter, B., Amekudzi, L. K., Aryee, J. N. A., Atiah, W. A., Ayoola,
M., Babić, K., Bärfuss, K., Bezombes, Y., Bret, G., Brilouet, P.-E.,
Cayle-Aethelhard, F., Danuor, S., Delon, C., Derrien, S., Dione, C., Durand,
P., Fosu-Amankwah, K., Gabella, O., Groves, J., Handwerker, J., Kalthoff,
N., Kohler, M., Kunka, N., Jambert, C., Jegede, G., Lampert, A., Leclercq,
J., Lohou, F., Lothon, M., Medina, P., Pätzold, F., Pedruzo Bagazgoitia,
X., Reinares, I., Sharpe, S., Smith, V., Sunmonu, L. A., Tan, N., and
Wieser, A.: A new high-quality dataset of the diurnal cycle of the southern
West African atmospheric boundary layer during the Monsoon season – an
overview from the DACCIWA campaign, Sci. Data, in preparation,
2018.
Brooks, B. J.: DACCIWA field campaign, Kumasi super-site,
Instrumentation, SEDOO OMP, https://doi.org/10.6096/dacciwa.1663, 2016.
Browning, K., Blyth, A., Clark, P., Corsmeier, U., Morcrette, C., Agner, J.,
Bamber, D., Barthlott, C., Bennett, L., Beswick, K., Bitter, M., Bozier, K.,
Brooks, B., Collier, C., Cook, C., Davies, F., Deny, B., Engelhardt, M.,
Feuerle, T., Forbes, R., Gaffard, C., Gray, M., Hanken, R., Hewison, T.,
Huckle, R., Kalthoff, N., Khodayar, S., Kohler, M., Kraut, S., Kunz, M.,
Ladd, D., Lenfant, J., Marsham, J., McGregor, J., Nicol, J., Norton, E.,
Parker, D., Perry, D., Ramatschi, M., Roberts, H., Russel, A., Schulz, H.,
Slack, E., Vauhan, G., Waight, J., Watson, R., Webb, A., Wieser, A., and
Zink, K.: The Convective Storm Initiation Project, B. Am. Meteorol. Soc., 88,
1939–1955, https://doi.org/10.1175/BAMS-88-12-1939, 2007.
Derrien, S., Bezombes, Y., Bret, G., Gabella, O., Jarnot, C., Medina, P.,
Piques, E., Delon, C., Dione, C., Campistron, B., Durand, P., Jambert, C.,
Lohou, F., Lothon, M., Pacifico, F., and Meyerfeld, Y.: DACCIWA field
campaign, Savè super-site, UPS instrumentation; SEDOO OMP,
https://doi.org/10.6096/DACCIWA.1618, 2016.
Doswell III, C. A. and Rasmussen, E. N.: The effect of neglecting the
virtual temperature correction on CAPE calculations, Weather Forecast., 9,
625–629, https://doi.org/10.1175/1520-0434(1994)009<0625:TEONTV>2.0.CO;2, 1994.
Fink, A. H., Vincent, D. G., and Ermert, V.: Rainfall types in the West
African Soudanian zone during the summer monsoon 2002, Mon. Weather Rev., 134, 2143–2164, https://doi.org/10.1175/MWR3182.1, 2006.
Fink, A. H., Engel, T., Ermert, V., van der Linden, R., Schneidewind, M.,
Redl, R., Afiesimama, E., Thiaw, W., Yorke, C., and Evans, M.: Mean climate
and seasonal cycle, in: Meteorology of tropical West Africa: The forecasters'
handbook, edited by: Parker, D. J. and Diop-Kane, M., John Wiley & Sons, Ltd,
Chichester, UK, 1–39, https://doi.org/10.1002/9781118391297.ch1, 2017.
Flamant, C., Knippertz, Fink, A.,, P., Akpo, A., Brooks, B., Chiu, C., Coe,
H., Danuor, S., Evans, M., Jegede, O., Kalthoff, N., Konaré, A., Liousse,
C., Lohou, F., Mari, C, Schlager, H., Schwarzenboeck, A., Adler, B.,
Amekudzi, L., Aeyee, J., Ayoola, M., Bessardon, G., Bower, K., Burnet, F.,
Catoire, V., Colomb, A., Fossu-Amankwah, K., Lee, J., Lothon, M., Manaran,
M., Marsham, J., Meynadier, R., Ngamini, J.-B., Rosenberg, P., Sauer, D.,
Schneider, J., Smith, V., Stratmann, G., Voigt, C., and Yoboue, V.: The
Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa field campaigns:
Overview and research highlights, B. Am. Meteorol. Soc., 99, 83–104,
https://doi.org/10.1175/BAMS-D-16-0256.1, 2017.
Handwerker, J., Scheer, S., and Gamer, T.: DACCIWA field campaign, Savè
super-site, Cloud and precipitation; SEDOO OMP,
https://doi.org/10.6096/DACCIWA.1686, 2016.
