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93 results on '"Amraoui, Laaziz"'

1. Assimilation of Aerosol Observations from the Future Spaceborne Lidar Onboard the AOS Mission into the MOCAGE Chemistry: Transport Model

Author

Cornut, Flavien, El Amraoui, Laaziz, Cuesta, Juan, Schmisser, Roseline, Blanc, Jérôme, Josse, Béatrice, Sullivan, John T., editor, Leblanc, Thierry, editor, Tucker, Sara, editor, Demoz, Belay, editor, Eloranta, Edwin, editor, Hostetler, Chris, editor, Ishii, Shoken, editor, Mona, Lucia, editor, Moshary, Fred, editor, Papayannis, Alexandros, editor, and Rupavatharam, Krishna, editor

Published
2023
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3. Aerosol data assimilation in the chemical transport model MOCAGE during the TRAQA/ChArMEx campaign: aerosol optical depth

Author

Sič, Bojan, Amraoui, Laaziz El, Piacentini, Andrea, Marécal, Virginie, Emili, Emanuele, Cariolle, Daniel, Prather, Michael, and Attié, Jean-Luc

Subjects
Atmospheric Sciences, Meteorology & Atmospheric Sciences
Abstract

In this study, we describe the development of the aerosol optical depth (AOD) assimilation module in the chemistry transport model (CTM) MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle). Our goal is to assimilate the spatially averaged 2-D column AOD data from the National Aeronautics and Space Administration (NASA) Moderate-resolution Imaging Spectroradiometer (MODIS) instrument, and to estimate improvements in a 3-D CTM assimilation run compared to a direct model run. Our assimilation system uses 3-D-FGAT (first guess at appropriate time) as an assimilation method and the total 3-D aerosol concentration as a control variable. In order to have an extensive validation dataset, we carried out our experiment in the northern summer of 2012 when the pre-ChArMEx (CHemistry and AeRosol MEditerranean EXperiment) field campaign TRAQA (TRAnsport à longue distance et Qualité de l'Air dans le bassin méditerranéen) took place in the western Mediterranean basin. The assimilated model run is evaluated independently against a range of aerosol properties (2-D and 3-D) measured by in situ instruments (the TRAQA size-resolved balloon and aircraft measurements), the satellite Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument and ground-based instruments from the Aerosol Robotic Network (AERONET) network. The evaluation demonstrates that the AOD assimilation greatly improves aerosol representation in the model. For example, the comparison of the direct and the assimilated model run with AERONET data shows that the assimilation increased the correlation (from 0.74 to 0.88), and reduced the bias (from 0.050 to 0.006) and the root mean square error in the AOD (from 0.12 to 0.07). When compared to the 3-D concentration data obtained by the in situ aircraft and balloon measurements, the assimilation consistently improves the model output. The best results as expected occur when the shape of the vertical profile is correctly simulated by the direct model. We also examine how the assimilation can influence the modelled aerosol vertical distribution. The results show that a 2-D continuous AOD assimilation can improve the 3-D vertical profile, as a result of differential horizontal transport of aerosols in the model.

Published
2016

5. THE GLAM AIRBORNE CAMPAIGN ACROSS THE MEDITERRANEAN BASIN

Author

Ricaud, Philippe, Zbinden, Régina, Catoire, Valéry, Brocchi, Vanessa, Dulac, François, Hamonou, Eric, Canonici, Jean-Christophe, El Amraoui, Laaziz, Massart, Sébastien, Piguet, Bruno, Dayan, Uri, Nabat, Pierre, Sciare, Jean, Ramonet, Michel, Delmotte, Marc, di Sarra, Alcide, Sferlazzo, Damiano, di Iorio, Tatiana, Piacentino, Salvatore, Cristofanelli, Paolo, Mihalopoulos, Nikos, Kouvarakis, Giorgos, Pikridas, Michael, Savvides, Chrysanthos, Mamouri, Rodanthi-Elisavet, Nisantzi, Argyro, Hadjimitsis, Diofantos, Attié, Jean-Luc, Ferré, Hélène, Kangah, Yannick, Jaidan, Nizar, Guth, Jonathan, Jacquet, Patrick, Chevrier, Stéphane, Robert, Claude, Bourdon, Aurélien, Bourdinot, Jean-François, Etienne, Jean-Claude, Krysztofiak, Gisèle, and Theron, Pierre

Published
2018

8. THE CONCORDIASI PROJECT IN ANTARCTICA

Author

Rabier, Florence, Bouchard, Aurélie, Brun, Eric, Doerenbecher, Alexis, Guedj, Stéphanie, Guidard, Vincent, Karbou, Fatima, Peuch, Vincent-Henri, El Amraoui, Laaziz, Puech, Dominique, Genthon, Christophe, Picard, Ghislain, Town, Michael, Hertzog, Albert, Vial, François, Cocquerez, Philippe, Cohn, Stephen A., Hock, Terry, Fox, Jack, Cole, Hal, Parsons, David, Powers, Jordan, Romberg, Keith, VanAndel, Joseph, Deshler, Terry, Mercer, Jennifer, Haase, Jennifer S., Avallone, Linnea, Kalnajs, Lars, Mechoso, C. Roberto, Tangborn, Andrew, Pellegrini, Andrea, Frenot, Yves, Thépaut, Jean-Noël, McNally, Anthony, Balsamo, Gianpaolo, and Steinle, Peter

Published
2010

10. Modelling the volcanic ash plume from Eyjafjallajökull eruption (May 2010) over Europe: evaluation of the benefit of source term improvements and of the assimilation of aerosol measurements

Author

Plu, Matthieu, primary, Bigeard, Guillaume, additional, Sič, Bojan, additional, Emili, Emanuele, additional, Bugliaro, Luca, additional, El Amraoui, Laaziz, additional, Guth, Jonathan, additional, Josse, Beatrice, additional, Mona, Lucia, additional, and Piontek, Dennis, additional

Published
2021
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11. An ensemble of state-of-the-art ash dispersion models: towards probabilistic forecasts to increase the resilience of air traffic against volcanic eruptions

Author

Plu, Matthieu, primary, Scherllin-Pirscher, Barbara, additional, Arnold Arias, Delia, additional, Baro, Rocio, additional, Bigeard, Guillaume, additional, Bugliaro, Luca, additional, Carvalho, Ana, additional, El Amraoui, Laaziz, additional, Eschbacher, Kurt, additional, Hirtl, Marcus, additional, Maurer, Christian, additional, Mulder, Marie D., additional, Piontek, Dennis, additional, Robertson, Lennart, additional, Rokitansky, Carl-Herbert, additional, Zobl, Fritz, additional, and Zopp, Raimund, additional

Published
2021
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12. An ensemble of state-of-the-art ash dispersion models : towards probabilistic forecasts to increase the resilience of air traffic against volcanic eruptions

