WorldCat Identities

Catoire, Valéry

Overview
Works: 14 works in 15 publications in 2 languages and 23 library holdings
Roles: Opponent, Thesis advisor, Author, Other
Publication Timeline
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Most widely held works by Valéry Catoire
Intercontinental transport of biomass burning pollutants over the Mediterranean Basin during the summer 2014 ChArMEx-GLAM airborne campaign by Vanessa Brocchi( )

2 editions published between 2017 and 2018 in English and held by 4 WorldCat member libraries worldwide

The SPIRIT airborne instrument: a three-channel infrared absorption spectrometer with quantum cascade lasers for in situ atmospheric trace-gas measurements by Valéry Catoire( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Développements de spectromètres ultrasensibles pour l'analyse de gaz par « optical feedback cavity enhanced absorption spectrocopy » dans le moyen infrarouge avec des lasers à cascades inter-bandes by Lucile Richard( )

1 edition published in 2019 in French and held by 2 WorldCat member libraries worldwide

This work of these has made it possible to develop and characterize the use of instruments on the "OF-CEAS" technique in the mid-infrared for traces' detection in different mixtures in the gas phase. Inter-band Cascade Laser (ICL) is the latest innovation in semiconductor lasers in this spectral region. Compatibility of ICL with OF-CEAS offers new applications for compact and robust instruments with fast response time and a low detection limit. A demonstration of the good sensitivity and stability of the OF-CEAS instruments was performed with continua absorption measurements (water vapor and nitrogen). But also with the detection of a very low intensity quadrupole line of nitrogen (3x10-29 cm-1/(moléc cm-2). The main objective of this work was to develop an instrument dedicated to nitrogen oxide detection for the analysis of exhaled breath. The analyzer is presented at the sensitivity of 6x10-10 cm-1 in an acquisition of 180 ms. Its limit of detection on NO is at the state of the art, with short term (180 ms) limit of 50 ppt. It reaches the sub-ppt level (0.9 ppt) with 12 min of integration
In situ quantification of CH4 bubbling events from a peat soil using a new infrared laser spectrometer by Sébastien Gogo( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Local air pollution from oil rig emissions observed during the airborne DACCIWA campaign by Vanessa Brocchi( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Improved OSIRIS NO 2 retrieval algorithm: description and validation by Christopher E Sioris( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Impact of a moderate volcanic eruption on chemistry in the lower stratosphere: balloon-borne observations and model calculations by Gwenaël Berthet( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Caractérisation de sources de pollution troposphérique en régions méditerranéenne et ouest-africaine par mesures in situ en avion et modélisation. by Vanessa Brocchi( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

L'étude de la pollution troposphérique inclut l'étude des gaz traces provenant de sources anthropiquesdiverses, dont l'impact varie de l'échelle locale à globale. Pour caractériser cette pollution, il est nécessairede mesurer avec précision les concentrations en polluants. Dans le cadre de projets européens, troiscampagnes aéroportées ont été conduites, dans le bassin méditerranéen, en Afrique de l'ouest et enMalaisie, pour mesurer différents types de polluants grâce, entre autres, à un spectromètre à lasersinfrarouges, SPIRIT, capable de mesurer rapidement en ligne de faibles variations de NO2 et CO. Les jeuxde données de ces gaz traces (et d'autres) ont été combinés avec un modèle lagrangien de dispersion departicules, FLEXPART, pour identifier différentes sources de pollution locales et régionales de l'air. Cettethèse présente ainsi les mesures et le travail de modélisation entrepris afin de définir les sources depollution de chaque région. Il a été montré que le bassin méditerranéen a été impacté, de la moyenne à lahaute troposphère pendant l'été, par des émissions de feux de biomasse venant de Sibérie et du continentnord-américain. Les régions ouest-africaine et malaisienne sont aussi impactées par des émissions de feuxde biomasse transportées depuis l'Afrique centrale dans le premier cas, et de feux locaux dans le second.En outre, ces régions sont influencées par des émissions provenant de l'exploitation du pétrole et du traficmaritime. FLEXPART a été utilisé afin d'identifier l'origine des pics de pollution mesurés au cours descampagnes. Nous avons ainsi montré que les conditions atmosphériques, qui définissent la hauteurd'injection du panache de la plateforme pétrolière, ainsi que le flux d'émission sont des paramètres clésdans la caractérisation des mesures par le modèle
Transport et chimie d'espèces soufrées et bromées dans la haute troposphère et basse stratosphère diagnostiqués par des mesures sous ballon et en avion et par modélisation by Gisèle Krysztofiak( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

