Articles | Volume 22, issue 17
https://doi.org/10.5194/acp-22-11867-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-22-11867-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
14 Sep 2022
Research article |
| 14 Sep 2022
| 14 Sep 2022
Quantifying vertical wind shear effects in shallow cumulus clouds over Amazonia
Micael Amore Cecchini
CORRESPONDING AUTHOR
Institute of Astronomy, Geophysics and Atmospheric Sciences,
University of São Paulo, São Paulo, Brazil
Department of Atmospheric Science, Colorado State University, Fort
Collins, USA
Marco de Bruine
Institute for Marine and Atmospheric Research, Utrecht University,
Utrecht, the Netherlands
Jordi Vilà-Guerau de Arellano
Meteorology and Air Quality Section, Wageningen University,
Wageningen, the Netherlands
Atmospheric Chemistry Department, Max Planck Institute for Chemistry,
Mainz, Germany
Paulo Artaxo
Institute of Physics, University of São Paulo, São Paulo,
Brazil
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Composite analysis of gas concentration before and after rainfall, during the day and night, gives insight into the complex relationship between trace gas variability and precipitation. The analysis helps us to understand the sources and sinks of trace gases within a forest ecosystem. It elucidates processes that are not discernible under undisturbed conditions and contributes to a deeper understanding of the trace gas life cycle and its intricate interactions with cloud dynamics in the Amazon.
Marco A. Franco, Rafael Valiati, Bruna A. Holanda, Bruno B. Meller, Leslie A. Kremper, Luciana V. Rizzo, Samara Carbone, Fernando G. Morais, Janaína P. Nascimento, Meinrat O. Andreae, Micael A. Cecchini, Luiz A. T. Machado, Milena Ponczek, Ulrich Pöschl, David Walter, Christopher Pöhlker, and Paulo Artaxo
Atmos. Chem. Phys., 24, 8751–8770, https://doi.org/10.5194/acp-24-8751-2024, https://doi.org/10.5194/acp-24-8751-2024, 2024
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The Amazon wet-season atmosphere was studied at the Amazon Tall Tower Observatory site, revealing vertical variations (between 60 and 325 m) in natural aerosols. Daytime mixing contrasted with nighttime stratification, with distinct rain-induced changes in aerosol populations. Notably, optical property recovery at higher levels was faster, while near-canopy aerosols showed higher scattering efficiency. These findings enhance our understanding of aerosol impacts on climate dynamics.
Kim A. P. Faassen, Jordi Vilà-Guerau de Arellano, Raquel González-Armas, Bert G. Heusinkveld, Ivan Mammarella, Wouter Peters, and Ingrid T. Luijkx
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Amazonian aerosols and their interactions with precipitation were studied by understanding them in a 3D space based on three parameters that characterize the concentration and size distribution of aerosols. The results showed characteristic arrangements regarding seasonal and diurnal cycles, as well as when interacting with precipitation. The use of this 3D space appears to be a promising tool for aerosol population analysis and for model validation and parameterization.
Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankarararman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Hannele Hakola, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbiginiw Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gomez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal Weagle, and Xi Zhao
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-1, https://doi.org/10.5194/essd-2024-1, 2024
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Aerosol particles can interact with incoming solar radiation and outgoing long wave radiation, change cloud properties, affect photochemistry, impact surface air quality, and when deposited impact surface albedo of snow and ice, and modulate carbon dioxide uptake by the land and ocean. Here we present a new compilation of aerosol observations including composition, a methodology for comparing the datasets to model output, and show the implications of these results using one model.
Ruben B. Schulte, Jordi Vilà-Guerau de Arellano, Susanna Rutledge-Jonker, Shelley van der Graaf, Jun Zhang, and Margreet C. van Zanten
Biogeosciences, 21, 557–574, https://doi.org/10.5194/bg-21-557-2024, https://doi.org/10.5194/bg-21-557-2024, 2024
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We analyzed measurements with the aim of finding relations between the surface atmosphere exchange of NH3 and the CO2 uptake and transpiration by vegetation. We found a high correlation of daytime NH3 emissions with both latent heat flux and photosynthetically active radiation. Very few simultaneous measurements of NH3, CO2 fluxes and meteorological variables exist at sub-diurnal timescales. This study paves the way to finding more robust relations between the NH3 exchange flux and CO2 uptake.
Robbert P. J. Moonen, Getachew A. Adnew, Oscar K. Hartogensis, Jordi Vilà-Guerau de Arellano, David J. Bonell Fontas, and Thomas Röckmann
Atmos. Meas. Tech., 16, 5787–5810, https://doi.org/10.5194/amt-16-5787-2023, https://doi.org/10.5194/amt-16-5787-2023, 2023
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Isotope fluxes allow for net ecosystem gas exchange fluxes to be partitioned into sub-components like plant assimilation, respiration and transpiration, which can help us better understand the environmental drivers of each partial flux. We share the results of a field campaign isotope fluxes were derived using a combination of laser spectroscopy and eddy covariance. We found lag times and high frequency signal loss in the isotope fluxes we derived and present methods to correct for both.
Xurong Wang, Qiaoqiao Wang, Maria Prass, Christopher Pöhlker, Daniel Moran-Zuloaga, Paulo Artaxo, Jianwei Gu, Ning Yang, Xiajie Yang, Jiangchuan Tao, Juan Hong, Nan Ma, Yafang Cheng, Hang Su, and Meinrat O. Andreae
Atmos. Chem. Phys., 23, 9993–10014, https://doi.org/10.5194/acp-23-9993-2023, https://doi.org/10.5194/acp-23-9993-2023, 2023
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In this work, with an optimized particle mass size distribution, we captured observed aerosol optical depth (AOD) and coarse aerosol concentrations over source and/or receptor regions well, demonstrating good performance in simulating export of African dust toward the Amazon Basin. In addition to factors controlling the transatlantic transport of African dust, the study investigated the impact of African dust over the Amazon Basin, including the nutrient inputs associated with dust deposition.
Kim A. P. Faassen, Linh N. T. Nguyen, Eadin R. Broekema, Bert A. M. Kers, Ivan Mammarella, Timo Vesala, Penelope A. Pickers, Andrew C. Manning, Jordi Vilà-Guerau de Arellano, Harro A. J. Meijer, Wouter Peters, and Ingrid T. Luijkx
Atmos. Chem. Phys., 23, 851–876, https://doi.org/10.5194/acp-23-851-2023, https://doi.org/10.5194/acp-23-851-2023, 2023
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The exchange ratio (ER) between atmospheric O2 and CO2 provides a useful tracer for separately estimating photosynthesis and respiration processes in the forest carbon balance. This is highly relevant to better understand the expected biosphere sink, which determines future atmospheric CO2 levels. We therefore measured O2, CO2, and their ER above a boreal forest in Finland and investigated their diurnal behaviour for a representative day, and we show the most suitable way to determine the ER.
Wiebke Scholz, Jiali Shen, Diego Aliaga, Cheng Wu, Samara Carbone, Isabel Moreno, Qiaozhi Zha, Wei Huang, Liine Heikkinen, Jean Luc Jaffrezo, Gaelle Uzu, Eva Partoll, Markus Leiminger, Fernando Velarde, Paolo Laj, Patrick Ginot, Paolo Artaxo, Alfred Wiedensohler, Markku Kulmala, Claudia Mohr, Marcos Andrade, Victoria Sinclair, Federico Bianchi, and Armin Hansel
Atmos. Chem. Phys., 23, 895–920, https://doi.org/10.5194/acp-23-895-2023, https://doi.org/10.5194/acp-23-895-2023, 2023
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Dimethyl sulfide (DMS), emitted from the ocean, is the most abundant biogenic sulfur emission into the atmosphere. OH radicals, among others, can oxidize DMS to sulfuric and methanesulfonic acid, which are relevant for aerosol formation. We quantified DMS and nearly all DMS oxidation products with novel mass spectrometric instruments for gas and particle phase at the high mountain station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes in free tropospheric air after long-range transport.
Yunfan Liu, Hang Su, Siwen Wang, Chao Wei, Wei Tao, Mira L. Pöhlker, Christopher Pöhlker, Bruna A. Holanda, Ovid O. Krüger, Thorsten Hoffmann, Manfred Wendisch, Paulo Artaxo, Ulrich Pöschl, Meinrat O. Andreae, and Yafang Cheng
Atmos. Chem. Phys., 23, 251–272, https://doi.org/10.5194/acp-23-251-2023, https://doi.org/10.5194/acp-23-251-2023, 2023
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The origins of the abundant cloud condensation nuclei (CCN) in the upper troposphere (UT) of the Amazon remain unclear. With model developments of new secondary organic aerosol schemes and constrained by observation, we show that strong aerosol nucleation and condensation in the UT is triggered by biogenic organics, and organic condensation is key for UT CCN production. This UT CCN-producing mechanism may prevail over broader vegetation canopies and deserves emphasis in aerosol–climate feedback.
Felipe Lobos-Roco, Oscar Hartogensis, Francisco Suárez, Ariadna Huerta-Viso, Imme Benedict, Alberto de la Fuente, and Jordi Vilà-Guerau de Arellano
Hydrol. Earth Syst. Sci., 26, 3709–3729, https://doi.org/10.5194/hess-26-3709-2022, https://doi.org/10.5194/hess-26-3709-2022, 2022
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This research brings a multi-scale temporal analysis of evaporation in a saline lake of the Atacama Desert. Our findings reveal that evaporation is controlled differently depending on the timescale. Evaporation is controlled sub-diurnally by wind speed, regulated seasonally by radiation and modulated interannually by ENSO. Our research extends our understanding of evaporation, contributing to improving the climate change assessment and efficiency of water management in arid regions.
Ruben B. Schulte, Margreet C. van Zanten, Bart J. H. van Stratum, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 22, 8241–8257, https://doi.org/10.5194/acp-22-8241-2022, https://doi.org/10.5194/acp-22-8241-2022, 2022
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We present a fine-scale simulation framework, utilizing large-eddy simulations, to assess NH3 measurements influenced by boundary-layer dynamics and turbulent dispersion of a nearby emission source. The minimum required distance from an emission source differs for concentration and flux measurements, from 0.5–3.0 km and 0.75–4.5 km, respectively. The simulation framework presented here proves to be a powerful and versatile tool for future NH3 research at high spatio-temporal resolutions.
Marco A. Franco, Florian Ditas, Leslie A. Kremper, Luiz A. T. Machado, Meinrat O. Andreae, Alessandro Araújo, Henrique M. J. Barbosa, Joel F. de Brito, Samara Carbone, Bruna A. Holanda, Fernando G. Morais, Janaína P. Nascimento, Mira L. Pöhlker, Luciana V. Rizzo, Marta Sá, Jorge Saturno, David Walter, Stefan Wolff, Ulrich Pöschl, Paulo Artaxo, and Christopher Pöhlker
Atmos. Chem. Phys., 22, 3469–3492, https://doi.org/10.5194/acp-22-3469-2022, https://doi.org/10.5194/acp-22-3469-2022, 2022
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In Central Amazonia, new particle formation in the planetary boundary layer is rare. Instead, there is the appearance of sub-50 nm aerosols with diameters larger than about 20 nm that eventually grow to cloud condensation nuclei size range. Here, 254 growth events were characterized which have higher predominance in the wet season. About 70 % of them showed direct relation to convective downdrafts, while 30 % occurred partly under clear-sky conditions, evidencing still unknown particle sources.
Luiz A. T. Machado, Marco A. Franco, Leslie A. Kremper, Florian Ditas, Meinrat O. Andreae, Paulo Artaxo, Micael A. Cecchini, Bruna A. Holanda, Mira L. Pöhlker, Ivan Saraiva, Stefan Wolff, Ulrich Pöschl, and Christopher Pöhlker
Atmos. Chem. Phys., 21, 18065–18086, https://doi.org/10.5194/acp-21-18065-2021, https://doi.org/10.5194/acp-21-18065-2021, 2021
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Several studies evaluate aerosol–cloud interactions, but only a few attempted to describe how clouds modify aerosol properties. This study evaluates the effect of weather events on the particle size distribution at the ATTO, combining remote sensing and in situ data. Ultrafine, Aitken and accumulation particles modes have different behaviors for the diurnal cycle and for rainfall events. This study opens up new scientific questions that need to be pursued in detail in new field campaigns.
Diego Aliaga, Victoria A. Sinclair, Marcos Andrade, Paulo Artaxo, Samara Carbone, Evgeny Kadantsev, Paolo Laj, Alfred Wiedensohler, Radovan Krejci, and Federico Bianchi
Atmos. Chem. Phys., 21, 16453–16477, https://doi.org/10.5194/acp-21-16453-2021, https://doi.org/10.5194/acp-21-16453-2021, 2021
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We investigate the origin of air masses sampled at Mount Chacaltaya, Bolivia. Three-quarters of the measured air has not been influenced by the surface in the previous 4 d. However, it is rare that, at any given time, the sampled air has not been influenced at all by the surface, and often the sampled air has multiple origins. The influence of the surface is more prevalent during day than night. Furthermore, during the 6-month study, one-third of the air masses originated from Amazonia.
Maria Prass, Meinrat O. Andreae, Alessandro C. de Araùjo, Paulo Artaxo, Florian Ditas, Wolfgang Elbert, Jan-David Förster, Marco Aurélio Franco, Isabella Hrabe de Angelis, Jürgen Kesselmeier, Thomas Klimach, Leslie Ann Kremper, Eckhard Thines, David Walter, Jens Weber, Bettina Weber, Bernhard M. Fuchs, Ulrich Pöschl, and Christopher Pöhlker
Biogeosciences, 18, 4873–4887, https://doi.org/10.5194/bg-18-4873-2021, https://doi.org/10.5194/bg-18-4873-2021, 2021
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Bioaerosols in the atmosphere over the Amazon rain forest were analyzed by molecular biological staining and microscopy. Eukaryotic, bacterial, and archaeal aerosols were quantified in time series and altitude profiles which exhibited clear differences in number concentrations and vertical distributions. Our results provide insights into the sources and dispersion of different Amazonian bioaerosol types as a basis for a better understanding of biosphere–atmosphere interactions.
James Weber, Scott Archer-Nicholls, Nathan Luke Abraham, Youngsub M. Shin, Thomas J. Bannan, Carl J. Percival, Asan Bacak, Paulo Artaxo, Michael Jenkin, M. Anwar H. Khan, Dudley E. Shallcross, Rebecca H. Schwantes, Jonathan Williams, and Alex T. Archibald
Geosci. Model Dev., 14, 5239–5268, https://doi.org/10.5194/gmd-14-5239-2021, https://doi.org/10.5194/gmd-14-5239-2021, 2021
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The new mechanism CRI-Strat 2 features state-of-the-art isoprene chemistry not previously available in UKCA and improves UKCA's ability to reproduce observed concentrations of isoprene, monoterpenes, and OH in tropical regions. The enhanced ability to model isoprene, the most widely emitted non-methane volatile organic compound (VOC), will allow understanding of how isoprene and other biogenic VOCs affect atmospheric composition and, through biosphere–atmosphere feedbacks, climate change.
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.
Felipe Lobos-Roco, Oscar Hartogensis, Jordi Vilà-Guerau de Arellano, Alberto de la Fuente, Ricardo Muñoz, José Rutllant, and Francisco Suárez
Atmos. Chem. Phys., 21, 9125–9150, https://doi.org/10.5194/acp-21-9125-2021, https://doi.org/10.5194/acp-21-9125-2021, 2021
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We investigate the influence of regional atmospheric circulation on the evaporation of a saline lake in the Altiplano region of the Atacama Desert through a field experiment and regional modeling. Our results show that evaporation is controlled by two regimes: (1) in the morning by local conditions with low evaporation rates and low wind speed and (2) in the afternoon with high evaporation rates and high wind speed. Afternoon winds are connected to the regional Pacific Ocean–Andes flow.
Djacinto Monteiro dos Santos, Luciana Varanda Rizzo, Samara Carbone, Patrick Schlag, and Paulo Artaxo
Atmos. Chem. Phys., 21, 8761–8773, https://doi.org/10.5194/acp-21-8761-2021, https://doi.org/10.5194/acp-21-8761-2021, 2021
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The metropolitan area of São Paulo (MASP), with very extensive biofuel use, has unique atmospheric chemistry among world megacities. In this study, we examine the complex relationships between aerosol chemical composition and particle size distribution. Our findings provide a better understanding of the dynamics of the physicochemical properties of submicron particles and highlight the key role of secondary organic aerosol formation in the pollution levels in São Paulo.
Robbie Ramsay, Chiara F. Di Marco, Mathew R. Heal, Matthias Sörgel, Paulo Artaxo, Meinrat O. Andreae, and Eiko Nemitz
Biogeosciences, 18, 2809–2825, https://doi.org/10.5194/bg-18-2809-2021, https://doi.org/10.5194/bg-18-2809-2021, 2021
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The exchange of the gas ammonia between the atmosphere and the surface is an important biogeochemical process, but little is known of this exchange for certain ecosystems, such as the Amazon rainforest. This study took measurements of ammonia exchange over an Amazon rainforest site and subsequently modelled the observed deposition and emission patterns. We observed emissions of ammonia from the rainforest, which can be simulated accurately by using a canopy resistance modelling approach.
