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.
Research article
| 
05 Jul 2022
Research article |
| 05 Jul 2022
| 05 Jul 2022
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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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.
Michael Sicard, Alexandre Baron, Marion Ranaivombola, Dominique Gantois, Tristan Millet, Pasquale Sellitto, Nelson Bègue, Hassan Bencherif, Guillaume Payen, Nicolas Marquestaut, and Valentin Duflot
EGUsphere, https://doi.org/10.22541/essoar.170231679.99186200/v1, https://doi.org/10.22541/essoar.170231679.99186200/v1, 2024
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This study quantifies the radiative impact over Reunion Island (21° S, 55° E) of the aerosols and water vapor injected in the stratosphere by the Hunga Tonga-Hunga Ha'apai 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, -0.54 ± 0.29 W m-2) and dominated by the aerosols. At the Earth’s surface, aerosols are the main driver and produce a negative (cooling, -1.19 ± 0.40 W m-2) radiative impact.
Marion Ranaivombola, Nelson Bègue, Farahnaz Fazel-Rastgar, Venkataraman Sivakumar, Gisèle Krysztofiak, Gwenaël Berthet, Fabrice Jegou, Stuart Piketh, and Hassan Bencherif
EGUsphere, https://doi.org/10.5194/egusphere-2024-921, https://doi.org/10.5194/egusphere-2024-921, 2024
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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 a southeastward transport over Southern Africa and the southwestern of Indian Ocean (SWIO) basin. The "river of smoke" phenomenon drove the plume during September toward the SWIO. One discusses the long-range transport of biomass burning from South America to Southern Africa is likely driven by climate forcings.
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
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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
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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.
Nelson Bègue, Lerato Shikwambana, Hassan Bencherif, Juan Pallotta, Venkataraman Sivakumar, Elian Wolfram, Nkanyiso Mbatha, Facundo Orte, David Jean Du Preez, Marion Ranaivombola, Stuart Piketh, and Paola Formenti
Ann. Geophys., 38, 395–420, https://doi.org/10.5194/angeo-38-395-2020, https://doi.org/10.5194/angeo-38-395-2020, 2020
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This study investigates the influence of the 2015 Calbuco eruption (41.2°S, 72.4°W; Chile) on the total columnar aerosol optical properties in the Southern Hemisphere. The well-known technique of sun photometry was applied to the investigation of the transport and the spatio-temporal evolution of the optical properties of the volcanic plume. The CIMEL sun photometer measurements performed over six South American and three African sites were statistically analyzed.
Gabriela Dornelles Bittencourt, Damaris Kirsch Pinheiro, José Valentin Bageston, Hassan Bencherif, Luis Angelo Steffenel, and Lucas Vaz Peres
Ann. Geophys., 37, 1049–1061, https://doi.org/10.5194/angeo-37-1049-2019, https://doi.org/10.5194/angeo-37-1049-2019, 2019
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The Antarctic ozone hole (AOH) directly influences the Antarctic region, where its levels can reach values below 220 DU. The temporary depletion of ozone in Antarctica generally occurs between the beginning and middle of August, during the austral spring, and extends to November, when a temporary reduction in ozone content is observed in a large region over Antarctica. However, masses of ozone-depleted air can break away from the ozone hole and reach mid-latitude regions.
Kévin Lamy, Thierry Portafaix, Béatrice Josse, Colette Brogniez, Sophie Godin-Beekmann, Hassan Bencherif, Laura Revell, Hideharu Akiyoshi, Slimane Bekki, Michaela I. Hegglin, Patrick Jöckel, Oliver Kirner, Ben Liley, Virginie Marecal, Olaf Morgenstern, Andrea Stenke, Guang Zeng, N. Luke Abraham, Alexander T. Archibald, Neil Butchart, Martyn P. Chipperfield, Glauco Di Genova, Makoto Deushi, Sandip S. Dhomse, Rong-Ming Hu, Douglas Kinnison, Michael Kotkamp, Richard McKenzie, Martine Michou, Fiona M. O'Connor, Luke D. Oman, Giovanni Pitari, David A. Plummer, John A. Pyle, Eugene Rozanov, David Saint-Martin, Kengo Sudo, Taichu Y. Tanaka, Daniele Visioni, and Kohei Yoshida
Atmos. Chem. Phys., 19, 10087–10110, https://doi.org/10.5194/acp-19-10087-2019, https://doi.org/10.5194/acp-19-10087-2019, 2019
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In this study, we simulate the ultraviolet radiation evolution during the 21st century on Earth's surface using the output from several numerical models which participated in the Chemistry-Climate Model Initiative. We present four possible futures which depend on greenhouse gases emissions. The role of ozone-depleting substances, greenhouse gases and aerosols are investigated. Our results emphasize the important role of aerosols for future ultraviolet radiation in the Northern Hemisphere.
