Assimilation de mesures chimiques d'ozone au niveau de la tropopause dans un modèle de chimie-transport global PDF Download

Author: Marie-Laure Cathala
Publisher:
ISBN:
Category :
Languages : fr
Pages : 190

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Book Description
La région de la tropopause est particulièrement importante du point de vue de la dynamique et de la composition chimique de l'atmosphère car elle est le siège d'échanges entre deux milieux très différents, la troposphère et la stratosphère. De forts gradients verticaux rendent toutefois sa représentation difficile dans les modèles numériques de chimie et de transport. L'objectif de cette thèse est de contraindre les simulations numériques à l'aide d'observations de manière à obtenir une meilleure représentation du champ d'ozone dans cette région, qui puisse servir de base pour des études phénoménologiques. Le modèle utilisé est le modèle de chimie-transport d'échelle globale MOCAGE de Météo-France. Les observations proviennent du programme européen MOZAIC, qui équipe depuis 1993 des avions de ligne commerciaux de capteurs d'ozone, de vapeur d'eau et d'autres composants minoritaires, et dont l'intérêt est de se situer au niveau de la tropopause. Notre étude a montré que le principal défaut du modèle sans assimilation est une tendance à lisser progressivement le gradient vertical d'ozone à la tropopause, et que l'assimilation a pour effet de corriger ce défaut : elle renforce ce gradient par un ajout d'ozone dans la basse stratosphère et une baisse d'ozone dans la haute troposphère. Plusieurs techniques d'assimilation ont été développées et ont été comparées ; les meilleurs résultats correspondent à une assimilation dans un système de coordonnées épousant le flux...

Author: Télesphore Sime-Ngando
Publisher: Springer
ISBN: 3319399616
Category : Science
Languages : en
Pages : 422

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This book represents the first multidisciplinary scientific work on a deep volcanic maar lake in comparison with other similar temperate lakes. The syntheses of the main characteristics of Lake Pavin are, for the first time, set in a firmer footing comparative approach, encompassing regional, national, European and international aquatic science contexts. It is a unique lake because of its permanently anoxic monimolimnion, and furthermore, because of its small surface area, its substantially low human influence, and by the fact that it does not have a river inflow. The book reflects the scientific research done on the general limnology, history, origin, volcanology and geological environment as well as on the geochemistry and biogeochemical cycles. Other chapters focus on the biology and microbial ecology whereas the sedimentology and paleolimnology are also given attention. This volume will be of special interest to researchers and advanced students, primarily in the fields of limnology, biogeochemistry, and aquatic ecology.

Author: Marie-Laure Cathala
Publisher: Editions Universitaires Europeennes
ISBN: 9783841794819
Category :
Languages : fr
Pages : 196

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Book Description
La region de la tropopause est particulierement importante du point de vue de la dynamique et de la chimie de l'atmosphere. L'objectif est ici de contraindre des simulations numeriques par assimilation d'observations afin d'obtenir une meilleure representation du champ d'ozone dans cette region. Pour cela on utilise le modele de chimie-transport MOCAGE de Meteo-France, et les observations d'ozone du programme europeen MOZAIC. Notre etude a montre que le principal defaut du modele est une tendance a lisser le gradient vertical d'ozone a la tropopause, et que l'assimilation a pour effet de corriger ce defaut. Plusieurs techniques d'assimilation ont ete developpees et comparees. Les meilleurs resultats correspondent a une assimilation dans un systeme de coordonnees epousant le flux. Les analyses produites servent ensuite de base a une etude des echanges d'ozone a la tropopause.

Author: Collectif
Publisher: IRD Éditions
ISBN: 2709922207
Category : Nature
Languages : en
Pages : 736

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Book Description
This book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines.

Author: Carole Bedos
Publisher: Springer Nature
ISBN: 9402420584
Category : Technology & Engineering
Languages : en
Pages : 340

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Book Description
This book gives an overview of the relationships between agriculture and air quality, which is an issue of increasing importance for practitioners and policy makers. It provides the keys to understand natural and anthropogenic mechanisms governing emission and deposition of pollutants produced by and/or impacting agricultural activities It identifies how management practices can help mitigating emissions and how public policies on air pollution progressively addressed the agricultural sector This book was written for students, researchers and agriculture actors as well as for public decision-makers

Author: Peter Hess
Publisher: Springer
ISBN: 9783662137048
Category : Science
Languages : en
Pages : 575

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Book Description
photoacoustic and Photothermal Phenomena contains reviews and a large numberof selected contributed papers reporting progress in the application of new photoacoustic and photo- thermal techniques in physics, chemistry, biology, medicine and materials science. Theoretical and experimental work is presented on spectroscopy, kinetics and relaxation, trace analysis, mass and heat transport, surfaces and thin films, nondestructive evaluation,ultrasonics and semiconductors.