Janaína P. Nascimento, Megan M. Bela, Bruno B. Meller, Alessandro L. Banducci, Luciana V. Rizzo, Angel Liduvino Vara-Vela, Henrique M. J. Barbosa, Helber Gomes, Sameh A. A. Rafee, Marco A. Franco, Samara Carbone, Glauber G. Cirino, Rodrigo A. F. Souza, Stuart A. McKeen, and Paulo Artaxo
Atmos. Chem. Phys., 21, 6755–6779, https://doi.org/10.5194/acp-21-6755-2021, https://doi.org/10.5194/acp-21-6755-2021, 2021
Guilherme F. Camarinha-Neto, Julia C. P. Cohen, Cléo Q. Dias-Júnior, Matthias Sörgel, José Henrique Cattanio, Alessandro Araújo, Stefan Wolff, Paulo A. F. Kuhn, Rodrigo A. F. Souza, Luciana V. Rizzo, and Paulo Artaxo
Atmos. Chem. Phys., 21, 339–356, https://doi.org/10.5194/acp-21-339-2021, https://doi.org/10.5194/acp-21-339-2021, 2021
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It was observed that friagem phenomena (incursion of cold waves from the high latitudes of the Southern Hemisphere to the Amazon region), very common in the dry season of the Amazon region, produced significant changes in microclimate and atmospheric chemistry. Moreover, the effects of the friagem change the surface O3 and CO2 mixing ratios and therefore interfere deeply in the microclimatic conditions and the chemical composition of the atmosphere above the rainforest.
Jann Schrod, Erik S. Thomson, Daniel Weber, Jens Kossmann, Christopher Pöhlker, Jorge Saturno, Florian Ditas, Paulo Artaxo, Valérie Clouard, Jean-Marie Saurel, Martin Ebert, Joachim Curtius, and Heinz G. Bingemer
Atmos. Chem. Phys., 20, 15983–16006, https://doi.org/10.5194/acp-20-15983-2020, https://doi.org/10.5194/acp-20-15983-2020, 2020
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Long-term ice-nucleating particle (INP) data are presented from four semi-pristine sites located in the Amazon, the Caribbean, Germany and the Arctic. Average INP concentrations did not differ by orders of magnitude between the sites. For all sites short-term variability dominated the time series, which lacked clear trends and seasonalities. Common drivers to explain the INP levels and their variations could not be identified, illustrating the complex nature of heterogeneous ice nucleation.
Robbie Ramsay, Chiara F. Di Marco, Matthias Sörgel, Mathew R. Heal, Samara Carbone, Paulo Artaxo, Alessandro C. de Araùjo, Marta Sá, Christopher Pöhlker, Jost Lavric, Meinrat O. Andreae, and Eiko Nemitz
Atmos. Chem. Phys., 20, 15551–15584, https://doi.org/10.5194/acp-20-15551-2020, https://doi.org/10.5194/acp-20-15551-2020, 2020
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The Amazon rainforest is a unique
laboratoryto study the processes which govern the exchange of gases and aerosols to and from the atmosphere. This study investigated these processes by measuring the atmospheric concentrations of trace gases and particles at the Amazon Tall Tower Observatory. We found that the long-range transport of pollutants can affect the atmospheric composition above the Amazon rainforest and that the gases ammonia and nitrous acid can be emitted from the rainforest.
Lixia Liu, Yafang Cheng, Siwen Wang, Chao Wei, Mira L. Pöhlker, Christopher Pöhlker, Paulo Artaxo, Manish Shrivastava, Meinrat O. Andreae, Ulrich Pöschl, and Hang Su
Atmos. Chem. Phys., 20, 13283–13301, https://doi.org/10.5194/acp-20-13283-2020, https://doi.org/10.5194/acp-20-13283-2020, 2020
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This modeling paper reveals how aerosol–cloud interactions (ACIs) and aerosol–radiation interactions (ARIs) induced by biomass burning (BB) aerosols act oppositely on radiation, cloud, and precipitation in the Amazon during the dry season. The varying relative significance of ACIs and ARIs with BB aerosol concentration leads to a nonlinear dependence of the total climate response on BB aerosol loading and features the growing importance of ARIs at high aerosol loading.
Kouji Adachi, Naga Oshima, Zhaoheng Gong, Suzane de Sá, Adam P. Bateman, Scot T. Martin, Joel F. de Brito, Paulo Artaxo, Glauber G. Cirino, Arthur J. Sedlacek III, and Peter R. Buseck
Atmos. Chem. Phys., 20, 11923–11939, https://doi.org/10.5194/acp-20-11923-2020, https://doi.org/10.5194/acp-20-11923-2020, 2020
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Occurrences, size distributions, and number fractions of individual aerosol particles from the Amazon basin during the GoAmazon2014/5 campaign were analyzed using transmission electron microscopy. Aerosol particles from natural sources (e.g., mineral dust, primary biological aerosols, and sea salts) during the wet season originated from the Amazon forest and long-range transports (the Saharan desert and the Atlantic Ocean). They commonly mix at an individual particle scale during transport.
Jordi Vilà-Guerau de Arellano, Patrizia Ney, Oscar Hartogensis, Hugo de Boer, Kevin van Diepen, Dzhaner Emin, Geiske de Groot, Anne Klosterhalfen, Matthias Langensiepen, Maria Matveeva, Gabriela Miranda-García, Arnold F. Moene, Uwe Rascher, Thomas Röckmann, Getachew Adnew, Nicolas Brüggemann, Youri Rothfuss, and Alexander Graf
Biogeosciences, 17, 4375–4404, https://doi.org/10.5194/bg-17-4375-2020, https://doi.org/10.5194/bg-17-4375-2020, 2020
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The CloudRoots field experiment has obtained an open comprehensive observational data set that includes soil, plant, and atmospheric variables to investigate the interactions between a heterogeneous land surface and its overlying atmospheric boundary layer, including the rapid perturbations of clouds in evapotranspiration. Our findings demonstrate that in order to understand and represent diurnal variability, we need to measure and model processes from the leaf to the landscape scales.
Camille Mouchel-Vallon, Julia Lee-Taylor, Alma Hodzic, Paulo Artaxo, Bernard Aumont, Marie Camredon, David Gurarie, Jose-Luis Jimenez, Donald H. Lenschow, Scot T. Martin, Janaina Nascimento, John J. Orlando, Brett B. Palm, John E. Shilling, Manish Shrivastava, and Sasha Madronich
Atmos. Chem. Phys., 20, 5995–6014, https://doi.org/10.5194/acp-20-5995-2020, https://doi.org/10.5194/acp-20-5995-2020, 2020
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The GoAmazon 2014/5 field campaign took place near the city of Manaus, Brazil, isolated in the Amazon rainforest, to study the impacts of urban pollution on natural air masses. We simulated this campaign with an extremely detailed organic chemistry model to understand how the city would affect the growth and composition of natural aerosol particles. Discrepancies between the model and the measurements indicate that the chemistry of naturally emitted organic compounds is still poorly understood.
William T. Morgan, James D. Allan, Stéphane Bauguitte, Eoghan Darbyshire, Michael J. Flynn, James Lee, Dantong Liu, Ben Johnson, Jim Haywood, Karla M. Longo, Paulo E. Artaxo, and Hugh Coe
Atmos. Chem. Phys., 20, 5309–5326, https://doi.org/10.5194/acp-20-5309-2020, https://doi.org/10.5194/acp-20-5309-2020, 2020
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We flew a large atmospheric research aircraft across a number of different environments in the Amazon basin during the 2012 biomass burning season. Smoke from fires builds up and has a significant impact on weather, climate, health and natural ecosystems. Our goal was to quantify changes in the properties of the smoke emitted by fires as it is transported through the atmosphere. We found that the major control on the properties of the smoke was due to differences in the fires themselves.
Bruna A. Holanda, Mira L. Pöhlker, David Walter, Jorge Saturno, Matthias Sörgel, Jeannine Ditas, Florian Ditas, Christiane Schulz, Marco Aurélio Franco, Qiaoqiao Wang, Tobias Donth, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Ramon Braga, Joel Brito, Yafang Cheng, Maximilian Dollner, Johannes W. Kaiser, Thomas Klimach, Christoph Knote, Ovid O. Krüger, Daniel Fütterer, Jošt V. Lavrič, Nan Ma, Luiz A. T. Machado, Jing Ming, Fernando G. Morais, Hauke Paulsen, Daniel Sauer, Hans Schlager, Johannes Schneider, Hang Su, Bernadett Weinzierl, Adrian Walser, Manfred Wendisch, Helmut Ziereis, Martin Zöger, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Chem. Phys., 20, 4757–4785, https://doi.org/10.5194/acp-20-4757-2020, https://doi.org/10.5194/acp-20-4757-2020, 2020
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Biomass burning smoke from African savanna and grassland is transported across the South Atlantic Ocean in defined layers within the free troposphere. The combination of in situ aircraft and ground-based measurements aided by satellite observations showed that these layers are transported into the Amazon Basin during the early dry season. The influx of aged smoke, enriched in black carbon and cloud condensation nuclei, has important implications for the Amazonian aerosol and cloud cycling.
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.
Fan Mei, Jian Wang, Jennifer M. Comstock, Ralf Weigel, Martina Krämer, Christoph Mahnke, John E. Shilling, Johannes Schneider, Christiane Schulz, Charles N. Long, Manfred Wendisch, Luiz A. T. Machado, Beat Schmid, Trismono Krisna, Mikhail Pekour, John Hubbe, Andreas Giez, Bernadett Weinzierl, Martin Zoeger, Mira L. Pöhlker, Hans Schlager, Micael A. Cecchini, Meinrat O. Andreae, Scot T. Martin, Suzane S. de Sá, Jiwen Fan, Jason Tomlinson, Stephen Springston, Ulrich Pöschl, Paulo Artaxo, Christopher Pöhlker, Thomas Klimach, Andreas Minikin, Armin Afchine, and Stephan Borrmann
Atmos. Meas. Tech., 13, 661–684, https://doi.org/10.5194/amt-13-661-2020, https://doi.org/10.5194/amt-13-661-2020, 2020
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In 2014, the US DOE G1 aircraft and the German HALO aircraft overflew the Amazon basin to study how aerosols influence cloud cycles under a clean condition and around a tropical megacity. This paper describes how to meaningfully compare similar measurements from two research aircraft and identify the potential measurement issue. We also discuss the uncertainty range for each measurement for further usage in model evaluation and satellite data validation.
Nina Löbs, Cybelli G. G. Barbosa, Sebastian Brill, David Walter, Florian Ditas, Marta de Oliveira Sá, Alessandro C. de Araújo, Leonardo R. de Oliveira, Ricardo H. M. Godoi, Stefan Wolff, Meike Piepenbring, Jürgen Kesselmeier, Paulo Artaxo, Meinrat O. Andreae, Ulrich Pöschl, Christopher Pöhlker, and Bettina Weber
Atmos. Meas. Tech., 13, 153–164, https://doi.org/10.5194/amt-13-153-2020, https://doi.org/10.5194/amt-13-153-2020, 2020
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Bioaerosols are considered to play a relevant role in atmospheric processes, but their sources, properties, and spatiotemporal distribution in the atmosphere are not yet well characterized. Measurement data on the release of fungal spores under natural conditions are also sparse. Here, we present an experimental approach to analyze and quantify the spore release from fungi and other spore-producing organisms under natural and laboratory conditions.
Marco de Bruine, Maarten Krol, Jordi Vilà-Guerau de Arellano, and Thomas Röckmann
Geosci. Model Dev., 12, 5177–5196, https://doi.org/10.5194/gmd-12-5177-2019, https://doi.org/10.5194/gmd-12-5177-2019, 2019
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An aerosol scheme with multiple aerosol species is introduced in the Dutch Atmospheric Large-Eddy Simulation model (DALES) and focused to simulate the feedback of aerosol–cloud interaction (ACI) on the aerosol population. Cloud aerosol processing is found to be sensitive to the numerical method, while removal by precipitation is more stable. How ACI increases or decreases the mean aerosol size depends on the balance between the evaporation of clouds/rain and ultimate removal by precipitation.
Hayley S. Glicker, Michael J. Lawler, John Ortega, Suzane S. de Sá, Scot T. Martin, Paulo Artaxo, Oscar Vega Bustillos, Rodrigo de Souza, Julio Tota, Annmarie Carlton, and James N. Smith
Atmos. Chem. Phys., 19, 13053–13066, https://doi.org/10.5194/acp-19-13053-2019, https://doi.org/10.5194/acp-19-13053-2019, 2019
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An understanding of the chemical composition of the smallest particles in the air over the Amazon Basin provides insights into the natural and human-caused influences on particle production in this sensitive region. We present measurements of the composition of sub-100 nm diameter particles performed during the wet season and identify unique constituents that point to both natural and human-caused sources and processes.
Pierre Gentine, Adam Massmann, Benjamin R. Lintner, Sayed Hamed Alemohammad, Rong Fu, Julia K. Green, Daniel Kennedy, and Jordi Vilà-Guerau de Arellano
Hydrol. Earth Syst. Sci., 23, 4171–4197, https://doi.org/10.5194/hess-23-4171-2019, https://doi.org/10.5194/hess-23-4171-2019, 2019
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Land–atmosphere interactions are key for the exchange of water, energy, and carbon dioxide, especially in the tropics. We here review some of the recent findings on land–atmosphere interactions in the tropics and where we see potential challenges and paths forward.
Carly L. Reddington, William T. Morgan, Eoghan Darbyshire, Joel Brito, Hugh Coe, Paulo Artaxo, Catherine E. Scott, John Marsham, and Dominick V. Spracklen
Atmos. Chem. Phys., 19, 9125–9152, https://doi.org/10.5194/acp-19-9125-2019, https://doi.org/10.5194/acp-19-9125-2019, 2019
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We use an aerosol model and observations to explore model representation of aerosol emissions from fires in the Amazon. We find that observed aerosol concentrations are captured by the model over deforestation fires in the western Amazon but underestimated over savanna fires in the Cerrado environment. The model underestimates observed aerosol optical depth (AOD) even when the observed aerosol vertical profile is reproduced. We suggest this may be due to uncertainties in the AOD calculation.
Christopher Pöhlker, David Walter, Hauke Paulsen, Tobias Könemann, Emilio Rodríguez-Caballero, Daniel Moran-Zuloaga, Joel Brito, Samara Carbone, Céline Degrendele, Viviane R. Després, Florian Ditas, Bruna A. Holanda, Johannes W. Kaiser, Gerhard Lammel, Jošt V. Lavrič, Jing Ming, Daniel Pickersgill, Mira L. Pöhlker, Maria Praß, Nina Löbs, Jorge Saturno, Matthias Sörgel, Qiaoqiao Wang, Bettina Weber, Stefan Wolff, Paulo Artaxo, Ulrich Pöschl, and Meinrat O. Andreae
Atmos. Chem. Phys., 19, 8425–8470, https://doi.org/10.5194/acp-19-8425-2019, https://doi.org/10.5194/acp-19-8425-2019, 2019
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The Amazon Tall Tower Observatory (ATTO) has been established to monitor the rain forest's biosphere–atmosphere exchange, which experiences the combined pressures from human-made deforestation and progressing climate change. This work is meant to be a reference study, which characterizes various geospatial properties of the ATTO footprint region and shows how the human-made transformation of Amazonia may impact future atmospheric observations at ATTO.
Suzane S. de Sá, Luciana V. Rizzo, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Joel Brito, Samara Carbone, Yingjun J. Liu, Arthur Sedlacek, Stephen Springston, Allen H. Goldstein, Henrique M. J. Barbosa, M. Lizabeth Alexander, Paulo Artaxo, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 19, 7973–8001, https://doi.org/10.5194/acp-19-7973-2019, https://doi.org/10.5194/acp-19-7973-2019, 2019
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This study investigates the impacts of urban and fire emissions on the concentration, composition, and optical properties of submicron particulate matter (PM1) in central Amazonia during the dry season. Biomass-burning and urban emissions appeared to contribute at least 80 % of brown carbon absorption while accounting for 30 % to 40 % of the organic PM1 mass concentration. Only a fraction of the 9-fold increase in mass concentration relative to the wet season was due to biomass burning.
Lianet Hernández Pardo, Luiz Augusto Toledo Machado, Micael Amore Cecchini, and Madeleine Sánchez Gácita
Atmos. Chem. Phys., 19, 7839–7857, https://doi.org/10.5194/acp-19-7839-2019, https://doi.org/10.5194/acp-19-7839-2019, 2019
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This work analyzes the effects of changes in the environmental aerosol population on Amazonian clouds. The results confirm that the clouds can be very sensitive to changes in the aerosol properties, but the relative importance of each property is variable and depends on the values of the other aerosol characteristics, especially aerosol size. This is controlled by the degree to which the cloud mixes with the surrounding air and by the efficiency with which aerosols are consumed by droplets.
