Articles | Volume 29, issue 3
https://doi.org/10.5194/npg-29-265-2022
© 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/npg-29-265-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Empirical adaptive wavelet decomposition (EAWD): an adaptive decomposition for the variability analysis of observation time series in atmospheric science
Olivier Delage
CORRESPONDING AUTHOR
Laboratoire de l'Atmosphère et des Cyclones, (LACy, UMR 8105
CNRS, Université de la Réunion, Météo-France),
Université de La Réunion, 97400 Saint-Denis de La Réunion,
France
Thierry Portafaix
Laboratoire de l'Atmosphère et des Cyclones, (LACy, UMR 8105
CNRS, Université de la Réunion, Météo-France),
Université de La Réunion, 97400 Saint-Denis de La Réunion,
France
Hassan Bencherif
Laboratoire de l'Atmosphère et des Cyclones, (LACy, UMR 8105
CNRS, Université de la Réunion, Météo-France),
Université de La Réunion, 97400 Saint-Denis de La Réunion,
France
School of Chemistry and Physics, University of KwaZulu-Natal,
Westville, Durban 4041, South Africa
Alain Bourdier
Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
Emma Lagracie
Laboratoire de l'Atmosphère et des Cyclones, (LACy, UMR 8105
CNRS, Université de la Réunion, Météo-France),
Université de La Réunion, 97400 Saint-Denis de La Réunion,
France
École Nationale Supérieure des Techniques Avancées, 91120, Palaiseau, France
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Gregori de Arruda Moreira, Hassan Bencherif, Tristan Millet, and Damaris Kirsch Pinheiro
EGUsphere, https://doi.org/10.5194/egusphere-2025-3398, https://doi.org/10.5194/egusphere-2025-3398, 2025
This preprint is open for discussion and under review for Annales Geophysicae (ANGEO).
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Tropopause temperature and height serve as key indicators of anthropogenic climate change. However, monitoring their variability remains challenging due to the sparse distribution of observation stations, particularly in the Southern Hemisphere. To address this, we compared temperature profiles from three datasets—SHADOZ, COSMIC-1, and MERRA-2—to assess their similarities and differences and to develop a refined dataset for trend analysis.
Marion Ranaivombola, Nelson Bègue, Lucas Vaz Peres, Farahnaz Fazel-Rastgar, Venkataraman Sivakumar, Gisèle Krysztofiak, Gwenaël Berthet, Fabrice Jegou, Stuart Piketh, and Hassan Bencherif
Atmos. Chem. Phys., 25, 3519–3540, https://doi.org/10.5194/acp-25-3519-2025, https://doi.org/10.5194/acp-25-3519-2025, 2025
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From September to October 2022, the Biomass Burning Aerosol Campaign (BiBAC) in Kruger National Park revealed a significant aerosol loading linked to biomass burning activity, with southeastward transport over southern Africa and the southwestern Indian Ocean (SWIO) basin. The study revealed a predominance of biomass burning aerosols and two distinct transport mechanisms of aerosol plumes and CO, underscoring the importance of east-coast observations in understanding atmospheric dynamics.
Michaël Sicard, Alexandre Baron, Marion Ranaivombola, Dominique Gantois, Tristan Millet, Pasquale Sellitto, Nelson Bègue, Hassan Bencherif, Guillaume Payen, Nicolas Marquestaut, and Valentin Duflot
Atmos. Chem. Phys., 25, 367–381, https://doi.org/10.5194/acp-25-367-2025, https://doi.org/10.5194/acp-25-367-2025, 2025
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This study quantifies the radiative impact over Réunion Island (21° S, 55° E) of the aerosols and water vapor injected into the stratosphere by the Hunga volcano in the South Pacific. The overall aerosol and water vapor impact on the Earth’s radiation budget for the whole period is negative (cooling, -0.82 ± 0.35 W m-2) and dominated by the aerosols. At the Earth’s surface, aerosols are the main drivers and produce a negative (cooling, -1.04 ± 0.36 W m-2) radiative impact.
