Articles | Volume 17, issue 11 
            
                
                    
                    
            
            
            https://doi.org/10.5194/acp-17-6839-2017
                    © Author(s) 2017. This work is distributed under 
the Creative Commons Attribution 3.0 License.
                the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acp-17-6839-2017
                    © Author(s) 2017. This work is distributed under 
the Creative Commons Attribution 3.0 License.
                the Creative Commons Attribution 3.0 License.
A new methodology for PBL height estimations based on lidar depolarization measurements: analysis and comparison against MWR and WRF model-based results
                                            Andalusian Institute for Earth System Research (IISTA-CEAMA), Granada, Spain
                                        
                                    
                                            Department of Applied Physics, University of Granada, Granada, Spain
                                        
                                    
                                            now at: Institut Pierre-Simon Laplace, CNRS–Ecole Polytechnique, Paris, France
                                        
                                    Gregori de Arruda Moreira
                                            Institute of Energetic and Nuclear Research (IPEN), São Paulo, Brazil
                                        
                                    Francisco Navas-Guzmán
                                            Institute of Applied Physics (IAP), University of Bern, Bern, Switzerland
                                        
                                    María José Granados-Muñoz
                                            Andalusian Institute for Earth System Research (IISTA-CEAMA), Granada, Spain
                                        
                                    
                                            Department of Applied Physics, University of Granada, Granada, Spain
                                        
                                    
                                            currently at: Table Mountain Facility, NASA/Jet Propulsion Laboratory, California Institute of Technology, Wrightwood, California, USA
                                        
                                    Juan Luis Guerrero-Rascado
                                            Andalusian Institute for Earth System Research (IISTA-CEAMA), Granada, Spain
                                        
                                    
                                            Department of Applied Physics, University of Granada, Granada, Spain
                                        
                                    David Pozo-Vázquez
                                            Department of Physics, University of Jaén, Jaén, Spain
                                        
                                    Clara Arbizu-Barrena
                                            Department of Physics, University of Jaén, Jaén, Spain
                                        
                                    Francisco José Olmo Reyes
                                            Andalusian Institute for Earth System Research (IISTA-CEAMA), Granada, Spain
                                        
                                    
                                            Department of Applied Physics, University of Granada, Granada, Spain
                                        
                                    Marc Mallet
                                            Centre National de Recherches Météorologiques, UMR 3589, Météo-France/CNRS, Toulouse, France
                                        
                                    Lucas Alados Arboledas
                                            Andalusian Institute for Earth System Research (IISTA-CEAMA), Granada, Spain
                                        
                                    
                                            Department of Applied Physics, University of Granada, Granada, Spain
                                        
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                                                Validation activities of Aeolus wind products were performed in Granada with different upward-probing instrumentation (Doppler lidar system and radiosondes) and spatiotemporal collocation criteria. Specific advantages and disadvantages of each instrument were identified, and an optimal comparison criterion is proposed. Aeolus was proven to provide reliable wind products, and the upward-probing instruments were proven to be useful for Aeolus wind product validation activities.
                                            
                                            
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                                        Jesús Abril-Gago, Juan Luis Guerrero-Rascado, Maria João Costa, Juan Antonio Bravo-Aranda, Michaël Sicard, Diego Bermejo-Pantaleón, Daniele Bortoli, María José Granados-Muñoz, Alejandro Rodríguez-Gómez, Constantino Muñoz-Porcar, Adolfo Comerón, Pablo Ortiz-Amezcua, Vanda Salgueiro, Marta María Jiménez-Martín, and Lucas Alados-Arboledas
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                                        Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-759, https://doi.org/10.5194/acp-2021-759, 2021
                                    Revised manuscript not accepted 
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                                    This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP). 
                                    Short summary
                                    Short summary
                                            
                                                Due to the major radiative role of dust in Climate Change, a vertical assessment of the long-wave (and net) dust direct radiative effect of both fine and coarse dust, separately, is introduced. The study relies on an intense Saharan dust outbreak across the Iberian Peninsula, observed by five lidar stations with SW-centre-NE coverage. A comparative evaluation of the differences by considering the total dust (no separation) is also examined. It complements a similar study in the short-wave range.
                                            
                                            
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                                    Short summary
                                    Short summary
                                            
                                                This study applies machine learning (ML) techniques to classify aerosols using high-resolution multiwavelength lidar data from EARLINET network. We developed a reference dataset and evaluated six ML models, with LightGBM achieving over 90 % accuracy. Depolarization data proved critical for improving dust classification. Validated against independent datasets, our approach improves aerosol classification and may help refine lidar-based processing strategies.
                                            
                                            
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                                                We have used absorption from a photothermal interferometer and scattering measurements to evaluate the most deployed filter photometers used to measure absorption for monitoring networks. We used soot- and dust-dominated aerosol samples in both laboratory and ambient settings. Our results indicated that one of these filter photometers, the MAAP (Multiangle Absorption Photometer), usually used as a pseudo-reference instrument, had 47 % higher absorption values than our reference measurements.
                                            