Hendrik Wouters, Irina Y. Petrova, Chiel C. van Heerwaarden, Jordi Vilà-Guerau de Arellano, Adriaan J. Teuling, Vicky Meulenberg, Joseph A. Santanello, and Diego G. Miralles
Geosci. Model Dev., 12, 2139–2153, https://doi.org/10.5194/gmd-12-2139-2019, https://doi.org/10.5194/gmd-12-2139-2019, 2019
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The free software CLASS4GL (http://class4gl.eu) is designed to investigate the dynamic atmospheric boundary layer (ABL) with weather balloons. It mines observational data from global radio soundings, satellite and reanalysis data from the last 40 years to constrain and initialize an ABL model and automizes multiple experiments in parallel. CLASS4GL aims at fostering a better understanding of land–atmosphere feedbacks and the drivers of extreme weather.
Eoghan Darbyshire, William T. Morgan, James D. Allan, Dantong Liu, Michael J. Flynn, James R. Dorsey, Sebastian J. O'Shea, Douglas Lowe, Kate Szpek, Franco Marenco, Ben T. Johnson, Stephane Bauguitte, Jim M. Haywood, Joel F. Brito, Paulo Artaxo, Karla M. Longo, and Hugh Coe
Atmos. Chem. Phys., 19, 5771–5790, https://doi.org/10.5194/acp-19-5771-2019, https://doi.org/10.5194/acp-19-5771-2019, 2019
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A novel analysis of aerosol and gas-phase vertical profiles shows a marked regional pollution contrast: composition is driven by the fire regime and vertical distribution is driven by thermodynamics. These drivers ought to be well represented in simulations to ensure realistic prediction of climate and air quality impacts. The BC : CO ratio in haze and plumes increases with altitude – long-range transport or fire stage coupled to plume dynamics may be responsible. Further enquiry is advocated.
Jon Ander Arrillaga, Carlos Yagüe, Carlos Román-Cascón, Mariano Sastre, Maria Antonia Jiménez, Gregorio Maqueda, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 19, 4615–4635, https://doi.org/10.5194/acp-19-4615-2019, https://doi.org/10.5194/acp-19-4615-2019, 2019
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Thermally driven downslope winds develop in mountainous areas under a weak large-scale forcing and clear skies. In this work, we find that their onset time and intensity are closely connected with both the large-scale wind and soil moisture. We also show how the distinct downslope intensities shape the turbulent and thermal features of the nocturnal atmosphere. The analysis concludes that the downslope–turbulence interaction and the horizontal transport explain the important CO2 variability.
Florent F. Malavelle, Jim M. Haywood, Lina M. Mercado, Gerd A. Folberth, Nicolas Bellouin, Stephen Sitch, and Paulo Artaxo
Atmos. Chem. Phys., 19, 1301–1326, https://doi.org/10.5194/acp-19-1301-2019, https://doi.org/10.5194/acp-19-1301-2019, 2019
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Diffuse light can increase the efficiency of vegetation photosynthesis. Diffuse light results from scattering by either clouds or aerosols in the atmosphere. During the dry season biomass burning (BB) on the edges of the Amazon rainforest contributes significantly to the aerosol burden over the entire region. We show that despite a modest effect of change in light conditions, the overall impact of BB aerosols on the vegetation is still important when indirect climate feedbacks are considered.
Juhi Nagori, Ruud H. H. Janssen, Juliane L. Fry, Maarten Krol, Jose L. Jimenez, Weiwei Hu, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 19, 701–729, https://doi.org/10.5194/acp-19-701-2019, https://doi.org/10.5194/acp-19-701-2019, 2019
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Secondary organic aerosol (SOA) is produced through a complex interaction of sunlight, volatile organic compounds emitted from trees, anthropogenic emissions, and atmospheric chemistry. We are able to successfully model the formation and diurnal evolution of SOA using a model that takes into consideration the surface and boundary layer dynamics (1–2 km from the surface) and photochemistry above the southeastern US with data collected during the SOAS campaign to constrain the model.
Christiane Schulz, Johannes Schneider, Bruna Amorim Holanda, Oliver Appel, Anja Costa, Suzane S. de Sá, Volker Dreiling, Daniel Fütterer, Tina Jurkat-Witschas, Thomas Klimach, Christoph Knote, Martina Krämer, Scot T. Martin, Stephan Mertes, Mira L. Pöhlker, Daniel Sauer, Christiane Voigt, Adrian Walser, Bernadett Weinzierl, Helmut Ziereis, Martin Zöger, Meinrat O. Andreae, Paulo Artaxo, Luiz A. T. Machado, Ulrich Pöschl, Manfred Wendisch, and Stephan Borrmann
Atmos. Chem. Phys., 18, 14979–15001, https://doi.org/10.5194/acp-18-14979-2018, https://doi.org/10.5194/acp-18-14979-2018, 2018
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Aerosol chemical composition measurements in the tropical upper troposphere over the Amazon region show that 78 % of the aerosol in the upper troposphere consists of organic matter. Up to 20 % of the organic aerosol can be attributed to isoprene epoxydiol secondary organic aerosol (IEPOX-SOA). Furthermore, organic nitrates were identified, suggesting a connection to the IEPOX-SOA formation.
Daniela Wimmer, Stephany Buenrostro Mazon, Hanna Elina Manninen, Juha Kangasluoma, Alessandro Franchin, Tuomo Nieminen, John Backman, Jian Wang, Chongai Kuang, Radovan Krejci, Joel Brito, Fernando Goncalves Morais, Scot Turnbull Martin, Paulo Artaxo, Markku Kulmala, Veli-Matti Kerminen, and Tuukka Petäjä
Atmos. Chem. Phys., 18, 13245–13264, https://doi.org/10.5194/acp-18-13245-2018, https://doi.org/10.5194/acp-18-13245-2018, 2018
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This work focuses on understanding the production of very small airborne particles in the undisturbed environment of the Amazon basin. Computer models have shown that up to 70 % of these tiny particles are responsible for cloud formation on a global scale. The processes behind the production of these very small particles have been studied intensely recently. Their appearance has been observed almost all over the world. We directly measure sub-3 nm aerosols for the first time in the Amazon basin.
Jorge Saturno, Bruna A. Holanda, Christopher Pöhlker, Florian Ditas, Qiaoqiao Wang, Daniel Moran-Zuloaga, Joel Brito, Samara Carbone, Yafang Cheng, Xuguang Chi, Jeannine Ditas, Thorsten Hoffmann, Isabella Hrabe de Angelis, Tobias Könemann, Jošt V. Lavrič, Nan Ma, Jing Ming, Hauke Paulsen, Mira L. Pöhlker, Luciana V. Rizzo, Patrick Schlag, Hang Su, David Walter, Stefan Wolff, Yuxuan Zhang, Paulo Artaxo, Ulrich Pöschl, and Meinrat O. Andreae
Atmos. Chem. Phys., 18, 12817–12843, https://doi.org/10.5194/acp-18-12817-2018, https://doi.org/10.5194/acp-18-12817-2018, 2018
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Biomass burning emits light-absorbing aerosol particles that warm the atmosphere. One of them is the primarily emitted black carbon, which strongly absorbs radiation in the visible and UV spectral regions. Another one is the so-called brown carbon, a fraction of organic aerosol particles that are able to absorb radiation, especially in the UV spectral region. The contribution of both kinds of aerosol particles to light absorption over the Amazon rainforest is studied in this paper.
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Joel Brito, Samara Carbone, Igor O. Ribeiro, Glauber G. Cirino, Yingjun Liu, Ryan Thalman, Arthur Sedlacek, Aaron Funk, Courtney Schumacher, John E. Shilling, Johannes Schneider, Paulo Artaxo, Allen H. Goldstein, Rodrigo A. F. Souza, Jian Wang, Karena A. McKinney, Henrique Barbosa, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 18, 12185–12206, https://doi.org/10.5194/acp-18-12185-2018, https://doi.org/10.5194/acp-18-12185-2018, 2018
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This study aimed at understanding and quantifying the changes in mass concentration and composition of submicron airborne particulate matter (PM) in Amazonia due to urban pollution. Downwind of Manaus, PM concentrations increased by up to 200 % under polluted compared with background conditions. The observed changes included contributions from both primary and secondary processes. The differences in organic PM composition suggested a shift in the pathways of secondary production with pollution.
John E. Shilling, Mikhail S. Pekour, Edward C. Fortner, Paulo Artaxo, Suzane de Sá, John M. Hubbe, Karla M. Longo, Luiz A. T. Machado, Scot T. Martin, Stephen R. Springston, Jason Tomlinson, and Jian Wang
Atmos. Chem. Phys., 18, 10773–10797, https://doi.org/10.5194/acp-18-10773-2018, https://doi.org/10.5194/acp-18-10773-2018, 2018
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We report aircraft observations of the evolution of organic aerosol in the Manaus urban plume as it ages. We observe dynamic changes in the organic aerosol. The mean carbon oxidation state of the OA increases from −0.6 to −0.45. Hydrocarbon-like organic aerosol (HOA) mass is lost and is balanced out by formation of oxygenated organic aerosol (OOA). Because HOA loss is balanced by OOA formation, we observe little change in the net Δorg / ΔCO values with aging.
Jorge Saturno, Florian Ditas, Marloes Penning de Vries, Bruna A. Holanda, Mira L. Pöhlker, Samara Carbone, David Walter, Nicole Bobrowski, Joel Brito, Xuguang Chi, Alexandra Gutmann, Isabella Hrabe de Angelis, Luiz A. T. Machado, Daniel Moran-Zuloaga, Julian Rüdiger, Johannes Schneider, Christiane Schulz, Qiaoqiao Wang, Manfred Wendisch, Paulo Artaxo, Thomas Wagner, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Chem. Phys., 18, 10391–10405, https://doi.org/10.5194/acp-18-10391-2018, https://doi.org/10.5194/acp-18-10391-2018, 2018
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This study uses satellite observations to track volcanic emissions in eastern Congo and their subsequent transport across the Atlantic Ocean into the Amazon Basin. Aircraft and ground-based observations are used to characterize the influence of volcanogenic aerosol on the chemical and microphysical properties of Amazonian aerosols. Further, this work is an illustrative example of the conditions and dynamics driving the transatlantic transport of African emissions to South America.
Lindsay D. Yee, Gabriel Isaacman-VanWertz, Rebecca A. Wernis, Meng Meng, Ventura Rivera, Nathan M. Kreisberg, Susanne V. Hering, Mads S. Bering, Marianne Glasius, Mary Alice Upshur, Ariana Gray Bé, Regan J. Thomson, Franz M. Geiger, John H. Offenberg, Michael Lewandowski, Ivan Kourtchev, Markus Kalberer, Suzane de Sá, Scot T. Martin, M. Lizabeth Alexander, Brett B. Palm, Weiwei Hu, Pedro Campuzano-Jost, Douglas A. Day, Jose L. Jimenez, Yingjun Liu, Karena A. McKinney, Paulo Artaxo, Juarez Viegas, Antonio Manzi, Maria B. Oliveira, Rodrigo de Souza, Luiz A. T. Machado, Karla Longo, and Allen H. Goldstein
Atmos. Chem. Phys., 18, 10433–10457, https://doi.org/10.5194/acp-18-10433-2018, https://doi.org/10.5194/acp-18-10433-2018, 2018
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Biogenic volatile organic compounds react in the atmosphere to form secondary organic aerosol, yet the chemical pathways remain unclear. We collected filter samples and deployed a semi-volatile thermal desorption aerosol gas chromatograph in the central Amazon. We measured 30 sesquiterpenes and 4 diterpenes and find them to be important for reactive ozone loss. We estimate that sesquiterpene oxidation contributes at least 0.4–5 % (median 1 %) of observed submicron organic aerosol mass.
Mira L. Pöhlker, Florian Ditas, Jorge Saturno, Thomas Klimach, Isabella Hrabě de Angelis, Alessandro C. Araùjo, Joel Brito, Samara Carbone, Yafang Cheng, Xuguang Chi, Reiner Ditz, Sachin S. Gunthe, Bruna A. Holanda, Konrad Kandler, Jürgen Kesselmeier, Tobias Könemann, Ovid O. Krüger, Jošt V. Lavrič, Scot T. Martin, Eugene Mikhailov, Daniel Moran-Zuloaga, Luciana V. Rizzo, Diana Rose, Hang Su, Ryan Thalman, David Walter, Jian Wang, Stefan Wolff, Henrique M. J. Barbosa, Paulo Artaxo, Meinrat O. Andreae, Ulrich Pöschl, and Christopher Pöhlker
Atmos. Chem. Phys., 18, 10289–10331, https://doi.org/10.5194/acp-18-10289-2018, https://doi.org/10.5194/acp-18-10289-2018, 2018
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This paper presents the aerosol and cloud condensation nuclei (CCN) variability for characteristic atmospheric states – such as biomass burning, long-range transport, and pristine rain forest conditions – in the vulnerable and climate-relevant Amazon Basin. It summarizes the key properties of aerosol and CCN and, thus, provides a basis for an in-depth analysis of aerosol–cloud interactions in the Amazon region.
Luciana Varanda Rizzo, Pontus Roldin, Joel Brito, John Backman, Erik Swietlicki, Radovan Krejci, Peter Tunved, Tukka Petäjä, Markku Kulmala, and Paulo Artaxo
Atmos. Chem. Phys., 18, 10255–10274, https://doi.org/10.5194/acp-18-10255-2018, https://doi.org/10.5194/acp-18-10255-2018, 2018
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Aerosols are tiny particles suspended in the air that can interact with sunlight and form clouds, which in turn affect the climate. They can also recycle nutrients in forest environments. Aerosols are naturally emitted at the surface in the Amazon forest, in addition to being brought down from above the boundary layer by intense air movements. In this work, we describe how the particle size number concentrations of aerosols change over hours, days and seasons in a multi-year study in Amazonia.
Daniel Moran-Zuloaga, Florian Ditas, David Walter, Jorge Saturno, Joel Brito, Samara Carbone, Xuguang Chi, Isabella Hrabě de Angelis, Holger Baars, Ricardo H. M. Godoi, Birgit Heese, Bruna A. Holanda, Jošt V. Lavrič, Scot T. Martin, Jing Ming, Mira L. Pöhlker, Nina Ruckteschler, Hang Su, Yaqiang Wang, Qiaoqiao Wang, Zhibin Wang, Bettina Weber, Stefan Wolff, Paulo Artaxo, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Chem. Phys., 18, 10055–10088, https://doi.org/10.5194/acp-18-10055-2018, https://doi.org/10.5194/acp-18-10055-2018, 2018
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This study presents multiple years of aerosol coarse mode observations at the remote ATTO site in the Amazon Basin. The results are discussed in light of the frequent and episodic long-range transport of Saharan dust plumes in the early wet season as well as the persistent background bioaerosol cycling in the rain forest ecosystem. This work provides a solid basis for future studies on the dynamic coarse mode aerosol cycling and its biogeochemical relevance in the Amazon.
Luiz A. T. Machado, Alan J. P. Calheiros, Thiago Biscaro, Scott Giangrande, Maria A. F. Silva Dias, Micael A. Cecchini, Rachel Albrecht, Meinrat O. Andreae, Wagner F. Araujo, Paulo Artaxo, Stephan Borrmann, Ramon Braga, Casey Burleyson, Cristiano W. Eichholz, Jiwen Fan, Zhe Feng, Gilberto F. Fisch, Michael P. Jensen, Scot T. Martin, Ulrich Pöschl, Christopher Pöhlker, Mira L. Pöhlker, Jean-François Ribaud, Daniel Rosenfeld, Jaci M. B. Saraiva, Courtney Schumacher, Ryan Thalman, David Walter, and Manfred Wendisch
Atmos. Chem. Phys., 18, 6461–6482, https://doi.org/10.5194/acp-18-6461-2018, https://doi.org/10.5194/acp-18-6461-2018, 2018
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This overview discuss the main precipitation processes and their sensitivities to environmental conditions in the Central Amazon Basin. It presents a review of the knowledge acquired about cloud processes and rainfall formation in Amazonas. In addition, this study provides a characterization of the seasonal variation and rainfall sensitivities to topography, surface cover, and aerosol concentration. Airplane measurements were evaluated to characterize and contrast cloud microphysical properties.
Amy K. Hodgson, William T. Morgan, Sebastian O'Shea, Stéphane Bauguitte, James D. Allan, Eoghan Darbyshire, Michael J. Flynn, Dantong Liu, James Lee, Ben Johnson, Jim M. Haywood, Karla M. Longo, Paulo E. Artaxo, and Hugh Coe
Atmos. Chem. Phys., 18, 5619–5638, https://doi.org/10.5194/acp-18-5619-2018, https://doi.org/10.5194/acp-18-5619-2018, 2018
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We flew a large atmospheric research aircraft across a number of different biomass burning environments in the Amazon Basin in September and October 2012. In this paper, we focus on smoke sampled very close to fresh fires (only 600–900 m above the fires and smoke that was 4–6 min old) to examine the chemical components that make up the smoke and their abundance. We found substantial differences in the emitted smoke that are due to the fuel type and combustion processes driving the fires.