Dominique Gantois, Guillaume Payen, Michaël Sicard, Valentin Duflot, Nelson Bègue, Nicolas Marquestaut, Thierry Portafaix, Sophie Godin-Beekmann, Patrick Hernandez, and Eric Golubic
Earth Syst. Sci. Data, 16, 4137–4159, https://doi.org/10.5194/essd-16-4137-2024, https://doi.org/10.5194/essd-16-4137-2024, 2024
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We describe three instruments that have been measuring interactions between aerosols (particles of various origin) and light over Réunion Island since 2012. Aerosols directly or indirectly influence the temperature in the atmosphere and can interact with clouds. Details are given on how we derived aerosol properties from our measurements and how we assessed the quality of our data before sharing them with the scientific community. A good correlation was found between the three instruments.
Gabriela Dornelles Bittencourt, Hassan Bencherif, Damaris Kirsch Pinheiro, Nelson Begue, Lucas Vaz Peres, José Valentin Bageston, Douglas Lima de Bem, Francisco Raimundo da Silva, and Tristan Millet
Atmos. Meas. Tech., 17, 5201–5220, https://doi.org/10.5194/amt-17-5201-2024, https://doi.org/10.5194/amt-17-5201-2024, 2024
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The study examines the behavior of ozone at equatorial and subtropical latitudes in South America, in a multi-instrumental analysis. The methodology applied used ozonesondes (SHADOZ/NASA) and satellite data (TIMED/SABER), as well as analysis with ground-based and satellite instruments, allowing a more in-depth study at both latitudes. The main motivation is to understand how latitudinal differences in the observation of ozone content can interfere with the behavior of this trace gas.
Tristan Millet, Hassan Bencherif, Thierry Portafaix, Nelson Bègue, Alexandre Baron, Valentin Duflot, Cathy Clerbaux, Pierre-François Coheur, Andrea Pazmino, Michaël Sicard, Jean-Marc Metzger, Guillaume Payen, Nicolas Marquestaut, and Sophie Godin-Beekmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-2350, https://doi.org/10.5194/egusphere-2024-2350, 2024
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On 15 January 2022, the Hunga volcano erupted, releasing aerosols, sulfur dioxide, and water vapor into the stratosphere, impacting ozone levels over the Indian Ocean. MLS and IASI data show that the volcanic plume decreased ozone levels within the stratospheric ozone layer, shaping a structure similar to an ozone mini-hole. A stable stratosphere, free of dynamical barriers, enabled the volcanic plume's transport over the Indian Ocean.
Nelson Bègue, Alexandre Baron, Gisèle Krysztofiak, Gwenaël Berthet, Corinna Kloss, Fabrice Jégou, Sergey Khaykin, Marion Ranaivombola, Tristan Millet, Thierry Portafaix, Valentin Duflot, Philippe Keckhut, Hélène Vérèmes, Guillaume Payen, Mahesh Kumar Sha, Pierre-François Coheur, Cathy Clerbaux, Michaël Sicard, Tetsu Sakai, Richard Querel, Ben Liley, Dan Smale, Isamu Morino, Osamu Uchino, Tomohiro Nagai, Penny Smale, John Robinson, and Hassan Bencherif
Atmos. Chem. Phys., 24, 8031–8048, https://doi.org/10.5194/acp-24-8031-2024, https://doi.org/10.5194/acp-24-8031-2024, 2024
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During the 2020 austral summer, the pristine atmosphere of the southwest Indian Ocean basin experienced significant perturbations. Numerical models indicated that the lower-stratospheric aerosol content was influenced by the intense and persistent stratospheric aerosol layer generated during the 2019–2020 extreme Australian bushfire events. Ground-based observations at Réunion confirmed the simultaneous presence of African and Australian aerosol layers.
