1,720,966 research outputs found
Ozone et transport dans la haute troposphère tropicale de l’Océan Indien et de l’Asie du Sud : apport des données spatiales (IASI) et de la modélisation
No full textTo better understand the processes controling for the distribution of upper tropospheric (UT) ozone (O3) in the tropics, this thesis examines different aspects of pollution transport from sources regions to UT level, through two case studies that take place in the still debated issues.. First study is based on IASI space observations identified an event of transport of UT enriched O3 air masses from Africa to India. During the pre-monsoon season, events of O3 enrichment in UT above the Indian Ocean were essentially attributed to stratospherics intrusions. Simulations have been used to determine its origin, it excludes a stratospheric origin for the event and indicates a probable important contribution by lightning (LiNOx) that occurs over Africa regions. This study could be extended to the whole region and other seasons with a focus on the spring season in order to complete the conclusions obtained during the INDOEX program. The second part focuses on the characterisation of the impact of a deep convective system upon the UTLS composition during the asian summer monsoon. Simulation with a passive tracer highlights the potential of the convective system located over the central Himalaya foothills, to uplift polluted air masses in UTLS to 100 hPa, where the pollutants are rapidly transported by the asian monsoon anticyclone circulation. In agreement with transport pipe towards the UTLS identified by Bergman et al. 2013. However simulation including reactive chemistry show an overestimation by the model of the amount of LiNOx produced, so an adjustment of their parameterization must be made and sensitivity analysis are foreseen to determine precisely O3 production. This study is established in connection with actual major problematic at the center of general debate of the international collaboration. Like ACAM (Atmospheric Composition and the Asian Monsoon) whose targeting the complexe interaction of asian summer monsoon to atmospheric dynamics and chemistry, as well as climate change impact.Afin de mieux comprendre les processus responsables de la distribution de l’ozone (O3) dans la haute troposphère (UT) tropicale, cette thèse étudie différents aspects du transport de la pollution depuis les régions sources jusque dans l'UT. La première étude repose sur les observations spatiales IASI qui identifient un évènement de transport de masses d’air enrichies en O3 dans l'UT depuis l’Afrique vers l’Inde. Pour la saison de pré-mousson de tels enrichissement d’O3 dans l'UT au-dessus de l’Océan Indien sont essentiellement attribués à des intrusions stratosphériques. Afin de déterminer son origine des simulations ont été effectuées permettant d'exclure une origine stratosphérique et montrent l’impact prépondérant des NOx produit par les éclairs (LiNOx) en Afrique pour expliquer cet enrichissement d’O3. Cette étude pourra être étendue à d'autres saisons, pour consolider les conclusions obtenues dans le cadre du projet INDOEX. La deuxième partie porte sur l'étude de l’impact d’un système convectif très profond sur la composition de l'UT pendant la mousson asiatique d’été. La simulation avec un traceur passif montre la capacité du système situé le long de l’Himalaya centrale à soulever des masses d’air polluées jusqu’à 100 hPa, altitudes auxquelles la pollution est transportée rapidement par la circulation de l’anticyclone de la mousson asiatique. Confirmant le conduit privilégié de transport vers l’UTLS identifié par Bergman et al. 2013. Cependant l'activation du schéma chimique montre une surestimation des LiNOx produites, un ajustement de leur paramétrisation devra être effectué ainsi que des simulations de sensibilité pour correctement quantifier la production d’O3. Ce travail prend place dans des problématiques actuellement au centre d'une collaboration internationale, ACAM (Atmospheric Composition and the Asian Monsoon) visant à étudier les interactions complexes de la mousson asiatique d'été entre dynamique et chimie, jusqu'à l'échelle du changement climatique
Ozone et transport dans la haute troposphère tropicale de l'océan Indien et de l'Asie du Sud : apport des données spatiales (IASI) et de la modélisation
Full text linkAfin de mieux comprendre les processus responsables de la distribution de l'ozone (O3) dans la haute troposphère (UT) tropicale, cette thèse étudie différents aspects du transport de la pollution depuis les régions sources jusque dans l'UT. La première étude repose sur les observations spatiales IASI qui identifient un évènement de transport de masses d'air enrichies en O3 dans l'UT depuis l'Afrique vers l'Inde. Pour la saison de pré-mousson de tels enrichissement d'O3 dans l'UT au-dessus de l'Océan Indien sont essentiellement attribués à des intrusions stratosphériques. Afin de déterminer son origine des simulations ont été effectuées permettant d'exclure une origine stratosphérique et montrent l'impact prépondérant des NOx produit par les éclairs (LiNOx) en Afrique pour expliquer cet enrichissement d'O3. Cette étude pourra être étendue à d'autres saisons, pour consolider les conclusions obtenues dans le cadre du projet INDOEX. La deuxième partie porte sur l'étude de l'impact d'un système convectif très profond sur la composition de l'UT pendant la mousson asiatique d'été. La simulation avec un traceur passif montre la capacité du système situé le long de l'Himalaya centrale à soulever des masses d'air polluées jusqu'à 100 hPa, altitudes auxquelles la pollution est transportée rapidement par la circulation de l'anticyclone de la mousson asiatique. Confirmant le conduit privilégié de transport vers l'UTLS identifié par Bergman et al. 2013. Cependant l'activation du schéma chimique montre une surestimation des LiNOx produites, un ajustement de leur paramétrisation devra être effectué ainsi que des simulations de sensibilité pour correctement quantifier la production d'O3. Ce travail prend place dans des problématiques actuellement au centre d'une collaboration internationale, ACAM (Atmospheric Composition and the Asian Monsoon) visant à étudier les interactions complexes de la mousson asiatique d'été entre dynamique et