Lianet Hernández Pardo, Luiz Augusto Toledo Machado, and Micael Amore Cecchini
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-190, https://doi.org/10.5194/acp-2018-190, 2018
Revised manuscript not accepted
Julia Schmale, Silvia Henning, Stefano Decesari, Bas Henzing, Helmi Keskinen, Karine Sellegri, Jurgita Ovadnevaite, Mira L. Pöhlker, Joel Brito, Aikaterini Bougiatioti, Adam Kristensson, Nikos Kalivitis, Iasonas Stavroulas, Samara Carbone, Anne Jefferson, Minsu Park, Patrick Schlag, Yoko Iwamoto, Pasi Aalto, Mikko Äijälä, Nicolas Bukowiecki, Mikael Ehn, Göran Frank, Roman Fröhlich, Arnoud Frumau, Erik Herrmann, Hartmut Herrmann, Rupert Holzinger, Gerard Kos, Markku Kulmala, Nikolaos Mihalopoulos, Athanasios Nenes, Colin O'Dowd, Tuukka Petäjä, David Picard, Christopher Pöhlker, Ulrich Pöschl, Laurent Poulain, André Stephan Henry Prévôt, Erik Swietlicki, Meinrat O. Andreae, Paulo Artaxo, Alfred Wiedensohler, John Ogren, Atsushi Matsuki, Seong Soo Yum, Frank Stratmann, Urs Baltensperger, and Martin Gysel
Atmos. Chem. Phys., 18, 2853–2881, https://doi.org/10.5194/acp-18-2853-2018, https://doi.org/10.5194/acp-18-2853-2018, 2018
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Collocated long-term observations of cloud condensation nuclei (CCN) number concentrations, particle number size distributions and chemical composition from 12 sites are synthesized. Observations cover coastal environments, the Arctic, the Mediterranean, the boreal and rain forest, high alpine and continental background sites, and Monsoon-influenced areas. We interpret regional and seasonal variability. CCN concentrations are predicted with the κ–Köhler model and compared to the measurements.
Adriana Rocha-Lima, J. Vanderlei Martins, Lorraine A. Remer, Martin Todd, John H. Marsham, Sebastian Engelstaedter, Claire L. Ryder, Carolina Cavazos-Guerra, Paulo Artaxo, Peter Colarco, and Richard Washington
Atmos. Chem. Phys., 18, 1023–1043, https://doi.org/10.5194/acp-18-1023-2018, https://doi.org/10.5194/acp-18-1023-2018, 2018
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We present results of ground-based measurements and subsequent laboratory analysis of Sahara dust samples collected in Algeria and Mauritania during the Fennec campaign in 2011. The results show that the sampled dust has low absorption characteristics and exhibits a distinct spectral bow-like shape. We find distinctive differences in the composition and optical characteristics of the dust from the two sites, corroborating with other studies that not all Saharan dust is the same.
Meinrat O. Andreae, Armin Afchine, Rachel Albrecht, Bruna Amorim Holanda, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Micael A. Cecchini, Anja Costa, Maximilian Dollner, Daniel Fütterer, Emma Järvinen, Tina Jurkat, Thomas Klimach, Tobias Konemann, Christoph Knote, Martina Krämer, Trismono Krisna, Luiz A. T. Machado, Stephan Mertes, Andreas Minikin, Christopher Pöhlker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, Daniel Sauer, Hans Schlager, Martin Schnaiter, Johannes Schneider, Christiane Schulz, Antonio Spanu, Vinicius B. Sperling, Christiane Voigt, Adrian Walser, Jian Wang, Bernadett Weinzierl, Manfred Wendisch, and Helmut Ziereis
Atmos. Chem. Phys., 18, 921–961, https://doi.org/10.5194/acp-18-921-2018, https://doi.org/10.5194/acp-18-921-2018, 2018
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We made airborne measurements of aerosol particle concentrations and properties over the Amazon Basin. We found extremely high concentrations of very small particles in the region between 8 and 14 km altitude all across the basin, which had been recently formed by gas-to-particle conversion at these altitudes. This makes the upper troposphere a very important source region of atmospheric particles with significant implications for the Earth's climate system.
Brett B. Palm, Suzane S. de Sá, Douglas A. Day, Pedro Campuzano-Jost, Weiwei Hu, Roger Seco, Steven J. Sjostedt, Jeong-Hoo Park, Alex B. Guenther, Saewung Kim, Joel Brito, Florian Wurm, Paulo Artaxo, Ryan Thalman, Jian Wang, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Allen H. Goldstein, Yingjun Liu, Stephen R. Springston, Rodrigo Souza, Matt K. Newburn, M. Lizabeth Alexander, Scot T. Martin, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 467–493, https://doi.org/10.5194/acp-18-467-2018, https://doi.org/10.5194/acp-18-467-2018, 2018
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Ambient air was oxidized by OH or O3 in an oxidation flow reactor during both wet and dry seasons in the GoAmazon2014/5 campaign to study secondary organic aerosol (SOA) formation. We investigated how much biogenic, urban, and biomass burning sources contributed to the ambient concentrations of SOA precursor gases and how their contributions changed diurnally and seasonally. SOA yields and hygroscopicity of organic aerosol in the oxidation flow reactor were also studied.
Micael A. Cecchini, Luiz A. T. Machado, Manfred Wendisch, Anja Costa, Martina Krämer, Meinrat O. Andreae, Armin Afchine, Rachel I. Albrecht, Paulo Artaxo, Stephan Borrmann, Daniel Fütterer, Thomas Klimach, Christoph Mahnke, Scot T. Martin, Andreas Minikin, Sergej Molleker, Lianet H. Pardo, Christopher Pöhlker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, and Bernadett Weinzierl
Atmos. Chem. Phys., 17, 14727–14746, https://doi.org/10.5194/acp-17-14727-2017, https://doi.org/10.5194/acp-17-14727-2017, 2017
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This study introduces and explores the concept of gamma phase space. This space is able to represent all possible variations in the cloud droplet size distributions (DSDs). The methodology was applied to recent in situ aircraft measurements over the Amazon. It is shown that the phase space is able to represent several processes occurring in the clouds in a simple manner. The consequences for cloud studies, modeling, and the representation of the transition from warm to mixed phase are discussed.
Eugene F. Mikhailov, Svetlana Mironova, Gregory Mironov, Sergey Vlasenko, Alexey Panov, Xuguang Chi, David Walter, Samara Carbone, Paulo Artaxo, Martin Heimann, Jost Lavric, Ulrich Pöschl, and Meinrat O. Andreae
Atmos. Chem. Phys., 17, 14365–14392, https://doi.org/10.5194/acp-17-14365-2017, https://doi.org/10.5194/acp-17-14365-2017, 2017
Ryan Thalman, Suzane S. de Sá, Brett B. Palm, Henrique M. J. Barbosa, Mira L. Pöhlker, M. Lizabeth Alexander, Joel Brito, Samara Carbone, Paulo Castillo, Douglas A. Day, Chongai Kuang, Antonio Manzi, Nga Lee Ng, Arthur J. Sedlacek III, Rodrigo Souza, Stephen Springston, Thomas Watson, Christopher Pöhlker, Ulrich Pöschl, Meinrat O. Andreae, Paulo Artaxo, Jose L. Jimenez, Scot T. Martin, and Jian Wang
Atmos. Chem. Phys., 17, 11779–11801, https://doi.org/10.5194/acp-17-11779-2017, https://doi.org/10.5194/acp-17-11779-2017, 2017
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Particle hygroscopicity, mixing state, and the hygroscopicity of organic components were characterized in central Amazonia for 1 year; their seasonal and diel variations were driven by a combination of primary emissions, photochemical oxidation, and boundary layer development. The relationship between the hygroscopicity of organic components and their oxidation level was examined, and the results help to reconcile the differences among the relationships observed in previous studies.
Micael A. Cecchini, Luiz A. T. Machado, Meinrat O. Andreae, Scot T. Martin, Rachel I. Albrecht, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Daniel Fütterer, Tina Jurkat, Christoph Mahnke, Andreas Minikin, Sergej Molleker, Mira L. Pöhlker, Ulrich Pöschl, Daniel Rosenfeld, Christiane Voigt, Bernadett Weinzierl, and Manfred Wendisch
Atmos. Chem. Phys., 17, 10037–10050, https://doi.org/10.5194/acp-17-10037-2017, https://doi.org/10.5194/acp-17-10037-2017, 2017
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We study the effects of aerosol particles and updraft speed on the warm phase of Amazonian clouds. We expand the sensitivity analysis usually found in the literature by concomitantly considering cloud evolution and the effects on droplet size distribution (DSD) shape. The quantitative results show that particle concentration is the primary driver for the vertical profiles of effective diameter and droplet concentration in the warm phase of Amazonian convective clouds.
Jorge Saturno, Christopher Pöhlker, Dario Massabò, Joel Brito, Samara Carbone, Yafang Cheng, Xuguang Chi, Florian Ditas, Isabella Hrabě de Angelis, Daniel Morán-Zuloaga, Mira L. Pöhlker, Luciana V. Rizzo, David Walter, Qiaoqiao Wang, Paulo Artaxo, Paolo Prati, and Meinrat O. Andreae
Atmos. Meas. Tech., 10, 2837–2850, https://doi.org/10.5194/amt-10-2837-2017, https://doi.org/10.5194/amt-10-2837-2017, 2017
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Different Aethalometer correction schemes were compared to a multi-wavelength absorption reference measurement. One of the correction schemes was found to artificially increase the short-wavelength absorption coefficients. It was found that accounting for aerosol scattering properties in the correction is crucial to retrieve the proper absorption Ångström exponent (AAE). We found that the raw AAE of uncompensated Aethalometer attenuation significantly correlates with a measured reference AAE.
Evelyn Jäkel, Manfred Wendisch, Trismono C. Krisna, Florian Ewald, Tobias Kölling, Tina Jurkat, Christiane Voigt, Micael A. Cecchini, Luiz A. T. Machado, Armin Afchine, Anja Costa, Martina Krämer, Meinrat O. Andreae, Ulrich Pöschl, Daniel Rosenfeld, and Tianle Yuan
Atmos. Chem. Phys., 17, 9049–9066, https://doi.org/10.5194/acp-17-9049-2017, https://doi.org/10.5194/acp-17-9049-2017, 2017
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Vertical profiles of the cloud particle phase state in tropical deep convective clouds (DCCs) were investigated using airborne imaging spectrometer measurements during the ACRIDICON-CHUVA campaign, which was conducted over the Brazilian rainforest in September 2014. A phase discrimination retrieval was applied to observations of clouds formed in different aerosol conditions. The profiles were compared to in situ and satellite measurements.
Ramon Campos Braga, Daniel Rosenfeld, Ralf Weigel, Tina Jurkat, Meinrat O. Andreae, Manfred Wendisch, Mira L. Pöhlker, Thomas Klimach, Ulrich Pöschl, Christopher Pöhlker, Christiane Voigt, Christoph Mahnke, Stephan Borrmann, Rachel I. Albrecht, Sergej Molleker, Daniel A. Vila, Luiz A. T. Machado, and Paulo Artaxo
Atmos. Chem. Phys., 17, 7365–7386, https://doi.org/10.5194/acp-17-7365-2017, https://doi.org/10.5194/acp-17-7365-2017, 2017
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Matthew K. Newburn, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Ryan Thalman, Joel Brito, Samara Carbone, Paulo Artaxo, Allen H. Goldstein, Antonio O. Manzi, Rodrigo A. F. Souza, Fan Mei, John E. Shilling, Stephen R. Springston, Jian Wang, Jason D. Surratt, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 17, 6611–6629, https://doi.org/10.5194/acp-17-6611-2017, https://doi.org/10.5194/acp-17-6611-2017, 2017
Oleg Travnikov, Hélène Angot, Paulo Artaxo, Mariantonia Bencardino, Johannes Bieser, Francesco D'Amore, Ashu Dastoor, Francesco De Simone, María del Carmen Diéguez, Aurélien Dommergue, Ralf Ebinghaus, Xin Bin Feng, Christian N. Gencarelli, Ian M. Hedgecock, Olivier Magand, Lynwill Martin, Volker Matthias, Nikolay Mashyanov, Nicola Pirrone, Ramesh Ramachandran, Katie Alana Read, Andrei Ryjkov, Noelle E. Selin, Fabrizio Sena, Shaojie Song, Francesca Sprovieri, Dennis Wip, Ingvar Wängberg, and Xin Yang
Atmos. Chem. Phys., 17, 5271–5295, https://doi.org/10.5194/acp-17-5271-2017, https://doi.org/10.5194/acp-17-5271-2017, 2017
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The study provides a complex analysis of processes governing Hg fate in the atmosphere involving both measurement data and simulation results of chemical transport models. Evaluation of the model simulations and numerical experiments against observations allows explaining spatial and temporal variations of Hg concentration in the near-surface atmospheric layer and shows possibility of multiple pathways of Hg oxidation occurring concurrently in various parts of the atmosphere.
Diego A. Gouveia, Boris Barja, Henrique M. J. Barbosa, Patric Seifert, Holger Baars, Theotonio Pauliquevis, and Paulo Artaxo
Atmos. Chem. Phys., 17, 3619–3636, https://doi.org/10.5194/acp-17-3619-2017, https://doi.org/10.5194/acp-17-3619-2017, 2017
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We derive the first comprehensive statistics of cirrus clouds over a tropical rain forest. Monthly frequency of occurrence can be as high as 88 %. The diurnal cycle follows that of precipitation, and frequently cirrus is found in the tropopause layer. The mean values of cloud top, base, thickness, optical depth and lidar ratio were 14.3 km, 12.9 km, 1.4 km, 0.25, and 23 sr respectively. The high fraction (42 %) of subvisible clouds may contaminate satellite measurements to an unknown extent.
Joana A. Rizzolo, Cybelli G. G. Barbosa, Guilherme C. Borillo, Ana F. L. Godoi, Rodrigo A. F. Souza, Rita V. Andreoli, Antônio O. Manzi, Marta O. Sá, Eliane G. Alves, Christopher Pöhlker, Isabella H. Angelis, Florian Ditas, Jorge Saturno, Daniel Moran-Zuloaga, Luciana V. Rizzo, Nilton E. Rosário, Theotonio Pauliquevis, Rosa M. N. Santos, Carlos I. Yamamoto, Meinrat O. Andreae, Paulo Artaxo, Philip E. Taylor, and Ricardo H. M. Godoi
Atmos. Chem. Phys., 17, 2673–2687, https://doi.org/10.5194/acp-17-2673-2017, https://doi.org/10.5194/acp-17-2673-2017, 2017
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Particles collected from the air above the Amazon Basin during the wet season were identified as Saharan dust. Soluble minerals were analysed to assess the bioavailability of iron. Dust deposited onto the canopy and topsoil can likely benefit organisms such as fungi and lichens. The ongoing deposition of Saharan dust across the Amazon rainforest provides an iron-rich source of essential macronutrients and micronutrients to plant roots, and also directly to plant leaves during the wet season.
Francesco De Simone, Paulo Artaxo, Mariantonia Bencardino, Sergio Cinnirella, Francesco Carbone, Francesco D'Amore, Aurélien Dommergue, Xin Bin Feng, Christian N. Gencarelli, Ian M. Hedgecock, Matthew S. Landis, Francesca Sprovieri, Noriuki Suzuki, Ingvar Wängberg, and Nicola Pirrone
Atmos. Chem. Phys., 17, 1881–1899, https://doi.org/10.5194/acp-17-1881-2017, https://doi.org/10.5194/acp-17-1881-2017, 2017
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Biomass burning (BB) releases of Hg, usually considered to be Hg(0), are a significant global source of atmospheric Hg. However there is experimental evidence that a fraction of this Hg is bound to particulate matter, Hg(P). This modelling study shows how increasing fractions of Hg(P) reduce the availability of Hg to the global pool, raising Hg exposure for those regions characterized by high BB, with implications for the sub-Arctic and also rice-growing areas in South-East Asia.
Adam P. Bateman, Zhaoheng Gong, Tristan H. Harder, Suzane S. de Sá, Bingbing Wang, Paulo Castillo, Swarup China, Yingjun Liu, Rachel E. O'Brien, Brett B. Palm, Hung-Wei Shiu, Glauber G. Cirino, Ryan Thalman, Kouji Adachi, M. Lizabeth Alexander, Paulo Artaxo, Allan K. Bertram, Peter R. Buseck, Mary K. Gilles, Jose L. Jimenez, Alexander Laskin, Antonio O. Manzi, Arthur Sedlacek, Rodrigo A. F. Souza, Jian Wang, Rahul Zaveri, and Scot T. Martin
Atmos. Chem. Phys., 17, 1759–1773, https://doi.org/10.5194/acp-17-1759-2017, https://doi.org/10.5194/acp-17-1759-2017, 2017
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The occurrence of nonliquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Air masses representing background conditions, urban pollution, and regional- and continental-scale biomass were measured. Anthropogenic influences contributed to the presence of nonliquid PM in the atmospheric particle population, while liquid PM dominated during periods of biogenic influence.