Author

Plu, Matthieu, Scherllin-Pirscher, Barbara, Arnold Arias, Delia, Baro, Rocio, Bigeard, Guillaume, Bugliaro, Luca, Carvalho, Ana Cristina, El Amraoui, Laaziz, Eschbacher, Kurt, Hirtl, Marcus, Maurer, Christian, Mulder, Marie D., Piontek, Dennis, Robertson, Lennart, Rokitansky, Carl-Herbert, Zobl, Fritz, Zopp, Raimund, Plu, Matthieu, Scherllin-Pirscher, Barbara, Arnold Arias, Delia, Baro, Rocio, Bigeard, Guillaume, Bugliaro, Luca, Carvalho, Ana Cristina, El Amraoui, Laaziz, Eschbacher, Kurt, Hirtl, Marcus, Maurer, Christian, Mulder, Marie D., Piontek, Dennis, Robertson, Lennart, Rokitansky, Carl-Herbert, Zobl, Fritz, and Zopp, Raimund

Published
2021
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13. Examination of the 2002 major warming in the Southern Hemisphere using ground-based and Odin/SMR assimilated data: stratospheric ozone distributions and tropic/midlatitude exchange

Author

Bencherif, Hassan, Amraoui, Laaziz El, Semane, Noureddine, Massart, Sebastien, Charyulu, D. Vidyaranya, Hauchecorne, Alain, and Peuch, Vincent-Henry

Subjects
Global warming -- Models -- Usage -- 2002 AD, Atmospheric ozone -- Models -- Distribution -- Usage -- 2002 AD, Radiometers -- Usage -- Distribution -- 2002 AD, Artificial satellites, European -- Usage -- Models -- 2002 AD, Meteorological satellites -- Usage -- Distribution -- 2002 AD, Physics, Company distribution practices, Distribution, Usage, Models
Abstract

Abstract: Following an exceptionally active winter, the 2002 Southern Hemisphere (SH) major warming occurred in late September. It was preceded by three minor warming events that occurred in late August [...]

Published
2007

14. Assessment of the quality of the ozone measurements from the Odin/SMR instrument using data assimilation (1)

Author

Massart, Sebastien, Piacentini, Andrea, Cariolle, Daniel, El Amraoui, Laaziz, and Semane, Noureddine

Subjects
Atmospheric ozone -- Measurement -- Models -- Methods, Radiometers -- Testing -- Models -- Measurement -- Methods, Artificial satellites, European -- Testing -- Models -- Measurement -- Methods, Simulation methods -- Methods -- Measurement -- Models, Meteorological satellites -- Testing -- Methods -- Models -- Measurement, Physics, Testing, Models, Measurement, Methods
Abstract

Abstract: Space-based remote-sensing instruments providing atmospheric measurements have different time and space resolutions, and coverage. This makes the direct comparison of the measurements very difficult. Data assimilation has proven to [...]

Published
2007

15. Supplementary material to "A tailored multi-model ensemble for air traffic management: Demonstration and evaluation for the Eyjafjallajökull eruption in May 2010"

Author

Plu, Matthieu, primary, Scherllin-Pirscher, Barbara, additional, Arnold Arias, Delia, additional, Baro, Rocio, additional, Bigeard, Guillaume, additional, Bugliaro, Luca, additional, Carvalho, Ana, additional, El Amraoui, Laaziz, additional, Eschbacher, Kurt, additional, Hirtl, Marcus, additional, Maurer, Christian, additional, Mulder, Marie, additional, Piontek, Dennis, additional, Robertson, Lennart, additional, Rokitansky, Carl-Herbert, additional, Zobl, Fritz, additional, and Zopp, Raimund, additional

Published
2021
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16. A tailored multi-model ensemble for air traffic management: Demonstration and evaluation for the Eyjafjallajökull eruption in May 2010

Author

Plu, Matthieu, primary, Scherllin-Pirscher, Barbara, additional, Arnold Arias, Delia, additional, Baro, Rocio, additional, Bigeard, Guillaume, additional, Bugliaro, Luca, additional, Carvalho, Ana, additional, El Amraoui, Laaziz, additional, Eschbacher, Kurt, additional, Hirtl, Marcus, additional, Maurer, Christian, additional, Mulder, Marie, additional, Piontek, Dennis, additional, Robertson, Lennart, additional, Rokitansky, Carl-Herbert, additional, Zobl, Fritz, additional, and Zopp, Raimund, additional

Published
2021
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19. Impact of synthetic spaceborne NO2 observations from the Sentinel-4 and Sentinel-5p platforms on tropospheric NO2 analyses

Author

Timmermans, Renske, Segers, Arjo, Curier, Lyana, Abida, Rachid, Attié, Jean-Luc, Amraoui, Laaziz, Eskes, Henk, Haan, Johan, Kujanpää, Jukka, Lahoz, William, Oude Nijhuis, Albert, Quesada, Samuel, Ricaud, Philippe, Veefkind, Pepijn, and Schaap, Martijn

Abstract

We present an Observing System Simulation Experiment (OSSE) dedicated to the evaluation of the added value of the Sentinel 4 and Sentinel 5P missions for tropospheric nitrogen dioxide (NO2). Sentinel 4 is a geostationary (GEO) mission covering the European continent, providing observations with high temporal resolution (hourly). Sentinel 5P is a low-Earth Orbiting (LEO) mission providing daily observations but with a global coverage. The OSSE experiment has been carefully designed, with separate models for the simulation of observations and for the assimilation experiments, and with conservative estimates of the total observation uncertainties. In the experiment we simulate Sentinel 4 and Sentinel 5P tropospheric NO2 columns and surface ozone concentrations at 7 by 7 km resolution over Europe for two three-month summer and winter periods. The synthetic observations are based on a nature run (NR) from a chemistry transport model (MOCAGE) and error estimates using instrument characteristics. We assimilate the simulated observations into a chemistry transport model (LOTOS-EUROS) independent from the NR to evaluate their impact on modelled NO2 tropospheric columns and surface concentrations. The results are compared to an operational system where only ground-based ozone observations are ingested. Both instruments have an added value on analysed NO2 columns and surface values, reflected in decreased biases, and improved correlations. The Sentinel 4 NO2 observations with hourly temporal resolution benefit modelled NO2 analyses throughout the entire day where the daily Sentinel 5P NO2 observations have a slightly lower impact that lasts up to 3–6 hours after overpass. The evaluated benefits may be even higher in reality as the applied error estimates were shown to be higher than actual errors in the now operational Sentinel 5P NO2 products. We show that an accurate representation of the NO2 profile is crucial for the benefit of the column observations on surface values. The results support the need for having a combination of GEO and LEO missions for NO2 analyses in view of the complementary benefits of hourly temporal resolution (GEO, Sentinel 4) and global coverage (LEO, Sentinel 5P).

Published
2019

20. Impact of synthetic space-borne NO2 observations from the Sentinel-4 and Sentinel-5P missions on tropospheric NO2 analyses

Author

Timmermans, Renske, Schaap, Martijn, Segers, Arjo, Curier, Lyana, Abida, Rachid, Attié, Jean-Luc, Amraoui, Laaziz El, Eskes, Henk, Haan, Johan De, and Kujanpää, Jukka [U.V.M.]

