Download or read book Secondary Organic Aerosol Formation of Relevance to the Marine Boundary Layer written by Xuyi Cai and published by . This book was released on 2008 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding the Role of Organic Aerosol in the Coastal and Remote Pacic Marine Boundary Layer written by Lelia Nahid Hawkins and published by . This book was released on 2010 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosol particles were collected over three field experiments in the remote and coastal marine boundary layer of the eastern Pacific Ocean from aircraft, ship, and stationary platforms and were analyzed using Fourier Transform Infrared (FTIR) spectroscopy, Aerosol Mass Spectrometry (AMS), and Scanning Transmission X-ray Microscopy with Near-Edge Absorption Fine Structure (STXM-NEXAFS) for organic functional groups and organic mass fragments. X-ray fluorescence (XRF) and Scanning Electron Microscopy with Energy Dispersive X-rays (SEM-EDX) analyses were used to investigate the elemental composition of the analyzed particles. The aim of these studies was to better characterize particle sources and composition in the stratocumulus-topped marine boundary layer (MBL), where aerosol-cloud interactions play an important role in controlling the reflectivity of the large cloud decks. Particle composition was linked to distinct particle sources including primary marine emissions, biomass burning, and fossil fuel combustion. Fossil fuel combustion particles were characterized by large contributions from saturated alkane and carboxylic acid groups. Biomass burning aerosol particles were characterized as mixtures of alkane, carboxylic acid, and ketone groups, consistent with biogenic secondary organic aerosol particles observed in chamber studies. Photochemical aging of the transported smoke particles was observed on diurnal and multi-day timescales as an increase in the relative amount of oxygenated groups and oxygen-containing molecular fragments. Marine primary organic aerosol (POA) particles were observed in shipboard samples and were characterized by large contributions from organic hydroxyl groups, suggesting a carbohydrate-containing source in the ocean surface emitted during bubble bursting. Marine particles were also identified in single particle STXM-NEXAFS and were classified into four distinct categories including soluble and insoluble polysaccharides, proteins, and calcareous phytoplankton fragments. The presence of oxidized (polar) organic components--ketone, organic hydroxyl, and carboxylic acid groups--in submicron particles suggests that many of the measured particles could contribute to cloud condensation nuclei number concentration and mass in both open ocean and coastal regions. Together, these measurements show that marine POA provides a significant contribution to submicron particle mass in the clean MBL, whereas fossil fuel combustion and biomass burning emissions contribute the majority of the organic mass in coastal regions.
Download or read book Understanding the Global Effect of Secondary Organic Aerosol on Size Distributions in Past and Present Climates written by Stephen D'Andrea and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Simulation Chambers Application to Atmospheric Chemical Processes written by Ian Barnes and published by Springer Science & Business Media. This book was released on 2006-01-13 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives in the first instance descriptions of different types of so-called environment chambers or photoreactors used mainly for the simulation and/or investigation of important chemical processes occurring in the atmosphere. The types of reactor described include outdoor and indoor chambers, temperature regulated chambers and glass and Teflon foil chambers The practical use of chambers is demonstrated in contributions by leading scientists in the field of atmospheric chemistry using, in many cases, current results. The types of atmospherically relevant investigations described include the measurement of reactivities, the measurement of radicals, the measurement of photolysis frequencies and products, kinetic and product studies on the oxidation of different types of hydrocarbons by important oxidant species (OH, N03, 03), formation of secondary organic aerosol from hydrocarbon oxidation etc. A special section includes contributions from eastern European countries which highlight some of the environmental research being performed in these countries. An abridged version of a specially commissioned review by the JRC Ispra on the status of environmental research in eastern European countries is also included in this section.
Download or read book Sea Salt Aerosol Production written by Ernie R. Lewis and published by American Geophysical Union. This book was released on 2004-01-09 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 152. Sea salt aerosol (SSA) exerts a major influence over a broad reach of geophysics. It is important to the physics and chemistry of the marine atmosphere and to marine geochemistry and biogeochemistry generally. It affects visibility, remote sensing, atmospheric chemistry, and air quality. Sea salt aerosol particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of these other aerosols and more broadly influencing the geochemical cycles of substances with which they interact. As the key aerosol constituent over much of Earth's surface at present, and all the more so in pre-industrial times, SSA is central to description of Earth's aerosol burden.