Metodija M. Shapkalijevski, Huug G. Ouwersloot, Arnold F. Moene, and Jordi Vilà-Guerau de Arrellano
Atmos. Chem. Phys., 17, 1623–1640, https://doi.org/10.5194/acp-17-1623-2017, https://doi.org/10.5194/acp-17-1623-2017, 2017
Mira L. Pöhlker, Christopher Pöhlker, Florian Ditas, Thomas Klimach, Isabella Hrabe de Angelis, Alessandro Araújo, Joel Brito, Samara Carbone, Yafang Cheng, Xuguang Chi, Reiner Ditz, Sachin S. Gunthe, Jürgen Kesselmeier, Tobias Könemann, Jošt V. Lavrič, Scot T. Martin, Eugene Mikhailov, Daniel Moran-Zuloaga, Diana Rose, Jorge Saturno, Hang Su, Ryan Thalman, David Walter, Jian Wang, Stefan Wolff, Henrique M. J. Barbosa, Paulo Artaxo, Meinrat O. Andreae, and Ulrich Pöschl
Atmos. Chem. Phys., 16, 15709–15740, https://doi.org/10.5194/acp-16-15709-2016, https://doi.org/10.5194/acp-16-15709-2016, 2016
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The paper presents a systematic characterization of cloud condensation nuclei (CCN) concentration in the central Amazonian atmosphere. Our results show that the CCN population in this globally important ecosystem follows a pollution-related seasonal cycle, in which it mainly depends on changes in total aerosol size distribution and to a minor extent in the aerosol chemical composition. Our results allow an efficient modeling and prediction of the CCN population based on a novel approach.
Qiaoqiao Wang, Jorge Saturno, Xuguang Chi, David Walter, Jost V. Lavric, Daniel Moran-Zuloaga, Florian Ditas, Christopher Pöhlker, Joel Brito, Samara Carbone, Paulo Artaxo, and Meinrat O. Andreae
Atmos. Chem. Phys., 16, 14775–14794, https://doi.org/10.5194/acp-16-14775-2016, https://doi.org/10.5194/acp-16-14775-2016, 2016
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We use a chemical transport model to interpret observed aerosol concentrations and absorption over the Amazon Basin during the wet season. With daily temporal resolution for open fire emissions and modified aerosol optical properties, our model successfully captures the observed variation in aerosol concentrations and absorption over the Amazon Basin. The simulation indicates the important influence of open fire mainly from northern South America and from northern Africa in the wet season.
Ben T. Johnson, James M. Haywood, Justin M. Langridge, Eoghan Darbyshire, William T. Morgan, Kate Szpek, Jennifer K. Brooke, Franco Marenco, Hugh Coe, Paulo Artaxo, Karla M. Longo, Jane P. Mulcahy, Graham W. Mann, Mohit Dalvi, and Nicolas Bellouin
Atmos. Chem. Phys., 16, 14657–14685, https://doi.org/10.5194/acp-16-14657-2016, https://doi.org/10.5194/acp-16-14657-2016, 2016
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Biomass burning is a large source of carbonaceous aerosols, which scatter and absorb solar radiation, and modify cloud properties. We evaluate the simulation of biomass burning aerosol processes and properties in the HadGEM3 climate model using observations, including those from the South American Biomass Burning Analysis. We find that modelled aerosol optical depths are underestimated unless aerosol emissions (Global Fire Emission Database v3) are increased by a factor of 1.6–2.0.
Xuan Wang, Colette L. Heald, Arthur J. Sedlacek, Suzane S. de Sá, Scot T. Martin, M. Lizabeth Alexander, Thomas B. Watson, Allison C. Aiken, Stephen R. Springston, and Paulo Artaxo
Atmos. Chem. Phys., 16, 12733–12752, https://doi.org/10.5194/acp-16-12733-2016, https://doi.org/10.5194/acp-16-12733-2016, 2016
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We describe a new approach to estimate the absorption of brown carbon (BrC) from multiple-wavelength absorption measurements. By applying this method to column and surface observations globally, we find that BrC contributes up to 40 % of the absorption measured at 440 nm. The analysis of two surface sites also suggests that BrC absorptivity decreases with photochemical aging in biomass burning plumes, but not in typical urban conditions.
Francesca Sprovieri, Nicola Pirrone, Mariantonia Bencardino, Francesco D'Amore, Francesco Carbone, Sergio Cinnirella, Valentino Mannarino, Matthew Landis, Ralf Ebinghaus, Andreas Weigelt, Ernst-Günther Brunke, Casper Labuschagne, Lynwill Martin, John Munthe, Ingvar Wängberg, Paulo Artaxo, Fernando Morais, Henrique de Melo Jorge Barbosa, Joel Brito, Warren Cairns, Carlo Barbante, María del Carmen Diéguez, Patricia Elizabeth Garcia, Aurélien Dommergue, Helene Angot, Olivier Magand, Henrik Skov, Milena Horvat, Jože Kotnik, Katie Alana Read, Luis Mendes Neves, Bernd Manfred Gawlik, Fabrizio Sena, Nikolay Mashyanov, Vladimir Obolkin, Dennis Wip, Xin Bin Feng, Hui Zhang, Xuewu Fu, Ramesh Ramachandran, Daniel Cossa, Joël Knoery, Nicolas Marusczak, Michelle Nerentorp, and Claus Norstrom
Atmos. Chem. Phys., 16, 11915–11935, https://doi.org/10.5194/acp-16-11915-2016, https://doi.org/10.5194/acp-16-11915-2016, 2016
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This work presents atmospheric Hg concentrations recorded within the GMOS global network analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. The over-arching benefit of this coordinated Hg monitoring network would clearly be the production of high-quality measurement datasets on a global scale useful in developing and validating models on different spatial and temporal scales.
Carly L. Reddington, Dominick V. Spracklen, Paulo Artaxo, David A. Ridley, Luciana V. Rizzo, and Andrea Arana
Atmos. Chem. Phys., 16, 11083–11106, https://doi.org/10.5194/acp-16-11083-2016, https://doi.org/10.5194/acp-16-11083-2016, 2016
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We use a global aerosol model evaluated against long-term observations of surface aerosol and aerosol optical depth (AOD) to better understand the impacts of biomass burning on tropical aerosol. We use three satellite-derived fire emission datasets in the model, identifying regions where these datasets capture observations and where emissions are likely to be underestimated. For coincident observations of surface aerosol and AOD, model underestimation of AOD is greater than of surface aerosol.
A. M. Yáñez-Serrano, A. C. Nölscher, E. Bourtsoukidis, B. Derstroff, N. Zannoni, V. Gros, M. Lanza, J. Brito, S. M. Noe, E. House, C. N. Hewitt, B. Langford, E. Nemitz, T. Behrendt, J. Williams, P. Artaxo, M. O. Andreae, and J. Kesselmeier
Atmos. Chem. Phys., 16, 10965–10984, https://doi.org/10.5194/acp-16-10965-2016, https://doi.org/10.5194/acp-16-10965-2016, 2016
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This paper provides a general overview of methyl ethyl ketone (MEK) ambient observations in different ecosystems around the world in order to provide insights into the sources, sink and role of MEK in the atmosphere.
James D. Whitehead, Eoghan Darbyshire, Joel Brito, Henrique M. J. Barbosa, Ian Crawford, Rafael Stern, Martin W. Gallagher, Paul H. Kaye, James D. Allan, Hugh Coe, Paulo Artaxo, and Gordon McFiggans
Atmos. Chem. Phys., 16, 9727–9743, https://doi.org/10.5194/acp-16-9727-2016, https://doi.org/10.5194/acp-16-9727-2016, 2016
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We present measurements of aerosols during the transition from wet to dry seasons at a pristine rainforest site in central Amazonia. By excluding pollution episodes, we focus on natural biogenic aerosols. Submicron aerosols are dominated by organic material, similar to previous wet season measurements. Larger particles are dominated by biological material, mostly fungal spores, with higher concentrations at night. This study provides important data on the nature of particles above the Amazon.
Luping Su, Edward G. Patton, Jordi Vilà-Guerau de Arellano, Alex B. Guenther, Lisa Kaser, Bin Yuan, Fulizi Xiong, Paul B. Shepson, Li Zhang, David O. Miller, William H. Brune, Karsten Baumann, Eric Edgerton, Andrew Weinheimer, Pawel K. Misztal, Jeong-Hoo Park, Allen H. Goldstein, Kate M. Skog, Frank N. Keutsch, and John E. Mak
Atmos. Chem. Phys., 16, 7725–7741, https://doi.org/10.5194/acp-16-7725-2016, https://doi.org/10.5194/acp-16-7725-2016, 2016
Micael A. Cecchini, Luiz A. T. Machado, Jennifer M. Comstock, Fan Mei, Jian Wang, Jiwen Fan, Jason M. Tomlinson, Beat Schmid, Rachel Albrecht, Scot T. Martin, and Paulo Artaxo
Atmos. Chem. Phys., 16, 7029–7041, https://doi.org/10.5194/acp-16-7029-2016, https://doi.org/10.5194/acp-16-7029-2016, 2016
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This work focuses on the analysis of anthropogenic impacts on Amazonian clouds. The experiment was conducted around Manaus (Brazil), which is a city with 2 million inhabitants and is surrounded by the Amazon forest in every direction. The clouds that form over the pristine atmosphere of the forest are understood as the background clouds and the ones that form over the city pollution are the anthropogenically impacted ones. The paper analyses microphysical characteristics of both types of clouds.
Stijn Hantson, Almut Arneth, Sandy P. Harrison, Douglas I. Kelley, I. Colin Prentice, Sam S. Rabin, Sally Archibald, Florent Mouillot, Steve R. Arnold, Paulo Artaxo, Dominique Bachelet, Philippe Ciais, Matthew Forrest, Pierre Friedlingstein, Thomas Hickler, Jed O. Kaplan, Silvia Kloster, Wolfgang Knorr, Gitta Lasslop, Fang Li, Stephane Mangeon, Joe R. Melton, Andrea Meyn, Stephen Sitch, Allan Spessa, Guido R. van der Werf, Apostolos Voulgarakis, and Chao Yue
Biogeosciences, 13, 3359–3375, https://doi.org/10.5194/bg-13-3359-2016, https://doi.org/10.5194/bg-13-3359-2016, 2016
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Our ability to predict the magnitude and geographic pattern of past and future fire impacts rests on our ability to model fire regimes. A large variety of models exist, and it is unclear which type of model or degree of complexity is required to model fire adequately at regional to global scales. In this paper we summarize the current state of the art in fire-regime modelling and model evaluation, and outline what lessons may be learned from the Fire Model Intercomparison Project – FireMIP.
Holger Baars, Thomas Kanitz, Ronny Engelmann, Dietrich Althausen, Birgit Heese, Mika Komppula, Jana Preißler, Matthias Tesche, Albert Ansmann, Ulla Wandinger, Jae-Hyun Lim, Joon Young Ahn, Iwona S. Stachlewska, Vassilis Amiridis, Eleni Marinou, Patric Seifert, Julian Hofer, Annett Skupin, Florian Schneider, Stephanie Bohlmann, Andreas Foth, Sebastian Bley, Anne Pfüller, Eleni Giannakaki, Heikki Lihavainen, Yrjö Viisanen, Rakesh Kumar Hooda, Sérgio Nepomuceno Pereira, Daniele Bortoli, Frank Wagner, Ina Mattis, Lucja Janicka, Krzysztof M. Markowicz, Peggy Achtert, Paulo Artaxo, Theotonio Pauliquevis, Rodrigo A. F. Souza, Ved Prakesh Sharma, Pieter Gideon van Zyl, Johan Paul Beukes, Junying Sun, Erich G. Rohwer, Ruru Deng, Rodanthi-Elisavet Mamouri, and Felix Zamorano
Atmos. Chem. Phys., 16, 5111–5137, https://doi.org/10.5194/acp-16-5111-2016, https://doi.org/10.5194/acp-16-5111-2016, 2016
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The findings from more than 10 years of global aerosol lidar measurements with Polly systems are summarized, and a data set of optical properties for specific aerosol types is given. An automated data retrieval algorithm for continuous Polly lidar observations is presented and discussed by means of a Saharan dust advection event in Leipzig, Germany. Finally, a statistic on the vertical aerosol distribution including the seasonal variability at PollyNET locations around the globe is presented.
S. T. Martin, P. Artaxo, L. A. T. Machado, A. O. Manzi, R. A. F. Souza, C. Schumacher, J. Wang, M. O. Andreae, H. M. J. Barbosa, J. Fan, G. Fisch, A. H. Goldstein, A. Guenther, J. L. Jimenez, U. Pöschl, M. A. Silva Dias, J. N. Smith, and M. Wendisch
Atmos. Chem. Phys., 16, 4785–4797, https://doi.org/10.5194/acp-16-4785-2016, https://doi.org/10.5194/acp-16-4785-2016, 2016
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The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment took place in central Amazonia throughout 2014 and 2015. The experiment focused on the complex links among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and precipitation on the other, especially when altered by urban pollution. This article serves as an introduction to the special issue of publications presenting findings of this experiment.
Eliane G. Alves, Kolby Jardine, Julio Tota, Angela Jardine, Ana Maria Yãnez-Serrano, Thomas Karl, Julia Tavares, Bruce Nelson, Dasa Gu, Trissevgeni Stavrakou, Scot Martin, Paulo Artaxo, Antonio Manzi, and Alex Guenther
Atmos. Chem. Phys., 16, 3903–3925, https://doi.org/10.5194/acp-16-3903-2016, https://doi.org/10.5194/acp-16-3903-2016, 2016
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For a long time, it was thought that tropical rainforests are evergreen forests and the processes involved in these ecosystems do not change all year long. However, some satellite retrievals have suggested that ecophysiological processes may present seasonal variations mainly due to variation in light and leaf phenology in Amazonia. These in situ measurements are the first showing of a seasonal trend of volatile organic compound emissions, correlating with light and leaf phenology in Amazonia.
Franco Marenco, Ben Johnson, Justin M. Langridge, Jane Mulcahy, Angela Benedetti, Samuel Remy, Luke Jones, Kate Szpek, Jim Haywood, Karla Longo, and Paulo Artaxo
Atmos. Chem. Phys., 16, 2155–2174, https://doi.org/10.5194/acp-16-2155-2016, https://doi.org/10.5194/acp-16-2155-2016, 2016
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A widespread and persistent smoke layer was observed in the Amazon
region during the biomass burning season, spanning a distance of 2200 km
and a period of 14 days. The larger smoke content was typically found
in elevated layers, from 1–1.5 km to 4–6 km.
Measurements have been compared to model predictions, and the latter
were able to reproduce the general features of the smoke layer, but
with some differences which are analysed and described in the paper.
C. E. Scott, D. V. Spracklen, J. R. Pierce, I. Riipinen, S. D. D'Andrea, A. Rap, K. S. Carslaw, P. M. Forster, P. Artaxo, M. Kulmala, L. V. Rizzo, E. Swietlicki, G. W. Mann, and K. J. Pringle
Atmos. Chem. Phys., 15, 12989–13001, https://doi.org/10.5194/acp-15-12989-2015, https://doi.org/10.5194/acp-15-12989-2015, 2015
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To understand the radiative effects of biogenic secondary organic aerosol (SOA) it is necessary to consider the manner in which it is distributed across the existing aerosol size distribution. We explore the importance of the approach taken by global-scale models to do this, when calculating the direct radiative effect (DRE) & first aerosol indirect effect (AIE) due to biogenic SOA. This choice has little effect on the DRE, but a substantial impact on the magnitude and even sign of the first AIE
A. M. Womack, P. E. Artaxo, F. Y. Ishida, R. C. Mueller, S. R. Saleska, K. T. Wiedemann, B. J. M. Bohannan, and J. L. Green
Biogeosciences, 12, 6337–6349, https://doi.org/10.5194/bg-12-6337-2015, https://doi.org/10.5194/bg-12-6337-2015, 2015
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Fungi in the atmosphere can affect precipitation by nucleating the formation of clouds and ice. This process is important over the Amazon rainforest where precipitation is limited by the types and amount of airborne particles. We found that the total and metabolically active fungi communities were dominated by different taxonomic groups, and the active community unexpectedly contained many lichen fungi, which are effective at nucleating ice.
W. W. Hu, P. Campuzano-Jost, B. B. Palm, D. A. Day, A. M. Ortega, P. L. Hayes, J. E. Krechmer, Q. Chen, M. Kuwata, Y. J. Liu, S. S. de Sá, K. McKinney, S. T. Martin, M. Hu, S. H. Budisulistiorini, M. Riva, J. D. Surratt, J. M. St. Clair, G. Isaacman-Van Wertz, L. D. Yee, A. H. Goldstein, S. Carbone, J. Brito, P. Artaxo, J. A. de Gouw, A. Koss, A. Wisthaler, T. Mikoviny, T. Karl, L. Kaser, W. Jud, A. Hansel, K. S. Docherty, M. L. Alexander, N. H. Robinson, H. Coe, J. D. Allan, M. R. Canagaratna, F. Paulot, and J. L. Jimenez
Atmos. Chem. Phys., 15, 11807–11833, https://doi.org/10.5194/acp-15-11807-2015, https://doi.org/10.5194/acp-15-11807-2015, 2015
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This work summarized all the studies reporting isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) measured globally by aerosol mass spectrometer and compare them with modeled gas-phase IEPOX, with results suggestive of the importance of IEPOX-SOA for regional and global OA budgets. A real-time tracer of IEPOX-SOA is thoroughly evaluated for the first time by combing multiple field and chamber studies. A quick and easy empirical method on IEPOX-SOA estimation is also presented.