Subjects
Sentinel-5P, tropospheric NO2 analyses, 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::551 Geologie, Hydrologie, Meteorologie, Sentinel-4
Abstract

We present an Observing System Simulation Experiment (OSSE) dedicated to the evaluation of the added value of the Sentinel-4 and Sentinel-5P missions for tropospheric nitrogen dioxide (NO2). Sentinel-4 is a geostationary (GEO) mission covering the European continent, providing observations with high temporal resolution (hourly). Sentinel-5P is a low Earth orbit (LEO) mission providing daily observations with a global coverage. The OSSE experiment has been carefully designed, with separate models for the simulation of observations and for the assimilation experiments and with conservative estimates of the total observation uncertainties. In the experiment we simulate Sentinel-4 and Sentinel-5P tropospheric NO2 columns and surface ozone concentrations at 7 by 7 km resolution over Europe for two 3-month summer and winter periods. The synthetic observations are based on a nature run (NR) from a chemistry transport model (MOCAGE) and error estimates using instrument characteristics. We assimilate the simulated observations into a chemistry transport model (LOTOS-EUROS) independent of the NR to evaluate their impact on modelled NO2 tropospheric columns and surface concentrations. The results are compared to an operational system where only ground-based ozone observations are ingested. Both instruments have an added value to analysed NO2 columns and surface values, reflected in decreased biases and improved correlations. The Sentinel-4 NO2 observations with hourly temporal resolution benefit modelled NO2 analyses throughout the entire day where the daily Sentinel-5P NO2 observations have a slightly lower impact that lasts up to 3–6 h after overpass. The evaluated benefits may be even higher in reality as the applied error estimates were shown to be higher than actual errors in the now operational Sentinel-5P NO2 products. We show that an accurate representation of the NO2 profile is crucial for the benefit of the column observations on surface values. The results support the need for having a combination of GEO and LEO missions for NO2 analyses in view of the complementary benefits of hourly temporal resolution (GEO, Sentinel-4) and global coverage (LEO, Sentinel-5P).

Published
2019
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21. Impact of synthetic space-borne NO 2 observations from the Sentinel-4 and Sentinel-5P missions on tropospheric NO 2 analyses

Author

Timmermans, Renske, Segers, Arjo, Curier, Lyana, Abida, Rachid, Attié, Jean-Luc, El Amraoui, Laaziz, Eskes, Henk, de Haan, Johan, Kujanpää, Jukka, Lahoz, William, Oude Nijhuis, Albert, Quesada-Ruiz, Samuel, Ricaud, Philippe, Veefkind, Pepijn, Schaap, Martijn, Laboratoire de météorologie physique (LaMP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'Enseignement et de Recherche en Environnement Atmosphérique (CEREA), École des Ponts ParisTech (ENPC)-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Royal Netherlands Meteorological Institute (KNMI), Delft University of Technology (TU Delft), TNO Climate, Air and Sustainability [Utrecht], The Netherlands Organisation for Applied Scientific Research (TNO), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; The amount of ice injected up to the tropical tropopause layer has a strong radiative impact on climate. In the tropics, the Maritime Continent (MariCont) region presents the largest injection of ice by deep convection into the upper troposphere (UT) and tropopause level (TL) (from results presented in the companion paper Part 1). This study focuses on the MariCont region and aims to assess the processes, the areas and the diurnal amount and duration of ice injected by deep convection over islands and over seas using a 2 • × 2 • horizontal resolution during the austral convective season of December, January and February. The model presented in the companion paper is used to estimate the amount of ice injected (∆IWC) up to the TL by combining ice water content (IWC) measured twice a day in tropical UT and TL by the Microwave Limb Sounder (MLS; Version 4.2), from 2004 to 2017, and precipitation (Prec) measurement from the Tropical Rainfall Measurement Mission (TRMM; Version 007) at high temporal resolution (1 hour). The horizontal distribution of ∆IWC estimated from Prec (∆IWC P rec) is presented at 2 • × 2 • horizontal resolution over the MariCont. ∆IWC is also evaluated by using the number of lightnings (Flash) from the TRMM-LIS instrument (Lightning Imaging Sensor, from 2004 to 2015 at 1-h and 0.25 • ×0.25 • resolutions). ∆IWC P rec and ∆IWC estimated from Flash (∆IWC F lash) are compared to ∆IWC estimated from the ERA5 reanalyses (∆IWC ERA5) degrading the vertical resolution to that of MLS observations (∆IW C ERA5). Our study shows that, while the diurnal cycles of Prec and Flash are consistent to each other in timing and phase over lands and different over offshore and coastal areas of the MariCont, the observational ∆IWC range between ∆IWC P rec and ∆IWC F lash is small (to within 4-20% over land and to within 6-50% over ocean) in the UT and TL. The reanalysis ∆IWC range between ∆IWC ERA5 and ∆IW C ERA5 has been also found to be small in the UT (22-32 %) but large in the TL (68-71 %), highlighting the stronger impact of the vertical resolution on the TL than in the UT. Combining observational and reanalysis ∆IWC ranges, the total ∆IWC range is estimated in the UT between 4.17 and 9.97 mg m-3 (20 % of variability per study zone) over land and between 0.35 and 4.37 mg m-3 (30% of variability per study zone) over sea, and, in the TL, between 0.63 and 3.65 mg m-3 (70% of variability per study zone) over land and between 0.04 and 0.74 mg m-3 (80% of variability per study zone) over sea. Finally, from IWC ERA5 , Prec and Flash, this study highlights 1) ∆IWC over land has been found larger than ∆IWC over sea, and 2) the Java Island is the area of the largest ∆IWC in the UT (7.89-8.72 mg m-3 daily mean).

Published
2019
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23. Benefit of ozone observations from Sentinel-5P and future Sentinel-4 missions on tropospheric composition

Author

Quesada-Ruiz, Samuel, primary, Attié, Jean-Luc, additional, Lahoz, William A., additional, Abida, Rachid, additional, Ricaud, Philippe, additional, El Amraoui, Laaziz, additional, Zbinden, Régina, additional, Piacentini, Andrea, additional, Joly, Mathieu, additional, Eskes, Henk, additional, Segers, Arjo, additional, Curier, Lyana, additional, de Haan, Johan, additional, Kujanpää, Jukka, additional, Oude Nijhuis, Albert Christiaan Plechelmus, additional, Tamminen, Johanna, additional, Timmermans, Renske, additional, and Veefkind, Pepijn, additional

Published
2020
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24. Impact of synthetic space-borne NO<sub>2</sub> observations from the Sentinel-4 and Sentinel-5P missions on tropospheric NO<sub>2</sub> analyses

Author

Timmermans, Renske, primary, Segers, Arjo, additional, Curier, Lyana, additional, Abida, Rachid, additional, Attié, Jean-Luc, additional, El Amraoui, Laaziz, additional, Eskes, Henk, additional, de Haan, Johan, additional, Kujanpää, Jukka, additional, Lahoz, William, additional, Oude Nijhuis, Albert, additional, Quesada-Ruiz, Samuel, additional, Ricaud, Philippe, additional, Veefkind, Pepijn, additional, and Schaap, Martijn, additional

Published
2019
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25. A tailored multi-model ensemble for air traffic management: Demonstration and evaluation for the Eyjafjallajökull eruption in May 2010.