Author: Noureddine Semane
Publisher:
ISBN:
Category :
Languages : en
Pages : 160

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Book Description
As in meteorology and oceanography, data assimilation combines in an optimal way chemistry-transport models and observations. In this work, the assimilation of remote-sensing chemical measurements of ozone (O3) and nitrous oxide (N2O) aims at better characterizing their three-dimensional distributions. The objective is to get insight into the coupled chemical and dynamical phenomena in the upper troposphere - lower stratosphere (UTLS). This work uses two complementary tools in Météo-France: one is based on the three dimensional chemistry and transport model MOCAGE and the PALM software of CERFACS using the 3D-FGAT variational technique; the other is an extension of the operational suite of the numerical weather prediction ARPEGE using the 4D-Var variational technique. On one hand, the assimilated fields (MOCAGE-PALM analyses) are used for the study of the polar stratospheric chemistry and dynamics and also for the meridional transport and stratosphere-troposphere exchanges. On the other hand, the chemistry-dynamics coupled assimilation in ARPEGE is used to assess the dynamical impact of ozone observation in the UTLS region.

Author: Gérard Guyot
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 656

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Book Description
Physics of the Environment and Climate Gérard Guyot This introductory text reviews, for the first time in a unified form, information which is generally scattered between more specialized books in physics, meteorology, climatology, ecophysiology, agronomy and instrumental physics. In Physics of the Environment and Climate, Gérard Guyot brings together physical, meteorological, ecological, and agronomical data, with a view to clarifying our understanding of complex global and climatological phenomena relating to the environment. In addition to the intrinsic scientific interest of this subject, it also has important applications in planning and production in agriculture, management of the rural environment, and evaluation of the impact of human activity on our surroundings. The first three chapters analyse energy and mass exchanges within and above the plant canopy and in the upper layers of the soil. They describe also the interaction existing between plant activity (photosynthesis, transpiration, etc.) and environmental factors. The following two chapters introduce the basic knowledge necessary for an understanding of the mechanisms affecting climates at different scales from the synoptic to local microclimates. The utilization of climatic data is then presented. Beginning with statistical analyses, the author leads on to practical applications, such as the determination of climatic risks, climatic and agro-climatic distribution in zones, and crop forecasting. The final chapter reviews the equipment and measurement methods used for the determination of various climatic factors. The broad nature of the book's approach, its inclusion of large-scale processes, explanations of how to measure climatic factors, and their use in solving practical problems in agro-climatology, will give the book immediate appeal. It provides the necessary information for land management planning from an agro-meteorological point of view, and is suitable for the undergraduate student and non-specialist reader with only a basic understanding of physics and mathematics. Readership: Students of agronomy, meteorology, climatology, geography, environmental science, atmospheric physics and environmental physics. Engineers and professionals in many fields such as agriculture, forestry, ecology, the rural environment, and the management of land, water and other natural resources.

Author: Peter Borrell
Publisher: Springer Science & Business Media
ISBN: 3642597181
Category : Science
Languages : en
Pages : 446

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Book Description
A major environmental concern is the increasing burden on all scales of photo-oxidants, acidifying substances and potential nutrients in the troposphere. These lead to episodes of summer smog, and appreciable damage to eco-systems both on land and at sea. Underlying the environmental effects is the complex scientific problem of linking the man-made and biological emissions to the myriad chemical reactions that transform the pollutants as they are transported to and deposited in the surroundings and also pristine areas remote from the sources. The project, the scientific results of which are described in this book, was set up to study the problem in an inter-disciplinary way by co-ordinating the work of more than 150 research groups in some 20 countries.

Author: Adolf Ebel
Publisher: Springer Science & Business Media
ISBN: 3662034700
Category : Science
Languages : en
Pages : 449

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Book Description
The end result of policy-related experimental and theoretical scientific work on the abatement of atmospheric emissions is a hierarchy of computer models that can be used to analyse and predict the behaviour of pollutants on urban, local regional and global scales. Such models are required to simulate an extremely complex natural situation in which a non-linear chemistry must be included together with the vagaries of the meteorology and the terrain. This book describes recent advances in the development and application of models on all scales, and in the techniques for the estimation and verification of emissions. It includes reviews of recent work together with detailed results and provides a useful picture of the field in a European context.