Hannak, L., Knippertz, P., Fink, A. H., Kniffka, A., and Pante, G.: Why do
global climate models struggle to represent low-level clouds in the West
African summer monsoon?, J. Climate, 30, 1665–1687,
https://doi.org/10.1175/JCLI-D-16-0451.1, 2017.
Jegede, O. O., Ayoola, M. A., Sunmonu, L. A., Ajao, A. I., and Babić, K.:
DACCIWA field campaign, Ile Ife super-site, OAU instrumentation; SEDOO OMP,
https://doi.org/10.6096/DACCIWA.1702, 2016.
Khodayar, S., Kalthoff, N., Wickert, J., Corsmeier, U., Morcrette, C. J., and
Kottmeier, C.: The increase of spatial data resolution for the detection of
the initiation of convection. A case study from CSIP, Meteorol. Z.,
19, 179–198, https://doi.org/10.1127/0941-2948/2010/0439, 2010.
Kohler, M., Kalthoff, N., and Kottmeier, C.: The impact of soil moisture
modifications on CBL characteristics in West Africa: A case-study from the
AMMA campaign, Q. J. Roy. Meteor. Soc., 136, 442–455,
https://doi.org/10.1002/qj.430, 2010.
Kohler, M., Kalthoff, N., Seringer, J., and Kraut, S.: DACCIWA field
campaign, Savè super-site, Surface measurements; SEDOO OMP,
https://doi.org/10.6096/DACCIWA.1690, 2016.
Knippertz, P., Fink, A. H., Schuster, R., Trentmann, J., Schrage, J. M., and
Yorke, C.: Ultra-low clouds over the southern West African monsoon region,
Geophys. Res. Lett., 38, https://doi.org/10.1029/2011GL049278, 2011.
Knippertz, P., Coe, H., Chiu, C., Evans, M., Fink, A. H., Kalthoff, N.,
Liousse, C., Mari, C., Allan, R., Brooks, B., Danour, S., Flamant, C.,
Jegede, O. O., Lohou, F., and Marsham, J. H.: The DACCIWA project:
Dynamics-aerosol-chemistry-cloud interactions in West Africa, B. Am. Meteor.
Soc., 96, 1451–1460, https://doi.org/10.1175/BAMS-D-14-00108.1, 2015a.
Knippertz, P., Evans, M., Field, P., Fink, A. H., Liousse, C., and Marsham,
J. H.: The possible role of air pollution in climate change in West Africa,
Nat. Clim. Change, 5, 815–822, https://doi.org/10.1038/nclimate2727, 2015b.
Knippertz, P., Fink, A. H., Deroubaix, A., Morris, E., Tocquer, F., Evans, M.
J., Flamant, C., Gaetani, M., Lavaysse, C., Mari, C., Marsham, J. H.,
Meynadier, R., Affo-Dogo, A., Bahaga, T., Brosse, F., Deetz, K., Guebsi, R.,
Latifou, I., Maranan, M., Rosenberg, P. D., and Schlueter, A.: A
meteorological and chemical overview of the DACCIWA field campaign in West
Africa in June–July 2016, Atmos. Chem. Phys., 17, 10893–10918,
https://doi.org/10.5194/acp-17-10893-2017, 2017.
Leung, W.-Y. H., Savre, J., Bender, F. A.-M., Komppula, M., Portin, H.,
Romakkaniemi, S., Sedlar, J., Noone, K., and Ekman, A. M. L.: Sensitivity of
a continental night-time stratocumulus-topped boundary layer to varying
environmental conditions, Q. J. Roy. Meteor. Soc., 142, 2911–2924,
https://doi.org/10.1002/qj.2877, 2016.
Löhnert, U. and Crewell, S.: Accuracy of cloud liquid water path from
ground-based microwave radiometry. 1: Dependency on cloud model statistics,
Radio Sci., 38, 8041, https://doi.org/10.1029/2002RS002654, 2003.
Löhnert, U., Turner, D., and Crewell, S.: Ground-based temperature and
humidity profiling using spectral infrared and microwave observations. Part
I: Simulated retrieval performance in clear-sky conditions, J. Appl.
Meteorol. Clim., 48, 1017–1032, https://doi.org/10.1175/2008JAMC2060.1, 2009.
Lohou, F., Kergoat, L., Guichard, F., Boone, A., Cappelaere, B., Cohard,
J.-M., Demarty, J., Galle, S., Grippa, M., Peugeot, C., Ramier, D., Taylor,
C. M., and Timouk, F.: Surface response to rain events throughout the West
African monsoon, Atmos. Chem. Phys., 14, 388–3898,
https://doi.org/10.5194/acp-14-3883-2014, 2014.
Lothon, M., Saïd, F., Lohou, F., and Campistron, B.: Observation of the
diurnal cycle in the low troposphere of West Africa, Mon. Weather Rev., 136,
3477–3500, https://doi.org/10.1175/2008MWR2427.1, 2008.