                                            
                                        Elena Bazo, Daniel Pérez-Ramírez, Antonio Valenzuela, J. Vanderlei Martins, Gloria Titos, Alberto Cazorla, Fernando Rejano, Diego Patrón, Arlett Díaz-Zurita, Francisco José García-Izquierdo, David Fuertes, Lucas Alados-Arboledas, and Francisco José Olmo
                                    Atmos. Chem. Phys., 25, 6325–6352, https://doi.org/10.5194/acp-25-6325-2025, https://doi.org/10.5194/acp-25-6325-2025, 2025
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                                                This works analyzes the aerosol scattering phase function for transported Saharan dust to the city of Granada – located in southwestern Europe. We use the novel technique polar imaging nephelometry that helps to determine the phase functions using a CMOS camera. The capability of measuring with polarized light helps to infer new properties about the mixture of Saharan dust particles with those of anthropogenic origin.
                                            
                                            
                                        María-Ángeles López-Cayuela, Carmen Córdoba-Jabonero, Michaël Sicard, Jesús Abril-Gago, Vanda Salgueiro, Adolfo Comerón, María José Granados-Muñoz, Maria João Costa, Constantino Muñoz-Porcar, Juan Antonio Bravo-Aranda, Daniele Bortoli, Alejandro Rodríguez-Gómez, Lucas Alados-Arboledas, and Juan Luis Guerrero-Rascado
                                    Atmos. Chem. Phys., 25, 3213–3231, https://doi.org/10.5194/acp-25-3213-2025, https://doi.org/10.5194/acp-25-3213-2025, 2025
                                    Short summary
                                    Short summary
                                            
                                                Due to the significant radiative role of dust in climate change, vertical assessments of the short-wave dust direct radiative effect of both fine and coarse dust particles are performed separately. The study is focused on an intense Saharan dust outbreak crossing the Iberian Peninsula in springtime monitored by five Iberian lidar stations with southwest–northeast coverage. A comparative study to evaluate the differences found by considering the total dust (no separation) is also examined.
                                            
                                            
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                                        Fernando Rejano, Andrea Casans, Marta Via, Juan Andrés Casquero-Vera, Sonia Castillo, Hassan Lyamani, Alberto Cazorla, Elisabeth Andrews, Daniel Pérez-Ramírez, Andrés Alastuey, Francisco Javier Gómez-Moreno, Lucas Alados-Arboledas, Francisco José Olmo, and Gloria Titos
                                    Atmos. Chem. Phys., 24, 13865–13888, https://doi.org/10.5194/acp-24-13865-2024, https://doi.org/10.5194/acp-24-13865-2024, 2024
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                                                This study provides valuable insights to improve cloud condensation nuclei (CCN) estimations at a high-altitude remote site which is influenced by nearby urban pollution. Understanding the factors that affect CCN estimations is essential to improve the CCN data coverage worldwide and assess aerosol–cloud interactions on a global scale. This is crucial for improving climate models, since aerosol–cloud interactions are the most important source of uncertainty in climate projections.
                                            
                                            
                                        Marc Mallet, Aurore Voldoire, Fabien Solmon, Pierre Nabat, Thomas Drugé, and Romain Roehrig
                                    Atmos. Chem. Phys., 24, 12509–12535, https://doi.org/10.5194/acp-24-12509-2024, https://doi.org/10.5194/acp-24-12509-2024, 2024
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                                                This study investigates the interactions between smoke aerosols and climate in tropical Africa using a coupled ocean–atmosphere–aerosol climate model. The work shows that smoke plumes have a significant impact by increasing the low-cloud fraction, decreasing the ocean and continental surface temperature and reducing the precipitation of coastal western Africa. It also highlights the role of the ocean temperature response and its feedbacks for the September–November season.
                                            
                                            
                                        Celia Herrero del Barrio, Roberto Román, Ramiro González, Alberto Cazorla, Marcos Herreras-Giralda, Juan Carlos Antuña-Sánchez, Francisco Molero, Francisco Navas-Guzmán, Antonio Serrano, María Ángeles Obregón, Yolanda Sola, Marco Pandolfi, Sara Herrero-Anta, Daniel González-Fernández, Jorge Muñiz-Rosado, David Mateos, Abel Calle, Carlos Toledano, Victoria Eugenia Cachorro, and Ángel Máximo de Frutos
                                        EGUsphere, https://doi.org/10.5194/egusphere-2024-581, https://doi.org/10.5194/egusphere-2024-581, 2024
                                    Preprint withdrawn 
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                                        Wenyue Wang, Klemens Hocke, Leonardo Nania, Alberto Cazorla, Gloria Titos, Renaud Matthey, Lucas Alados-Arboledas, Agustín Millares, and Francisco Navas-Guzmán
                                    Atmos. Chem. Phys., 24, 1571–1585, https://doi.org/10.5194/acp-24-1571-2024, https://doi.org/10.5194/acp-24-1571-2024, 2024
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                                                The south-central interior of Andalusia experiences complex precipitation patterns as a result of the semi-arid Mediterranean climate and the influence of Saharan dust. This study monitored the inter-relations between aerosols, clouds, meteorological variables, and precipitation systems using ground-based remote sensing and in situ instruments.
                                            
