Modelling Tropospheric Volcanic Aerosol


Book Description

Anja Schmidt's thesis is a unique and comprehensive evaluation of the impacts of tropospheric volcanic aerosol on the atmosphere, climate, air quality and human health. Using a state-of-the-art global microphysics model, the thesis describes and quantifies the impact of volcanic sulphur emissions on global aerosol, clouds and the radiative forcing of climate. The advanced model enables the first ever estimate of the impact of the emissions on aerosol microphysical properties such as particle number concentrations and sizes, and therefore a considerably improved ability to quantify the climate and air quality effects. There are several important discoveries in this thesis. Firstly, it is shown that continuously degassing volcanoes exert a major effect on global clouds and climate. Secondly, the impact of the 1783 Laki eruption in Iceland is re-examined to show that this long-lasting flood lava eruption would have had major effects on clouds and climate. Thirdly, by combining her research on volcanism, atmospheric science and epidemiology, she shows that a present-day Laki-like eruption would seriously affect European air quality and cause over 100000 premature deaths in the first year.




The Stratospheric Aerosol Layer


Book Description

It is now a quarter of a century since Junge and his coworkers recovered the first sample from the sulfate aerosol layer in the stratosphere. Since that time vast strides have been made in determining its physical properties and morphology. These investigations have been performed with instruments on board aircraft and balloon platforms as in the early days, with ground-based lidar (optical radar), and most recently with satellite-borne optical instruments. It will become evident in Chapter 2 that in situ measurements by aircI'aft and ,balloon sensors complement rather than duplicate the remote techniques (lidar and satellite). Hence future programs will probably continue to utilize direct as well as indirect experimental techniques. Concurrently, with the observations of the gross properties of the aerosol layer, la~oratory and theoretical studies have sought to elucidate the chemical and micro physical processes which influence the formation and growth of the aerosol par ticles. The laboratory investigations have included studies of gas phase chemistry, and particle nucleation and growth mechanisms. Theoretical studies have revolved mainly around a series of models developed by atmospheric scientists. The earliest of these models was constructed by Junge and his colleagues. With the advent of third- and fourth-generation computers, the capacity to solve the quite complex continuity equations whi~h govern particle formation, growth, and removal has ad vanced to the point where most of the particle properties can be simulated with reasonable confidence.




Volcanic Plumes


Book Description

Volcanoes release plumes of gas and ash to the atmosphere during episodes of passive and explosive behavior. These ejecta have important implications for the chemistry and composition of the troposphere and stratosphere, with the capacity to alter Earth's radiation budget and climate system over a range of temporal and spatial scales. Volcanogenic sulphur dioxide reacts to form sulphate aerosols, which increase global albedo, e.g., by reducing surface temperatures, in addition to perturbing the formation processes and optical properties of clouds. Released halogen species can also deplete stratospheric and tropospheric ozone. Volcanic degassing, furthermore, played a key role in the formation of Earth’s atmosphere, and volcanic plumes can affect air quality, pose hazards to aviation and human health, as well as damage ecosystems. The chemical compositions and emission rates of volcanic plumes are also monitored via a range of direct-sampling and remote-sensing instrumentation, in order to gain insights into subterranean processes, in the respect of the magmatic bodies these volatiles exsolve from. Given the significant role these gases play in driving volcanic activity, e.g., via pressurisation, the study of volcanic plumes is proving to be an increasingly fruitful means of improving our understanding of volcanic systems, potentially in concert with observations from geophysics and contributions from fluid dynamical modelling of conduit dynamics. This Special Issue is aimed at presenting the state of the art of the multidisciplinary science concerning all aspects of volcanic plumes, of relevance to the volcanology, climatology, atmospheric science, and remote sensing communities.




Global Physical Climatology


Book Description

Global Physical Climatology is an introductory text devoted to the fundamental physical principles and problems of climate sensitivity and change. Addressing some of the most critical issues in climatology, this text features incisive coverage of topics that are central to understanding orbital parameter theory for past climate changes, and for anthropogenic and natural causes of near-future changes--Key Features* Covers the physics of climate change* Examines the nature of the current climate and its previous changes* Explores the sensitivity of climate and the mechanisms by which humans are likely to produce near-future climate changes* Provides instructive end-of-chapter exercises and appendices