Jean-Marcel Rivonirina, Thierry Portafaix, Solofoarisoa Rakotoniaina, Béatrice Morel, Chao Tang, Kévin Lamy, Marie Lothon, Tom Toulouse, Olivier Liandrat, Solofo Rakotondraompiana, and Hassan Bencherif
EGUsphere, https://doi.org/10.5194/egusphere-2024-1827, https://doi.org/10.5194/egusphere-2024-1827, 2024
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The lack of ground observation instruments and the vast ocean coverage make the Southwest Indian Ocean (SWIO) region difficult to access and poorly studied. For gathering ground-based camera information, satellite measurements have been used with the primary goal of characterizing both sites Saint-Denis of Reunion Island and Antananarivo Madagascar in terms of cloudiness. This study shows the particularity of each site and enhances our understanding of cloud properties, particularly in the SWIO.
Tristan Millet, Hassan Bencherif, Thierry Portafaix, Nelson Bègue, Alexandre Baron, Valentin Duflot, Michaël Sicard, Jean-Marc Metzger, Guillaume Payen, Nicolas Marquestaut, and Sophie Godin-Beekmann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2645, https://doi.org/10.5194/egusphere-2023-2645, 2023
Preprint withdrawn
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The eruption of the Hunga Tonga volcano in January 2022 released substantial amounts of aerosols, sulfur dioxide, and water vapor into the stratosphere. Satellite and ground instruments followed the displacement of the volcanic aerosol plume and its impact on ozone levels over the Indian Ocean. Ozone data reveal the presence of a persistent ozone mini-hole structure from 17 January to 22 January, with most ozone depletion occurring within the ozone layer at the location of the aerosol plume.
Bibiana Lopes, Damaris Kirsch Pinheiro, Hassan Bencherif, Gabriela Dornelles Bittencourt, Lucas Vaz Peres, Jean-Maurice Cadet, Thierry Portafaix, and Nathalie Tissot Boiaski
EGUsphere, https://doi.org/10.5194/egusphere-2023-1474, https://doi.org/10.5194/egusphere-2023-1474, 2023
Preprint archived
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This is a study of the climatology and behavior of UV radiation on the surface during events of secondary effects of the Antarctic ozone hole over south of Brazil. Considering all implications of excess exposure to UV radiation on the surface on human health it is important to know how much radiation the population is being exposed to during those events. Results showed that for each 1 % decrease in the ozone total column, the UV index tends to increase by 4 % in the region of study.
Gabriela Dornelles Bittencourt, Damaris Kirsch Pinheiro, Hassan Bencherif, Lucas Vaz Peres, Nelson Begue, José Valentin Bageston, Douglas Lima de Bem, Vagner Anabor, and Luiz Angelo Steffenel
EGUsphere, https://doi.org/10.5194/egusphere-2023-1471, https://doi.org/10.5194/egusphere-2023-1471, 2023
Preprint archived
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The study examines ozone depletions at mid-latitudes in Brazil during austral spring Antarctic Ozone Hole influence events. The methodology applied used data from the total column ozone, vertical profile of the atmosphere, and reanalysis data to analyze the atmospheric dynamics. The main motivation of this work is to show how this important trace gas dynamically behaves in the atmosphere in the active period of the Antarctic Ozone Hole in regions of medium latitudes.
Kevin Lamy, Thierry Portafaix, Colette Brogniez, Kaisa Lakkala, Mikko R. A. Pitkänen, Antti Arola, Jean-Baptiste Forestier, Vincent Amelie, Mohamed Abdoulwahab Toihir, and Solofoarisoa Rakotoniaina
Earth Syst. Sci. Data, 13, 4275–4301, https://doi.org/10.5194/essd-13-4275-2021, https://doi.org/10.5194/essd-13-4275-2021, 2021
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This paper is about the presentation of the UV-Indien measurement network. This network measures the ultraviolet radiation emitted by the Sun received at the Earth's surface and the clouding above each station. It has been deployed at several sites in the Indian Ocean region representing different environmental conditions. A description of the instruments and their calibration, maintenance, and data processing is presented in this paper along with a valuation of the data quality.