                                            
                                        Juan Andrés Casquero-Vera, Daniel Pérez-Ramírez, Hassan Lyamani, Fernando Rejano, Andrea Casans, Gloria Titos, Francisco José Olmo, Lubna Dada, Simo Hakala, Tareq Hussein, Katrianne Lehtipalo, Pauli Paasonen, Antti Hyvärinen, Noemí Pérez, Xavier Querol, Sergio Rodríguez, Nikos Kalivitis, Yenny González, Mansour A. Alghamdi, Veli-Matti Kerminen, Andrés Alastuey, Tuukka Petäjä, and Lucas Alados-Arboledas
                                    Atmos. Chem. Phys., 23, 15795–15814, https://doi.org/10.5194/acp-23-15795-2023, https://doi.org/10.5194/acp-23-15795-2023, 2023
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                                                Here we present the first study of the effect of mineral dust on the inhibition/promotion of new particle formation (NPF) events in different dust-influenced areas. Unexpectedly, we show that the occurrence of NPF events is highly frequent during mineral dust outbreaks, occurring even during extreme dust outbreaks. We also show that the occurrence of NPF events during mineral dust outbreaks significantly affects the potential cloud condensation nuclei budget.
                                            
                                            
                                        Alexandra Tsekeri, Anna Gialitaki, Marco Di Paolantonio, Davide Dionisi, Gian Luigi Liberti, Alnilam Fernandes, Artur Szkop, Aleksander Pietruczuk, Daniel Pérez-Ramírez, Maria J. Granados Muñoz, Juan Luis Guerrero-Rascado, Lucas Alados-Arboledas, Diego Bermejo Pantaleón, Juan Antonio Bravo-Aranda, Anna Kampouri, Eleni Marinou, Vassilis Amiridis, Michael Sicard, Adolfo Comerón, Constantino Muñoz-Porcar, Alejandro Rodríguez-Gómez, Salvatore Romano, Maria Rita Perrone, Xiaoxia Shang, Mika Komppula, Rodanthi-Elisavet Mamouri, Argyro Nisantzi, Diofantos Hadjimitsis, Francisco Navas-Guzmán, Alexander Haefele, Dominika Szczepanik, Artur Tomczak, Iwona S. Stachlewska, Livio Belegante, Doina Nicolae, Kalliopi Artemis Voudouri, Dimitris Balis, Athena A. Floutsi, Holger Baars, Linda Miladi, Nicolas Pascal, Oleg Dubovik, and Anton Lopatin
                                    Atmos. Meas. Tech., 16, 6025–6050, https://doi.org/10.5194/amt-16-6025-2023, https://doi.org/10.5194/amt-16-6025-2023, 2023
                                    Short summary
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                                                EARLINET/ACTRIS organized an intensive observational campaign in May 2020, with the objective of monitoring the atmospheric state over Europe during the COVID-19 lockdown and relaxation period. The work presented herein focuses on deriving a common methodology for applying a synergistic retrieval that utilizes the network's ground-based passive and active remote sensing measurements and deriving the aerosols from anthropogenic activities over Europe.
                                            
                                            
                                        Jesús Abril-Gago, Pablo Ortiz-Amezcua, Diego Bermejo-Pantaleón, Juana Andújar-Maqueda, Juan Antonio Bravo-Aranda, María José Granados-Muñoz, Francisco Navas-Guzmán, Lucas Alados-Arboledas, Inmaculada Foyo-Moreno, and Juan Luis Guerrero-Rascado
                                    Atmos. Chem. Phys., 23, 8453–8471, https://doi.org/10.5194/acp-23-8453-2023, https://doi.org/10.5194/acp-23-8453-2023, 2023
                                    Short summary
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                                                Validation activities of Aeolus wind products were performed in Granada with different upward-probing instrumentation (Doppler lidar system and radiosondes) and spatiotemporal collocation criteria. Specific advantages and disadvantages of each instrument were identified, and an optimal comparison criterion is proposed. Aeolus was proven to provide reliable wind products, and the upward-probing instruments were proven to be useful for Aeolus wind product validation activities.
                                            
