Do You Really Care about Clouds, Aerosols and Climate Change ? PDF Download

Author: Jérôme Riédi
Publisher:
ISBN:
Category :
Languages : en
Pages : 306

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Book Description
Nos activités ont porté à la fois sur le développement de moyens d'observations et sur la mise au point de nouvelles méthodes de restitution des propriétés des nuages et des aérosols, leur validation et l'analyse géophysique des produits dérivés pour application à la modélisation. Ces recherches mettent en œuvre principalement des observations depuis l'espace et visent, à travers la description à l'échelle globale des propriétés des nuages et des aérosols, à comprendre les processus qui gouvernent leur évolution. Dans un premier temps, les résultats obtenus ont principalement permis de mieux déterminer l'un des paramètres clés pour l'évolution d'un nuage et son impact radiatif : la phase thermodynamique de l'eau condensée. Par la suite, en cherchant à mieux comprendre les paramètres déterminant la phase du nuage, nous avons tenté d'établir les liens entre phase thermodynamique, propriétés microphysiques et conditions thermodynamique. Dans le même temps, les problématiques d'observation des nuages nous ont amené à nous pencher sur des questions plus générales de l'observation de l'atmosphère par télédétection concernant les aérosols et, de manière plus prospective, la vapeur d'eau. L'ensemble de ces travaux nous a conduit à proposer récemment un nouveau concept pour l'observation des nuages, des aérosols et de la vapeur d'eau depuis l'espace. Ce projet a été déposé auprès de l'Agence Spatiale Européenne (ESA) en réponse à son appel à idée pour la 8ème mission Earth Explorer. En remettant en perspective les travaux réalisés depuis dix ans, et concrétisés notamment au travers du projet récemment soumis à l'ESA, mais également en replaçant notre activité de recherche dans son contexte social, politique et économique, nous posons la question suivante sans avoir la prétention d'y répondre : "Qui se soucie vraiment des nuages, des aérosols et du climat ?"

Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309443458
Category : Science
Languages : en
Pages : 53

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Book Description
One of the most significant and uncertain aspects of climate change projections is the impact of aerosols on the climate system. Aerosols influence the climate indirectly by interacting with nearby clouds leading to small changes in cloud cover, thickness, and altitude, which significantly affect Earth's radiative balance. Advancements have been made in recent years on understanding the complex processes and atmospheric interactions involved when aerosols interact with surrounding clouds, but further progress has been hindered by limited observations. The National Academies of Sciences, Engineering, and Medicine organized a workshop to discuss the usefulness of the classified observing systems in advancing understanding of cloud and aerosol interactions. Because these systems were not developed with weather and climate modeling as a primary mission objective, many participants said it is necessary for scientists to find creative ways to utilize the data. The data from these systems have the potential to be useful in advancing understanding of cloud and aerosol interactions. This publication summarizes the presentations and discussions from the workshop.

Author: Panel on Aerosol Radiative Forcing and Climate Change
Publisher: National Academies Press
ISBN: 0309588871
Category : Science
Languages : en
Pages : 180

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Book Description
This book recommends the initiation of an "integrated" research program to study the role of aerosols in the predicted global climate change. Current understanding suggest that, even now, aerosols, primarily from anthropogenic sources, may be reducing the rate of warming caused by greenhouse gas emissions. In addition to specific research recommendations, this book forcefully argues for two kinds of research program integration: integration of the individual laboratory, field, and theoretical research activities and an integrated management structure that involves all of the concerned federal agencies.

Author: R. J. Charlson
Publisher:
ISBN:
Category : Nature
Languages : en
Pages : 460

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Book Description
Global climate change as a consequence of anthropogenic changes in the chemical composition of the atmosphere poses scientific questions of a nature and interdisciplinary scope that are unprecedented. Uncertainties in the climate forecast are large and thus far have hampered the establishment of a clear world plan for preventing or mitigating against unacceptable effects. The forecast of global and regional climate changes depends upon the development of a sound understanding of the factors that change the global heat balance and thus influence the climate. Changes in heat balance due to anthropogenic or externally imposed changes in the chemical composition of the atmosphere are referred to as forcings. While the uncertainties in the global mean greenhouse-gas forcing are not negligible (??? 15%), uncertainties in forcings by changes in the atmospheric aerosol and in clouds are much larger, and in some cases even include uncertainty in the sign of the forcing. Reductionist science, with its compartmentalized disciplines, has not coped effectively with the scientific problems of aerosols and their effects, largely because of a need for simultaneous consideration of chemical processes, chemical properties, physical properties, and a wide variety of physical processes and consequences. In the case of natural aerosols and their effects on clouds, it is even necessary to include studies of microbiology and of biochemistry. This volume ? the record of intense, interdisciplinary debate between atmospheric chemists, meteorologists, physicists, and biogeochemists - considers the subset of climate forcings due to atmospheric aerosols, with particular emphasis on integrating the necessary disciplinary components. It is truly unique in its interdisciplinary approach. The information contained in the overview papers and summary reports will be of interest to policymakers and scientists alike. Goal of this Dahlem Workshop to assess the controlling factors, geographic and temporal variations of the radiative properties of atmospheric aerosols, and to examine the extent to which their forcing through direct and indirect effects counteracts greenhouse-gas forcing on regional and global climate.