Download or read book Secondary Organic Aerosol Formation from Aromatic Hydrocarbons written by Chen Song and published by . This book was released on 2006 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Dennis A. Hansell and published by Academic Press. This book was released on 2014-10-02 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic matter (DOM) is a complex mixture of molecules found throughout the world's oceans. It plays a key role in the export, distribution, and sequestration of carbon in the oceanic water column, posited to be a source of atmospheric climate regulation. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, focuses on the chemical constituents of DOM and its biogeochemical, biological, and ecological significance in the global ocean, and provides a single, unique source for the references, information, and informed judgments of the community of marine biogeochemists. Presented by some of the world's leading scientists, this revised edition reports on the major advances in this area and includes new chapters covering the role of DOM in ancient ocean carbon cycles, the long term stability of marine DOM, the biophysical dynamics of DOM, fluvial DOM qualities and fate, and the Mediterranean Sea. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, is an extremely useful resource that helps people interested in the largest pool of active carbon on the planet (DOC) get a firm grounding on the general paradigms and many of the relevant references on this topic. Features up-to-date knowledge of DOM, including five new chapters The only published work to synthesize recent research on dissolved organic carbon in the Mediterranean Sea Includes chapters that address inputs from freshwater terrestrial DOM
Download or read book Atmospheric Aerosols written by Claudio Tomasi and published by John Wiley & Sons. This book was released on 2017-03-20 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterizing the Formation of Secondary Organic Aerosols written by and published by . This book was released on 2004 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic aerosol is an important fraction of the fine particulate matter present in the atmosphere. This organic aerosol comes from a variety of sources; primary organic aerosol emitted directly from combustion process, and secondary aerosol formed in the atmosphere from condensable vapors. This secondary organic aerosol (SOA) can result from both anthropogenic and biogenic sources. In rural areas of the United States, organic aerosols can be a significant part of the aerosol load in the atmosphere. However, the extent to which gas-phase biogenic emissions contribute to this organic load is poorly understood. Such an understanding is crucial to properly apportion the effect of anthropogenic emissions in these rural areas that are sometimes dominated by biogenic sources. To help gain insight on the effect of biogenic emissions on particle concentrations in rural areas, we have been conducting a field measurement program at the University of California Blodgett Forest Research Facility. The field location includes has been used to acquire an extensive suite of measurements resulting in a rich data set, containing a combination of aerosol, organic, and nitrogenous species concentration and meteorological data with a long time record. The field location was established in 1997 by Allen Goldstein, a professor in the Department of Environmental Science, Policy and Management at the University of California at Berkeley to study interactions between the biosphere and the atmosphere. The Goldstein group focuses on measurements of concentrations and whole ecosystem biosphere-atmosphere fluxes for volatile organic compounds (VOC's), oxygenated volatile organic compounds (OVOC's), ozone, carbon dioxide, water vapor, and energy. Another important collaborator at the Blodgett field location is Ronald Cohen, a professor in the Chemistry Department at the University of California at Berkeley. At the Blodgett field location, his group his group performs measurements of the concentrations of important gas phase nitrogen compounds. Experiments have been ongoing at the Blodgett field site since the fall of 2000, and have included portions of the summer and fall of 2001, 2002, and 2003. Analysis of both the gas and particle phase data from the year 2000 show that the particle loading at the site correlates with both biogenic precursors emitted in the forest and anthropogenic precursors advected to the site from Sacramento and the Central Valley of California. Thus the particles at the site are affected by biogenic processing of anthropogenic emissions. Size distribution measurements show that the aerosol at the site has a geometric median diameter of approximately 100 nm. On many days, in the early afternoon, growth of nuclei mode particles (
Download or read book Marine Aerosol Physical Properties and Influences by Meteorology in the North Atlantic Ocean written by Nicole Chisholm and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine aerosols play an important role in earth's climate, but their effects remain highly uncertain due to a poor understanding of their sources, properties, and atmospheric processing, partly due to limited measurements. The Coastal-Fog (C-FOG) study investigated the processes controlling the formation and properties of fog in the North Atlantic Ocean. As part of this study, aerosol particle size distributions and chemical composition were measured off the shore of the northeastern United States and Atlantic Canada, and used to investigate the sources and processes affecting the observed aerosols. Processed marine air during the study was characterized by single and bi-modal aerosol size distributions. Aerosols in the port city of St. John's, Newfoundland reflected local emissions built up due to poor ventilation, whereas aerosols in Halifax, Nova Scotia were lower in concentration because the harbour is more spread out. Finally, two particle growth events were observed. The first event captured the appearance of 10 nm particles that grew to 30 nm over 4 h. These aerosols appeared to be newly formed in the upper portion of the boundary layer with influence from the free troposphere before subsiding to the surface. In the second event, 45 nm particles grew to 70 nm over 8 h. The growth of these aerosols was most likely due to the direct condensation of organic vapours emitted from boreal forests and/or the ocean. Our observations provide important insight into the processes affecting marine aerosols and highlight the crucial role of boundary layer meteorology.
