Investigation Of The Sources And Composition Of Submicron Organic Aerosol Particles In Marine Environments Through Artificial Generation And Atmospheric Measurements

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Investigation of the Sources and Composition of Submicron Organic Aerosol Particles in Marine Environments Through Artificial Generation and Atmospheric Measurements

Author : Amanda A. Frossard
Publisher :
ISBN 13 : 9781303878527
Total Pages : 220 pages
Book Rating : 4.8/5 (785 download)

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Book Synopsis Investigation of the Sources and Composition of Submicron Organic Aerosol Particles in Marine Environments Through Artificial Generation and Atmospheric Measurements by : Amanda A. Frossard

Download or read book Investigation of the Sources and Composition of Submicron Organic Aerosol Particles in Marine Environments Through Artificial Generation and Atmospheric Measurements written by Amanda A. Frossard and published by . This book was released on 2014 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosol particles in the marine boundary layer (MBL) play an important role in the Earth's radiative balance, and recent studies have proposed a variety of interpretations of their sources and compositions. This dissertation improves the characterization of the sources and organic composition of aerosol particles in the MBL. Atmospheric aerosol particles were collected in the MBL of five ocean regions and analyzed using Fourier transform infrared (FTIR) spectroscopy, high resolution time of flight aerosol mass spectrometry (HR-ToF-AMS), HR-ToF-AMS with a light scattering module HR-ToF-AMS (LS-ToF-AMS), and scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure (STXM-NEXAFS) to determine their organic functional group and mass fragment composition. Model ocean systems were used to generate ocean-derived primary marine aerosol particles (gPMA), which include particles resulting from seawater bubble bursting. The methods for measuring the organic composition of gPMA are compared, and the discrepancy between high resolution time of flight aerosol mass spectrometry (HR-ToF-AMS) and Fourier transform infrared (FTIR) spectroscopy measurements is attributed to the refractory nature of organics on sea salt in the HR-ToF-AMS. A method for dehydrating samples prior to analysis by FTIR spectroscopy is also presented. Both ocean-derived and anthropogenic emissions contribute to the organic mass (OM) in the MBL. Primary marine aerosol particles (PMA) were found to have similar compositions to marine saccharides and amino sugars, with 65% hydroxyl, 21% alkane, 6% amine, and 7% carboxylic acid functional groups. Contributions from photochemical reactions add carboxylic acid groups (15%-25%) to the PMA OM. Non-ocean-derived sources include shipping and other anthropogenic combustion emissions that together contribute more than half of the OM in the MBL. Seawater and gPMA have very similar compositions to the ocean-derived marine aerosol (mainly PMA). But there is a slightly larger fraction of alkane functional groups in gPMA from biologically productive seawater (35%) compared to oligotrophic seawater (16%). Surfactants in productive seawater may stabilize bubbles at the sea surface, enhancing drainage of soluble organics from their films before bursting and emitting particles. gPMA has a hydroxyl group absorption peak location characteristic of monosaccharides and disaccharides, while the seawater hydroxyl group peak location is more consistent with polysaccharides. This may result from the polysaccharides preferentially remaining in the seawater during PMA production.

Sources and Composition of Submicron Organic Mass in Marine Aerosol Particles

Author :
Publisher :
ISBN 13 :
Total Pages : 7 pages
Book Rating : 4.:/5 (925 download)

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Book Synopsis Sources and Composition of Submicron Organic Mass in Marine Aerosol Particles by :

Download or read book Sources and Composition of Submicron Organic Mass in Marine Aerosol Particles written by and published by . This book was released on 2014 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies have proposed a variety of interpretations of the sources and composition of atmospheric marine aerosol particles (aMA) based on a range of physical and chemical measurements collected during open-ocean research cruises. To investigate the processes that affect marine organic particles, this study uses the characteristic functional group composition (from Fourier transform infrared (FTIR) spectroscopy) of aMAP from five ocean regions to show that: (i) The organic functional group composition of aMAP that can be identified as atmospheric primary marine (ocean-derived) aerosol (aPMA) is 65"12% hydroxyl, 21"9% alkane, 6"6% amine, and 7"8% carboxylic acid functional groups. Contributions from photochemical reactions add carboxylic acid groups (15%-25%), shipping effluent in seawater and ship emissions add additional alkane groups (up to 70%), and coastal emissions mix in alkane and carboxylic acid groups from coastal pollution sources. (ii) The organic composition of aPMA is nearly identical to model generated primary marine aerosol particles (gPMA) from bubbled seawater (55% hydroxyl, 32% alkane, and 13% amine functional groups), indicating that its overall functional group composition is the direct consequence of the organic constituents of the seawater source. (iii) While the seawater organic functional group composition was nearly invariant across all three ocean regions studied, the gPMA alkane group fraction increased with chlorophyll-a concentrations (r = 0.79). gPMA from productive seawater had a larger fraction of alkane functional groups (35%) compared to gPMA from non-productive seawater (16%), likely due to the presence of surfactants in productive seawater that stabilize the bubble film and lead to preferential drainage of the more soluble (lower alkane group fraction) organic components. gPMA has a hydroxyl group absorption peak location characteristic of monosaccharides and disaccharides, where the seawater OM hydroxyl group peak location is closer to that of polysaccharides. This may result from the larger saccharides preferentially remaining in the seawater during gPMA and aPMA production.

