Investigation of Carbonaceous Aerosol Optical Properties to Understand Impacts on Air Quality and Composition PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Investigation of Carbonaceous Aerosol Optical Properties to Understand Impacts on Air Quality and Composition PDF full book. Access full book title Investigation of Carbonaceous Aerosol Optical Properties to Understand Impacts on Air Quality and Composition by Michael Robert Olson. Download full books in PDF and EPUB format.
Author: Michael Robert Olson
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The optical properties of carbonaceous aerosols were investigated to understand the impact source emissions and ambient particulate matter (PM) have on atmospheric radiative forcing. Black carbon (BC) is a strong absorber of visible light and contributes highly to atmospheric radiative forcing, therefore it is important to link BC properties to combustion emission sources. Brown carbon (BrC) is poorly understood and may be an important contributor to both positive and negative radiative forcing. The research investigates these primary knowledge gaps. The optical properties of carbonaceous aerosols were investigated to understand the impact source emissions and ambient particulate matter (PM) have on atmospheric radiative forcing. Black carbon (BC) is a strong absorber of visible light and contributes highly to atmospheric radiative forcing, therefore it is important to link BC properties to combustion emission sources. Brown carbon (BrC) is poorly understood and may be an important contributor to both positive and negative radiative forcing. The research investigates these primary knowledge gaps. Multiple methods were developed and applied to quantify the mass absorption cross-section (MAC) at multiple wavelengths of source and ambient samples. The MAC of BC was determined to be approximately 7.5 m2g−1 at 520nm. However, the MAC was highly variable with OC fraction and wavelength. The BrC MAC was similar for all sources, with the highest absorption in the UV at 370nm; the MAC quickly decreases at larger wavelengths. In the UV, the light absorption by BrC could exceed BC contribution by over 100 times, but only when the OC fraction is large (>90%) as compared to the total carbon. BrC was investigated by measuring the light absorption of solvent extracted fractions in water, dichloromethane, and methanol. Source emissions exhibited greater light absorption in methanol extractions as compared to water and DCM extracts. The BrC MAC was 2.4 to 3.7 m2g−1 at 370nm in methanol. Ambient samples showed similar MACs for the water and methanol extracts. Dichloromethane extracts did not have a significant light absorption characteristics for ambient samples. BrC and BC were measured in Beijing, China. Both were reduced significantly when restrictive air pollution controls were put in place. The industrial regions south and east of Beijing were the highest contributors to ambient BrC and BC. The controls reduced BrC more than BC as compared to observations during the regions heating period. Using the color characteristics of ambient PM, a model was developed to estimate elemental and organic carbon (EC/OC). The method will allow fast and cost effective quantification of PM composition in combination with large climate and health studies, especially in the developing world.
Author: Michael Robert Olson
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The optical properties of carbonaceous aerosols were investigated to understand the impact source emissions and ambient particulate matter (PM) have on atmospheric radiative forcing. Black carbon (BC) is a strong absorber of visible light and contributes highly to atmospheric radiative forcing, therefore it is important to link BC properties to combustion emission sources. Brown carbon (BrC) is poorly understood and may be an important contributor to both positive and negative radiative forcing. The research investigates these primary knowledge gaps. The optical properties of carbonaceous aerosols were investigated to understand the impact source emissions and ambient particulate matter (PM) have on atmospheric radiative forcing. Black carbon (BC) is a strong absorber of visible light and contributes highly to atmospheric radiative forcing, therefore it is important to link BC properties to combustion emission sources. Brown carbon (BrC) is poorly understood and may be an important contributor to both positive and negative radiative forcing. The research investigates these primary knowledge gaps. Multiple methods were developed and applied to quantify the mass absorption cross-section (MAC) at multiple wavelengths of source and ambient samples. The MAC of BC was determined to be approximately 7.5 m2g−1 at 520nm. However, the MAC was highly variable with OC fraction and wavelength. The BrC MAC was similar for all sources, with the highest absorption in the UV at 370nm; the MAC quickly decreases at larger wavelengths. In the UV, the light absorption by BrC could exceed BC contribution by over 100 times, but only when the OC fraction is large (>90%) as compared to the total carbon. BrC was investigated by measuring the light absorption of solvent extracted fractions in water, dichloromethane, and methanol. Source emissions exhibited greater light absorption in methanol extractions as compared to water and DCM extracts. The BrC MAC was 2.4 to 3.7 m2g−1 at 370nm in methanol. Ambient samples showed similar MACs for the water and methanol extracts. Dichloromethane extracts did not have a significant light absorption characteristics for ambient samples. BrC and BC were measured in Beijing, China. Both were reduced significantly when restrictive air pollution controls were put in place. The industrial regions south and east of Beijing were the highest contributors to ambient BrC and BC. The controls reduced BrC more than BC as compared to observations during the regions heating period. Using the color characteristics of ambient PM, a model was developed to estimate elemental and organic carbon (EC/OC). The method will allow fast and cost effective quantification of PM composition in combination with large climate and health studies, especially in the developing world.