                                            
                                        Ian Chang, Lan Gao, Connor J. Flynn, Yohei Shinozuka, Sarah J. Doherty, Michael S. Diamond, Karla M. Longo, Gonzalo A. Ferrada, Gregory R. Carmichael, Patricia Castellanos, Arlindo M. da Silva, Pablo E. Saide, Calvin Howes, Zhixin Xue, Marc Mallet, Ravi Govindaraju, Qiaoqiao Wang, Yafang Cheng, Yan Feng, Sharon P. Burton, Richard A. Ferrare, Samuel E. LeBlanc, Meloë S. Kacenelenbogen, Kristina Pistone, Michal Segal-Rozenhaimer, Kerry G. Meyer, Ju-Mee Ryoo, Leonhard Pfister, Adeyemi A. Adebiyi, Robert Wood, Paquita Zuidema, Sundar A. Christopher, and Jens Redemann
                                    Atmos. Chem. Phys., 23, 4283–4309, https://doi.org/10.5194/acp-23-4283-2023, https://doi.org/10.5194/acp-23-4283-2023, 2023
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                                                Abundant aerosols are present above low-level liquid clouds over the southeastern Atlantic during late austral spring. The model simulation differences in the proportion of aerosol residing in the planetary boundary layer and in the free troposphere can greatly affect the regional aerosol radiative effects. This study examines the aerosol loading and fractional aerosol loading in the free troposphere among various models and evaluates them against measurements from the NASA ORACLES campaign.
                                            
                                            
                                        Konstantinos Michailidis, Maria-Elissavet Koukouli, Dimitris Balis, J. Pepijn Veefkind, Martin de Graaf, Lucia Mona, Nikolaos Papagianopoulos, Gesolmina Pappalardo, Ioanna Tsikoudi, Vassilis Amiridis, Eleni Marinou, Anna Gialitaki, Rodanthi-Elisavet Mamouri, Argyro Nisantzi, Daniele Bortoli, Maria João Costa, Vanda Salgueiro, Alexandros Papayannis, Maria Mylonaki, Lucas Alados-Arboledas, Salvatore Romano, Maria Rita Perrone, and Holger Baars
                                    Atmos. Chem. Phys., 23, 1919–1940, https://doi.org/10.5194/acp-23-1919-2023, https://doi.org/10.5194/acp-23-1919-2023, 2023
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                                                Comparisons with ground-based correlative lidar measurements constitute a key component in the validation of satellite aerosol products. This paper presents the validation of the TROPOMI aerosol layer height (ALH) product, using archived quality assured ground-based data from lidar stations that belong to the EARLINET network. Comparisons between the TROPOMI ALH and co-located EARLINET measurements show good agreement over the ocean.
                                            
                                            
                                        Simone Kotthaus, Juan Antonio Bravo-Aranda, Martine Collaud Coen, Juan Luis Guerrero-Rascado, Maria João Costa, Domenico Cimini, Ewan J. O'Connor, Maxime Hervo, Lucas Alados-Arboledas, María Jiménez-Portaz, Lucia Mona, Dominique Ruffieux, Anthony Illingworth, and Martial Haeffelin
                                    Atmos. Meas. Tech., 16, 433–479, https://doi.org/10.5194/amt-16-433-2023, https://doi.org/10.5194/amt-16-433-2023, 2023
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                                                Profile observations of the atmospheric boundary layer now allow for layer heights and characteristics to be derived at high temporal and vertical resolution. With novel high-density ground-based remote-sensing measurement networks emerging, horizontal information content is also increasing. This review summarises the capabilities and limitations of various sensors and retrieval algorithms which need to be considered during the harmonisation of data products for high-impact applications.
                                            
                                            
                                        María Ángeles López-Cayuela, Carmen Córdoba-Jabonero, Diego Bermejo-Pantaleón, Michaël Sicard, Vanda Salgueiro, Francisco Molero, Clara Violeta Carvajal-Pérez, María José Granados-Muñoz, Adolfo Comerón, Flavio T. Couto, Rubén Barragán, María-Paz Zorzano, Juan Antonio Bravo-Aranda, Constantino Muñoz-Porcar, María João Costa, Begoña Artíñano, Alejandro Rodríguez-Gómez, Daniele Bortoli, Manuel Pujadas, Jesús Abril-Gago, Lucas Alados-Arboledas, and Juan Luis Guerrero-Rascado
                                    Atmos. Chem. Phys., 23, 143–161, https://doi.org/10.5194/acp-23-143-2023, https://doi.org/10.5194/acp-23-143-2023, 2023
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                                                An intense Saharan dust outbreak crossing the Iberian Peninsula in springtime was monitored to determinine the specific contribution of fine and coarse dust particles at five lidar stations, strategically covering its SW–central–NE pathway. Expected dust ageing along the transport started unappreciated. A different fine-dust impact on optical (~30 %) and mass (~10 %) properties was found. Use of polarized lidar measurements (mainly in elastic systems) for fine/coarse dust separation is crucial.
                                            
                                            
                                        Thomas Drugé, Pierre Nabat, Marc Mallet, Martine Michou, Samuel Rémy, and Oleg Dubovik
                                    Atmos. Chem. Phys., 22, 12167–12205, https://doi.org/10.5194/acp-22-12167-2022, https://doi.org/10.5194/acp-22-12167-2022, 2022
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                                                This study presents the implementation of brown carbon in the atmospheric component of the CNRM global climate model and particularly in its aerosol scheme TACTIC. Several simulations were carried out with this climate model, over the period 2000–2014, to evaluate the model by comparison with different reference datasets (PARASOL-GRASP, OMI-OMAERUVd, MACv2, FMI_SAT, AERONET) and to analyze the brown carbon radiative and climatic effects.
                                            