Pablo Facundo Orte, Elian Wolfram, Jacobo Salvador, Akira Mizuno, Nelson Bègue, Hassan Bencherif, Juan Lucas Bali, Raúl D'Elia, Andrea Pazmiño, Sophie Godin-Beekmann, Hirofumi Ohyama, and Jonathan Quiroga
Ann. Geophys., 37, 613–629, https://doi.org/10.5194/angeo-37-613-2019, https://doi.org/10.5194/angeo-37-613-2019, 2019
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We analysed an event of short-term ozone variability due to the passage of the polar vortex over Río Gallegos (southern Argentina) with the aim of highlighting the capability of a millimetre-wave radiometer to observe ozone in the stratosphere and the low mesosphere with a high temporal resolution. It is particularly important in this subpolar region due to the high variation that this gas can suffer as a consequence of the passage of the polar vortex and the ozone hole during spring.
David J. du Preez, Jelena V. Ajtić, Hassan Bencherif, Nelson Bègue, Jean-Maurice Cadet, and Caradee Y. Wright
Ann. Geophys., 37, 129–141, https://doi.org/10.5194/angeo-37-129-2019, https://doi.org/10.5194/angeo-37-129-2019, 2019
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Reduced atmospheric ozone results in increased solar ultraviolet radiation (UVR) at the surface which may potentially negative impact public health. We aimed to assess whether or not the break-up of the Antarctic ozone hole had an impact on ozone and UVR at Cape Point (South Africa). We found a moderate inverse relationship between ozone and UVR at midday on clear-sky days. The Antarctic ozone hole had a limited effect on ozone levels while tropical air masses more frequently affected the site.
Abdoulwahab Mohamed Toihir, Thierry Portafaix, Venkataraman Sivakumar, Hassan Bencherif, Andréa Pazmiño, and Nelson Bègue
Ann. Geophys., 36, 381–404, https://doi.org/10.5194/angeo-36-381-2018, https://doi.org/10.5194/angeo-36-381-2018, 2018
Gabriela Dornelles Bittencourt, Caroline Bresciani, Damaris Kirsch Pinheiro, José Valentin Bageston, Nelson Jorge Schuch, Hassan Bencherif, Neusa Paes Leme, and Lucas Vaz Peres
Ann. Geophys., 36, 415–424, https://doi.org/10.5194/angeo-36-415-2018, https://doi.org/10.5194/angeo-36-415-2018, 2018
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Ozone-poor air mass can be released and leave through the Antarctic ozone hole, thus reaching midlatitude regions. The objective of this study is to show how tropospheric and stratospheric dynamics behaved during the event. The ozone-poor air mass began to operate in the region on 20 October 2016. A reduction of ozone content of approximately 23 % was observed in relation to the climatology average. The advance of the ozone-poor air mass caused intense reductions in total ozone content.
Caroline Bresciani, Gabriela Dornelles Bittencourt, José Valentin Bageston, Damaris Kirsch Pinheiro, Nelson Jorge Schuch, Hassan Bencherif, Neusa Paes Leme, and Lucas Vaz Peres
Ann. Geophys., 36, 405–413, https://doi.org/10.5194/angeo-36-405-2018, https://doi.org/10.5194/angeo-36-405-2018, 2018
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This paper investigates the passage of the ozone secondary effect (OSE) over southern Brazil and Uruguay in October 2016 by using multi-instrumental data, i.e. ozonesonde, satellites and ground-based instruments, and the large OSE influence on the ozone concentration and on the temperature was shown.
Mateus S. Venturini, José V. Bageston, Nattan R. Caetano, Lucas V. Peres, Hassan Bencherif, and Nelson J. Schuch
Ann. Geophys., 36, 301–310, https://doi.org/10.5194/angeo-36-301-2018, https://doi.org/10.5194/angeo-36-301-2018, 2018
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In the past years, the study of the temperature trend and its variability in the upper atmosphere has increased. However, most works were conducted in regions of medium and high latitude. Therefore, we aim to analyze a low-latitude region, the south of Brazil and surrounding areas. Using data from the TIMED/SABER instrument and applying the Trend-Run model for temperature trend analyses, no substantial temperature trend was found in the MLT region (80–100 km) from the years 2003 to 2014.