Author

Plu, Matthieu, Scherllin-Pirscher, Barbara, Arias, Delia Arnold, Baro, Rocio, Bigeard, Guillaume, Bugliaro, Luca, Carvalho, Ana, El Amraoui, Laaziz, Eschbacher, Kurt, Hirtl, Marcus, Maurer, Christian, Mulder, Marie, Piontek, Dennis, Robertson, Lennart, Rokitansky, Carl-Herbert, Zobl, Fritz, and Zopp, Raimund

Subjects
AIR traffic, VOLCANIC ash clouds, DIFFUSION processes, TRAFFIC congestion, TRAFFIC flow, VOLCANIC ash, tuff, etc., EXPLOSIVE volcanic eruptions
Abstract

High quality volcanic ash forecasts are crucial to minimize the economic impact of volcanic hazards on air traffic. Decision-making is usually based on numerical dispersion modeling with only one model realization. Given the inherent uncertainty of such approach, a multi-model multi-source term ensemble has been designed and evaluated for the Eyjafjallajökull eruption in May 2010. Its use for air traffic management is discussed. Two multi-model ensembles were built: the first is based on the output of four dispersion models and their own implementation of ash ejection. All a priori model source terms were constrained by observational evidence of the volcanic ash cloud top as a function of time. The second ensemble is based on the same four dispersion models, which were run with three additional source terms: (i) a source term obtained with background modeling constrained with satellite data (a posteriori source term), (ii) its lower bound estimate, and (iii) its upper bound estimate. The a priori ensemble gives valuable information about the probability of ash dispersion during the early phase of the eruption, when observational evidence is limited. However, its evaluation with observational data reveals lower quality compared to the second ensemble. While the second ensemble ash column load and ash horizontal location compare well to satellite observations, 3D ash concentrations are negatively biased. This might be caused by the vertical distribution of ash, which is too much diluted in all model runs, probably due to defaults in the a posteriori source term and vertical transport and/or diffusion processes in all models. Relevant products for the air traffic management are horizontal maps of ash concentration quantiles (median, 75 %, 99 %) at a fine-resolved flight level grid. These maps can be used for route optimization in the areas where ash does not pose a direct and urgent threat to aviation. Cost-optimized consideration of such hazards will result in much less impact on flight cancellations, reroutings, and traffic flow congestions. [ABSTRACT FROM AUTHOR]

Published
2021
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26. Summertime upper tropospheric nitrous oxide over the Mediterranean as a footprint of Asian emissions

Author

Kangah, Yannick, Ricaud, Philippe, Attié, Jean-Luc, Saitoh, Naoko, Hauglustaine, Didier, Wang, Rong, El Amraoui, Laaziz, Zbinden, Régina, Delon, Claire, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Center for Environmental Remote Sensing [Chiba] (CEReS), Chiba University, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Global Ecology [Carnegie] (DGE), Carnegie Institution for Science, Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Carnegie Institution for Science [Washington], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; The aim of this paper is to study the transport of nitrous oxide (N$_2$O) from the Asian surface tothe eastern Mediterranean Basin (MB). We used measurements from the spectrometer Thermal and Nearinfrared Sensor for carbon Observation Fourier transform spectrometer on board the Greenhouse gasesObserving SATellite (GOSAT) over the period of 2010–2013. We also used the outputs from the chemicaltransport model LMDz-OR-INCA over the same period. By comparing GOSAT upper tropospheric retrievals toaircraft measurements from the High-performance Instrumented Airborne Platform for EnvironmentalResearch Pole-to-Pole Observations, we calculated a GOSAT High-performance Instrumented AirbornePlatform for Environmental Research standard deviation (SD error) of ~2.0 ppbv for a single pixel and a meanbias of approximately $-$1.3 ppbv (approximately $-$0.4%). This SD error is reduced to ~0.1 ppbv when weaverage the pixels regionally and monthly over the MB. The use of nitrogen fertilizer coupled with high soilhumidity during the summer Asian monsoon produces high N2O emissions, which are transported fromAsian surfaces to the eastern MB. This summertime enrichment over the eastern MB produces a maximum inthe difference between the eastern and the western MB upper tropospheric N$_2$O (east-west difference) in Julyin both the measurements and the model. N2O over the eastern MB can therefore be considered as afootprint of Asian summertime emissions. However, the peak-to-peak amplitude of the east-west differenceobserved by GOSAT (~1.4 ± 0.3 ppbv) is larger than that calculated by LMDz-OR-INCA (~0.8 ppbv). This is dueto an underestimation of N2O emissions in the model and to a relatively coarse spatial resolution of themodel that tends to underestimate the N2O accumulation into the Asian monsoon anticyclone.

Published
2017
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27. Impact of the intercontinental transport of biomass burning pollutants on the Mediterranean Basin during the CHARMEX-GLAM airborne campaign

Author

Brocchi, Vanessa, Krysztofiak, Gisèle, Catoire, Valéry, Zbinden, Régina, Guth, Jonathan, El Amraoui, Laaziz, Piguet, Bruno, Dulac, François, Hamonou, Eric, Ricaud, Philippe, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU]Sciences of the Universe [physics]
Abstract

International audience; The Mediterranean Basin (MB) is at the crossroad of pollutant emissions from Western and Central Europe and of major dust sources from Sahara and Arabian deserts and thus sensitive to climate change and air quality. Several studies (Formenti et al.,J. Geophys. Res., 2002; Ancellet et al., Atmos. Chem. Phys., 2016) also show the impact on the MB of long-range transport of polluted air masses. However, most of the studies have been dedicated to biomass burning aerosols. The aim of the present study is to show trace gases impact on the MB coming from long-range transport of biomass burning. The Gradient in Longitude of Atmospheric constituents above the Mediterranean basin (GLAM) campaign in August 2014, as part of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) project, aimed at studying the tropospheric chemical variability of gaseous pollutants and aerosols along a West-East transect above the MB. During the GLAM campaign, several instruments onboard the Falcon-20 aircraft (SAFIRE, INSU / Météo-France) were deployed including an infrared laser spectrometer (SPIRIT, LPC2E) able to detect weak variations in the concentration of pollutants. During two flights on 6 and 10 August, increases in CO, O3 and aerosols were measured over Sardinia at 5000 and 9000 m asl, respectively. To assess the origin of the air masses, 20-day backward trajectories with a nested-grid regional scale Lagrangian particle dispersion model (FLEXPART, Stohl et al., Atmos. Chem. Phys., 2005) were calculated. Combined with emissions coming from the Global Fire Assimilation System (GFAS) inventory (Kaiser et al., Biogeosciences, 2012), this leads to CO biomass burning contribution to aircraft measured values. Biomass burning emissions located in Siberia in the first case and in northern America in the second case were identified as the cause of this burden of pollutants in the mid and upper troposphere over the MB. By adjusting the injection height of the model and amplifying emissions, FLEXPART was able to reproduce the contribution of those fires to CO enhancements. Our results show that long-range transport of biomass burning induces, at local scale, an increase by a factor ranging from 1.7 to 3.7 with respect to O3 and CO backgrounds of ∼25 and ∼70 ppb, respectively. To assess the biomass burning effect on ozone level at regional scale over the MB, its tropospheric increase is estimated by using the chemical transport model MOCAGE.

