L'utilisation de mesures polarimétriques au sol pour améliorer la récupération de la microphysique des aérosols

Nous présentons dans ce travail l’analyse des données polarimétriques obtenues depuis le sol permettant de déterminer les propriétés des aérosols. Un travail préalable de préparation des données a été mené de manière à automatiser l’ensemble des traitements. Nous avons ensuite appliqué aux données l’algorithme d’inversion en usage au sein du réseau international de photomètre solaire AERONET (Aerosol RObotic Network) en y intégrant la polarisation. Une étude de sensibilité s’appuyant sur cinq modèles représentatifs de l’aérosol désertique, industriel et urbain, jusqu’aux aérosols marins a été réalisée. Les effets du bruit, de biais sur les mesures d'épaisseur optique aérosols et des erreurs de pointage ont été évalués. Les résultats montrent l’avantage la polarisation dans le cas de concentrations importantes en particules fines. A l’inverse, la polarisation s’est révélée moins sensible à la présence d’aérosols dominés par les grosses particules. Les données acquises sur trois sites d’observation (Beijing, Dakar, Washington), ont été traitées. Les résultats montrent l’intérêt de la polarisation dans le cas de la pollution industrielle pour améliorer la restitution de la distribution de taille des particules. La prise en compte de la polarisation améliore la qualité de la restitution de partie réelle de l’indice de réfraction et de la fraction de particules sphériques, et cela en raison de la haute sensibilité de la polarisation à la forme des particules. Cette approche est particulièrement intéressante pour mieux caractériser les aérosols dans les régions affectées par la présence d’aérosols d’origine anthropique (fraction fine prononcée) ou les aérosols de mélange.The thesis presents the efforts on including the polarimetric data to the routine inversion of the ground-based observations and analysis of the advantages obtained. To process large amount of observations a data preparation tool was developed. It is based on AERONET inversion code. To assess the importance of polarization for aerosol retrieval results, numerical test has been performed and the real measurements were processed. First, the sensitivity study has been carried out using simulated data based on five aerosol models: desert dust, urban industrial, urban clean, biomass burning and maritime. The test investigated the effects of various errors (random noise, bias in optical thickness data, pointing errors) on aerosol retrieval using polarization data. The results demonstrate the advantage of using polarization for characterization of aerosols with pronounced concentration of fine particles. In case of the coarse mode dominated aerosols, the use of polarimetric data led to minor improvements of the retrieval. Second, the extended set of AERONET observations were processed. The data for three sites have been used: GSFC, Beijing and Dakar. The results revealed advantages of polarimetric data use for characterizing fine mode aerosol including industrial pollution. The use of polarization improves the particle size distribution retrieval by decreasing overestimated fine mode and increasing the coarse mode. It increases underestimated refractive index real part and the fraction of spherical particles due to high sensitivity of polarization to particle shape. Overall, the study demonstrates a significant value of polarimetric data for improving aerosol characterization

Lidar&radiometer inversion code (LIRIC) for synergetic processing of earlinet, aeronet and calipso lidar data

Lidar&Radiometer Sounding (LRS) technique is used to obtain the “snapshot” of aerosol concentration profiles over the East European region during dust event, 07-08.04.2016 from EARLINET, AERONET and CALIPSO data. Aerosol concentration profiles retrieved from space and ground-based lidars are compared

Lidar&radiometer inversion code (LIRIC) for synergetic processing of earlinet, aeronet and calipso lidar data

Lidar&Radiometer Sounding (LRS) technique is used to obtain the “snapshot” of aerosol concentration profiles over the East European region during dust event, 07-08.04.2016 from EARLINET, AERONET and CALIPSO data. Aerosol concentration profiles retrieved from space and ground-based lidars are compared

Synergetic observations by ground-based and space lidar systems and aeronet sun-radiometers: a step to advanced regional monitoring of large scale aerosol changes