Ozone depletion is a complex subject involving several processes starting by the emission of the sources gases (SGs) in the lower troposphere. Recently the VSLS (very short lived substances) have been identified as potential SGs. However they do not have a lifetime long enough to reach directly the stratosphere. During the transport, the VSLS undergo degradation leading to products gases (PGs). The SGs and PGs of the VSLS reach the stratosphere in the Tropical region where a rapid vertical transport occurs, the convection. The SGs with longer lifetime can reach the stratosphere by any transport pathway from the location of their emissions. Once in stratosphere the SGs and PGs will be converted into reactive species able to deplete ozone. This thesis presents the study of the several steps occurring before the ozone depletion: SGs emission, SGs and PGs transport into the atmosphere, the chemical degradation occurring during their transport and finally their contribution to the ozone depletion. First, chemical tracers, as CO, are used to highlight the main pathways from the troposphere to the stratosphere. Then two studies of two different types of species entering in the process of ozone destruction are presented: for OCS (carbonyl sulfide) and the brominated VSLS (CHBr3 et CH2Br2). OCS is one of the sulfate aerosols precursors catalyzing the ozone depletion. However, OCS contribution to this layer has some uncertainties. OCS emission sources, the latitude repartition and the contribution to the sulfate aerosols are presented. The contribution of the brominated VSLS to the stratospheric bromine is a key issue that being almost resolved. The brominated VSLS chemical degradation during the atmospheric transport will be described in detail
Chimie des espèces réactives et leur rôle sur la capacité oxydante en régions polaires by Albane Barbero( )

1 edition published in 2021 in English and held by 1 WorldCat member library worldwide

Over the last two decades, the paradigm of snow as an inert material has been challenged by the discovery of substantial chemical activity within the snowpack and, in particular, its elevated nitrogen oxides content. When sunlight resumes at the end of the polar night, it triggers photochemistry within the porous snowpack. The highly reactive products of this photochemistry can be exchanged between snow and atmosphere, and these exchanges will redistribute the species governing the oxidizing capacity of the atmosphere.Many studies that sought to better understand these polar processes have shown that: i) highly reactive species (such as NO_x, OH, HO_2, RO_2, and XO) play a key role in such a remote environment, controlling the oxidative capacity and the atmospheric chemistry and ii) snow emissions also locally control the oxidative capacity. Indeed, gaseous nitrogen species, especially nitrogen oxides NO_x (NO_x equiv NO + NO_2), emitted from the photolysis of nitrate contained in the snowpack, lead to a strong production of O_3 and OH radicals in the atmosphere. Unfortunately, these mechanisms are still poorly understood due to the lack of information on the behavior of nitrate in snow and the absence of direct measurements of NO_2 at the snow-atmosphere interface.First, we applied a NO_x measurement technique based on incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) that is different from those previously used in Antarctica. This technique allows direct measurement of NO_2 and NO_x, and thus it reduces concentration level uncertainties. We developed, tested, and validated two robust instruments, for NO_2 and NO_x detection, respectively, that reached detection limits around 30 times 10^{-12} mol mol^{-1} (3sigma) and we deployed these instruments in the Antarctic field at Dome C.Two hypotheses explain the behavior of nitrate in the snowpack facing the absorption of a photon. The first one, commonly accepted, assumes the existence of two nitrate fractions: one subject to photolysis and the other not easily accessible to photons. However, recent studies have proposed a single mechanism for the localization of nitrate into the snow during its deposition. In order to better understand the nitrate behavior, we performed flux chamber experiments using different types of snow of various ages and locations. These innovative experiments showed that the photolysis rate constant of nitrate is similar for all snow samples. This result suggests that the localization of nitrate in snow is identical regardless of snow type and age, which supports the single nitrate fraction model of recent theoretical studies.Finally, using the developed IBBCEAS instruments, we studied the summer diurnal variability of NO and NO_2 levels above the snowpack. The NO_2:NO ratio observed at the beginning of the photolytic season (December) appears to be too high with respect to the expected photochemical equilibrium, while in January, the photochemical equilibirum seems reached. This excess of NO_2 could be explained by summer variability of the main NO_2 source, where the photo denitrification of the snowpack is stronger in December than in January.These three years of research have validated the use of optical cavity instruments in remote and challenging field sites such as Antarctica. Their stability, specificity, and ease of use open the way to new measurement and scientific opportunities in polar regions. The use of flux chambers for the first time in Antarctica has confirmed the existence of a single mechanism of nitrate photolysis
Les sources de HONO atmosphérique rural et leur impact sur la qualité de l'air régional dans la Plaine de Chine du Nord by Chaoyang Xue( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