M. O. Andreae, O. C. Acevedo, A. Araùjo, P. Artaxo, C. G. G. Barbosa, H. M. J. Barbosa, J. Brito, S. Carbone, X. Chi, B. B. L. Cintra, N. F. da Silva, N. L. Dias, C. Q. Dias-Júnior, F. Ditas, R. Ditz, A. F. L. Godoi, R. H. M. Godoi, M. Heimann, T. Hoffmann, J. Kesselmeier, T. Könemann, M. L. Krüger, J. V. Lavric, A. O. Manzi, A. P. Lopes, D. L. Martins, E. F. Mikhailov, D. Moran-Zuloaga, B. W. Nelson, A. C. Nölscher, D. Santos Nogueira, M. T. F. Piedade, C. Pöhlker, U. Pöschl, C. A. Quesada, L. V. Rizzo, C.-U. Ro, N. Ruckteschler, L. D. A. Sá, M. de Oliveira Sá, C. B. Sales, R. M. N. dos Santos, J. Saturno, J. Schöngart, M. Sörgel, C. M. de Souza, R. A. F. de Souza, H. Su, N. Targhetta, J. Tóta, I. Trebs, S. Trumbore, A. van Eijck, D. Walter, Z. Wang, B. Weber, J. Williams, J. Winderlich, F. Wittmann, S. Wolff, and A. M. Yáñez-Serrano
Atmos. Chem. Phys., 15, 10723–10776, https://doi.org/10.5194/acp-15-10723-2015, https://doi.org/10.5194/acp-15-10723-2015, 2015
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This paper describes the Amazon Tall Tower Observatory (ATTO), a new atmosphere-biosphere observatory located in the remote Amazon Basin. It presents results from ecosystem ecology, meteorology, trace gas, and aerosol measurements collected at the ATTO site during the first 3 years of operation.
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.
J. G. Levine, A. R. MacKenzie, O. J. Squire, A. T. Archibald, P. T. Griffiths, N. L. Abraham, J. A. Pyle, D. E. Oram, G. Forster, J. F. Brito, J. D. Lee, J. R. Hopkins, A. C. Lewis, S. J. B. Bauguitte, C. F. Demarco, P. Artaxo, P. Messina, J. Lathière, D. A. Hauglustaine, E. House, C. N. Hewitt, and E. Nemitz
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-15-24251-2015, https://doi.org/10.5194/acpd-15-24251-2015, 2015
Revised manuscript has not been submitted
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This study explores our ability to simulate atmospheric chemistry stemming from isoprene emissions—a reactive gas emitted from vegetation—in pristine and polluted regions of the Amazon basin. We explore how two contrasting models fare in reproducing recent airborne measurements in the region. Their differing treatments of transport and mixing are found to: profoundly affect their performance; and yield very different pictures of the exposure of the rainforest to harmful ozone concentrations.
E. T. Sena and P. Artaxo
Atmos. Chem. Phys., 15, 5471–5483, https://doi.org/10.5194/acp-15-5471-2015, https://doi.org/10.5194/acp-15-5471-2015, 2015
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A new methodology was developed for retrieving the daily direct radiative forcing of smoke aerosols (24h-DARF) using satellite remote sensing. This method was used to assess the DARF at high temporal resolution and over a large area in Amazonia. We showed that our methodology considerably reduces statistical sources of uncertainties in the estimate of the DARF. DARF assessments using the new methodology agree well with ground-based measurements and radiative transfer models.
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
Q. Chen, D. K. Farmer, L. V. Rizzo, T. Pauliquevis, M. Kuwata, T. G. Karl, A. Guenther, J. D. Allan, H. Coe, M. O. Andreae, U. Pöschl, J. L. Jimenez, P. Artaxo, and S. T. Martin
Atmos. Chem. Phys., 15, 3687–3701, https://doi.org/10.5194/acp-15-3687-2015, https://doi.org/10.5194/acp-15-3687-2015, 2015
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Submicron particle mass concentration in the Amazon during the wet season of 2008 was dominated by organic material. The PMF analysis finds a comparable importance of gas-phase (gas-to-particle condensation) and particle-phase (reactive uptake of isoprene oxidation products, especially of epoxydiols to acidic haze, fog, or cloud droplets) production of secondary organic material during the study period, together accounting for >70% of the organic-particle mass concentration.
A. M. Yáñez-Serrano, A. C. Nölscher, J. Williams, S. Wolff, E. Alves, G. A. Martins, E. Bourtsoukidis, J. Brito, K. Jardine, P. Artaxo, and J. Kesselmeier
Atmos. Chem. Phys., 15, 3359–3378, https://doi.org/10.5194/acp-15-3359-2015, https://doi.org/10.5194/acp-15-3359-2015, 2015
F. Pacifico, G. A. Folberth, S. Sitch, J. M. Haywood, L. V. Rizzo, F. F. Malavelle, and P. Artaxo
Atmos. Chem. Phys., 15, 2791–2804, https://doi.org/10.5194/acp-15-2791-2015, https://doi.org/10.5194/acp-15-2791-2015, 2015
G. Snider, C. L. Weagle, R. V. Martin, A. van Donkelaar, K. Conrad, D. Cunningham, C. Gordon, M. Zwicker, C. Akoshile, P. Artaxo, N. X. Anh, J. Brook, J. Dong, R. M. Garland, R. Greenwald, D. Griffith, K. He, B. N. Holben, R. Kahn, I. Koren, N. Lagrosas, P. Lestari, Z. Ma, J. Vanderlei Martins, E. J. Quel, Y. Rudich, A. Salam, S. N. Tripathi, C. Yu, Q. Zhang, Y. Zhang, M. Brauer, A. Cohen, M. D. Gibson, and Y. Liu
Atmos. Meas. Tech., 8, 505–521, https://doi.org/10.5194/amt-8-505-2015, https://doi.org/10.5194/amt-8-505-2015, 2015
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We have initiated a global network of ground-level monitoring stations to measure concentrations of fine aerosols in urban environments. Our findings include major ions species, total mass, and total scatter at three wavelengths. Results will be used to further evaluate and enhance satellite remote sensing estimates.
M. M. Bela, K. M. Longo, S. R. Freitas, D. S. Moreira, V. Beck, S. C. Wofsy, C. Gerbig, K. Wiedemann, M. O. Andreae, and P. Artaxo
Atmos. Chem. Phys., 15, 757–782, https://doi.org/10.5194/acp-15-757-2015, https://doi.org/10.5194/acp-15-757-2015, 2015
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In the Amazon Basin, gases that lead to the formation of ozone (O3), an air pollutant and greenhouse gas, are emitted from fire, urban and biogenic sources. This study presents the first basin wide aircraft measurements of O3 during the dry-to-wet and wet-to-dry transition seasons, which show extremely low values above undisturbed forest and increases from fires. This work also demonstrates the capabilities and limitations of regional atmospheric chemistry models in representing O3 in Amazonia.
M. Combe, J. Vilà-Guerau de Arellano, H. G. Ouwersloot, C. M. J. Jacobs, and W. Peters
Biogeosciences, 12, 103–123, https://doi.org/10.5194/bg-12-103-2015, https://doi.org/10.5194/bg-12-103-2015, 2015
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This study investigates the interactions among the carbon, water and heat cycles above a maize field at the diurnal scale. We couple two land-surface schemes, corresponding to two different modelling approaches, to the same atmospheric boundary-layer (ABL) model. We find the simpler meteorological approach best reproduces the surface and upper-air observations. Finally, we show that the interaction of subsidence with ABL dynamics is key to explain the daytime atmospheric CO2 budget.
J. Brito, L. V. Rizzo, W. T. Morgan, H. Coe, B. Johnson, J. Haywood, K. Longo, S. Freitas, M. O. Andreae, and P. Artaxo
Atmos. Chem. Phys., 14, 12069–12083, https://doi.org/10.5194/acp-14-12069-2014, https://doi.org/10.5194/acp-14-12069-2014, 2014
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This paper details the physical--chemical characteristics of aerosols in a region strongly impacted by biomass burning in the western part of the Brazilian Amazon region. For such, a large suite of state-of-the-art instruments for realtime analysis was deployed at a ground site. Among the key findings, we observe the strong prevalence of organic aerosols associated to fire emissions, with important climate effects, and indications of its very fast processing in the atmosphere.
J. D. Allan, W. T. Morgan, E. Darbyshire, M. J. Flynn, P. I. Williams, D. E. Oram, P. Artaxo, J. Brito, J. D. Lee, and H. Coe
Atmos. Chem. Phys., 14, 11393–11407, https://doi.org/10.5194/acp-14-11393-2014, https://doi.org/10.5194/acp-14-11393-2014, 2014
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
K. Tsigaridis, N. Daskalakis, M. Kanakidou, P. J. Adams, P. Artaxo, R. Bahadur, Y. Balkanski, S. E. Bauer, N. Bellouin, A. Benedetti, T. Bergman, T. K. Berntsen, J. P. Beukes, H. Bian, K. S. Carslaw, M. Chin, G. Curci, T. Diehl, R. C. Easter, S. J. Ghan, S. L. Gong, A. Hodzic, C. R. Hoyle, T. Iversen, S. Jathar, J. L. Jimenez, J. W. Kaiser, A. Kirkevåg, D. Koch, H. Kokkola, Y. H Lee, G. Lin, X. Liu, G. Luo, X. Ma, G. W. Mann, N. Mihalopoulos, J.-J. Morcrette, J.-F. Müller, G. Myhre, S. Myriokefalitakis, N. L. Ng, D. O'Donnell, J. E. Penner, L. Pozzoli, K. J. Pringle, L. M. Russell, M. Schulz, J. Sciare, Ø. Seland, D. T. Shindell, S. Sillman, R. B. Skeie, D. Spracklen, T. Stavrakou, S. D. Steenrod, T. Takemura, P. Tiitta, S. Tilmes, H. Tost, T. van Noije, P. G. van Zyl, K. von Salzen, F. Yu, Z. Wang, Z. Wang, R. A. Zaveri, H. Zhang, K. Zhang, Q. Zhang, and X. Zhang
Atmos. Chem. Phys., 14, 10845–10895, https://doi.org/10.5194/acp-14-10845-2014, https://doi.org/10.5194/acp-14-10845-2014, 2014
A. Rocha-Lima, J. V. Martins, L. A. Remer, N. A. Krotkov, M. H. Tabacniks, Y. Ben-Ami, and P. Artaxo
Atmos. Chem. Phys., 14, 10649–10661, https://doi.org/10.5194/acp-14-10649-2014, https://doi.org/10.5194/acp-14-10649-2014, 2014
G. P. Almeida, J. Brito, C. A. Morales, M. F. Andrade, and P. Artaxo
Atmos. Chem. Phys., 14, 7559–7572, https://doi.org/10.5194/acp-14-7559-2014, https://doi.org/10.5194/acp-14-7559-2014, 2014
G. G. Cirino, R. A. F. Souza, D. K. Adams, and P. Artaxo
Atmos. Chem. Phys., 14, 6523–6543, https://doi.org/10.5194/acp-14-6523-2014, https://doi.org/10.5194/acp-14-6523-2014, 2014
H. M. J. Barbosa, B. Barja, T. Pauliquevis, D. A. Gouveia, P. Artaxo, G. G. Cirino, R. M. N. Santos, and A. B. Oliveira
Atmos. Meas. Tech., 7, 1745–1762, https://doi.org/10.5194/amt-7-1745-2014, https://doi.org/10.5194/amt-7-1745-2014, 2014
J. A. Adame, M. Martínez, M. Sorribas, P. J. Hidalgo, H. Harder, J.-M. Diesch, F. Drewnick, W. Song, J. Williams, V. Sinha, M. A. Hernández-Ceballos, J. Vilà-Guerau de Arellano, R. Sander, Z. Hosaynali-Beygi, H. Fischer, J. Lelieveld, and B. De la Morena
Atmos. Chem. Phys., 14, 2325–2342, https://doi.org/10.5194/acp-14-2325-2014, https://doi.org/10.5194/acp-14-2325-2014, 2014
J. Brito, L. V. Rizzo, P. Herckes, P. C. Vasconcellos, S. E. S. Caumo, A. Fornaro, R. Y. Ynoue, P. Artaxo, and M. F. Andrade
Atmos. Chem. Phys., 13, 12199–12213, https://doi.org/10.5194/acp-13-12199-2013, https://doi.org/10.5194/acp-13-12199-2013, 2013
L. V. Rizzo, P. Artaxo, T. Müller, A. Wiedensohler, M. Paixão, G. G. Cirino, A. Arana, E. Swietlicki, P. Roldin, E. O. Fors, K. T. Wiedemann, L. S. M. Leal, and M. Kulmala
Atmos. Chem. Phys., 13, 2391–2413, https://doi.org/10.5194/acp-13-2391-2013, https://doi.org/10.5194/acp-13-2391-2013, 2013
J. A. Huffman, B. Sinha, R. M. Garland, A. Snee-Pollmann, S. S. Gunthe, P. Artaxo, S. T. Martin, M. O. Andreae, and U. Pöschl
Atmos. Chem. Phys., 12, 11997–12019, https://doi.org/10.5194/acp-12-11997-2012, https://doi.org/10.5194/acp-12-11997-2012, 2012
Related subject area
Subject: Clouds and Precipitation | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Impact of wildfire smoke on Arctic cirrus formation – Part 2: Simulation of MOSAiC 2019–2020 cases
Constraining aerosol–cloud adjustments by uniting surface observations with a perturbed parameter ensemble
Investigating ice formation pathways using a novel two-moment multi-class cloud microphysics scheme
Microphysics regimes due to haze–cloud interactions: cloud oscillation and cloud collapse
Impact of secondary ice production on thunderstorm electrification under different aerosol conditions
Accelerated impact of airborne glaciogenic seeding of stratiform clouds by turbulence
Model analysis of biases in the satellite-diagnosed aerosol effect on the cloud liquid water path
Evaluation of biases in mid-to-high-latitude surface snowfall and cloud phase in ERA5 and CMIP6 using satellite observations
Failed cyclogenesis of a mesoscale convective system near Cape Verde: The role of the Saharan trade wind layer among other inhibiting factors observed during the CADDIWA field campaign
Dynamical imprints on precipitation cluster statistics across a hierarchy of high-resolution simulations
Ice formation processes key in determining WCB outflow cirrus properties
Technical note: Phase space depiction of CCN activation and cloud droplet diffusional growth
Role of a key microphysical factor in mixed-phase stratocumulus clouds and their interactions with aerosols
High-resolution modelling of early contrail evolution from hydrogen-powered aircraft
Investigating the impact of subgrid-scale aerosol-cloud interaction on mesoscale meteorology prediction
Correction of ERA5 temperature and relative humidity biases by bivariate quantile mapping for contrail formation analysis
Can pollen affect precipitation?