Download or read book Modeling Atmospheric Secondary Organic Aerosol Dynamics Through Chemistry Emissions and Partition Theory written by Wayne Li-wen Chang and published by . This book was released on 2011 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: The detrimental impact on both human health and global climate of atmospheric particular matter (PM) is now well-established. Among the various classifications of PM, a significant portion is comprised of secondary organic aerosol (SOA). Despite its importance, there are still much uncertainty regarding the formation and evolution of SOA in the atmosphere, beginning with the oxidation of organic gases that leads to semi-volatile and low volatility products. The need to further improve the current knowledge SOA is made apparent by the observed large discrepancy between model predictions and field measurements of SOA. Proposed explanations behind the orders of magnitude underprediction of ambient SOA levels by state-of-the-art airshed models include: missing particle-forming oxidized organic products, unidentified SOA precursor emissions, and issues related to the fundamentals of current SOA partition theory, all of which are considered in this study to develop corresponding improvements to the latest airshed models. The model used in this study is the UCI-CIT airshed model, and the improvement scenario tests are set in the urban region of South Coast Air Basin of California. Recent chamber results have shown that the original implementation of alkane-derived SOA provided an underestimate for what was likely to be occurring in urban atmospheres. Thus, the original chemical mechanism is revised to include higher generation products of medium- and long-chain alkanes that can contribute to SOA in this study. Primary organic aerosol (POA) has been identified to be able to evaporate with dilution; therefore, test cases are developed that treat fractions of POA as semi-volatile, a source of SOA, rather than nonvolatile. While current atmospheric models assume that SOA are liquids into which semi-VOCs undergo equilibrium partitioning and grow the particles, recent laboratory and field experiments have shown otherwise. Hence, a new kinetics-driven partition theory is developed and analyzed against the original formulations. The results from the expanded chemical mechanism to include higher-generation products of alkane in the atmosphere shows that only the tetrahydrofurans will contribute to SOA and those contributions are only a small fraction compared to other SOA sources in the model, contrary to the prediction made based on chamber experiments and box models. In the tests for redistribution of POA as gas-phase parent VOCs sources, POA decreased with no commensurate increase in SOA. This is essentially due to the fact that the amount of mass that the POA can contribute is a small fraction of that already in the gas-phase parent VOC pool. Finally, using the newly developed kinetically determined SOA growth mechanism, to achieve the same level of predicted SOA levels as the original equilibrium approach requires 40-50% of SOA parent species to be allocated to the particle phase. The new formulation of SOA partition behavior based on kinetics will require the measurement of new input data and the corresponding parameterization for models in the future. The implication of this new approach should demand wider attention from the community.