Tijl Verhoelst, Steven Compernolle, Gaia Pinardi, Jean-Christopher Lambert, Henk J. Eskes, Kai-Uwe Eichmann, Ann Mari Fjæraa, José Granville, Sander Niemeijer, Alexander Cede, Martin Tiefengraber, François Hendrick, Andrea Pazmiño, Alkiviadis Bais, Ariane Bazureau, K. Folkert Boersma, Kristof Bognar, Angelika Dehn, Sebastian Donner, Aleksandr Elokhov, Manuel Gebetsberger, Florence Goutail, Michel Grutter de la Mora, Aleksandr Gruzdev, Myrto Gratsea, Georg H. Hansen, Hitoshi Irie, Nis Jepsen, Yugo Kanaya, Dimitris Karagkiozidis, Rigel Kivi, Karin Kreher, Pieternel F. Levelt, Cheng Liu, Moritz Müller, Monica Navarro Comas, Ankie J. M. Piters, Jean-Pierre Pommereau, Thierry Portafaix, Cristina Prados-Roman, Olga Puentedura, Richard Querel, Julia Remmers, Andreas Richter, John Rimmer, Claudia Rivera Cárdenas, Lidia Saavedra de Miguel, Valery P. Sinyakov, Wolfgang Stremme, Kimberly Strong, Michel Van Roozendael, J. Pepijn Veefkind, Thomas Wagner, Folkard Wittrock, Margarita Yela González, and Claus Zehner
Atmos. Meas. Tech., 14, 481–510, https://doi.org/10.5194/amt-14-481-2021, https://doi.org/10.5194/amt-14-481-2021, 2021
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This paper reports on the ground-based validation of the NO2 data produced operationally by the TROPOMI instrument on board the Sentinel-5 Precursor satellite. Tropospheric, stratospheric, and total NO2 columns are compared to measurements collected from MAX-DOAS, ZSL-DOAS, and PGN/Pandora instruments respectively. The products are found to satisfy mission requirements in general, though negative mean differences are found at sites with high pollution levels. Potential causes are discussed.
Kaisa Lakkala, Jukka Kujanpää, Colette Brogniez, Nicolas Henriot, Antti Arola, Margit Aun, Frédérique Auriol, Alkiviadis F. Bais, Germar Bernhard, Veerle De Bock, Maxime Catalfamo, Christine Deroo, Henri Diémoz, Luca Egli, Jean-Baptiste Forestier, Ilias Fountoulakis, Katerina Garane, Rosa Delia Garcia, Julian Gröbner, Seppo Hassinen, Anu Heikkilä, Stuart Henderson, Gregor Hülsen, Bjørn Johnsen, Niilo Kalakoski, Angelos Karanikolas, Tomi Karppinen, Kevin Lamy, Sergio F. León-Luis, Anders V. Lindfors, Jean-Marc Metzger, Fanny Minvielle, Harel B. Muskatel, Thierry Portafaix, Alberto Redondas, Ricardo Sanchez, Anna Maria Siani, Tove Svendby, and Johanna Tamminen
Atmos. Meas. Tech., 13, 6999–7024, https://doi.org/10.5194/amt-13-6999-2020, https://doi.org/10.5194/amt-13-6999-2020, 2020
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The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor (S5P) satellite was launched on 13 October 2017 to provide the atmospheric composition for atmosphere and climate research. Ground-based data from 25 sites located in Arctic, subarctic, temperate, equatorial and Antarctic
areas were used for the validation of the TROPOMI surface ultraviolet (UV) radiation product. For most sites 60 %–80 % of TROPOMI data was within ± 20 % of ground-based data.
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Short summary
The complexity of geophysics systems results in time series with fluctuations at all timescales. The analysis of their variability then consists in decomposing them into a set of basis signals. We developed here a new adaptive filtering method called empirical adaptive wavelet decomposition that optimizes the empirical-mode decomposition existing technique, overcoming its drawbacks using the rigour of wavelets as defined in the recently published empirical wavelet transform method.
The complexity of geophysics systems results in time series with fluctuations at all timescales....