The paper presents the preliminary results of the lidar&radiometer measurement campaign (LRMC-2017), estimation of statistical relations between aerosol mode concentrations retrieved from CALIOP and ground-based lidar stations and case study of fire smoke events in the Eurasian regions using combined ground-based and space lidar and radiometer observations.Peer ReviewedArticle signat per 71 autors/es: Anatoli Chaikovsky1*, Andrey Bril1, Oleg Dubovik2, Anton Fedarenka1, Philippe Goloub2, Qiaoyun Hu2, Anton Lopatin3, Tatyana Lapyonok2, Natallia Miatselskaya1, Benjamin Torres2, David Fuertes3, Vladislau Peshcharankou1, Thierry Podvin2,36, Ioana Popovici2, Dong Liu4, Zhengqiang Li5, Ourania Soupiona6, Maria Mylonaki6, Lucia Mona7, Aldo Giunta7, Nikolaos Papagiannopoulos7, Maria Rita Perrone8, Salvatore Romano8, Dimitris Balis9, Nikolaos Siomos9, Kalliopi-Artemis Voudouri9, Livio Belegante10, Doina Nicolae10, Dragos Ene10, Nicolae Ajtai11, Horatiu Stefanie11, Vassilis Amiridis12, Alexandra Tsekeri12, Daniele Bortoli13, Maria Joao Costa13, Ina Mattis14, Francesc Rocadenbosch15,16, Alejandro Rodríguez-Gomez15, Michael Sicard15,16, Alfonso J. Fernandez17, Francisco Molero17, Dietrich Althausen18, Holger Baars18, Juan Luis Guerrero Rascado19, Pablo Ortiz-Amezcua19, José Antonio Benavent Oltra19, Andrés Esteban Bedoya-Velásquez19, Roberto Román19, Lucas Alados-Arboledas19, Yurii Balin20, Grigorii Kokhanenko20, Ivan Penner20, Boris Chen21, Leonid Sverdlik21, Genadi Milinevsky22,23, Nobuo Sugimoto24, Atsushi Shimizu24, Tomoaki Nishizawa24, Rei Kudo25, Itaru Sano26, Teppei J. Yasunari27, Hitoshi Irie28, Toshihiko Takemura29, Sang-Woo Kim30, Nguyen Xuan Anh30, Pham Xuan Thanh31, Aleksander Pietruczuk32, Iwona S. Stachlewska33, Alessia Sannino34, Xuan Wang35 and Antonela Boselli7 1 Institute of Physics, NAS of Belarus, Minsk, Belarus, 2 Laboratoire d’Optique Atmosphérique, CNRS – Université Lille, France ; 3 GRASP-SAS, Villeneuve d’Ascq, France ; 4 Anhui institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China ; 5 Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China ; 6 National Technical University of Athens, Athens, Greece ; 7 CNR - Istituto di Metodologie per l’Analisi Ambientale, Potenza, Italy ; 8 University of Salento, Lecce, Italy ; 9 Aristotle University of Thessaloniki, Greece ; 10 National Institute of Research and Development for Optoelectronics, Magurele, Romania ; 11 Babeș-Bolyai University, Cluj-Napoca, Romania ; 12 IAASARS, National Observatory of Athens, Athens, Greece ; 13 Instituto de Ciências da Terra, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal ; 14 Meteorological observatory Hohenpeissenberg, DWD, Germany ; 15 COMMSENSLAB-Unidad María de Maeztu, Universitat Politècnica de Catalunya, Barcelona, Spain ; 16 Institut d’Estudis Espacials de Catalunya (CTE-CRAE / IEEC), Universitat Politècnica de Catalunya, Barcelona, Spain ; 17 Research Centre for Energy, Environment and Technology (CIEMAT), Madrid, Spain ; 18 Leibniz Institute for Tropospheric Research, Leipzig, Germany ; 19 Andalusian Institute for Earth System Research (IISTA-CEAMA), University of Granada. 18006, Granada, Spain ; 20 V.E. Zuev Institute of Atmospheric Optics of the Russian Academy of Science, Tomsk, Russia ; 21 Kyrgyz-Russian Slavic University, Bishkek, Kyrgyz Republic ; 22 Kyiv National Taras Shevchenko University, Kyiv, Ukraine ; 23 College of Physics, International Center of Future Science, Jilin University, Changchun, China ; 24 National Institute for Environmental Studies, Tsukuba, Japan ; 25 Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Ibaraki, Japan ; 26 Faculty of science and engineering, Kindai University, Higashi-Osaka, Japan ; 27 Arctic Research Center, Hokkaido University, Sapporo, Hokkaido, Japan ; 28 Center for Environmental Remote Sensing, Chiba University, Chiba, Japan ; 29 Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan ; 30 School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea ; 31 Institute of Geophysics, Vietnam Academy of Science and Technology, Hanoi, Vietnam ; 32 Institute of Geophysics Polish Academy of Sciences, Warsaw, Poland ; 33 University of Warsaw, Faculty of Physics, Warsaw, Poland ; 34 Dipartimento di Fisica dell’Università Federico II di Napoli, Napoli, Italy ; 35 CNR- Istituto Superconduttori, materiali Innovativi e dispostivi, Napoli, Italy ; 36 CIMEL Electronique, Paris, FrancePostprint (published version

Utilization of AERONET polarimetric measurements for improving retrieval of aerosol microphysics: GSFC, Beijing and Dakar data analysis