Potential impacts of marine fuel regulations on an Arctic stratocumulus case and its radiative response
The impact of the mesh size and microphysics scheme on the representation of mid-level clouds in the ICON model in hilly and complex terrain
The role of ascent timescales for warm conveyor belt (WCB) moisture transport into the upper troposphere and lower stratosphere (UTLS)
Magnitude and timescale of liquid water path adjustments to cloud droplet number concentration perturbations for nocturnal non-precipitating marine stratocumulus
On the Processes Determining the Slope of Cloud-Water Adjustments in Non-Precipitating Stratocumulus
Estimating the concentration of silver iodide needed to detect unambiguous signatures of glaciogenic cloud seeding
On the impact of thunder on cloud ice crystals and droplets
Ice-nucleating particle concentration impacts cloud properties over Dronning Maud Land, East Antarctica, in COSMO-CLM2
Numerical simulation of aerosol concentration effects on cloud droplet size spectrum evolutions of warm stratiform clouds in Jiangxi, China
The impact of aerosol on cloud water: a heuristic perspective
Cold pools mediate mesoscale adjustments of trade-cumulus fields to changes in cloud-droplet number concentration
The presence of clouds lowers climate sensitivity in the MPI-ESM1.2 climate model
Diurnal variation in an amplified canopy urban heat island during heat wave periods in the megacity of Beijing: roles of mountain–valley breeze and urban morphology
Diurnal evolution of non-precipitating marine stratocumuli in a large-eddy simulation ensemble
Ambient and Intrinsic Dependencies of Evolving Ice-Phase Particles within a Decaying Winter Storm During IMPACTS
Counteracting Influences of Gravitational Settling Modulate Aerosol Impacts on Cloud Base Lowering Fog Characteristics
Numerical Case Study of the Aerosol-Cloud-Interactions in Warm Boundary Layer Clouds over the Eastern North Atlantic with an Interactive Chemistry Module
High ice water content in tropical mesoscale convective systems (a conceptual model)
Evolution of cloud droplet temperature and lifetime in spatiotemporally varying subsaturated environments with implications for ice nucleation at cloud edges
Effect of secondary ice production processes on the simulation of ice pellets using the Predicted Particle Properties microphysics scheme
Simulated particle evolution within a winter storm: contributions of riming to radar moments and precipitation fallout
Arctic Multilayer Clouds Require Accurate Thermodynamic Profiles and Efficient Primary and Secondary Ice Processes for a Realistic Structure and Composition
A thermal-driven graupel generation process to explain dry-season convective vigor over the Amazon
Modeling homogeneous ice nucleation from drop-freezing experiments: impact of droplet volume dispersion and cooling rates
Cloud water adjustments to aerosol perturbations are buffered by solar heating in non-precipitating marine stratocumuli
Glaciation of mixed-phase clouds: insights from bulk model and bin-microphysics large-eddy simulation informed by laboratory experiment
Influence of Temperature and Humidity on Contrail Formation Regions in EMAC: A Spring Case Study
Microphysical processes involving the vapour phase dominate in simulated low-level Arctic clouds
Understanding aerosol–cloud interactions using a single-column model for a cold-air outbreak case during the ACTIVATE campaign
The Critical Number and Size of Precipitation Embryos to Accelerate Warm Rain Initiation
On the sensitivity of aerosol–cloud interactions to changes in sea surface temperature in radiative–convective equilibrium
Exploring aerosol–cloud interactions in liquid-phase clouds over eastern China and its adjacent ocean using the WRF-Chem–SBM model
Impact on the stratocumulus-to-cumulus transition of the interaction of cloud microphysics and macrophysics with large-scale circulation
Albert Ansmann, Cristofer Jimenez, Daniel A. Knopf, Johanna Roschke, Johannes Bühl, Kevin Ohneiser, and Ronny Engelmann
Atmos. Chem. Phys., 25, 4867–4884, https://doi.org/10.5194/acp-25-4867-2025, https://doi.org/10.5194/acp-25-4867-2025, 2025
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In this study, we focus on the potential impact of wildfire smoke on cirrus formation. Aerosol and cirrus observations with lidar and radar during the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition, presented in the companion paper (Ansmann et al., 2025), are closely linked to comprehensive modeling of ice nucleation in cirrus evolution processes, presented in this article. A clear impact of wildfire smoke on cirrus formation was found.
August Mikkelsen, Daniel T. McCoy, Trude Eidhammer, Andrew Gettelman, Ci Song, Hamish Gordon, and Isabel L. McCoy
Atmos. Chem. Phys., 25, 4547–4570, https://doi.org/10.5194/acp-25-4547-2025, https://doi.org/10.5194/acp-25-4547-2025, 2025
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Whether increased aerosol increases or decreases liquid cloud mass has been a longstanding question. Observed correlations suggest that aerosols thin liquid cloud, but we are able to show that observations were consistent with an increase in liquid cloud in response to aerosols by leveraging a model where causality could be traced.
Tim Lüttmer, Peter Spichtinger, and Axel Seifert
Atmos. Chem. Phys., 25, 4505–4529, https://doi.org/10.5194/acp-25-4505-2025, https://doi.org/10.5194/acp-25-4505-2025, 2025
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We investigate ice formation pathways in idealized convective clouds using a novel microphysics scheme that distinguishes between five ice classes each with their own unique formation mechanism. Ice crystals from rime splintering form the lowermost layer of ice crystals around the updraft core. The majority of ice crystals in the anvil of the convective cloud stems from frozen droplets. Ice stemming from homogeneous and deposition nucleation was only relevant in the overshoot.
Fan Yang, Hamed Fahandezh Sadi, Raymond A. Shaw, Fabian Hoffmann, Pei Hou, Aaron Wang, and Mikhail Ovchinnikov
Atmos. Chem. Phys., 25, 3785–3806, https://doi.org/10.5194/acp-25-3785-2025, https://doi.org/10.5194/acp-25-3785-2025, 2025
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Large-eddy simulations of a convection cloud chamber show two new microphysics regimes, cloud oscillation and cloud collapse, due to haze–cloud interactions. Our results suggest that haze particles and their interactions with cloud droplets should be considered especially in polluted conditions. To properly simulate haze–cloud interactions, we need to resolve droplet activation and deactivation processes, instead of using Twomey-type activation parameterization.
Shiye Huang, Jing Yang, Jiaojiao Li, Qian Chen, Qilin Zhang, and Fengxia Guo
Atmos. Chem. Phys., 25, 1831–1850, https://doi.org/10.5194/acp-25-1831-2025, https://doi.org/10.5194/acp-25-1831-2025, 2025
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Aerosol and secondary ice production are both vital to charge separation in thunderstorms, but the relative importance of different SIP processes to cloud electrification under different aerosol conditions is not well understood. In this study, we show in a clean environment, the shattering of freezing drops has the greatest effect on the charging rate, while in a polluted environment, both rime splintering and the shattering of freezing drops have a significant effect on cloud electrification.
Meilian Chen, Xiaoqin Jing, Jiaojiao Li, Jing Yang, Xiaobo Dong, Bart Geerts, Yan Yin, Baojun Chen, Lulin Xue, Mengyu Huang, Ping Tian, and Shaofeng Hua
EGUsphere, https://doi.org/10.5194/egusphere-2025-47, https://doi.org/10.5194/egusphere-2025-47, 2025
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Several recent studies have reported complete cloud glaciation induced by airborne-based glaciogenic cloud seeding over plains. Since turbulence is an important factor to maintain clouds in mixed-phase, it is hypothesized that turbulence may have an impact on the seeding effect. This hypothesis is evident in the present study, which shows turbulence can accelerate the impact of airborne glaciogenic seeding of stratiform clouds.
Harri Kokkola, Juha Tonttila, Silvia M. Calderón, Sami Romakkaniemi, Antti Lipponen, Aapo Peräkorpi, Tero Mielonen, Edward Gryspeerdt, Timo Henrik Virtanen, Pekka Kolmonen, and Antti Arola
Atmos. Chem. Phys., 25, 1533–1543, https://doi.org/10.5194/acp-25-1533-2025, https://doi.org/10.5194/acp-25-1533-2025, 2025
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Understanding how atmospheric aerosols affect clouds is a scientific challenge. One question is how aerosols affects the amount of cloud water. We used a cloud-scale model to study these effects on marine clouds. The study showed that variations in cloud properties and instrument noise can cause bias in satellite-derived cloud water content. However, our results suggest that for similar weather conditions with well-defined aerosol concentrations, satellite data can reliably track these effects.
Franziska Hellmuth, Tim Carlsen, Anne Sophie Daloz, Robert Oscar David, Haochi Che, and Trude Storelvmo
Atmos. Chem. Phys., 25, 1353–1383, https://doi.org/10.5194/acp-25-1353-2025, https://doi.org/10.5194/acp-25-1353-2025, 2025
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This article compares the occurrence of supercooled liquid-containing clouds (sLCCs) and their link to surface snowfall in CloudSat–CALIPSO, ERA5, and the CMIP6 models. Significant discrepancies were found, with ERA5 and CMIP6 consistently overestimating sLCC and snowfall frequency. This bias is likely due to cloud microphysics parameterization. This conclusion has implications for accurately representing cloud phase and snowfall in future climate projections.
Guillaume Feger, Jean-Pierre Chaboureau, Thibaut Dauhut, Julien Delanoë, and Pierre Coutris
EGUsphere, https://doi.org/10.5194/egusphere-2025-105, https://doi.org/10.5194/egusphere-2025-105, 2025
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The Saharan air at trade wind layer, cold pools, and upper tropospheric dry air are identified as the three main factors inhibiting the cyclogenesis of the Pierre Henri mesoscale convective system. The findings were obtained trough observations made during two flights of the CADDIWA campaign and a convection-permitting simulation run with the Meso-NH model. They provide new insights into the complex dynamics of cyclogenesis in the Cape Verde region and challenge the existing model of the SAL.
Claudia Christine Stephan and Bjorn Stevens
Atmos. Chem. Phys., 25, 1209–1226, https://doi.org/10.5194/acp-25-1209-2025, https://doi.org/10.5194/acp-25-1209-2025, 2025
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Tropical precipitation cluster area and intensity distributions follow power laws, but the physical processes responsible for this behavior remain unknown. We analyze global simulations that realistically represent precipitation processes. We consider Earth-like planets as well as virtual planets to realize different types of large-scale dynamics. Our finding is that power laws in Earth’s precipitation cluster statistics stem from the robust power laws in Earth’s atmospheric wind field.
Tim Lüttmer, Annette Miltenberger, and Peter Spichtinger
EGUsphere, https://doi.org/10.5194/egusphere-2025-185, https://doi.org/10.5194/egusphere-2025-185, 2025
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We investigate ice formation pathways in a warm conveyor belt case study. We employ a multi-phase microphysics scheme that distinguishes between ice from different nucleation processes. Ice crystals in the cirrus outflow mostly stem from in-situ formation. Hence they were formed directly from the vapor phase. Sedimentational redistribution modulates cirrus properties and leads to a disagreement between cirrus origin classifications based on thermodynamic history and nucleation processes.
Wojciech W. Grabowski and Hanna Pawlowska
EGUsphere, https://doi.org/10.5194/egusphere-2024-4104, https://doi.org/10.5194/egusphere-2024-4104, 2025
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A simple diagram to depict cloud droplets formation via activation of cloud condensation nuclei (CCN) as well as their subsequent growth and evaporation is presented.
Seoung Soo Lee, Chang Hoon Jung, Jinho Choi, Young Jun Yoon, Junshik Um, Youtong Zheng, Jianping Guo, Manguttathil G. Manoj, Sang-Keun Song, and Kyung-Ja Ha
Atmos. Chem. Phys., 25, 705–726, https://doi.org/10.5194/acp-25-705-2025, https://doi.org/10.5194/acp-25-705-2025, 2025
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This study attempts to test a general factor that explains differences in the properties of different mixed-phase clouds using a modeling tool. Although this attempt is not to identify a factor that can perfectly explain and represent the properties of different mixed-phase clouds, we believe that this attempt acts as a valuable stepping stone towards a more complete, general way of using climate models to better predict climate change.
Annemarie Lottermoser and Simon Unterstraßer
EGUsphere, https://doi.org/10.5194/egusphere-2024-3859, https://doi.org/10.5194/egusphere-2024-3859, 2025
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Contrail-cirrus significantly contributes to aviation's overall climate impact. As hydrogen combustion and fuel cell use are emerging technologies for aircraft propulsion, we simulated individual contrails from hydrogen propulsion during the first six minutes after exhaust emission, termed the vortex phase. The ice crystal loss during that stage is crucial as the number of ice crystals has a large impact on the further evolution of contrails into contrail-cirrus and their radiative forcing.
Wenjie Zhang, Hong Wang, Xiaoye Zhang, Yue Peng, Zhaodong Liu, Deying Wang, Da Zhang, Chen Han, Yang Zhao, Junting Zhong, Wenxing Jia, Huiqiong Ning, and Huizheng Che
EGUsphere, https://doi.org/10.5194/egusphere-2024-3677, https://doi.org/10.5194/egusphere-2024-3677, 2025
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We implement a real-time subgrid-scale aerosol-cloud interaction (ACI) mechanism in a mesoscale atmospheric chemistry system and find that subgrid-scale ACI can improve meteorological factors predictions. This study demonstrates the importance of real-time subgrid-scale ACI to weather forecast and the necessity of multiscale ACI studies.
Kevin Wolf, Nicolas Bellouin, Olivier Boucher, Susanne Rohs, and Yun Li
Atmos. Chem. Phys., 25, 157–181, https://doi.org/10.5194/acp-25-157-2025, https://doi.org/10.5194/acp-25-157-2025, 2025
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ERA5 atmospheric reanalysis and airborne in situ observations from IAGOS are compared in terms of the representation of the contrail formation potential and the presence of supersaturation. Differences are traced back to biases in ERA5 relative humidity fields. Those biases are addressed by applying a quantile mapping technique that significantly improved contrail estimation based on post-processed ERA5 data.
Marje Prank, Juha Tonttila, Xiaoxia Shang, Sami Romakkaniemi, and Tomi Raatikainen
Atmos. Chem. Phys., 25, 183–197, https://doi.org/10.5194/acp-25-183-2025, https://doi.org/10.5194/acp-25-183-2025, 2025
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Large primary bioparticles such as pollen can be abundant in the atmosphere. In humid conditions pollen can rupture and release a large number of fine sub-pollen particles (SPPs). The paper investigates what kind of birch pollen concentrations are needed for the pollen and SPPs to start playing a noticeable role in cloud processes and alter precipitation formation. In the studied cases only the largest observed pollen concentrations were able to noticeably alter the precipitation formation.
Luís Filipe Escusa dos Santos, Hannah C. Frostenberg, Alejandro Baró Pérez, Annica M. L. Ekman, Luisa Ickes, and Erik S. Thomson
Atmos. Chem. Phys., 25, 119–142, https://doi.org/10.5194/acp-25-119-2025, https://doi.org/10.5194/acp-25-119-2025, 2025
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The Arctic is experiencing enhanced surface warming. The observed decline in Arctic sea-ice extent is projected to lead to an increase in Arctic shipping activity, which may lead to further climatic feedbacks. Using an atmospheric model and results from marine engine experiments that focused on fuel sulfur content reduction and exhaust wet scrubbing, we investigate how ship exhaust particles influence the properties of Arctic clouds. Implications for radiative surface processes are discussed.
Nadja Omanovic, Brigitta Goger, and Ulrike Lohmann
Atmos. Chem. Phys., 24, 14145–14175, https://doi.org/10.5194/acp-24-14145-2024, https://doi.org/10.5194/acp-24-14145-2024, 2024
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We evaluated the numerical weather model ICON in two horizontal resolutions with two bulk microphysics schemes over hilly and complex terrain in Switzerland and Austria, respectively. We focused on the model's ability to simulate mid-level clouds in summer and winter. By combining observational data from two different field campaigns, we show that an increase in the horizontal resolution and a more advanced cloud microphysics scheme is strongly beneficial for cloud representation.
Cornelis Schwenk and Annette Miltenberger
Atmos. Chem. Phys., 24, 14073–14099, https://doi.org/10.5194/acp-24-14073-2024, https://doi.org/10.5194/acp-24-14073-2024, 2024
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Warm conveyor belts (WCBs) transport moisture into the upper atmosphere, where it acts as a greenhouse gas. This transport is not well understood, and the role of rapidly rising air is unclear. We simulate a WCB and look at fast- and slow-rising air to see how moisture is (differently) transported. We find that for fast-ascending air more ice particles reach higher into the atmosphere and that frozen cloud particles are removed differently than during slow ascent, which has more water vapour.
Yao-Sheng Chen, Prasanth Prabhakaran, Fabian Hoffmann, Jan Kazil, Takanobu Yamaguchi, and Graham Feingold
EGUsphere, https://doi.org/10.5194/egusphere-2024-3891, https://doi.org/10.5194/egusphere-2024-3891, 2024
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Injecting sea salt aerosols into marine stratiform clouds can distribute the cloud water over more droplets in smaller sizes. This process is expected to make the clouds brighter, allowing them to reflect more sunlight back to space. However, it may also cause the clouds to lose water over time, reducing their ability to reflect sunlight. We use a computer model to show that the loss of cloud water occurs relatively quickly and does not completely offset the initial brightening.
Fabian Hoffmann, Yao-Sheng Chen, and Graham Feingold
EGUsphere, https://doi.org/10.5194/egusphere-2024-3893, https://doi.org/10.5194/egusphere-2024-3893, 2024
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Clouds reflect a substantial portion of the incoming solar radiation back into space. This capacity is determined by the number of cloud droplets, which in turn is influenced by the number of aerosol particles, forming the basis for aerosol-cloud-climate interactions. In this study, we use a simple mixed-layer approach to understand the effect of aerosol on cloud water in non-precipitating stratocumulus.
Jing Yang, Jiaojiao Li, Meilian Chen, Xiaoqin Jing, Yan Yin, Bart Geerts, Zhien Wang, Yubao Liu, Baojun Chen, Shaofeng Hua, Hao Hu, Xiaobo Dong, Ping Tian, Qian Chen, and Yang Gao
Atmos. Chem. Phys., 24, 13833–13848, https://doi.org/10.5194/acp-24-13833-2024, https://doi.org/10.5194/acp-24-13833-2024, 2024
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Detecting unambiguous signatures is vital for examining cloud-seeding impacts, but often, seeding signatures are immersed in natural variability. In this study, reflectivity changes induced by glaciogenic seeding using different AgI concentrations are investigated under various conditions, and a method is developed to estimate the AgI concentration needed to detect unambiguous seeding signatures. The results aid in operational seeding-based decision-making regarding the amount of AgI dispersed.
Konstantinos Kourtidis, Stavros Stathopoulos, and Vassilis Amiridis
EGUsphere, https://doi.org/10.5194/egusphere-2024-3314, https://doi.org/10.5194/egusphere-2024-3314, 2024
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The loud sound of thunder will induce mechanical effects on cloud droplets and ice particles, causing changes in their size distribution.