Atmospheric Aerosols


Book Description

Ein Blick auf die morphologischen, physikalischen und chemischen Eigenschaften von Aerosolen aus den unterschiedlichsten natürlichen und anthropogenen Quellen trägt zum besseren Verständnis der Rolle bei, die Aerosolpartikel bei der Streuung und Absorption kurz- und langwelliger Strahlung spielen. Dieses Fachbuch bietet Informationen, die sonst schwer zu finden sind, und vermittelt ausführlich die Kenntnisse, die erforderlich sind, um die mikrophysikalischen, chemischen und Strahlungsparameter zu charakterisieren, die bei der Wechselwirkung von Sonnen- und Erdstrahlen so überaus wichtig sind. Besonderes Augenmerk liegt auf den indirekten Auswirkungen von Aerosolen auf das Klima im Rahmen des komplexen Systems aus Aerosolen, Wolken und der Atmosphäre. Auch geht es vorrangig um die Wirkungen natürlicher und anthropogener Aerosole auf die Luftqualität und die Umwelt, auf die menschliche Gesundheit und unser kulturelles Erbe. Mit einem durchgängig lösungsorientierten Ansatz werden nicht nur die Probleme und Gefahren dieser Aerosole behandelt, sondern auch praktikable Lösungswege aufgezeigt.




Aerosols and Climate


Book Description

The ever-diversifying field of aerosol effects on climate is comprehensively presented here, describing the strong connection between fundamental research and model applications in a way that will allow both experienced researchers and those new to the field to gain an understanding of a wide range of topics. The material is consistently presented at three levels for each topic: (i) an accessible "quick read" of the essentials, (ii) a more detailed description, and (iii) a section dedicated to how the processes are handled in models. The modelling section in each chapter summarizes the current level of knowledge and what the gaps in this understanding mean for the effects of aerosols on climate, enabling readers to quickly understand how new research fits into established knowledge. Definitions, case studies, reference data, and examples are included throughout. Aerosols and Climate is a vital resource for graduate students, postdoctoral researchers, senior researchers, and lecturers in departments of atmospheric science, meteorology, engineering, and environment. It will also be of interest to those working in operational centers and policy-facing organizations, providing strong reference material on the current state of knowledge. - Includes a section in each chapter that focuses on the treatment of relevant aerosol processes in climate models - Provides clear exposition of the challenges in understanding and reducing persistent gaps in knowledge and uncertainties in the field of aerosol-climate interaction, going beyond the fundamentals and existing knowledge - Authored by experts in modeling and aerosol processes, analysis or observations to ensure accessibility and balance




Tracking Volcanic Sulphate


Book Description

Volcanic emissions are a major source of sulphur. Volcanic sulphur is oxidized and forms sulphate aerosols that influence the climate by absorbing and dispersing incident solar radiation. Sulphur emissions in the troposphere influence local and regional climate, but large uncertainties remain regarding oxidation and its conversion into volcanic sulphate aerosols. The oxidation of sulphur in a wide range of volcanic plumes and the influence of volcanic halogens on plume chemistry are studied using a chemical box model. At the same time, the isotopic oxygen composition of volcanic sulphate, namely the excess of 17-O (∆17O), is being explored, which can provide constraints on sulphur oxidation pathways. The results suggest that in the presence of water droplets and ash, the oxidation of sulphur in plumes is mainly due to aqueous phase oxidation with O2 catalyzed by transition metal ions (TMI). Halogen emissions promote the domi- nance of O2 /TMI by inducing ozone depletion events (ODEs). In the absence of water droplets, plume chemistry is largely determined by heterogeneous chemistry on primary sulphate aerosols. The dominant oxidants in these plumes are OH and H2O2. The oxidation rate of sulphur is significantly reduced compared to plumes containing water droplets. The results show that oxygen isotopes in sulphates provide strong constraints on the chemical balance of sulphur in volcanic plumes and on the role of volcanic halogens.




Climate Intervention


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.




Guide to Global Aerosol Models


Book Description

The purpose of this work (G-065) is to describe, in a convenient form, a standard guide to a set of existing reference global aerosol models. The guide contains tables, plots and other information describing the properties of atmospheric aerosols, both natural and manmade.




Remote Sensing of Volcanoes and Volcanic Processes


Book Description

This volume focuses on how advances in both remote sensing and modelling can be brought together to improve our understanding of the behaviour of active volcanoes. It includes review papers, papers reporting technical advances and case studies showing how the integration of remote-sensing observations with models can be put to good use.