International audienceThe study presents the efforts on including the polarimetric data to the routine inversion of the radiometric ground-based measurements for characterization of the atmospheric aerosols and analysis of the obtained advantages in retrieval results. First, to operationally process the large amount of polarimetric data the data preparation tool was developed. The AERONET inversion code adapted for inversion of both intensity and polarization measurements was used for processing. Second, in order to estimate the effect from utilization of polarimetric information on aerosol retrieval results, both synthetic data and the real measurements were processed using developed routine and analyzed. The sensitivity study has been carried out using simulated data based on three main aerosol models: desert dust, urban industrial and urban clean aerosols. The test investigated the effects of utilization of polarization data in the presence of random noise, bias in measurements of optical thickness and angular pointing shift. The results demonstrate the advantage of polarization data utilization in the cases of aerosols with pronounced concentration of fine particles. Further, the extended set of AERONET observations was processed. The data for three sites have been used: GSFC, USA (clean urban aerosol dominated by fine particles), Beijing, China (polluted industrial aerosol characterized by pronounced mixture of both fine and coarse modes) and Dakar, Senegal (desert dust dominated by coarse particles). The results revealed considerable advantage of polarimetric data applying for characterizing fine mode dominated aerosols including industrial pollution (Beijing). The use of polarization corrects particle size distribution by decreasing overestimated fine mode and increasing the coarse mode. It also increases underestimated real part of the refractive index and improves the retrieval of the fraction of spherical particles due to high sensitivity of polarization to particle shape. Overall, the study demonstrates a substantial value of polarimetric data for improving aerosol characterization

Utilization of AERONET polarimetric measurements for improving retrieval of aerosol microphysics: GSFC, Beijing and Dakar data analysis

International audienceThe study presents the efforts on including the polarimetric data to the routine inversion of the radiometric ground-based measurements for characterization of the atmospheric aerosols and analysis of the obtained advantages in retrieval results. First, to operationally process the large amount of polarimetric data the data preparation tool was developed. The AERONET inversion code adapted for inversion of both intensity and polarization measurements was used for processing. Second, in order to estimate the effect from utilization of polarimetric information on aerosol retrieval results, both synthetic data and the real measurements were processed using developed routine and analyzed. The sensitivity study has been carried out using simulated data based on three main aerosol models: desert dust, urban industrial and urban clean aerosols. The test investigated the effects of utilization of polarization data in the presence of random noise, bias in measurements of optical thickness and angular pointing shift. The results demonstrate the advantage of polarization data utilization in the cases of aerosols with pronounced concentration of fine particles. Further, the extended set of AERONET observations was processed. The data for three sites have been used: GSFC, USA (clean urban aerosol dominated by fine particles), Beijing, China (polluted industrial aerosol characterized by pronounced mixture of both fine and coarse modes) and Dakar, Senegal (desert dust dominated by coarse particles). The results revealed considerable advantage of polarimetric data applying for characterizing fine mode dominated aerosols including industrial pollution (Beijing). The use of polarization corrects particle size distribution by decreasing overestimated fine mode and increasing the coarse mode. It also increases underestimated real part of the refractive index and improves the retrieval of the fraction of spherical particles due to high sensitivity of polarization to particle shape. Overall, the study demonstrates a substantial value of polarimetric data for improving aerosol characterization

Synergetic observations by ground-based and space lidar systems and aeronet sun-radiometers: a step to advanced regional monitoring of large scale aerosol changes

The financial support by the European Union's Horizon 2020 research and innovation program (ACTRIS-2, grant agreement no. 654109) is gratefully acknowledged. The investigation was supported by the Belarusian Republican Foundation for Fundamental, Research Agreement No. F18EA-011, by the Russian Foundation for Basic Research (grant No. 18-55-81001), and also by Vietnam Academy of Science and Technology (project code QTRU05.01/18-20). The Portuguese team acknowledges the support from the Portuguese Science Foundation, in the frame of the European Regional Development Fund -COMPETE 2020, under the projects UID/GEO/04683/2013 (POCI-01-0145-FEDER-007690)The paper presents the preliminary results of the lidar&radiometer measurement campaign (LRMC2017), estimation of statistical relations between aerosol mode concentrations retrieved from CALIOP and ground-based lidar stations and case study of fire smoke events in the Eurasian regions using combined ground-based and space lidar and radiometer observations.European Union's Horizon 2020 research and innovation program (ACTRIS-2) 654109Belarusian Republican Foundation for Fundamental, Research F18EA-011Russian Foundation for Basic Research (RFBR) 18-55-81001Vietnam Academy of Science and Technology QTRU05.01/18-20Portuguese Science Foundation, in the frame of the European Regional Development Fund -COMPETE 2020 UID/GEO/04683/2013 (POCI-01-0145-FEDER-007690