La pollution de l'air est toujours un problème environnemental qui doit être résolu de toute urgence dans la Plaine de Chine du Nord (PCN). Dans le but d'explorer la formation de l'acide nitreux (HONO) et son impact sur la qualité de l'air régional dans la PCN, le développement et l'évaluation systématique d'instruments pour mesurer la concentration de HONO atmosphérique et son flux d'émission du sol ont été réalisés. Sur la base de mesures sur le terrain, un modèle 3D de chimie-transport (le système communautaire de modélisation de la qualité de l'air à plusieurs échelles : CMAQ, de l'EPA) et un modèle de boîte (0D) de mécanisme chimique (Master Chemical Mechanism : MCM) ont été utilisés pour explorer le bilan de HONO et son impact sur la pollution atmosphérique régionale, par exemple la pollution estivale à l'ozone (O3) et la pollution par la brume hivernale. Nous avons constaté que le sol agricole était une source importante de HONO avec un impact significatif sur la pollution régionale à l'ozone en été. Un nouveau mécanisme d'émission de HONO du sol lié à la nitrification a été proposé. HONO joue également un rôle important dans la capacité oxydante de l'atmosphère et la détérioration de la qualité de l'air régional en hiver
Évolution de la colonne totale d'ozone à deux stations tropicales : observations et modélisation by Aymen Frihi( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

While the tropics cover a large part of the globe, few long-term ozone observations data exist in this region. In addition, the tropics are the regions where most of the stratospheric ozone is formed. Indeed, the tropical region is the main entry point for tropospheric chemical species and water vapor in the stratosphere, subsequently redistributed at mid-latitudes by the Brewer-Dobson circulation. Monitoring the evolution of the ozone layer in these regions is based on observations (satellite, ground-based and aircraft instruments). This monitoring allows the quantification of stratospheric ozone variability and trends to understand past changes and validate the models used to predict the ozone evolution in these regions. In this perspective, the work of this thesis is divided into two parts: firstly, the analysis and comparison between the UV-Visible SAOZ spectrometer data and those of 10 satellite instruments in the tropics above the Bauru stations (22.18S, 49.06W) in Brazil and Reunion Island (21.11S, 55.53E) in the Indian Ocean. The ozone columns show a negative average bias (-0.84%) between the satellite columns and SAOZ (SAT-SAOZ) in Bauru unlike Réunion (0.75%), where the bias is positive. Moreover, we observe an increase in this bias from 2004 in Bauru of -1.78% / decade, less important in Reunion (-0.8% / decade). The study of this drift has shown that the latter is correlated with an uplift of the vertical ozone profile at equatorial latitudes characterized by an equivalent latitude drift of the Bauru station, which is not considered in the calculation of the Air Mass Factor (AMF) used to convert the slant column measured by SAOZ into vertical column (TOC). Subsequently, the capacity of 9 CCMI-derived climate-chemistry models to reproduce the observed columns, its variations and external forcing on variability was evaluated by comparing the simulations with those of SAOZ and the monthly mean satellites at both stations. The models show a good restitution of the variability of the ozone column with however an overestimation of 3% at both stations compared to the observations. The analysis of the forcings shows a contribution dominated by QBO (~ 40%), followed by ENSO (~ 20%), solar activity (~ 20%), equivalent latitude drift > 10% at Bauru and < 10% at Reunion and lower for aerosols (<10%) consistently with observations
Cinétique et mécanisme de réactions des radicaux méthylpéroxyles chlore etéthylpéroxyle d'intérêt en chimie de l'atmosphère et de la combustion by Valéry Catoire( )

1 edition published in 1994 in French and held by 1 WorldCat member library worldwide