Kévin Lamy, Thierry Portafaix, Colette Brogniez, Sophie Godin-Beekmann, Hassan Bencherif, Béatrice Morel, Andrea Pazmino, Jean Marc Metzger, Frédérique Auriol, Christine Deroo, Valentin Duflot, Philippe Goloub, and Charles N. Long
Atmos. Chem. Phys., 18, 227–246, https://doi.org/10.5194/acp-18-227-2018, https://doi.org/10.5194/acp-18-227-2018, 2018
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This work focuses on solar radiation in the tropics, more specifically on ultraviolet radiation. From ground-based and satellite observations of the chemical state of the atmosphere, we were able to model the ultraviolet measurements measured in the southern tropics with a very small error. This is a first step to modelling and predicting future ultraviolet levels in the tropics from chemistry-climate projections.
Nelson Bègue, Damien Vignelles, Gwenaël Berthet, Thierry Portafaix, Guillaume Payen, Fabrice Jégou, Hassan Benchérif, Julien Jumelet, Jean-Paul Vernier, Thibaut Lurton, Jean-Baptiste Renard, Lieven Clarisse, Vincent Duverger, Françoise Posny, Jean-Marc Metzger, and Sophie Godin-Beekmann
Atmos. Chem. Phys., 17, 15019–15036, https://doi.org/10.5194/acp-17-15019-2017, https://doi.org/10.5194/acp-17-15019-2017, 2017
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The space–time evolutions of the Calbuco plume are investigated by combining satellite, in situ aerosol counting and lidar observations, and a numerical model. All the data at Reunion Island reveal a twofold increase in the amount of aerosol with respect to the values observed before the eruption. The dynamic context has favored the spread of the plume exclusively in the Southern Hemisphere. This study highlights the role played by dynamical barriers in the transport of atmospheric species.
Nelson Bègue, Nkanyiso Mbatha, Hassan Bencherif, René Tato Loua, Venkataraman Sivakumar, and Thierry Leblanc
Ann. Geophys., 35, 1177–1194, https://doi.org/10.5194/angeo-35-1177-2017, https://doi.org/10.5194/angeo-35-1177-2017, 2017
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In this investigation a statistical analysis of the characteristics of mesospheric inversion layers (MILs) over tropical regions is presented. This study involves the analysis of 16 years of lidar observations recorded at Reunion (20.8° S, 55.5° E) and 21 years of lidar observations recorded at Mauna Loa (19.5° N, 155.6° W) together with SABER observations at these two locations. Results presented in this study confirm that SAO contributes to the formation of MILs over the tropical region.
Valentin Duflot, Jean-Luc Baray, Guillaume Payen, Nicolas Marquestaut, Francoise Posny, Jean-Marc Metzger, Bavo Langerock, Corinne Vigouroux, Juliette Hadji-Lazaro, Thierry Portafaix, Martine De Mazière, Pierre-Francois Coheur, Cathy Clerbaux, and Jean-Pierre Cammas
Atmos. Meas. Tech., 10, 3359–3373, https://doi.org/10.5194/amt-10-3359-2017, https://doi.org/10.5194/amt-10-3359-2017, 2017
Pierre Tulet, Andréa Di Muro, Aurélie Colomb, Cyrielle Denjean, Valentin Duflot, Santiago Arellano, Brice Foucart, Jérome Brioude, Karine Sellegri, Aline Peltier, Alessandro Aiuppa, Christelle Barthe, Chatrapatty Bhugwant, Soline Bielli, Patrice Boissier, Guillaume Boudoire, Thierry Bourrianne, Christophe Brunet, Fréderic Burnet, Jean-Pierre Cammas, Franck Gabarrot, Bo Galle, Gaetano Giudice, Christian Guadagno, Fréderic Jeamblu, Philippe Kowalski, Jimmy Leclair de Bellevue, Nicolas Marquestaut, Dominique Mékies, Jean-Marc Metzger, Joris Pianezze, Thierry Portafaix, Jean Sciare, Arnaud Tournigand, and Nicolas Villeneuve
Atmos. Chem. Phys., 17, 5355–5378, https://doi.org/10.5194/acp-17-5355-2017, https://doi.org/10.5194/acp-17-5355-2017, 2017
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The STRAP campaign was conducted in 2015 to investigate the volcanic plumes of Piton de La Fournaise (La Réunion, France). For the first time, measurements were conducted at the local (near the vent) and regional scales around the island. The STRAP 2015 campaign gave a unique set of multi-disciplinary data that can now be used by modellers to improve the numerical parameterisations of the physical and chemical evolution of the volcanic plumes.