Published
2017

28. Impact of synthetic spaceborne NO2 observations from the Sentinel-4 and Sentinel-5p platforms on tropospheric NO2 analyses

Author

Timmermans, Renske, primary, Segers, Arjo, additional, Curier, Lyana, additional, Abida, Rachid, additional, Attié, Jean-Luc, additional, El Amraoui, Laaziz, additional, Eskes, Henk, additional, de Haan, Johan, additional, Kujanpää, Jukka, additional, Lahoz, William, additional, Oude Nijhuis, Albert, additional, Quesada, Samuel, additional, Ricaud, Philippe, additional, Veefkind, Pepijn, additional, and Schaap, Martijn, additional

Published
2019
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29. Benefit of ozone observations from Sentinel-5P and future Sentinel-4 missions on tropospheric composition

Author

Quesada-Ruiz, Samuel, primary, Attié, Jean-Luc, additional, Lahoz, William A., additional, Abida, Rachid, additional, Ricaud, Philippe, additional, El Amraoui, Laaziz, additional, Zbinden, Régina, additional, Piacentini, Andrea, additional, Joly, Mathieu, additional, Eskes, Henk, additional, Segers, Arjo, additional, Curier, Lyana, additional, de Haan, Johan, additional, Kujanpää, Jukka, additional, Oude-Nijhuis, Albert, additional, Tamminen, Johanna, additional, Timmermans, Renske, additional, and Veefkind, Pepijn, additional

Published
2019
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32. Overview of the Gradient in Longitude of Atmospheric constituents above the Mediterranean basin (GLAM) airborne summer campaign

Author

Ricaud, Philippe, Zbinden, Regina, Catoire, Valery, Brocchi, Vanessa, Dulac, Francois, Hamonou, Eric, Canonici, Jean-Christophe, El Amraoui, Laaziz, Massart, Sebastien, Piguet, Bruno, Dayan, Uri, Nabat, Pierre, Sciare, Jean, Ramonet, Michel, Di Sarra, Alcide, Mihalopoulos, Nikolaos, Kouvarakis, Giorgos, Kleanthous, Savvas, Pikridas, Michael, Attié, Jean-Luc, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU]Sciences of the Universe [physics]
Abstract

International audience; The Gradient in Longitude of Atmospheric constituents above the Mediterranean basin (GLAM) airborne campaign has been set up to investigate the variability of constituents (pollutants and greenhouse gases) and aerosols between the West and the East of the Mediterranean Basin in summer 2014. This campaign occurred in the framework of the Chemistry-Aerosol Mediterranean Experiment (CHARMEX) as part of the Mediterranean Integrated STudies at Regional And Local Scales (MISTRALS) programme. During the campaign, several instruments including the Spectromètre InfraRouge In situ Toute altitude (SPIRIT) instrument onboard the SAFIRE Falcon-20 aircraft measured aerosols, winds, radiation, humidity and chemical compounds such as O3, CO, CH4, N2O, and CO2. The campaign took place from 6 to 10 August 2014 from Toulouse (France) to Larnaca (Cyprus) and back, via Menorca (Spain), Lampedusa (Italy) and Heraklion (Crete). The aircraft flew at about 5000 m altitude above sea level to go and at about 9000 m altitude to return. The campaign also provided some vertical profilings from the surface to about 12 km in the vicinity of the landing sites listed above. The present paper shows an overview of the measurements and of the scientific results obtained during GLAM combining space-borne and surface station measurements, modelling (MOCAGE and ALADIN-CLIMAT) and chemical forecasts and analyses from Copernicus Atmospheric Monitoring Service (CAMS) run by the European Centre for Medium range Weather Forecasting (ECMWF). Along an East-West axis or along the vertical, we analyze different processes. Among the different processes that have been studied in detail, we will particularly focus on aerosol results concentrating on the intercontinental transport and comparisons with surface stations. Combining GLAM, back-trajectories, satellite and model data, we demonstrate that the biomass burning from northern America, desert dust from Sahara and O3-depleted maritime boundary layer air masses from the Arabian Sea impacted the upper tropospheric Mediterranean Basin after 10-15 days of transport. Finally, vertical profiles of aerosols measured by Lidars at different stations of the Mediterranean Basin are compared with in situ GLAM measurements and model outputs.

Published
2016

33. The (uncertain) future of air quality

Author

Colette, Augustin, El Amraoui, Laaziz, Solmon, Fabien, and Civs, Gestionnaire

Subjects
[SDE] Environmental Sciences
Abstract

The assessment of the future evolution of air quality requires accounting for both climate projections and the development of environmental policies. In the context of climate change adaptation, the geophysical changes to be expected in the decades to come will have an impact on chronic and extreme air pollution events (Jacob and Winner, 2009). But air quality is also sensitive to climate mitigation strategies: the social and technological changes required to reduce greenhouse gases emissions will also be accompanied by changes in the emission of air pollutants and precursors thereof. There are potentially large co-benefits between air quality and climate change mitigation that could help in leveraging efforts to engage in win-win strategies. But mitigating climate change can also potentially induce collateral damages to air quality. It is thus very important to precisely identify what are the co-benefits and the possible collateral damages in order to maximize the former while minimizing the later. Here we briefly review recent results on climate change impacts on Mediterranean regional air quality in terms of ozone and particles, and list identified positive and negative feedbacks of climate change on air quality.

Published
2016

36. Variability of tropospheric pollutants and aerosols in the context of the airborne GLAM campaign

Author

Zbinden, Régina, Ricaud, Philippe, El Amraoui, Laaziz, Attié, Jean-Luc, Catoire, Valéry, Brocchi, Vanessa, Nabat, Pierre, Dulac, François, Dayan, Uri, Météo-France [Paris], Météo France, Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), EGU General Assembly 2015, COPERNICUS, Météo-France, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU]Sciences of the Universe [physics]
Abstract

International audience; In the framework of the ChArMEx (Chemistry-Aerosol Mediterranean Experiment) program, the airborne campaign GLAM (Gradient in Longitude of Atmospheric constituents above the Mediterranean basin) has been set up to study the variability of gazeous pollutants with different lifetimes and of aerosols over the Mediterranean Basin (MB). The project mainly focuses on the East-West gradients in pollutants within the mid to upper-troposphere induced by the impact of the Asian Monsoon Anticyclone on the pollutants in the Eastern MB, and on the comparisons with space-borne measurements and model results. On board the Falcon-20, together with an ozone analyzer, humidity and temperature sensors and optical particle counters, a laser absorption spectrometer SPIRIT developed at LPC2E was able to detect very weak changes in the concentration of greenhouse gases. GLAM performed measurements of O 3 , CO, CH4, N2O, CO 2 , H 2 O, temperature and the winds components over the Mediterranean Basin in summer (6-10 August 2014), flying at 5000 m altitude from France to Cyprus and at 9000 m on the flight back. In addition, GLAM performed vertical profiles between about 0.3 and 11 km altitude near the different landing sites. These in situ profiles are an original source to validate what the space-borne instruments detect within the same altitudes. Some of these profiles are also performed close to the surface stations of Lampedusa, Finokalia (Crete) and Ineia (Cyprus), allowing comparison between aircraft and surface measurements. This presentation will provide the first major GLAM results, highlight the variability of the chemical pollutants and aerosols and synthesize what is learnt from this campaign when compared to model results.