                                            
                                        Witali Krochin, Francisco Navas-Guzmán, David Kuhl, Axel Murk, and Gunter Stober
                                    Atmos. Meas. Tech., 15, 2231–2249, https://doi.org/10.5194/amt-15-2231-2022, https://doi.org/10.5194/amt-15-2231-2022, 2022
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                                                This study leverages atmospheric temperature measurements performed with a ground-based radiometer making use of data that was collected during a 4-year observational campaign applying a new retrieval algorithm that improves the maximal altitude range from 45 to 55 km. The measurements are validated against two independent data sets, MERRA2 reanalysis data and the meteorological analysis of NAVGEM-HA.
                                            
                                            
                                        Jesús Abril-Gago, Juan Luis Guerrero-Rascado, Maria João Costa, Juan Antonio Bravo-Aranda, Michaël Sicard, Diego Bermejo-Pantaleón, Daniele Bortoli, María José Granados-Muñoz, Alejandro Rodríguez-Gómez, Constantino Muñoz-Porcar, Adolfo Comerón, Pablo Ortiz-Amezcua, Vanda Salgueiro, Marta María Jiménez-Martín, and Lucas Alados-Arboledas
                                    Atmos. Chem. Phys., 22, 1425–1451, https://doi.org/10.5194/acp-22-1425-2022, https://doi.org/10.5194/acp-22-1425-2022, 2022
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                                                A validation of Aeolus reprocessed optical products is carried out via an intercomparison with ground-based measurements taken at several ACTRIS/EARLINET stations in western Europe. Case studies and a statistical analysis are presented. The stations are located in a hot spot between Africa and the rest of Europe, which guarantees a variety of aerosol types, from mineral dust layers to continental/anthropogenic aerosol, and allows us to test Aeolus performance under different scenarios.
                                            
                                            
                                        Sabrina P. Cochrane, K. Sebastian Schmidt, Hong Chen, Peter Pilewskie, Scott Kittelman, Jens Redemann, Samuel LeBlanc, Kristina Pistone, Michal Segal Rozenhaimer, Meloë Kacenelenbogen, Yohei Shinozuka, Connor Flynn, Rich Ferrare, Sharon Burton, Chris Hostetler, Marc Mallet, and Paquita Zuidema
                                    Atmos. Meas. Tech., 15, 61–77, https://doi.org/10.5194/amt-15-61-2022, https://doi.org/10.5194/amt-15-61-2022, 2022
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                                                This work presents heating rates derived from aircraft observations from the 2016 and 2017 field campaigns of ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS). We separate the total heating rates into aerosol and gas (primarily water vapor) absorption and explore some of the co-variability of heating rate profiles and their primary drivers, leading to the development of a new concept: the heating rate efficiency (HRE; the heating rate per unit aerosol extinction).
                                            
                                            
                                        Sarah J. Doherty, Pablo E. Saide, Paquita Zuidema, Yohei Shinozuka, Gonzalo A. Ferrada, Hamish Gordon, Marc Mallet, Kerry Meyer, David Painemal, Steven G. Howell, Steffen Freitag, Amie Dobracki, James R. Podolske, Sharon P. Burton, Richard A. Ferrare, Calvin Howes, Pierre Nabat, Gregory R. Carmichael, Arlindo da Silva, Kristina Pistone, Ian Chang, Lan Gao, Robert Wood, and Jens Redemann
                                    Atmos. Chem. Phys., 22, 1–46, https://doi.org/10.5194/acp-22-1-2022, https://doi.org/10.5194/acp-22-1-2022, 2022
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                                                Between July and October, biomass burning smoke is advected over the southeastern Atlantic Ocean, leading to climate forcing. Model calculations of forcing by this plume vary significantly in both magnitude and sign. This paper compares aerosol and cloud properties observed during three NASA ORACLES field campaigns to the same in four models. It quantifies modeled biases in properties key to aerosol direct radiative forcing and evaluates how these biases propagate to biases in forcing.
                                            
                                            
                                        Mariana Adam, Iwona S. Stachlewska, Lucia Mona, Nikolaos Papagiannopoulos, Juan Antonio Bravo-Aranda, Michaël Sicard, Doina N. Nicolae, Livio Belegante, Lucja Janicka, Dominika Szczepanik, Maria Mylonaki, Christina-Anna Papanikolaou, Nikolaos Siomos, Kalliopi Artemis Voudouri, Luca Alados-Arboledas, Arnoud Apituley, Ina Mattis, Anatoli Chaikovsky, Constantino Muñoz-Porcar, Aleksander Pietruczuk, Daniele Bortoli, Holger Baars, Ivan Grigorov, and Zahary Peshev
                                        Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-759, https://doi.org/10.5194/acp-2021-759, 2021
                                    Revised manuscript not accepted 
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                                                Results over 10 years of biomass burning events measured by EARLINET are analysed by means of the intensive parameters, based on the methodology described in Part I. Smoke type is characterized for each of the four geographical regions based on continental smoke origin. Relationships between intensive parameters or colour ratios are shown. The smoke is labelled in average as aged smoke.
                                            