Download or read book Phase Partitioning During the Formation of Secondary Organic Aerosol written by Chen Wang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A sound parameterization of the gas-particle partitioning process is essential for understanding and quantifying secondary organic aerosol (SOA) formation. This thesis aimed to improve the understanding and description of phase partitioning during SOA formation through a combination of both laboratory and modeling studies. Partitioning of organic compounds between gas and particle phase is influenced by the presence of a large quantity of inorganic salts in aerosol, which is known as the salt effect. The salt effects of atmospherically relevant inorganic salts for a large number of organic compounds with various functional groups were measured in this study. The results revealed the importance of both salt species and organic compound identities on the salt effect, with the former as the dominant determinant. Models in predicting salt effect were calibrated and evaluated using the experimental data. Salt effect in mixtures was also investigated, which assists the understanding of salt effect in mixture salt solutions, including aerosols. A new approach for predicting gas-particle partitioning during SOA formation based on quantum chemical calculations was presented, which considers the partitioning species explicitly and captures the dynamic aspects of the aerosol formation processes. The role of different atmospheric parameters and chemical properties (organic loading, liquid water content, salinity, chemical ageing, etc.) was investigated and compared. Performance of the model was found to be comparable to the best currently used group contribution methods. SOA formation from constant emission and oxidation of precursor compounds was simulated to resemble the realistic scenario in the ambient atmosphere. The differential yield that describes the amount of SOA formed from a certain amount of added oxidation products was introduced, which is more relevant for SOA formation in the ambient atmosphere. The necessity of considering kinetic processes in addition to the thermodynamic equilibrium process was also discussed.
Download or read book Investigating Marine Boundary Layer Aerosol Budgets and Variability written by Johannes Karel Christiaan Mohrmann and published by . This book was released on 2016 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine boundary layer (MBL) aerosol particles are an important feature of the climate system due in major part to their effect on marine boundary layer clouds, but the factors controlling their variability are not fully understood. A better understanding of the budget and controlling factors of these aerosol particles is needed to evaluate the effect of anthropogenic perturbations on aerosol concentrations and ultimately cloud radiative properties. Using data primarily collected during the MAGIC field campaign in the northeast Pacific, complemented by aerosol and meteorological reanalysis, we consider a simplified aerosol budget consisting of advection, precipitation loss, wind-mediated sea-surface generation, and entrainment from the lower free-troposphere. A major feature in MBL aerosol variability is the strong seasonal cycle, with concentrations observed to be approximately 50 cm−3 in winter and 100 cm−3 in the summer in the focus region (northeast Pacific). We explore seasonal differences in the concentration of accumulation mode aerosol particle number concentration using a steady-state model, which captures approximately two-thirds of the observed summer-winter difference. We find that precipitation differences account for approximately 53\% of the seasonal difference in aerosol particle concentrations, seasonal differences in advection account for 25%, and wind-driven surface sources and entrainment account for 18% and 4% respectively. Secondary particle formation and growth from smaller modes are not considered. The longitudinal gradient in aerosol particle number concentration is well-reproduced in summer, but overestimated in winter. Sensitivity analysis weighted by estimated variable uncertainty show that uncertainty in aerosol particle advection and free-tropospheric aerosol concentrations are the largest contributors to modeled aerosol uncertainty. On subseasonal timescales, high aerosol concentration events (in the top quartile of 6-hourly means) are found to correlate with shallow, non-precipitating boundary layers with high overlying aerosol concentrations, with no correlation with wind speed; this was observed in both summer and winter.
Download or read book Biogenic Volatile Organic Compounds and Climate Change written by Federico Brilli and published by Elsevier. This book was released on 2024-06-11 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biogenic Volatile Organic Compounds and Climate Change highlights the relationship between climate change and biogenic VOC and the impact they have on each other. Topics include the synthesis and emission of VOC in plants, how they respond to environmental stresses, how sustainable agricultural practices plants can be used to directly impact climate change beyond carbon sequestration, a review of biogenic VOCs as air pollutants, and the impact of biogenic VOC on clouds. This groundbreaking work is essential for anyone in climate change, global warming and cooling, atmospheric chemistry, clouds, fate and transport of chemicals in the atmosphere, air pollution, sustainability or agriculture. - Explains how volatile organic compound (VOC) production and emission in plants can ameliorate the consequences of climate change induced abiotic and biotic stresses - Comprehensively addresses the complex interactions between global warming, atmospheric composition and plant ecology beyond carbon sequestration - Reviews the use of biogenic VOC in sustainability
Download or read book Treatise on Geochemistry written by and published by Newnes. This book was released on 2013-10-19 with total page 14787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated new edition of the widely acclaimed Treatise on Geochemistry has increased its coverage beyond the wide range of geochemical subject areas in the first edition, with five new volumes which include: the history of the atmosphere, geochemistry of mineral deposits, archaeology and anthropology, organic geochemistry and analytical geochemistry. In addition, the original Volume 1 on "Meteorites, Comets, and Planets" was expanded into two separate volumes dealing with meteorites and planets, respectively. These additions increased the number of volumes in the Treatise from 9 to 15 with the index/appendices volume remaining as the last volume (Volume 16). Each of the original volumes was scrutinized by the appropriate volume editors, with respect to necessary revisions as well as additions and deletions. As a result, 27% were republished without major changes, 66% were revised and 126 new chapters were added. In a many-faceted field such as Geochemistry, explaining and understanding how one sub-field relates to another is key. Instructors will find the complete overviews with extensive cross-referencing useful additions to their course packs and students will benefit from the contextual organization of the subject matter Six new volumes added and 66% updated from 1st edition. The Editors of this work have taken every measure to include the many suggestions received from readers and ensure comprehensiveness of coverage and added value in this 2nd edition The esteemed Board of Volume Editors and Editors-in-Chief worked cohesively to ensure a uniform and consistent approach to the content, which is an amazing accomplishment for a 15-volume work (16 volumes including index volume)!