Published
2015

37. Aerosol data assimilation in the chemical transport model MOCAGE during the TRAQA/ChArMEx campaign: Lidar observations.

Author

El Amraoui, Laaziz, Sič, Bojan, Piacentini, Andrea, Marécal, Virginie, Attié, Jean-Luc, and Frebourg, Nicolas

Subjects
*CHEMICAL models, *AEROSOLS, *MODIS (Spectroradiometer), *ALTITUDES, *LIDAR, *OZONE layer
Abstract

This paper presents the first results about the assimilation of CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) extinction coefficient measurements on-board the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite in the chemistry transport model MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle) of Météo-France. This assimilation module is an extension of the Aerosol Optical Depth (AOD) assimilation system already presented by Sic et al. (2016). We focus on the period of TRAQA (TRAnsport à longue distance et Qualité de l'Air dans le bassin méditerranéen) field campaign that took place during the summer 2012. This period offers the opportunity to have access to a large set of aerosol observations from instrumented aircraft, balloons, satellite and ground-based stations. We evaluate the added value of CALIOP assimilation with respect to the model free run by comparing both fields to independent observations issued from the TRAQA field campaign. In this study we focus on the desert dust outbreak which happened during late June 2012 over the Mediterranean Basin (MB) during TRAQA campaign. The comparison with the AERONET (Aerosol Robotic Network) AOD measurements shows that the assimilation of CALIOP lidar observations improves the statistics compared to the model free run. The correlation between AERONET and the model (assimilation) is 0.682 (0.753), the bias and the RMSE, due to CALIOP assimilation, are reduced from -0.063 to 0.048 and from 0.183 to 0.148, respectively. Compared to MODIS (Moderate-resolution Imaging Spectroradiometer) AOD observations, the model free run shows an underestimation of the AOD values whereas the CALIOP assimilation corrects this underestimation and shows a quantitative good improvement in terms of AOD maps over the MB. The correlation between MODIS and the model (assimilation) during the dust outbreak is 0.47 (0.52), whereas the bias is -0.18 (-0.02) and the RMSE is 0.36 (0.30). The comparison of in-situ aircraft and balloon measurements to both modelled and assimilated outputs shows that the CALIOP lidar assimilation highly improves themodel aerosol field. The evaluation with the LOAC (Light Optical Particle Counter) measurements indicates that the aerosol vertical profiles are well simulated by the direct model but with a general underestimation of the aerosol number concentration especially in the altitude range 2-5 km. The CALIOP assimilation improves these results by a factor of 2.5 to 5. Analysis of the vertical distribution of the desert aerosol concentration shows that the aerosol dust transport event is well captured by the model but with an underestimated intensity. The assimilation of CALIOP observations allows the improvement of the geographical representation of the event within the model as well as its intensity by a factor of two in the altitude range 1-5 km. [ABSTRACT FROM AUTHOR]

Published
2020
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38. Impact of spaceborne carbon monoxide observations from the S-5P platform on tropospheric composition analyses and forecasts

Author

Abida, Rachid, primary, Attié, Jean-Luc, additional, El Amraoui, Laaziz, additional, Ricaud, Philippe, additional, Lahoz, William, additional, Eskes, Henk, additional, Segers, Arjo, additional, Curier, Lyana, additional, de Haan, Johan, additional, Kujanpää, Jukka, additional, Nijhuis, Albert Oude, additional, Tamminen, Johanna, additional, Timmermans, Renske, additional, and Veefkind, Pepijn, additional

Published
2017
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39. Apport de l'observation satellitaire à l'analyse et à la prévision de la qualité de l'air

Author

Menut, Laurent, primary, Attié, Jean-Luc, additional, Beekmann, Matthias, additional, Bessagnet, Bertrand, additional, Clerbaux, Cathy, additional, Cuesta, Juan, additional, Dufour, Gaelle, additional, Forêt, Gilles, additional, El Amraoui, Laaziz, additional, Mallet, Marc, additional, Meleux, Frédérik, additional, Ricaud, Philippe, additional, Tanré, Didier, additional, and Turquety, Solène, additional

Published
2017
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40. Adapted ECC ozonesonde for long-duration flights aboard boundary-layer pressurised balloons

Author

Gheusi, François, primary, Durand, Pierre, additional, Verdier, Nicolas, additional, Dulac, François, additional, Attié, Jean-Luc, additional, Commun, Philippe, additional, Barret, Brice, additional, Basdevant, Claude, additional, Clenet, Antoine, additional, Derrien, Solène, additional, Doerenbecher, Alexis, additional, El Amraoui, Laaziz, additional, Fontaine, Alain, additional, Hache, Emeric, additional, Jambert, Corinne, additional, Jaumouillé, Elodie, additional, Meyerfeld, Yves, additional, Roblou, Laurent, additional, and Tocquer, Flore, additional

Published
2016
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43. Impact of synthetic spaceborne NO2 observations from the Sentinel-4 and Sentinel-5p platforms on tropospheric NO2 analyses.

Author

Timmermans, Renske, Segers, Arjo, Curier, Lyana, Abida, Rachid, Attié, Jean-Luc, El Amraoui, Laaziz, Eskes, Henk, de Haan, Johan, Kujanpää, Jukka, Lahoz, William, Nijhuis, Albert Oude, Quesada, Samuel, Ricaud, Philippe, Veefkind, Pepijn, and Schaap, Martijn

Abstract

We present an Observing System Simulation Experiment (OSSE) dedicated to the evaluation of the added value of the Sentinel 4 and Sentinel 5P missions for tropospheric nitrogen dioxide (NO2). Sentinel 4 is a geostationary (GEO) mission covering the European continent, providing observations with high temporal resolution (hourly). Sentinel 5P is a low-Earth Orbiting (LEO) mission providing daily observations but with a global coverage. The OSSE experiment has been carefully designed, with separate models for the simulation of observations and for the assimilation experiments, and with conservative estimates of the total observation uncertainties. In the experiment we simulate Sentinel 4 and Sentinel 5P tropospheric NO2 columns and surface ozone concentrations at 7 by 7 km resolution over Europe for two three-month summer and winter periods. The synthetic observations are based on a nature run (NR) from a chemistry transport model (MOCAGE) and error estimates using instrument characteristics. We assimilate the simulated observations into a chemistry transport model (LOTOS-EUROS) independent from the NR to evaluate their impact on modelled NO2 tropospheric columns and surface concentrations. The results are compared to an operational system where only ground-based ozone observations are ingested. Both instruments have an added value on analysed NO2 columns and surface values, reflected in decreased biases, and improved correlations. The Sentinel 4 NO2 observations with hourly temporal resolution benefit modelled NO2 analyses throughout the entire day where the daily Sentinel 5P NO2 observations have a slightly lower impact that lasts up to 3–6 hours after overpass. The evaluated benefits may be even higher in reality as the applied error estimates were shown to be higher than actual errors in the now operational Sentinel 5P NO2 products. We show that an accurate representation of the NO2 profile is crucial for the benefit of the column observations on surface values. The results support the need for having a combination of GEO and LEO missions for NO2 analyses in view of the complementary benefits of hourly temporal resolution (GEO, Sentinel 4) and global coverage (LEO, Sentinel 5P). [ABSTRACT FROM AUTHOR]

Published
2019
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44. Benefit of ozone observations from Sentinel-5P and future Sentinel-4 missions on tropospheric composition.