DANS LE BUT DE MIEUX CERNER LES PROCESSUS D'OXYDATION DES HYDROCARBURES METHYLCHLORES (CH#3CL, CH#2CL#2, CHCL#3, CCL#4) ET DE L'ETHANE (C#2H#6) DANS LES CONDITIONS DE L'ATMOSPHERE ET DE LA COMBUSTION, LA CINETIQUE ET LE MECANISME DES REACTIONS DES RADICAUX LIBRES PEROXYLES (CH#2CLO#2, CHCL#2O#2, CCL#3O#2, C#2H#5O#2) AVEC EUX-MEMES ET AVEC LE RADICAL HO#2 ONT ETE ETUDIES EN FONCTION DE LA TEMPERATURE (250 A 600 K) ET A LA PRESSION ATMOSPHERIQUE. LA METHODE UTILISEE EST LA PHOTOLYSE ECLAIR POUR GENERER LES RADICAUX, ASSOCIEE A LA SPECTROMETRIE D'ABSORPTION ULTRAVIOLET POUR LES DETECTER. DES EXPRESSIONS D'ARRHENIUS ONT ETE DEDUITES POUR CHACUNE DES CONSTANTES DE VITESSE DE CES HUIT REACTIONS. LES RESULTATS OBTENUS MONTRENT QUE LA CONSTANTE DE VITESSE DE LA REACTION MUTUELLE DU RADICAL METHYLPEROXYLE (CH#3O#2) AUGMENTE FORTEMENT DES QU'UN ATOME D'HYDROGENE EST SUBSTITUE PAR UN ATOME DE CHLORE, ALORS QU'ELLE DIMINUE SENSIBLEMENT DANS LE CAS DE LA SUBSTITUTION PAR UN GROUPEMENT METHYLE (CONDUISANT AU RADICAL C#2H#5O#2). LA REACTION MUTUELLE DES RADICAUX PEROXYLES CHLORES PRODUIT PRINCIPALEMENT LES RADICAUX ALCOXYLES CORRESPONDANTS (CH#2CLO, CHCL#2O, CCL#3O). CES DEUX DERNIERS REAGISSENT TOUJOURS PAR ELIMINATION D'UN ATOME DE CHLORE, AU CONTRAIRE DE CH#2CLO QUI REAGIT AVEC LE DIOXYGENE. LES RESULTATS DE CALCULS THEORIQUES SEMI-EMPIRIQUES ONT PERMIS DE RENDRE COMPTE DE CETTE DIFFERENCE DE COMPORTEMENT ET DE SUGGERER QUE LA DECOMPOSITION DE CH#2CLO PAR ELIMINATION DE HCL EST UNE VOIE POSSIBLE DE REACTION. LES REACTIONS DES RADICAUX METHYLPEROXYLES CHLORES AVEC HO#2 PRESENTENT UNE REACTIVITE TRES VOISINE DE CELLE DE CH#3O#2: IL N'Y A PAS D'EFFET DE SUBSTITUTION DES ATOMES DE CHLORE. PAR CONTRE, LA CONSTANTE DE VITESSE DE LA REACTION DE C#2H#5O#2 AVEC HO#2 EST NETTEMENT PLUS ELEVEE, SIGNALANT UNE REACTIVITE ACCRUE LORS DE LA SUBSTITUTION PAR UN GROUPEMENT METHYLE DANS LE RADICAL CH#3O#2
Mesures du chlorure d'hydrogène (HCI) et du formaldéhyde (H2CO) sous ballon strastosphérique en région intertropicale et interprétations by Yassine Mebarki( )

1 edition published in 2009 in French and held by 1 WorldCat member library worldwide

The work presented in this manuscript is devoted to the retrieval and the interpretation of the mixing ratiovertical profiles of hydrogen chloride (HCl) and formaldehyde (H2CO), derived from the measurementsperformed by the SPIRALE balloon-borne instrument (SPectroscopie InfraRouge par Absorption de LasersEmbarqués) over Teresina (Brazil, 5.1°S-42.9°S), on 22 June 2005 and 9 June 2008. The scientificquestions associated with the study of these compounds, the characteristics of the tropical uppertroposphere and lower stratosphere and those of the SPIRALE spectrometer are described. The feasibilitystudy of the H2CO measurement has allowed to define the position and the intensity of the most suitableabsorption line for the stratospheric measurement of this compound (at 2912.1 and 1701.5 cm-1). The mixingratio vertical profiles of H2CO obtained during the SPIRALE flights are presented and compared. The HClmeasurements presented are the first to be made in situ in the lower and mid-stratosphere. In the tropicaltransition layer, they have been combined with recent very short-lived species (VSLS) ones in order toestimate the contribution of these compounds to the chlorine budget of the stratosphere. In the midstratosphere,the signatures present on the vertical profiles of HCl and ozone acquired simultaneously arestudied in connection with the quasi-biennal oscillation
 
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