Combined sun-photometer–lidar inversion: lessons learned during the EARLINET/ACTRIS COVID-19 campaign

• Published in: Atmospheric Measurement Techniques
• Main Authors: Tsekeri, Alexandra, Gialitaki, Anna, Di Paolantonio, Marco, Dionisi, Davide, Liberti, Gian, Luigi, Fernandes, Alnilam, Szkop, Artur, Pietruczuk, Aleksander, Pérez-Ramírez, Daniel, Granados Muñoz, Maria, J, Guerrero-Rascado, Juan, Luis, Alados-Arboledas, Lucas, Bermejo Pantaleón, Diego, Bravo-Aranda, Juan, Antonio, Kampouri, Anna, Marinou, Eleni, Amiridis, Vassilis, Sicard, Michael, Comerón, Adolfo, Muñoz-Porcar, Constantino, Rodríguez-Gómez, Alejandro, Romano, Salvatore, Perrone, Maria, Rita, Shang, Xiaoxia, Komppula, Mika, Mamouri, Rodanthi-Elisavet, Nisantzi, Argyro, Hadjimitsis, Diofantos, Navas-Guzmán, Francisco, Haefele, Alexander, Szczepanik, Dominika, Tomczak, Artur, Stachlewska, Iwona, S, Belegante, Livio, Nicolae, Doina, Voudouri, Kalliopi, Artemis, Balis, Dimitris, Floutsi, Athena, A, Baars, Holger, Miladi, Linda, Pascal, Nicolas, Dubovik, Oleg, Lopatin, Anton
• Other Authors: Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing Penteli (IAASARS), National Observatory of Athens (NOA), Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece, Earth Observation Science Group Leicester (EOS), Space Research Centre Leicester, University of Leicester-University of Leicester, Istituto di Science Marine (ISMAR ), National Research Council of Italy, Scuola di Ingegneria Potenza, Università degli studi della Basilicata = University of Basilicata (UNIBAS), Institute of Geophysics Warsaw, Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences (PAN), Department of Applied Physics Granada, Universidad de Granada = University of Granada (UGR), Instituto Interuniversitario de Investigacion del Sistema Tierra en Andalucia (IISTA-CEAMA), Department of Meteorology and Climatology Thessaloniki, Aristotle University of Thessaloniki, Universitat Politècnica de Catalunya = Université polytechnique de Catalogne Barcelona (UPC), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Department of Mathematics and Physics Lecce, University of Salento Lecce, Finnish Meteorological Institute (FMI), Department of Civil Engineering and Geomatics Cyprus, Cyprus University of Technology, Federal Office of Meteorology and Climatology MeteoSwiss, Faculty of Physics, Warsaw University of Technology Warsaw, National Institute of Research and Development for Optoelectronics (INOE), Laboratory of Atmospheric Physics Thessaloniki, Leibniz Institute for Tropospheric Research (TROPOS), interaction Clouds Aerosols Radiations - ICARE/AERIS Data and Services Center - UMS 2877 (ICARE), Centre National d'Études Spatiales Toulouse (CNES)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Generalized Retrieval of Atmosphere and Surface Properties (GRASP SAS), This research was financially supported by D-TECT (grant agreement no. 725698) funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme and by PANGEA4CalVal (grant agreement no. 101079201) funded by the European Union https://amt.copernicus.org/articles/16/6025/2023/amt-16-6025-2023-g01. The Barcelona site has been funded by the REALISTIC project (grant agreement no. 101086690) under the European Union's Horizon Widera 2022 Talents programme. The Warsaw site has been supported by the European Commission H2020 (ACTRIS IMP (grant no. 871115)). The Belsk site has been supported by the National Science Centre, Poland (grant no. 2021/41/B/ST10/03660)., European Project: 101086690,REALISTIC, European Project: 871115,H2020,H2020-INFRADEV-2018-2020,ACTRIS IMP(2020), European Project: 101079201,PANGEA4CalVal
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Algorithm; meteorological; GRASP; GARRLIC; AOD; AERONET; lidar; radiometer; aerosol; particles; atmospheric; photometer; uncertainties; inversion algorithm; combined data; properties; characteristics; [SDE]Environmental Sciences; [SDU]Sciences of the Universe [physics]; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Aerosol Robotic Network
• Online Access: https://hal.science/hal-04459590; https://hal.science/hal-04459590/document; https://hal.science/hal-04459590/file/amt-16-6025-2023.pdf; https://doi.org/10.5194/amt-16-6025-2023

International audience Abstract. The European Aerosol Research Lidar Network (EARLINET), part of the Aerosols, Clouds and Trace gases Research Infrastructure (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. Besides the standard operational processing of the lidar data in EARLINET, for seven EARLINET sites having collocated sun-photometric observations in the Aerosol Robotic Network (AERONET), a network exercise was held in order to derive profiles of the concentration and effective column size distributions of the aerosols in the atmosphere, by applying the GRASP/GARRLiC (from Generalized Aerosol Retrieval from Radiometer and Lidar Combined data – GARRLiC – part of the Generalized Retrieval of Atmosphere and Surface Properties – GRASP) inversion algorithm. The objective of this network exercise was to explore the possibility of identifying the anthropogenic component and of monitoring its spatial and temporal characteristics in the COVID-19 lockdown and relaxation period. While the number of cases is far from being statistically significant so as to provide a conclusive description of the atmospheric aerosols over Europe during this period, this network exercise was fundamental to deriving a common methodology for applying GRASP/GARRLiC to a network of instruments with different characteristics. The limits of the approach are discussed, in particular the missing information close to the ground in the lidar measurements due to the instrument geometry and the sensitivity of the GRASP/GARRLiC retrieval to the settings used, especially for cases with low aerosol optical depth (AOD) like the ones we show here. We found that this sensitivity is well-characterized in the GRASP/GARRLiC products, since it is included in their retrieval uncertainties.