Author: Peter V. Hobbs
Publisher: Academic Press
ISBN: 0080959962
Category : Science
Languages : en
Pages : 259

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Book Description
Aerosol and clouds play important roles in determining the earth's climate, in ways that we are only beginning to comprehend. In conjunction with molecular scattering from gases, aerosol and clouds determine in part what fraction of solar radiation reaches the earth's surface, and what fraction of the longwave radiation from the earth escapes to space. This book provides an overview of the latest research on atmospheric aerosol and clouds and their effects on global climate. Subjects reviewed include the direct and indirect effects of aerosol on climate, the radiative properties of clouds and their effects on the Earth's radiation balance, the incorporation of cloud effects in numerical weather prediction models, and stratospheric aerosol and clouds.

Author: Yuan Wang
Publisher: Springer
ISBN: 3662471752
Category : Science
Languages : en
Pages : 100

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Book Description
The studies in this dissertation aim at advancing our scientific understandings about physical processes involved in the aerosol-cloud-precipitation interaction and quantitatively assessing the impacts of aerosols on the cloud systems with diverse scales over the globe on the basis of the observational data analysis and various modeling studies. As recognized in the Fifth Assessment Report by the Inter-government Panel on Climate Change, the magnitude of radiative forcing by atmospheric aerosols is highly uncertain, representing the largest uncertainty in projections of future climate by anthropogenic activities. By using a newly implemented cloud microphysical scheme in the cloud-resolving model, the thesis assesses aerosol-cloud interaction for distinct weather systems, ranging from individual cumulus to mesoscale convective systems. This thesis also introduces a novel hierarchical modeling approach that solves a long outstanding mismatch between simulations by regional weather models and global climate models in the climate modeling community. More importantly, the thesis provides key scientific solutions to several challenging questions in climate science, including the global impacts of the Asian pollution. As scientists wrestle with the complexities of climate change in response to varied anthropogenic forcing, perhaps no problem is more challenging than the understanding of the impacts of atmospheric aerosols from air pollution on clouds and the global circulation.

Author: Zev Levin
Publisher: Springer Science & Business Media
ISBN: 1402086903
Category : Science
Languages : en
Pages : 399

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Book Description
Life on Earth is critically dependent upon the continuous cycling of water between oceans, continents and the atmosphere. Precipitation (including rain, snow, and hail) is the primary mechanism for transporting water from the atmosphere back to the Earth’s surface. It is also the key physical process that links aspects of climate, weather, and the global hydrological cycle. Changes in precipitation regimes and the frequency of extreme weather events, such as floods, droughts, severe ice/snow storms, monsoon fluctuations and hurricanes are of great potential importance to life on the planet. One of the factors that could contribute to precipitation modification is aerosol pollution from various sources such as urban air pollution and biomass burning. Natural and anthropogenic changes in atmospheric aerosols might have important implications for precipitation by influencing the hydrological cycle, which in turn could feed back to climate changes. From an Earth Science perspective, a key question is how changes expected in climate will translate into changes in the hydrological cycle, and what trends may be expected in the future. We require a much better understanding and hence predictive capability of the moisture and energy storages and exchanges among the Earth’s atmosphere, oceans, continents and biological systems. This book is a review of our knowledge of the relationship between aerosols and precipitation reaching the Earth's surface and it includes a list of recommendations that could help to advance our knowledge in this area.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309314852
Category : Science
Languages : en
Pages : 270

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Book Description
The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.

Author: Paul J. Crutzen
Publisher: Springer Science & Business Media
ISBN: 364261051X
Category : Science
Languages : en
Pages : 337

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Book Description
The objective of this NATO Advanced Research Workshop was to discuss our current understanding of the role of clouds in climate and chemistry. The range of topics dis cussed during the workshop included: modeling of clouds in GCMs; observations of the cloud micro physical properties; the water vapor cycle; troposphere-stratosphere exchange; role of in-cloud transport in tropospheric ozone; regulation of current and paleo climate by clouds; and anthropogenic sulfate aerosols and modification of cloud properties. The essence of the discussions is captured in the accompanying summary by the rapporteurs and the chapters by some of the speakers. The underlying message is that significant progress has been made, resulting in exciting new developments in our perception of the role of clouds in the global system . .. The tropical convective-cirrus cloud systems emerge as a major influence on the climate system. Micro physical processes, such as the rate of precipitation and re evaporation of ice particles, seem to regulate the large scale vertical distribution of water vapor which is the dominant greenhouse gas. Water vapor data collected during the Central Equatorial Pacific Experiment (CEPEX), document the large moistening effect of deep convection on scales of thousands of kilometers. A major chemical finding in the same region was the observation of extremely low ozone 8 volume mixing ratios of less than 10- in the entire troposphere of the central equatorial Pacific extending over a distance of about 2000 km. This finding establishes the Pacific as a major chemical sink region for tropospheric ozone.

Author: A. Pier Siebesma
Publisher: Cambridge University Press
ISBN: 1108882781
Category : Science
Languages : en
Pages : 421

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Book Description
Cloud research is a rapidly developing branch of climate science that's vital to climate modelling. With new observational and simulation technologies our knowledge of clouds and their role in the warming climate is accelerating. This book provides a comprehensive overview of research on clouds and their role in our present and future climate, covering theoretical, observational, and modelling perspectives. Part I discusses clouds from three different perspectives: as particles, light and fluid. Part II describes our capability to model clouds, ranging from theoretical conceptual models to applied parameterised representations. Part III describes the interaction of clouds with the large-scale circulation in the tropics, mid-latitudes, and polar regions. Part IV describes how clouds are perturbed by aerosols, the land-surface, and global warming. Each chapter contains end-of-chapter exercises and further reading sections, making this an ideal resource for advanced students and researchers in climatology, atmospheric science, meteorology, and climate change.