chimie, jusqu'à l'échelle du changement climatique.To better understand the processes controling for the distribution of upper tropospheric (UT) ozone (O3) in the tropics, this thesis examines different aspects of pollution transport from sources regions to UT level, through two case studies that take place in the still debated issues.. First study is based on IASI space observations identified an event of transport of UT enriched O3 air masses from Africa to India. During the pre-monsoon season, events of O3 enrichment in UT above the Indian Ocean were essentially attributed to stratospherics intrusions. Simulations have been used to determine its origin, it excludes a stratospheric origin for the event and indicates a probable important contribution by lightning (LiNOx) that occurs over Africa regions. This study could be extended to the whole region and other seasons with a focus on the spring season in order to complete the conclusions obtained during the INDOEX program. The second part focuses on the characterisation of the impact of a deep convective system upon the UTLS composition during the asian summer monsoon. Simulation with a passive tracer highlights the potential of the convective system located over the central Himalaya foothills, to uplift polluted air masses in UTLS to 100 hPa, where the pollutants are rapidly transported by the asian monsoon anticyclone circulation. In agreement with transport pipe towards the UTLS identified by Bergman et al. 2013. However simulation including reactive chemistry show an overestimation by the model of the amount of LiNOx produced, so an adjustment of their parameterization must be made and sensitivity analysis are foreseen to determine precisely O3 production. This study is established in connection with actual major problematic at the center of general debate of the international collaboration. Like ACAM (Atmospheric Composition and the Asian Monsoon) whose targeting the complexe interaction of asian summer monsoon to atmospheric dynamics and chemistry, as well as climate change impact
Ozone and transport in tropical upper troposphere over Indian ocean and south Asia : contributon of spatial data (IASI) and modelling
No full textAfin de mieux comprendre les processus responsables de la distribution de l'ozone (O3) dans la haute troposphère (UT) tropicale, cette thèse étudie différents aspects du transport de la pollution depuis les régions sources jusque dans l'UT. La première étude repose sur les observations spatiales IASI qui identifient un évènement de transport de masses d'air enrichies en O3 dans l'UT depuis l'Afrique vers l'Inde. Pour la saison de pré-mousson de tels enrichissement d'O3 dans l'UT au-dessus de l'Océan Indien sont essentiellement attribués à des intrusions stratosphériques. Afin de déterminer son origine des simulations ont été effectuées permettant d'exclure une origine stratosphérique et montrent l'impact prépondérant des NOx produit par les éclairs (LiNOx) en Afrique pour expliquer cet enrichissement d'O3. Cette étude pourra être étendue à d'autres saisons, pour consolider les conclusions obtenues dans le cadre du projet INDOEX. La deuxième partie porte sur l'étude de l'impact d'un système convectif très profond sur la composition de l'UT pendant la mousson asiatique d'été. La simulation avec un traceur passif montre la capacité du système situé le long de l'Himalaya centrale à soulever des masses d'air polluées jusqu'à 100 hPa, altitudes auxquelles la pollution est transportée rapidement par la circulation de l'anticyclone de la mousson asiatique. Confirmant le conduit privilégié de transport vers l'UTLS identifié par Bergman et al. 2013. Cependant l'activation du schéma chimique montre une surestimation des LiNOx produites, un ajustement de leur paramétrisation devra être effectué ainsi que des simulations de sensibilité pour correctement quantifier la production d'O3. Ce travail prend place dans des problématiques actuellement au centre d'une collaboration internationale, ACAM (Atmospheric Composition and the Asian Monsoon) visant à étudier les interactions complexes de la mousson asiatique d'été entre dynamique et chimie, jusqu'à l'échelle du changement climatique.To better understand the processes controling for the distribution of upper tropospheric (UT) ozone (O3) in the tropics, this thesis examines different aspects of pollution transport from sources regions to UT level, through two case studies that take place in the still debated issues.. First study is based on IASI space observations identified an event of transport of UT enriched O3 air masses from Africa to India. During the pre-monsoon season, events of O3 enrichment in UT above the Indian Ocean were essentially attributed to stratospherics intrusions. Simulations have been used to determine its origin, it excludes a stratospheric origin for the event and indicates a probable important contribution by lightning (LiNOx) that occurs over Africa regions. This study could be extended to the whole region and other seasons with a focus on the spring season in order to complete the conclusions obtained during the INDOEX program. The second part focuses on the characterisation of the impact of a deep convective system upon the UTLS composition during the asian summer monsoon. Simulation with a passive tracer highlights the potential of the convective system located over the central Himalaya foothills, to uplift polluted air masses in UTLS to 100 hPa, where the pollutants are rapidly transported by the asian monsoon anticyclone circulation. In agreement with transport pipe towards the UTLS identified by Bergman et al. 2013. However simulation including reactive chemistry show an overestimation by the model of the amount of LiNOx produced, so an adjustment of their parameterization must be made and sensitivity analysis are foreseen to determine precisely O3 production. This study is established in connection with actual major problematic at the center of general debate of the international collaboration. Like ACAM (Atmospheric Composition and the Asian Monsoon) whose targeting the complexe interaction of asian summer monsoon to atmospheric dynamics and chemistry, as well as climate change impact
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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