Author: Ziying Lei
Publisher:
ISBN:
Category :
Languages : en
Pages : 80
Get Book Here
Book Description
Air pollution, one of the most concerning and widespread environmental issues has grown in importance in the world. The carbonaceous aerosols significantly contribute to air pollution, which not only causes public health concern, but also impacts climate change. The aerosol particles have properties to absorb or scatter solar radiation and thermal radiation; therefore, they play an important role in climate change. In order to improve the understanding and control the aerosol particles, it is crucial to study aerosol size distribution and chemical compounds. Black carbon is the strongest radiative absorber suspends in the atmosphere, and can have great influence on climate change. This study investigates the size-selected black carbon optical properties under laboratory conditions with varied relative humidity referred to “dry”, “humid”, and “wet” respectively. The single scattering albedo that measures the relative amount of aerosol light extinction due to scattering, and the absorption enhancement due to lensing effect are measured in this study, and compared with the modeling results based on Mie theory, which is used to predict the absorption and scattering of light by a spherical particle. The results show that the single scattering albedo under the dry, humid, and wet conditions are similar, while the single scattering albedo for black carbon particles that have undergone heating to 160 oC is slightly greater than other three conditions. In general, with respect to particle size, single scattering albedo increases with smaller particle size and then levels off at larger size diameters. In addition, the absorption enhancement for black carbon particles is estimated in this study, and it ranges from 1 to 2.5. The values based on observations generally follow the predicted trend from Mie theory. Comparing the observed and modeled values suggests that 25%-50% of the total particle diameter is attributable to coating material. Dry black carbon particles do not have high absorption enhancement because they likely have no or thin coating materials. However, the absorption enhancement for humid particles and wet particles are higher than the dry particles, likely due to an enhanced lensing effect due to water uptake by the black carbon particles. Future study will focus on improving the understanding of black carbon optical properties and accuracy of experimental results. Further research is recommended to focus on ranges of BC particles with the diameters smaller than 100 nm and larger than 650 nm, which are not included in this study and constrain the particle charge units.
Author: András Gelencsér
Publisher: Springer Science & Business Media
ISBN: 1402028873
Category : Science
Languages : en
Pages : 357
Get Book Here
Book Description
The concept of carbonaceous aerosol has only recently emerged from atmospheric pollution studies; even standard nomenclature and terminology are still unsettled. This monograph is the first to offer comprehensive coverage of the nature and atmospheric role of carbonaceous aerosol particles. Atmospheric chemists, physicists, meteorologists, and modellers will find this a thought-inspiring and sometimes provocative overview of all global phenomena affected by or related to carbonaceous aerosol.
Author:
Publisher:
ISBN:
Category : Atmospheric aerosols
Languages : en
Pages : 113
Get Book Here
Book Description
Scientists have been observing a change in the climate since the beginning of the 20th century that cannot be attributed to any of the natural influences of the past. Natural and anthropogenic substances and processes perturb the Earth's energy budget, contributing to climate change. In particular, aerosols (particles suspended in air) have long been recognized to be important in processes throughout the atmosphere that affect climate. They directly influence the radiative balance of the Earth's atmosphere, affect cloud formation and properties, and are also key air pollutants that contribute to a variety of respiratory and cardiovascular diseases. Despite their importance, aerosol particles are less well-characterized than greenhouse gases with respect to their sources, temporal and spatial concentration distribution, and physical and chemical properties. This uncertainty is mainly caused by the variable and insufficiently understood sources, formation and transformation processes, and complex composition of atmospheric particles. Instruments that can precisely and accurately measure and characterize the aerosol physical and chemical properties are in great demand. Atmospheric relative humidity (RH) has a crucial impact on the particles' optical properties; the RH dependence of the particle extinction coefficient is an important parameter for radiative forcing and thus climate change modeling. In this work a Humidity-Controlled Cavity Ring-Down (HC-CRD) aerosol optical instrument is described and its ability to measure RH dependent extinction coefficients and related hygroscopicity parameters is characterized.