Author

Quesada-Ruiz, Samuel, Attié, Jean-Luc, Lahoz, William A., Abida, Rachid, Ricaud, Philippe, Amraoui, Laaziz El, Zbinden, Régina, Piacentini, Andrea, Joly, Mathieu, Eskes, Henk, Segers, Arjo, Curier, Lyana, de Haan, Johan, Kujanpää, Jukka, Oude-Nijhuis, Albert, Tamminen, Johanna, Timmermans, Renske, and Veefkind, Pepijn

Subjects
TROPOSPHERIC chemistry, LOW earth orbit satellites, OZONIZATION, NEAR infrared radiation, GEOSTATIONARY satellites, EIGENVECTORS
Abstract

We present an observing simulated system experiment (OSSE) dedicated to evaluate the potential added value from the Sentinel-4 and the Sentinel-5P observations on tropospheric ozone composition. For this purpose, the ozone data of Sentinel-4 (Ultraviolet Visible Near-infrared) and Sentinel-5P (TROPOspheric Monitoring Instrument) onboard a geostationary (GEO) and a low Earth orbit (LEO) platform, respectively, has been simulated for the summer 2003. To ensure the robustness of the results, the OSSE has been configured with conservative assumptions. We simulate the reality by combining two chemistry transport models (CTMs): the Long Term Ozone Simulation-European Operational Smog (LOTOS-EUROS) and the Transport Model version 5 (TM5). The assimilation system is based on a different CTM, the MOdèle de Chimie Atmosphérique à Grande Echelle (MOCAGE), combined with the 3D variational technique. The background error covariance matrix does not evolve in time and its variance is proportional to the field values. The simulated data are formed of six eigenvectors to minimize the size of the dataset by removing the noise-dominated part of the observations. The results show that the satellite data clearly bring direct added value around 200 hPa for the whole assimilation period and for the whole European domain, while a likely indirect added value is identified but not for the whole period and domain at 500 hPa, and to a lower extent at 700 hPa. In addition, the ozone added value from Sentinel-5P (LEO) appears close to that from Sentinel-4 (GEO) in the free troposphere (200-500 hPa) in our OSSE. [ABSTRACT FROM AUTHOR]

Published
2019
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45. Total ozone variability and trend estimates from ground-based and satellite observations in the southern subtropics

Author

Bencherif, Hassan, El Amraoui, Laaziz, Bègue, Nelson, Mzé, Nahoudha, Pazmino, Andrea, Portafaix, Thierry, Coetzee, Gerrie, Sivakumar, Venkataraman, Held, Gerhard, Goutail, Florence, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), South African Weather Service (SAWS), School of Chemistry and Physics [Durban], University of KwaZulu-Natal (UKZN), Instituto de Pesquisas Meteorológicas (IPMet), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Despite its low abundance in the atmosphere, ozone is an important component that prevents solar UV from reaching the Earth's surface. It contributes to the radiative balance, and hence has impact on climate change. The long-term evolution of stratospheric ozone depends on changes of both stratospheric and tropospheric constituents such as ozone-depleting substances, greenhouse gases, water vapor, and aerosols. It also depends on changes in the troposphere and in the stratosphere caused by natural variability and anthropogenic forcing (WMO, 2006). As reported by many authors, air penetrates into the stratosphere primarily through the tropical tropopause, while the tropical stratosphere is a region of major exchange with mid-latitude regions through the subtropical barriers (Portafaix et al., 2003; Bencherif et al., 2003; Semane et al., 2006; Bencherif et al., 2007). The present contribution reports on a comparative study on total ozone observations obtained from ground-based and satellite measurements over subtropical sites. The study examines the climatology and variability of total ozone. It is based on more than 15 years of continuous observations at four sites in the southern subtropics: Reunion Island (21°S, 55.5°E), Bauru (22°S, 49°O), Irene (25.5°S, 28.1°E) and Springbok (29.6°S, 17.9°E). Depending on the observational periods of each instrument, ground-based total ozone measurements are compared with satellite datasets, in terms of daily and monthly variations. The study focuses on comparisons with total ozone values measured from space by TOMS (Total Ozone Mapping Spectrometer), OMI (Ozone Monitoring Spectrometer) and by IASI (Infrared Atmospheric Sounding Interferometer) on the MetOp satellite. The obtained monthly-mean time-series of total ozone are analyzed by a multi-regression model named Trend-Run (Bencherif et al., 2006; Bègue et al., 2010). It is a trend model based on the linear multi-regression principal, i.e., the ozone signal is broken into a sum of several forcings (seasonal cycles, QBO, ENSO, IOD, Solar cycles, ...) that explain most of its variability. The trend values are then derived from the residual terms as a linear function.

Published
2012

46. Adapted ECC ozone sonde for long-duration flights aboard boundary-layer pressurized balloons

Author

Gheusi, François, primary, Durand, Pierre, additional, Verdier, Nicolas, additional, Dulac, François, additional, Attié, Jean-Luc, additional, Commun, Philippe, additional, Barret, Brice, additional, Basdevant, Claude, additional, Clénet, Antoine, additional, Derrien, Solène, additional, Doerenbecher, Alexis, additional, El Amraoui, Laaziz, additional, Fontaine, Alain, additional, Hache, Emeric, additional, Jambert, Corinne, additional, Jaumouillé, Elodie, additional, Meyerfeld, Yves, additional, Roblou, Laurent, additional, and Tocquer, Flore, additional

Published
2016
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47. Intercontinental transport of biomass burning pollutants over the Mediterranean Basin during the summer 2014 ChArMEx-GLAM airborne campaign.