Download or read book Marine Reactive Trace Gases and Their Impacts on Atmospheric Chemistry in the Marine Boundary Layer written by Delaney Brenna Kilgour and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean is a globally significant source of reactive trace gases to the atmosphere, including volatile organic compounds (VOC) and organosulfur molecules like dimethyl sulfide (DMS) and methanethiol (MeSH). The emission and oxidation of these reactive trace gases control oxidant loadings, the formation and growth of secondary aerosol to cloud condensation nuclei sizes, and cloud properties in the marine atmosphere. Recent research has demonstrated an increased variety of trace gases beyond DMS produced via biological, heterogeneous, and photochemical mechanisms at the ocean surface. Additionally, findings within the last five years have shown the dominant impact of multiphase processes on dictating how oceanic emissions of DMS influence climate. This thesis work aims to provide constraints on the composition and yields of marine reactive trace gases produced via biological and heterogeneous oxidation pathways, and insights into their subsequent atmospheric processing and climate impacts through a combination of flow tube, wave channel, and field measurements and box modelling. Particular attention is given to the relative impacts of non-DMS reactive trace gases and the role of cloud processing in controlling the global sulfur budget.Chapter 2 examines the production and emission of organosulfur molecules as a function of ocean biogeochemical variables, with specific focus on MeSH, relative to DMS, during an induced phytoplankton bloom on coastal seawater at the Scripps Institution of Oceanography wave channel. This work shows MeSH is a large contributor to the marine gas-phase sulfur budget and should be included in future global model analyses to accurately portray the production of sulfur dioxide and sulfate aerosol. Chapter 3 describes a set of laboratory experiments probing the production of VOC from ozonolysis of the sea surface microlayer. Yields and chemical composition of VOC are reported and interpreted within the context of analogous measurements of VOC and O3 fluxes from Scripps Pier in La Jolla, California, where the seawater was collected. This work demonstrates that abiotic VOC production can be a significant reactive carbon source to the marine atmosphere even at the lower limit of measured yields. Chapter 4 reports the first collocated measurements of speciated monoterpenes and aerosol chemical composition in the remote marine atmosphere. This dataset reveals that despite their high reactivity and yields of secondary organic aerosol, monoterpenes are a minor contributor to secondary aerosol, relative to the sulfur species, DMS and MeSH, and other measured organics during this study. Lastly, Chapter 5 utilizes collocated measurements of the precursor DMS and oxidized, soluble product hydroperoxymethyl thioformate (HPMTF) to derive the loss rates of HPMTF to boundary layer cloud. This analysis suggests low-level clouds are the controlling variable setting the sulfur budget in this region of the Eastern North Atlantic during the study, and act even more efficiently than what is currently prescribed in global models. By acting as an efficient sink of HPMTF, clouds strongly regulate the production of sulfur dioxide, carbonyl sulfide, and sulfate aerosol. Collectively, the products of this thesis work provide constraints on marine reactive trace gas production, emission, and atmospheric processing to better inform global climate models.