Author: François Dulac
Publisher: Springer Nature
ISBN: 3030823857
Category : Science
Languages : en
Pages : 622
Get Book Here
Book Description
This two-volume set provides an extensive review of the abundant past and recent literature on the atmospheric chemistry in the Mediterranean region. The books document the experience gained on the atmospheric composition over the Mediterranean basin and close areas after six decades of research, starting from early studies of radioactive aerosol fallouts and intense desert dust events in the 1960s, followed by studies of aerosols collected during oceanographic cruises in the early 1980s, and including subsequent knowledge from various surface monitoring stations, intensive campaigns, satellite climatologies, laboratory studies, as well as chemistry-transport and climate models. Through ten thematic sections, the authors examine the sources and fates of atmospheric pollutants over the Mediterranean basin and what we know about the main impacts of the regional atmospheric chemistry. This overview not only considers the full regional cycle of both aerosol and reactive gases including emissions, transport, transformations, and sinks, but also addresses their major impacts on air quality and health, on the radiative budget and climate, on marine chemistry and biogeochemistry . The volumes are an initiative from the ChArMEx project that has federated many studies on those topics in the 2010-2020decade, and update the scientific knowledge by integrating the ChArMEx and non-ChArMEx literature. The books are contributed by a large pool of well-known authors from the respective fields, mainly from France and Greece, but also from six other Mediterranean and eight non-Mediterranean countries. All Chapters have been peer-reviewed by international scientific experts in the corresponding domains. Volume 2 focuses on emissions and their sources, recent progress on chemical processes, aerosol properties, atmospheric deposition, and the impacts of air pollution on human health, regional climate and ecosystems. Recommendations for future research in these fields are finally proposed. The targeted audience is the academic community working on atmospheric chemistry and its impacts, especially teams having a special interest in the Mediterranean region, which includes many countries and institutes worldwide.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 348
Get Book Here
Book Description
Author: Alan P. Waggoner
Publisher:
ISBN:
Category : Aerosols
Languages : en
Pages : 56
Get Book Here
Book Description
Author: Ken S. Carslaw
Publisher: Elsevier
ISBN: 0128197668
Category : Science
Languages : en
Pages : 854
Get Book Here
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
Author: Chandra Venkataraman
Publisher: Springer
ISBN: 9811302804
Category : Science
Languages : en
Pages : 320
Get Book Here
Book Description
This book provides a synthesis of research findings, in terms of strategic knowledge outcomes regarding emergence of recent regional climate signals, implications for impacts assessment, and mitigation and adaptation response, relevant in the Indian context. The first part discusses evidence of climate change and its underlying scientific processes across India, chiefly focusing on impacts that are already visible and attributable to anthropogenic activities. The latter part deals with the responses to climate change, highlighting the mitigation and adaptation strategies in various sectors and communities. The book presents a concise interpretation, distilling practical recommendations and policy prescriptions at national and sub-national levels. It serves as a reference point for understanding scientific advances and persisting uncertainty, future vulnerability and response capacity of interlinked human and natural systems, pertaining to India. It is an excellent resource for policy makers and industry watchers in addition to the research fraternity.
Author: Yue Zhang
Publisher: American Chemical Society
ISBN: 0841299293
Category : Science
Languages : en
Pages : 176
Get Book Here
Book Description
The uncertainties in the aerosol effects on radiative forcing limit our knowledge of climate change, presenting us with an important research challenge. Aerosols in Atmospheric Chemistry introduces basic concepts about the characterization, formation, and impacts of ambient aerosol particles as an introduction to graduate students new to the field. Each chapter also provides an up-to-date synopsis of the latest knowledge of aerosol particles in atmospheric chemistry.