                                            
                                        Gloria Titos, María A. Burgos, Paul Zieger, Lucas Alados-Arboledas, Urs Baltensperger, Anne Jefferson, James Sherman, Ernest Weingartner, Bas Henzing, Krista Luoma, Colin O'Dowd, Alfred Wiedensohler, and Elisabeth Andrews
                                    Atmos. Chem. Phys., 21, 13031–13050, https://doi.org/10.5194/acp-21-13031-2021, https://doi.org/10.5194/acp-21-13031-2021, 2021
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                                                This paper investigates the impact of water uptake on aerosol optical properties, in particular the aerosol light-scattering coefficient. Although in situ measurements are performed at low relative humidity (typically at 
RH < 40 %), to address the climatic impact of aerosol particles it is necessary to take into account the effect that water uptake may have on the aerosol optical properties.
                                            
                                            
                                        Daniel Pérez-Ramírez, David N. Whiteman, Igor Veselovskii, Richard Ferrare, Gloria Titos, María José Granados-Muñoz, Guadalupe Sánchez-Hernández, and Francisco Navas-Guzmán
                                    Atmos. Chem. Phys., 21, 12021–12048, https://doi.org/10.5194/acp-21-12021-2021, https://doi.org/10.5194/acp-21-12021-2021, 2021
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                                                This paper shows how aerosol hygroscopicity enhances the vertical profile of aerosol backscattering and extinction. The study is possible thanks to the large set of remote sensing instruments and focuses on the the Baltimore–Washington DC metropolitan area during hot and humid summer days with very relevant anthropogenic emission aerosol sources. The results illustrate how the combination of aerosol emissions and meteorological conditions ultimately alters the aerosol radiative forcing.
                                            
                                            
                                        Julien Jouanno, Rachid Benshila, Léo Berline, Antonin Soulié, Marie-Hélène Radenac, Guillaume Morvan, Frédéric Diaz, Julio Sheinbaum, Cristele Chevalier, Thierry Thibaut, Thomas Changeux, Frédéric Menard, Sarah Berthet, Olivier Aumont, Christian Ethé, Pierre Nabat, and Marc Mallet
                                    Geosci. Model Dev., 14, 4069–4086, https://doi.org/10.5194/gmd-14-4069-2021, https://doi.org/10.5194/gmd-14-4069-2021, 2021
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                                                The tropical Atlantic has been facing a massive proliferation of Sargassum since 2011, with severe environmental and socioeconomic impacts. We developed a modeling framework based on the NEMO ocean model, which integrates transport by currents and waves, and physiology of Sargassum with varying internal nutrient quota, and considers stranding at the coast. Results demonstrate the ability of the model to reproduce and forecast the seasonal cycle and large-scale distribution of Sargassum biomass.
                                            
                                            
                                        Jose Antonio Benavent-Oltra, Juan Andrés Casquero-Vera, Roberto Román, Hassan Lyamani, Daniel Pérez-Ramírez, María José Granados-Muñoz, Milagros Herrera, Alberto Cazorla, Gloria Titos, Pablo Ortiz-Amezcua, Andrés Esteban Bedoya-Velásquez, Gregori de Arruda Moreira, Noemí Pérez, Andrés Alastuey, Oleg Dubovik, Juan Luis Guerrero-Rascado, Francisco José Olmo-Reyes, and Lucas Alados-Arboledas
                                    Atmos. Chem. Phys., 21, 9269–9287, https://doi.org/10.5194/acp-21-9269-2021, https://doi.org/10.5194/acp-21-9269-2021, 2021
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                                                In this paper, we use the GRASP algorithm combining different remote sensing measurements to obtain the aerosol vertical and column properties during the SLOPE I and II campaigns. We show an overview of aerosol properties retrieved by GRASP during these campaigns and evaluate the retrievals of aerosol properties using the in situ measurements performed at a high-altitude station and airborne flights. For the first time we present an evaluation of the absorption coefficient by GRASP.
                                            
                                            
                                        Thomas Drugé, Pierre Nabat, Marc Mallet, and Samuel Somot
                                    Atmos. Chem. Phys., 21, 7639–7669, https://doi.org/10.5194/acp-21-7639-2021, https://doi.org/10.5194/acp-21-7639-2021, 2021
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                                                This study presents the surface mass concentration and AOD evolution of various aerosols over the Euro-Mediterranean region between the end of the 20th century and the mid-21st century. This study also describes the part of the expected climate change over the Euro-Mediterranean region that can be explained by the evolution of these different aerosols.
                                            