Lucas Vaz Peres, Hassan Bencherif, Nkanyiso Mbatha, André Passaglia Schuch, Abdoulwahab Mohamed Toihir, Nelson Bègue, Thierry Portafaix, Vagner Anabor, Damaris Kirsch Pinheiro, Neusa Maria Paes Leme, José Valentin Bageston, and Nelson Jorge Schuch
Ann. Geophys., 35, 25–37, https://doi.org/10.5194/angeo-35-25-2017, https://doi.org/10.5194/angeo-35-25-2017, 2017
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In this paper, we analyze the total ozone column over the Southern Space Observatory, Brazil, between 1992 and 2014 by Brewer spectrometer and TOMS and OMI satellite instruments, finding good agreement between the two. In addition, the seasonal TOC variation is dominated by an annual cycle, and the Quasi-Biennial Oscillation modulation was the main mode of interannual variability and in opposite phase to the total ozone column anomaly time series.
Susana Fernandez, Rolf Rüfenacht, Niklaus Kämpfer, Thierry Portafaix, Françoise Posny, and Guillaume Payen
Atmos. Chem. Phys., 16, 7531–7543, https://doi.org/10.5194/acp-16-7531-2016, https://doi.org/10.5194/acp-16-7531-2016, 2016
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We present a new ground based microwave radiometer for campaigns, GROMOS-C. It measures the vertical distribution of ozone in the middle atmosphere by observing spectra at 110.836 GHz. The paper presents a validation campaign that took place on La Réunion Island. The ozone retrieved profiles are validated against ozone profiles from the Microwave Limb Sounder, the ozone lidar located in the observatory, ozone profiles from weekly radiosondes and with ECMWF model data.
Daan Hubert, Jean-Christopher Lambert, Tijl Verhoelst, José Granville, Arno Keppens, Jean-Luc Baray, Adam E. Bourassa, Ugo Cortesi, Doug A. Degenstein, Lucien Froidevaux, Sophie Godin-Beekmann, Karl W. Hoppel, Bryan J. Johnson, Erkki Kyrölä, Thierry Leblanc, Günter Lichtenberg, Marion Marchand, C. Thomas McElroy, Donal Murtagh, Hideaki Nakane, Thierry Portafaix, Richard Querel, James M. Russell III, Jacobo Salvador, Herman G. J. Smit, Kerstin Stebel, Wolfgang Steinbrecht, Kevin B. Strawbridge, René Stübi, Daan P. J. Swart, Ghassan Taha, David W. Tarasick, Anne M. Thompson, Joachim Urban, Joanna A. E. van Gijsel, Roeland Van Malderen, Peter von der Gathen, Kaley A. Walker, Elian Wolfram, and Joseph M. Zawodny
Atmos. Meas. Tech., 9, 2497–2534, https://doi.org/10.5194/amt-9-2497-2016, https://doi.org/10.5194/amt-9-2497-2016, 2016
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A more detailed understanding of satellite O3 profile data records is vital for further progress in O3 research. To this end, we made a comprehensive assessment of 14 limb/occultation profilers using ground-based reference data. The mutual consistency of satellite O3 in terms of bias, short-term variability and decadal stability is generally good over most of the stratosphere. However, we identified some exceptions that impact the quality of recently merged data sets and ozone trend assessments.