Author

Brocchi, Vanessa, Krysztofiak, Gisèle, Catoire, Valéry, Guth, Jonathan, Marécal, Virginie, El Amraoui, Laaziz, Dulac, François, and Ricaud, Philippe

Abstract

The Gradient in Longitude of Atmospheric constituents above the Mediterranean basin (GLAM) campaign was set up in August 2014, as part of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) project. This campaign aimed at studying the chemical variability of gaseous pollutants and aerosols in the troposphere along a West-East transect above the Mediterranean Basin (MB). In the present work, we focus on two biomass burning events detected at 5.4 and 9.7 km altitude above sea level (asl) above Sardinia (from 39°12 N-9°15 E to 35°35 N-12°35 E and at 39°30 N-8°25 E, respectively). Concentration variations in trace gas carbon monoxide (CO) and aerosols were measured thanks to the standard instruments on-board the Falcon-20 aircraft operated by the Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE) and the Spectromètre InfraRouge In situ Toute Altitude (SPIRIT) developed by LPC2E. 20-day backward trajectories with Lagrangian particle dispersion model FLEXPART (FLEXible PARTicle) help understanding the transport processes and the origin of the emissions that contributed to these pollutions detected above Sardinia. Biomass burning emissions came (i) on 10 August from the Northern American continent with air masses transported during 5 days before arriving over the MB, and (ii) on 6 August from Siberia with air masses travelling during 12 days and enriched in fire emission products above Canada 5 days before arriving over the MB. In combination with the Global Fire Assimilation System (GFAS) inventory and the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite fire locations, FLEXPART reproduces well the contribution of those fires to CO and aerosols enhancements under adjustments of the injection height to 10 km in both cases, and application of an amplification factor of 2.5 on CO GFAS emissions for the 10 August event. The chemistry transport model (CTM) MOCAGE is used as a complementary tool for the case of 6 August to confirm the origin of the emissions by tracing the CO global atmospheric composition reaching the MB. For this event, both models agree on the origin of air masses with CO concentrations simulated with MOCAGE lower than the observed ones, likely caused by the coarse model horizontal resolution that yields the dilution of the emissions and diffusion during transport. In combination with wind fields, the analysis of the transport of the air mass documented on 6 August suggests the subsidence of CO pollution from Siberia towards North America and then a transport to the MB via fast jet winds located at around 5.5 km in altitude. [ABSTRACT FROM AUTHOR]

Published
2017
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48. Future changes in surface ozone over the Mediterranean basin in the framework of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx).

Author

Jaidan, Nizar, El Amraoui, Laaziz, Attié, Jean-Luc, Ricaud, Philippe, and Dulac, François

Abstract

In the framework of the Chemistry and Aerosol Mediterranean Experiment project (ChArMEx, http://charmex.lsce.ipsl.fr), we study the evolution of surface ozone (O3) over the Mediterranean Basin (MB) with a focus on summertime over the time period 2000-2100, using the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) outputs from 11 models. We consider three different periods (2000, 2030 and 2100) and the four Representative Concentration Pathways (RCP2.6, RCP4.5, RCP6.0 and RCP8.5) to study the changes in the future ozone trend and its budget. We use a statistical approach to compare and discuss the results of the models. We discuss the behavior of the models that simulate the surface O3 over the MB. The ensemble mean of ACCMIP models simulates very well the annual cycle of surface O3. Compared to measured summer surface O3 datasets, we found that most of the models overestimate surface O3 and underestimate its variability over the most recent period (1990-2010) when independent observations are available. Compared to the reference period (2000), we found a net decrease in the ensemble mean surface O3 over the MB in 2030 (2100) for 3 RCPs: -13 % (-36 %) for RCP2.6, -7 % (-22 %) for RCP4.5 and -11 % (-33 %) for RCP6.0. The surface O3 decrease over the MB for these scenarios is much more pronounced than the relative changes of the tropospheric ozone burden. This is mainly due to the reduction in O3 precursors and to the NOx-limited regime over the MB. For the RCP8.5, the ensemble mean surface O3 is almost constant over the MB from 2000 to 2100. We show how the future climate change and the increase in CH4 concentrations can offset the benefit of the reduction in emissions of O3 precursors over the MB. [ABSTRACT FROM AUTHOR]

Published
2017
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49. Aerosol data assimilation in the chemical transport model MOCAGE during the TRAQA/ChArMEx campaign: aerosol optical depth.

Author

El Amraoui, Laaziz, Marécal, Virginie, Sič, Bojan, Attié, Jean-Luc, Piacentini, Andrea, Emili, Emanuele, Cariolle, Daniel, and Prather, Michael

Subjects
*AEROSOLS, *IN situ (Civil engineering), *SOOT, *ALGORITHMS, *COST functions
Abstract

In this study, we describe the development of the aerosol optical depth (AOD) assimilation module in the chemistry transport model (CTM) MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle). Our goal is to assimilate the spatially averaged 2-D column AOD data from the National Aeronautics and Space Administration (NASA) Moderate-resolution Imaging Spectroradiometer (MODIS) instrument, and to estimate improvements in a 3-D CTM assimilation run compared to a direct model run. Our assimilation system uses 3-D-FGAT (first guess at appropriate time) as an assimilation method and the total 3-D aerosol concentration as a control variable. In order to have an extensive validation dataset, we carried out our experiment in the northern summer of 2012 when the pre-ChArMEx (CHemistry and AeRosol MEditerranean EXperiment) field campaign TRAQA (TRAnsport à longue distance et Qualité de l'Air dans le bassin méditerranéen) took place in the western Mediterranean basin. The assimilated model run is evaluated independently against a range of aerosol properties (2-D and 3-D) measured by in situ instruments (the TRAQA size-resolved balloon and aircraft measurements), the satellite Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument and ground-based instruments from the Aerosol Robotic Network (AERONET) network. The evaluation demonstrates that the AOD assimilation greatly improves aerosol representation in the model. For example, the comparison of the direct and the assimilated model run with AERONET data shows that the assimilation increased the correlation (from 0.74 to 0.88), and reduced the bias (from 0.050 to 0.006) and the root mean square error in the AOD (from 0.12 to 0.07). When compared to the 3-D concentration data obtained by the in situ aircraft and balloon measurements, the assimilation consistently improves the model output. The best results as expected occur when the shape of the vertical profile is correctly simulated by the direct model. We also examine how the assimilation can influence the modelled aerosol vertical distribution. The results show that a 2-D continuous AOD assimilation can improve the 3-D vertical profile, as a result of differential horizontal transport of aerosols in the model. [ABSTRACT FROM AUTHOR]

Published
2016
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50. Multisensor Assimilation for Aerosol forecasting.

Author

Amraoui, Laaziz El and Plu, Matthieu

Subjects
*AIR quality standards, *AEROSOLS, *ATMOSPHERIC aerosols, *CARBONACEOUS aerosols, *AIR quality, *DUST, *VOLCANIC ash, tuff, etc.
Abstract

Atmospheric aerosols are of natural and anthropogenic origin. They are the subject of many researches because of their involvement particularly in the climate system and the air quality standards with significant induced effects on human health. Regional air quality is particularly affected by local anthropogenic aerosols as well as the long-range transport of desert dust, biomass fires or volcanic ash. The MOCAGE model is able to describe the three-dimensional evolution of several types of primary and secondary aerosols involved in the definition of air quality standards. The MOCAGE model is also coupled to an assimilation system capable of assimilating the Aerosol Optical Depth (AOD) or lidar profiles in order to better constrain the three-dimensional distribution of the total aerosol concentration. The objective of this contribution is to evaluate the ability of different aerosol products from multisensor instruments (AOD and lidar profiles) assimilated individually or in synergy to improve the three-dimensional concentration of the aerosol and particularly the air quality at local scale. [ABSTRACT FROM AUTHOR]

Published
2019

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