Florian Sauerland, Niels Souverijns, Anna Possner, Heike Wex, Preben Van Overmeiren, Alexander Mangold, Kwinten Van Weverberg, and Nicole van Lipzig
Atmos. Chem. Phys., 24, 13751–13768, https://doi.org/10.5194/acp-24-13751-2024, https://doi.org/10.5194/acp-24-13751-2024, 2024
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We use a regional climate model, COSMO-CLM², enhanced with a module resolving aerosol processes, to study Antarctic clouds. We prescribe different concentrations of ice-nucleating particles to our model to assess how these clouds respond to concentration changes, validating results with cloud and aerosol observations from the Princess Elisabeth Antarctica station. Our results show that aerosol–cloud interactions vary with temperature, providing valuable insights into Antarctic cloud dynamics.
Yi Li, Xiaoli Liu, and Hengjia Cai
Atmos. Chem. Phys., 24, 13525–13540, https://doi.org/10.5194/acp-24-13525-2024, https://doi.org/10.5194/acp-24-13525-2024, 2024
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The influence of different aerosol modes on cloud processes remains controversial. We modified the aerosol spectra and concentrations to simulate a warm stratiform cloud process in Jiangxi, China, using the WRF-SBM scheme. Research shows that different aerosol spectra have diverse effects on cloud droplet spectra, cloud development, and the correlation between dispersion (ε) and cloud physics quantities. Compared to cloud droplet concentration, ε is more sensitive to the volume radius.
Fabian Hoffmann, Franziska Glassmeier, and Graham Feingold
Atmos. Chem. Phys., 24, 13403–13412, https://doi.org/10.5194/acp-24-13403-2024, https://doi.org/10.5194/acp-24-13403-2024, 2024
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Clouds constitute a major cooling influence on Earth's climate system by reflecting a large fraction of the incident solar radiation back to space. This ability is controlled by the number of cloud droplets, which is governed by the number of aerosol particles in the atmosphere, laying the foundation for so-called aerosol–cloud–climate interactions. In this study, a simple model to understand the effect of aerosol on cloud water is developed and applied.
Pouriya Alinaghi, Fredrik Jansson, Daniel A. Blázquez, and Franziska Glassmeier
EGUsphere, https://doi.org/10.5194/egusphere-2024-3501, https://doi.org/10.5194/egusphere-2024-3501, 2024
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Shallow clouds in the trades are a major source of uncertainty in climate projections. These clouds organize into striking mesoscale patterns that are exactly what climate models lack. This study explores the origin of such patterns and investigates how variations in microscale properties control them. The importance of microscale effects is compared to that of large-scale forcing on the mesoscale organization of trade-cumulus fields.
Andrea Mosso, Thomas Hocking, and Thorsten Mauritsen
Atmos. Chem. Phys., 24, 12793–12806, https://doi.org/10.5194/acp-24-12793-2024, https://doi.org/10.5194/acp-24-12793-2024, 2024
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Clouds play a crucial role in the Earth's energy balance, as they can either warm up or cool down the area they cover depending on their height and depth. They are expected to alter their behaviour under climate change, affecting the warming generated by greenhouse gases. This paper proposes a new method to estimate their overall effect on this warming by simulating a climate where clouds are transparent. Results show that with the model used, clouds have a stabilising effect on climate.
Tao Shi, Yuanjian Yang, Ping Qi, and Simone Lolli
Atmos. Chem. Phys., 24, 12807–12822, https://doi.org/10.5194/acp-24-12807-2024, https://doi.org/10.5194/acp-24-12807-2024, 2024
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This paper explored the formation mechanisms of the amplified canopy urban heat island intensity (ΔCUHII) during heat wave (HW) periods in the megacity of Beijing from the perspectives of mountain–valley breeze and urban morphology. During the mountain breeze phase, high-rise buildings with lower sky view factors (SVFs) had a pronounced effect on the ΔCUHII. During the valley breeze phase, high-rise buildings exerted a dual influence on the ΔCUHII.
Yao-Sheng Chen, Jianhao Zhang, Fabian Hoffmann, Takanobu Yamaguchi, Franziska Glassmeier, Xiaoli Zhou, and Graham Feingold
Atmos. Chem. Phys., 24, 12661–12685, https://doi.org/10.5194/acp-24-12661-2024, https://doi.org/10.5194/acp-24-12661-2024, 2024
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Marine stratocumulus cloud is a type of shallow cloud that covers the vast areas of Earth's surface. It plays an important role in Earth's energy balance by reflecting solar radiation back to space. We used numerical models to simulate a large number of marine stratocumuli with different characteristics. We found that how the clouds develop throughout the day is affected by the level of humidity in the air above the clouds and how closely the clouds connect to the ocean surface.
Andrew DeLaFrance, Lynn McMurdie, Angela Rowe, and Andrew Heymsfield
EGUsphere, https://doi.org/10.5194/egusphere-2024-3423, https://doi.org/10.5194/egusphere-2024-3423, 2024
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Numerical modeling simulations are used to investigate ice crystal growth and decay processes within a banded region of enhanced precipitation rates during a prominent winter storm. We identify robust primary ice growth in the upper portion of the cloud but decay exceeding 70 % during fallout through a subsaturated layer. The ice fall characteristics and decay rate are sensitive to the ambient cloud properties which has implications for radar-based measurements and precipitation accumulations.
Nathan H. Pope and Adele L. Igel
EGUsphere, https://doi.org/10.5194/egusphere-2024-3214, https://doi.org/10.5194/egusphere-2024-3214, 2024
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We used PAFOG, an atmospheric model that simulates a single column, to study the sensitivity of marine fog formed through the lowering of the base of a stratus cloud to meteorology and aerosols. We found that higher aerosol concentration reduces the likelihood and duration of fog, but leads to denser fog. This overall trend was caused by multiple physical mechanisms depending on conditions.
Hsiang-He Lee, Xue Zheng, Shaoyue Qiu, and Yuan Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3199, https://doi.org/10.5194/egusphere-2024-3199, 2024
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The study investigates how aerosol-cloud interactions affect warm boundary layer stratiform clouds over the Eastern North Atlantic. High-resolution WRF-Chem simulations reveal that non-rain clouds at the edges of cloud systems are prone to evaporation, leading to an aerosol drying effect and a transition of aerosols back to accumulation mode for future activation. The study emphasizes that this dynamic behavior is often not adequately represented in most previous prescribed-aerosol simulations.
Alexei Korolev, Zhipeng Qu, Jason Milbrandt, Ivan Heckman, Mélissa Cholette, Mengistu Wolde, Cuong Nguyen, Greg M. McFarquhar, Paul Lawson, and Ann M. Fridlind
Atmos. Chem. Phys., 24, 11849–11881, https://doi.org/10.5194/acp-24-11849-2024, https://doi.org/10.5194/acp-24-11849-2024, 2024
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The phenomenon of high ice water content (HIWC) occurs in mesoscale convective systems (MCSs) when a large number of small ice particles with typical sizes of a few hundred micrometers is found at high altitudes. It was found that secondary ice production in the vicinity of the melting layer plays a key role in the formation and maintenance of HIWC. This study presents a conceptual model of the formation of HIWC in tropical MCSs based on in situ observations and numerical simulation.
Puja Roy, Robert M. Rauber, and Larry Di Girolamo
Atmos. Chem. Phys., 24, 11653–11678, https://doi.org/10.5194/acp-24-11653-2024, https://doi.org/10.5194/acp-24-11653-2024, 2024
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Cloud droplet temperature and lifetime impact cloud microphysical processes such as the activation of ice-nucleating particles. We investigate the thermal and radial evolution of supercooled cloud droplets and their surrounding environments with an aim to better understand observed enhanced ice formation at supercooled cloud edges. This analysis shows that the magnitude of droplet cooling during evaporation is greater than estimated from past studies, especially for drier environments.
Mathieu Lachapelle, Mélissa Cholette, and Julie M. Thériault
Atmos. Chem. Phys., 24, 11285–11304, https://doi.org/10.5194/acp-24-11285-2024, https://doi.org/10.5194/acp-24-11285-2024, 2024
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Hazardous precipitation types such as ice pellets and freezing rain are difficult to predict because they are associated with complex microphysical processes. Using Predicted Particle Properties (P3), this work shows that secondary ice production processes increase the amount of ice pellets simulated while decreasing the amount of freezing rain. Moreover, the properties of the simulated precipitation compare well with those that were measured.
Andrew DeLaFrance, Lynn A. McMurdie, Angela K. Rowe, and Andrew J. Heymsfield
Atmos. Chem. Phys., 24, 11191–11206, https://doi.org/10.5194/acp-24-11191-2024, https://doi.org/10.5194/acp-24-11191-2024, 2024
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Using a numerical model, the process whereby falling ice crystals accumulate supercooled liquid water droplets is investigated to elucidate its effects on radar-based measurements and surface precipitation. We demonstrate that this process accounted for 55% of the precipitation during a wintertime storm and is uniquely discernable from other ice crystal growth processes in Doppler velocity measurements. These results have implications for measurements from airborne and spaceborne platforms.
Gabriella Wallentin, Annika Oertel, Luisa Ickes, Peggy Achtert, Matthias Tesche, and Corinna Hoose
EGUsphere, https://doi.org/10.5194/egusphere-2024-2988, https://doi.org/10.5194/egusphere-2024-2988, 2024
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Multilayer clouds are common in the Arctic but remain understudied. We use an atmospheric model to simulate multilayer cloud cases from the Arctic expedition MOSAiC 2019/2020. We find that it is complex to accurately model these cloud layers due to the lack of correct temperature and humidity profiles. The model also struggles to capture the observed cloud phase, the relative concentration of cloud droplets and cloud ice. We constrain our model to measured aerosols to mitigate this issue.
Toshi Matsui, Daniel Hernandez-Deckers, Scott E. Giangrande, Thiago S. Biscaro, Ann Fridlind, and Scott Braun
Atmos. Chem. Phys., 24, 10793–10814, https://doi.org/10.5194/acp-24-10793-2024, https://doi.org/10.5194/acp-24-10793-2024, 2024
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Using computer simulations and real measurements, we discovered that storms over the Amazon were narrower but more intense during the dry periods, producing heavier rain and more ice particles in the clouds. Our research showed that cumulus bubbles played a key role in creating these intense storms. This study can improve the representation of the effect of continental and ocean environments on tropical regions' rainfall patterns in simulations.
Ravi Kumar Reddy Addula, Ingrid de Almeida Ribeiro, Valeria Molinero, and Baron Peters
Atmos. Chem. Phys., 24, 10833–10848, https://doi.org/10.5194/acp-24-10833-2024, https://doi.org/10.5194/acp-24-10833-2024, 2024
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Ice nucleation from supercooled droplets is important in many weather and climate modeling efforts. For experiments where droplets are steadily supercooled from the freezing point, our work combines nucleation theory and survival probability analysis to predict the nucleation spectrum, i.e., droplet freezing probabilities vs. temperature. We use the new framework to extract approximately consistent rate parameters from experiments with different cooling rates and droplet sizes.
Jianhao Zhang, Yao-Sheng Chen, Takanobu Yamaguchi, and Graham Feingold
Atmos. Chem. Phys., 24, 10425–10440, https://doi.org/10.5194/acp-24-10425-2024, https://doi.org/10.5194/acp-24-10425-2024, 2024
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Quantifying cloud response to aerosol perturbations presents a major challenge in understanding the human impact on climate. Using a large number of process-resolving simulations of marine stratocumulus, we show that solar heating drives a negative feedback mechanism that buffers the persistent negative trend in cloud water adjustment after sunrise. This finding has implications for the dependence of the cloud cooling effect on the timing of deliberate aerosol perturbations.
Aaron Wang, Steve Krueger, Sisi Chen, Mikhail Ovchinnikov, Will Cantrell, and Raymond A. Shaw
Atmos. Chem. Phys., 24, 10245–10260, https://doi.org/10.5194/acp-24-10245-2024, https://doi.org/10.5194/acp-24-10245-2024, 2024
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We employ two methods to examine a laboratory experiment on clouds with both ice and liquid phases. The first assumes well-mixed properties; the second resolves the spatial distribution of turbulence and cloud particles. Results show that while the trends in mean properties generally align, when turbulence is resolved, liquid droplets are not fully depleted by ice due to incomplete mixing. This underscores the threshold of ice mass fraction in distinguishing mixed-phase clouds from ice clouds.
Patrick Peter, Sigrun Matthes, Christine Frömming, Patrick Jöckel, Luca Bugliaro, Andreas Giez, Martina Krämer, and Volker Grewe
EGUsphere, https://doi.org/10.5194/egusphere-2024-2142, https://doi.org/10.5194/egusphere-2024-2142, 2024
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Our study examines how temperature and humidity representations influence contrail (-cirrus) formation criteria. Using various model setups, we identified biases that lead to overestimation of contrail formation areas. By comparing simulations with in-flight and satellite observations, we confirmed that humidity threshold choices greatly affect contrail predictions. These findings can help develop strategies for climate-optimized flight routes, potentially reducing aviation's climate effect.
Theresa Kiszler, Davide Ori, and Vera Schemann
Atmos. Chem. Phys., 24, 10039–10053, https://doi.org/10.5194/acp-24-10039-2024, https://doi.org/10.5194/acp-24-10039-2024, 2024
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Microphysical processes impact the phase-partitioning of clouds. In this study we evaluate these processes while focusing on low-level Arctic clouds. To achieve this we used an extensive simulation set in combination with a new diagnostic tool. This study presents our findings on the relevance of these processes and their behaviour under different thermodynamic regimes.
Shuaiqi Tang, Hailong Wang, Xiang-Yu Li, Jingyi Chen, Armin Sorooshian, Xubin Zeng, Ewan Crosbie, Kenneth L. Thornhill, Luke D. Ziemba, and Christiane Voigt
Atmos. Chem. Phys., 24, 10073–10092, https://doi.org/10.5194/acp-24-10073-2024, https://doi.org/10.5194/acp-24-10073-2024, 2024
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We examined marine boundary layer clouds and their interactions with aerosols in the E3SM single-column model (SCM) for a case study. The SCM shows good agreement when simulating the clouds with high-resolution models. It reproduces the relationship between cloud droplet and aerosol particle number concentrations as produced in global models. However, the relationship between cloud liquid water and droplet number concentration is different, warranting further investigation.
Jung-Sub Lim, Yign Noh, Hyunho Lee, and Fabian Hoffmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-2636, https://doi.org/10.5194/egusphere-2024-2636, 2024
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The onset of rain is not fully understood. In this study, we address the impact of comparably large particles (precipitation embryos), speculated to initiate rain in clouds that do not contain ice. We showed that these particles can accelerate rain initiation only if their size and number exceed a threshold. As this threshold depends on the cloud's micro- and macrostructure, the impact of large particles on rain initiation is situation-dependent.
Suf Lorian and Guy Dagan
Atmos. Chem. Phys., 24, 9323–9338, https://doi.org/10.5194/acp-24-9323-2024, https://doi.org/10.5194/acp-24-9323-2024, 2024
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We examine the combined effect of aerosols and sea surface temperature (SST) on clouds under equilibrium conditions in cloud-resolving radiative–convective equilibrium simulations. We demonstrate that the aerosol–cloud interaction's effect on top-of-atmosphere energy gain strongly depends on the underlying SST, while the shortwave part of the spectrum is significantly more sensitive to SST. Furthermore, increasing aerosols influences upper-troposphere stability and thus anvil cloud fraction.
Jianqi Zhao, Xiaoyan Ma, Johannes Quaas, and Hailing Jia
Atmos. Chem. Phys., 24, 9101–9118, https://doi.org/10.5194/acp-24-9101-2024, https://doi.org/10.5194/acp-24-9101-2024, 2024
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We explore aerosol–cloud interactions in liquid-phase clouds over eastern China and its adjacent ocean in winter based on the WRF-Chem–SBM model, which couples a spectral-bin microphysics scheme and an online aerosol module. Our study highlights the differences in aerosol–cloud interactions between land and ocean and between precipitation clouds and non-precipitation clouds, and it differentiates and quantifies their underlying mechanisms.
Je-Yun Chun, Robert Wood, Peter N. Blossey, and Sarah J. Doherty
EGUsphere, https://doi.org/10.5194/egusphere-2024-2439, https://doi.org/10.5194/egusphere-2024-2439, 2024
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This study explores how aerosols affect clouds transitioning from stratocumulus to cumulus along trade winds under varying atmospheric conditions. We found that aerosols typically reduce precipitation and raise cloud height, but their impact changes when subsidence changes by aerosol enhancement are considered. Our findings indicate that the cooling effect of aerosols might be overestimated if these atmospheric changes are not accounted for.
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Short summary
Shallow clouds (vertical extent up to 3 km height) are ubiquitous throughout the Amazon and are responsible for redistributing the solar heat and moisture vertically and horizontally. They are a key component of the water cycle because they can grow past the shallow phase to contribute significantly to the precipitation formation. However, they need favourable environmental conditions to grow. In this study, we analyse how changing wind patterns affect the development of such shallow clouds.
Shallow clouds (vertical extent up to 3 km height) are ubiquitous throughout the Amazon and are...
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