A. M. Toihir, H. Bencherif, V. Sivakumar, L. El Amraoui, T. Portafaix, and N. Mbatha
Ann. Geophys., 33, 1135–1146, https://doi.org/10.5194/angeo-33-1135-2015, https://doi.org/10.5194/angeo-33-1135-2015, 2015
J.-L. Baray, Y. Courcoux, P. Keckhut, T. Portafaix, P. Tulet, J.-P. Cammas, A. Hauchecorne, S. Godin Beekmann, M. De Mazière, C. Hermans, F. Desmet, K. Sellegri, A. Colomb, M. Ramonet, J. Sciare, C. Vuillemin, C. Hoareau, D. Dionisi, V. Duflot, H. Vérèmes, J. Porteneuve, F. Gabarrot, T. Gaudo, J.-M. Metzger, G. Payen, J. Leclair de Bellevue, C. Barthe, F. Posny, P. Ricaud, A. Abchiche, and R. Delmas
Atmos. Meas. Tech., 6, 2865–2877, https://doi.org/10.5194/amt-6-2865-2013, https://doi.org/10.5194/amt-6-2865-2013, 2013
N. Mbatha, V. Sivakumar, H. Bencherif, and S. Malinga
Ann. Geophys., 31, 1709–1719, https://doi.org/10.5194/angeo-31-1709-2013, https://doi.org/10.5194/angeo-31-1709-2013, 2013
Related subject area
Subject: Time series, machine learning, networks, stochastic processes, extreme events | Topic: Climate, atmosphere, ocean, hydrology, cryosphere, biosphere | Techniques: Simulation
Lévy noise versus Gaussian-noise-induced transitions in the Ghil–Sellers energy balance model
Direct Bayesian model reduction of smaller scale convective activity conditioned on large-scale dynamics
Improvements to the use of the Trajectory-Adaptive Multilevel Sampling algorithm for the study of rare events
Simulation-based comparison of multivariate ensemble post-processing methods
A prototype stochastic parameterization of regime behaviour in the stably stratified atmospheric boundary layer
Valerio Lucarini, Larissa Serdukova, and Georgios Margazoglou
Nonlin. Processes Geophys., 29, 183–205, https://doi.org/10.5194/npg-29-183-2022, https://doi.org/10.5194/npg-29-183-2022, 2022
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In most of the investigations on metastable systems, the stochastic forcing is modulated by Gaussian noise. Lévy noise laws, which describe jump processes, have recently received a lot of attention, but much less is known. We study stochastic versions of the Ghil–Sellers energy balance model, and we highlight the fundamental difference between how transitions are performed between the competing warm and snowball states, depending on whether Gaussian or Lévy noise acts as forcing.
Robert Polzin, Annette Müller, Henning Rust, Peter Névir, and Péter Koltai
Nonlin. Processes Geophys., 29, 37–52, https://doi.org/10.5194/npg-29-37-2022, https://doi.org/10.5194/npg-29-37-2022, 2022
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In this study, a recent algorithmic framework called Direct Bayesian Model Reduction (DBMR) is applied which provides a scalable probability-preserving identification of reduced models directly from data. The stochastic method is tested in a meteorological application towards a model reduction to latent states of smaller scale convective activity conditioned on large-scale atmospheric flow.
Pascal Wang, Daniele Castellana, and Henk A. Dijkstra
Nonlin. Processes Geophys., 28, 135–151, https://doi.org/10.5194/npg-28-135-2021, https://doi.org/10.5194/npg-28-135-2021, 2021
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This paper proposes two improvements to the use of Trajectory-Adaptive Multilevel Sampling, a rare-event algorithm which computes noise-induced transition probabilities. The first improvement uses locally linearised dynamics in order to reduce the arbitrariness associated with defining what constitutes a transition. The second improvement uses empirical transition paths accumulated at high noise in order to formulate the score function which determines the performance of the algorithm.
Sebastian Lerch, Sándor Baran, Annette Möller, Jürgen Groß, Roman Schefzik, Stephan Hemri, and Maximiliane Graeter
Nonlin. Processes Geophys., 27, 349–371, https://doi.org/10.5194/npg-27-349-2020, https://doi.org/10.5194/npg-27-349-2020, 2020
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Accurate models of spatial, temporal, and inter-variable dependencies are of crucial importance for many practical applications. We review and compare several methods for multivariate ensemble post-processing, where such dependencies are imposed via copula functions. Our investigations utilize simulation studies that mimic challenges occurring in practical applications and allow ready interpretation of the effects of different misspecifications of the numerical weather prediction ensemble.
Carsten Abraham, Amber M. Holdsworth, and Adam H. Monahan
Nonlin. Processes Geophys., 26, 401–427, https://doi.org/10.5194/npg-26-401-2019, https://doi.org/10.5194/npg-26-401-2019, 2019
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Atmospheric stably stratified boundary layers display transitions between regimes of sustained and intermittent turbulence. These transitions are not well represented in numerical weather prediction and climate models. A prototype explicitly stochastic turbulence parameterization simulating regime dynamics is presented and tested in an idealized model. Results demonstrate that the approach can improve the regime representation in models.
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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....