                                            
                                        Nikolaos Evangeliou, Stephen M. Platt, Sabine Eckhardt, Cathrine Lund Myhre, Paolo Laj, Lucas Alados-Arboledas, John Backman, Benjamin T. Brem, Markus Fiebig, Harald Flentje, Angela Marinoni, Marco Pandolfi, Jesus Yus-Dìez, Natalia Prats, Jean P. Putaud, Karine Sellegri, Mar Sorribas, Konstantinos Eleftheriadis, Stergios Vratolis, Alfred Wiedensohler, and Andreas Stohl
                                    Atmos. Chem. Phys., 21, 2675–2692, https://doi.org/10.5194/acp-21-2675-2021, https://doi.org/10.5194/acp-21-2675-2021, 2021
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                                                Following the transmission of SARS-CoV-2 to Europe, social distancing rules were introduced to prevent further spread. We investigate the impacts of the European lockdowns on black carbon (BC) emissions by means of in situ observations and inverse modelling. BC emissions declined by 23 kt in Europe during the lockdowns as compared with previous years and by 11 % as compared to the period prior to lockdowns. Residential combustion prevailed in Eastern Europe, as confirmed by remote sensing data.
                                            
                                            
                                        Giovanni Martucci, Francisco Navas-Guzmán, Ludovic Renaud, Gonzague Romanens, S. Mahagammulla Gamage, Maxime Hervo, Pierre Jeannet, and Alexander Haefele
                                    Atmos. Meas. Tech., 14, 1333–1353, https://doi.org/10.5194/amt-14-1333-2021, https://doi.org/10.5194/amt-14-1333-2021, 2021
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                                                This article presents a validation of 1.5 years of pure rotational temperature data measured by the Raman lidar RALMO installed at the MeteoSwiss station of Payerne. The statistical results are in terms of bias and standard deviation with respect to two well-established radiosounding systems. The statistics are divided into daytime (bias = 0.28 K, SD = 0.62±0.03 K) and nighttime (bias = 0.29 K, SD = 0.66±0.06 K). The lidar temperature profiles are applied to cloud supersaturation studies.
                                            
                                            
                                        Simone Brunamonti, Giovanni Martucci, Gonzague Romanens, Yann Poltera, Frank G. Wienhold, Maxime Hervo, Alexander Haefele, and Francisco Navas-Guzmán
                                    Atmos. Chem. Phys., 21, 2267–2285, https://doi.org/10.5194/acp-21-2267-2021, https://doi.org/10.5194/acp-21-2267-2021, 2021
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                                                Lidar (light detection and ranging) is a class of remote-sensing instruments that are widely used for the monitoring of aerosol properties in the lower levels of the atmosphere, yet their measurements are affected by several sources of uncertainty. Here we present the first comparison of two lidar systems against a fully independent instrument carried by meteorological balloons. We show that both lidars achieve a good agreement with the high-precision balloon measurements up to 6 km altitude.
                                            
                                            
                                        Jens Redemann, Robert Wood, Paquita Zuidema, Sarah J. Doherty, Bernadette Luna, Samuel E. LeBlanc, Michael S. Diamond, Yohei Shinozuka, Ian Y. Chang, Rei Ueyama, Leonhard Pfister, Ju-Mee Ryoo, Amie N. Dobracki, Arlindo M. da Silva, Karla M. Longo, Meloë S. Kacenelenbogen, Connor J. Flynn, Kristina Pistone, Nichola M. Knox, Stuart J. Piketh, James M. Haywood, Paola Formenti, Marc Mallet, Philip Stier, Andrew S. Ackerman, Susanne E. Bauer, Ann M. Fridlind, Gregory R. Carmichael, Pablo E. Saide, Gonzalo A. Ferrada, Steven G. Howell, Steffen Freitag, Brian Cairns, Brent N. Holben, Kirk D. Knobelspiesse, Simone Tanelli, Tristan S. L'Ecuyer, Andrew M. Dzambo, Ousmane O. Sy, Greg M. McFarquhar, Michael R. Poellot, Siddhant Gupta, Joseph R. O'Brien, Athanasios Nenes, Mary Kacarab, Jenny P. S. Wong, Jennifer D. Small-Griswold, Kenneth L. Thornhill, David Noone, James R. Podolske, K. Sebastian Schmidt, Peter Pilewskie, Hong Chen, Sabrina P. Cochrane, Arthur J. Sedlacek, Timothy J. Lang, Eric Stith, Michal Segal-Rozenhaimer, Richard A. Ferrare, Sharon P. Burton, Chris A. Hostetler, David J. Diner, Felix C. Seidel, Steven E. Platnick, Jeffrey S. Myers, Kerry G. Meyer, Douglas A. Spangenberg, Hal Maring, and Lan Gao
                                    Atmos. Chem. Phys., 21, 1507–1563, https://doi.org/10.5194/acp-21-1507-2021, https://doi.org/10.5194/acp-21-1507-2021, 2021
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                                                Southern Africa produces significant biomass burning emissions whose impacts on regional and global climate are poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a 5-year NASA investigation designed to study the key processes that determine these climate impacts. The main purpose of this paper is to familiarize the broader scientific community with the ORACLES project, the dataset it produced, and the most important initial findings.
                                            