Madonna, F., Amato, F., Vande Hey, J., and Pappalardo, G.: Ceilometer aerosol
profiling versus Raman lidar in the frame of the INTERACT campaign of ACTRIS,
Atmos. Meas. Tech., 8, 2207–2223, https://doi.org/10.5194/amt-8-2207-2015, 2015.
Mauder, M., Cuntz, M., Drüe, C., Graf, A., Rebmann, C., Schmid, H. P.,
Schmidt, M., and Steinbrecher, R.: A strategy for quality and uncertainty
assessment of long-term eddy-covariance measurements, Agr. Forest Meteorol.,
169, 122–135, https://doi.org/10.1016/j.agrformet.2012.09.006, 2013.
Oke, T. R.: Boundary layer climates, Methuen Edn. 2, London, New York,
435 pp., 1987.
Parker, D., Burton, R., Diongue-Niang, A., Ellis, R., Felton, M., Taylor,
C., Thorncroft, C., Bessemoulin, P., and Tompkins, A.: The diurnal cycle of
the West African monsoon circulation, Q. J. Roy. Meteor. Soc., 131,
2839–2860, https://doi.org/10.1256/qj.04.52, 2005.
Parker, D. J., Fink, A., Janicot, S., Ngamini, J.-B., Douglas, M.,
Afiesimama, E., Agusti-Panareda, A., Beljaars, A., Dide, F., Diedhiou, A.,
Lebel, T., Polcher, J., Redelsperger, J.-L., Thorncroft, C., and Wilson, G.
A.: The AMMA radiosonde program and its implications for the future of
atmospheric monitoring over Africa, B. Am. Meteor. Soc., 89, 1015–1027,
https://doi.org/10.1175/2008BAMS2436.1, 2008.
Schrage, J. M. and Fink, A. H.: Nocturnal continental low-level stratus over
tropical West Africa: observations and possible mechanisms controlling its
onset, Mon. Weather Rev., 140, 1794–1809, https://doi.org/10.1175/MWR-D-11-00172.1,
2012.
Schrage, J. M., Fink, A. H., Ermert, V., and Ahlonsou, E. D.: Three MCS cases
occurring in different synoptic environments in the Sub-Sahelian wet zone
during the 2002 West African monsoon, J. Atmos. Sci., 63, 2369–2382,
https://doi.org/10.1175/JAS3757.1, 2006.
Schrage, J. M., Augustyn, S., and Fink, A. H.: Nocturnal stratiform
cloudiness during the West African monsoon, Meteorol. Atmos. Phys, 95,
73–86, https://doi.org/10.1007/s00703-006-0194-7, 2007.
Schuster, R., Fink, A. H., and Knippertz, P.: Formation and maintenance of
nocturnal low-level stratus over the southern West African monsoon region
during AMMA 2006, J. Atmos. Sci., 70, 2337–2355,
https://doi.org/10.1175/JAS-D-12-0241.1, 2013.
Schwendike, J., Kalthoff, N., and Kohler, M.: The impact of mesoscale
convective systems on the surface and boundary layer structure in West
Africa: case studies from the AMMA campaign, Q. J. Roy. Meteor. Soc., 136,
566–582, https://doi.org/10.1002/qj.599, 2010.
van der Linden, R., Fink, A. H., and Redl, R.: Satellite-based climatology of
low-level continental clouds in southern West Africa during the summer
monsoon season, J. Geophys. Res., 120, 1186–1201,
https://doi.org/10.1002/2014JD022614, 2015.
Viana, S., Terradellas, E., and Yagüe, C.: Analysis of gravity waves
generated at the top of a drainage flow, J. Atmos. Sci., 67, 3949–3966,
https://doi.org/10.1175/2010JAS3508.1, 2010.
Wang, J. H. and Rossow, W. B.: Determination of cloud structure from
upper-air observations, J. Appl. Meteor., 34, 2243–2258,
https://doi.org/10.1175/1520-0450(1995)034<2243:DOCVSF>2.0.CO;2,
1995.
Wieser, A., Adler, B., and Deny, B.: DACCIWA field campaign, Savè
super-site, Thermodynamic data sets; SEDOO OMP, https://doi.org/10.6096/DACCIWA.1659,
2016.
Yamartino, R. J.: A comparison of several “Single-Pass” Estimators of the
Standard Deviation of Wind Direction, J. Climate Appl. Meteor., 23,
1362–1366,
https://doi.org/10.1175/1520-0450(1984)023<1362:ACOSPE>2.0.CO;2,
1984.
Short summary
Extended low-level stratus clouds (LLC) form frequently in southern West Africa during the night-time and persist long into the next day. They affect the radiation budget, atmospheric boundary-layer (BL) evolution and regional climate. The relevant processes governing their formation and dissolution are not fully understood. Thus, a field campaign was conducted in summer 2016, which provided a comprehensive data set for process studies, specifically of interactions between LLC and BL conditions.
Extended low-level stratus clouds (LLC) form frequently in southern West Africa during the...
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