                                            
                                        Ourania Soupiona, Alexandros Papayannis, Panagiotis Kokkalis, Romanos Foskinis, Guadalupe Sánchez Hernández, Pablo Ortiz-Amezcua, Maria Mylonaki, Christina-Anna Papanikolaou, Nikolaos Papagiannopoulos, Stefanos Samaras, Silke Groß, Rodanthi-Elisavet Mamouri, Lucas Alados-Arboledas, Aldo Amodeo, and Basil Psiloglou
                                    Atmos. Chem. Phys., 20, 15147–15166, https://doi.org/10.5194/acp-20-15147-2020, https://doi.org/10.5194/acp-20-15147-2020, 2020
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                                                51 dust events over the Mediterranean from EARLINET were studied regarding the aerosol geometrical, optical and microphysical properties and radiative forcing. We found δp532 values of 0.24–0.28, LR532 values of 49–52 sr and AOT532 of 0.11–0.40. The aerosol mixing state was also examined. Depending on the dust properties, intensity and solar zenith angle, the estimated solar radiative forcing ranged from −59 to −22 W m−2 at the surface and from −24 to −1 W m−2 at the TOA (cooling effect).
                                            
                                            
                                        Juan Andrés Casquero-Vera, Hassan Lyamani, Lubna Dada, Simo Hakala, Pauli Paasonen, Roberto Román, Roberto Fraile, Tuukka Petäjä, Francisco José Olmo-Reyes, and Lucas Alados-Arboledas
                                    Atmos. Chem. Phys., 20, 14253–14271, https://doi.org/10.5194/acp-20-14253-2020, https://doi.org/10.5194/acp-20-14253-2020, 2020
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                                                New particle formation was investigated at two stations located close to each other but at different altitudes: urban and high-altitude sites. Results show that sulfuric acid is able to explain a minimal fraction contribution to the observed growth rates and point to the availability of volatile organic compounds as the main factor controlling NPF events at both sites. A closer analysis of the NPF events that were observed at high-altitude sites during a Saharan dust episode was carried out.
                                            
                                            
                                        Roberto Román, Ramiro González, Carlos Toledano, África Barreto, Daniel Pérez-Ramírez, Jose A. Benavent-Oltra, Francisco J. Olmo, Victoria E. Cachorro, Lucas Alados-Arboledas, and Ángel M. de Frutos
                                    Atmos. Meas. Tech., 13, 6293–6310, https://doi.org/10.5194/amt-13-6293-2020, https://doi.org/10.5194/amt-13-6293-2020, 2020
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                                                Atmospheric-aerosol and gaseous properties can be derived at night-time if the lunar irradiance at the ground is measured. To this end, the knowledge of lunar irradiance at the top of the atmosphere is necessary. This extraterrestrial lunar irradiance is usually calculated by models since it varies with several geometric factors mainly depending on time and location. This paper proposes a correction to the most used lunar-irradiance model to be applied for atmospheric-aerosol characterization.
                                            
                                            
                                        Cécile Guieu, Fabrizio D'Ortenzio, François Dulac, Vincent Taillandier, Andrea Doglioli, Anne Petrenko, Stéphanie Barrillon, Marc Mallet, Pierre Nabat, and Karine Desboeufs
                                    Biogeosciences, 17, 5563–5585, https://doi.org/10.5194/bg-17-5563-2020, https://doi.org/10.5194/bg-17-5563-2020, 2020
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                                                We describe here the objectives and strategy of the PEACETIME project and cruise, dedicated to dust deposition and its impacts in the Mediterranean Sea. Our strategy to go a step further forward than in previous approaches in understanding these impacts by catching a real deposition event at sea is detailed. We summarize the work performed at sea, the type of data acquired and their valorization in the papers published in the special issue.
                                            
                                            
                                        Marc Mallet, Fabien Solmon, Pierre Nabat, Nellie Elguindi, Fabien Waquet, Dominique Bouniol, Andrew Mark Sayer, Kerry Meyer, Romain Roehrig, Martine Michou, Paquita Zuidema, Cyrille Flamant, Jens Redemann, and Paola Formenti
                                    Atmos. Chem. Phys., 20, 13191–13216, https://doi.org/10.5194/acp-20-13191-2020, https://doi.org/10.5194/acp-20-13191-2020, 2020
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                                                This paper presents numerical simulations using two regional climate models to study the impact of biomass fire plumes from central Africa on the radiative balance of this region. The results indicate that biomass fires can either warm the regional climate when they are located above low clouds or cool it when they are located above land. They can also alter sea and land surface temperatures by decreasing solar radiation at the surface. Finally, they can also modify the atmospheric dynamics.
                                            
                                            
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                Short summary
                    The automatic detection of the planetary boundary layer height (PBL height) by means of lidar measurements still presents difficulties. This work shows an improvement in the PBL height detection using lidar depolarization measurements. To our knowledge, it is the first time that the lidar depolarization technique is used for this purpose. Also, the PBL height derived from the WRF model is compared with the PBL heights of this new method and from a microwave radiometer during CHARMEX campaigns.
                    The automatic detection of the planetary boundary layer height (PBL height) by means of lidar...
                    
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