Understanding the Role of Organic Aerosol in the Coastal and Remote Pacic Marine Boundary Layer

Author : Lelia Nahid Hawkins
Publisher :
ISBN 13 : 9781109762990
Total Pages : 366 pages
Book Rating : 4.7/5 (629 download)

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Book Synopsis Understanding the Role of Organic Aerosol in the Coastal and Remote Pacic Marine Boundary Layer by : Lelia Nahid Hawkins

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.

Characterizing the Organic Composition of Marine Aerosol from the North Atlantic to the Oceano Dunes

Author : Savannah Lee Lewis
Publisher :
ISBN 13 :
Total Pages : 179 pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis Characterizing the Organic Composition of Marine Aerosol from the North Atlantic to the Oceano Dunes by : Savannah Lee Lewis

Download or read book Characterizing the Organic Composition of Marine Aerosol from the North Atlantic to the Oceano Dunes written by Savannah Lee Lewis and published by . This book was released on 2022 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosol particles in the marine environment play an important role in the Earth's radiative budget which are affected by the sources and compositions of the aerosol particles. Atmospheric aerosol particles were collected over four cruises in the remote regions of the North Atlantic Ocean and one field experiment from a stationary platform in the Oceano Dunes and were quantified using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Transmission X-Ray Microscopy with Near-Edge Absorption Fine Structure (STXM-NEXAFS) for organic functional groups. X-ray fluorescence (XRF) analyses were used to understand the elemental composition of the Oceano Dunes samples. The four cruises' atmospheric primary marine aerosol (aPMA) organic functional group composition was compared to see whether seasonal and biological changes had an effect. The average composition was 78% hydroxyl, 10% alkane, 6% amine, and 7% carboxylic acid groups, which was consistent with previous marine studies with sources including marine saccharides and amino sugars. The standard deviation within each season was greater than the differences between seasons, showing a limited seasonal response in the organic fraction. Generated primary marine aerosol particles (gPMA), atmospheric aerosol particles, sea-surface microlayer samples, and seawater samples were collected to compare the particle and bulk organic compositional differences as organics rise through the water column and are ejected into the marine boundary layer. The bulk organic composition consisted of the same three organic functional groups (hydroxyl, alkane, and amine groups) that comprised 50-90% of the quantified organic mass, though STXM-NEXAFS did illuminate the particle-to-particle diversity in all sample sources. The sea-surface microlayer and atmospheric aerosol particles were found to have far more variability in composition than generated primary marine aerosol and seawater, which could be attributed to a closer linkage between the organic sources and greater secondary processing within these sample sources than either generated primary marine aerosol or seawater. Coastal aerosol from Oceano Dunes showed a mixture of sources, with the dominant sources being wind-driven dust from the Oceano Dunes, sea salt from sea spray, and marine-derived organics. While this coastal location has recorded PM10 exceedances, the natural sources are unlikely to be a health-risk because they have not been shown to include toxic components.

Chemical Characterization and Source Apportionment of Atmospheric Aerosols in Urban and Rural Regions

Author : Caroline Parworth
Publisher :
ISBN 13 : 9780355594157
Total Pages : 0 pages
Book Rating : 4.5/5 (941 download)

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Book Synopsis Chemical Characterization and Source Apportionment of Atmospheric Aerosols in Urban and Rural Regions by : Caroline Parworth

Download or read book Chemical Characterization and Source Apportionment of Atmospheric Aerosols in Urban and Rural Regions written by Caroline Parworth and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols, or particulate matter (PM), can affect climate through scattering and absorption of radiation and influence the radiative properties, precipitation efficiency, thickness, and lifetime of clouds. Aerosols are one of the greatest sources of uncertainty in climate model predictions of radiative forcing. To fully understand the sources of uncertainty contributing to the radiative properties of aerosols, measurements of PM mass, composition, and size distribution are needed globally and seasonally. To add to the current understanding of the seasonal and temporal variations in aerosol composition and chemistry, this study has focused on the quantification, speciation, and characterization of atmospheric PM in urban and rural regions of the United States (US) for short and long periods of time. In the first two chapters, we focus on 1 month of aerosol and gas-phase measurements taken in Fresno, CA, an urban and agricultural area, during the National Aeronautics and Space Administration's (NASA) field study called DISCOVER-AQ. This air quality measurement supersite included a plethora of highly detailed chemical measurements of aerosols and gases, which were made at the same time as similar aircraft column measurements of aerosols and gases. The goal of DISCOVER-AQ is to improve the interpretation of satellite observations to approximate surface conditions relating to air quality, which can be achieved by making concurrent ground- and aircraft-based measurements of aerosols and gases. We begin in chapter 2 by exploring the urban aerosol and gas-phase dataset from the NASA DISCOVER-AQ study in California. Specifically, we discuss the chemical composition and mass concentration of water-soluble PM2.5 that were measured using a particle-into-liquid sampler with ion chromatography (PILS-IC) in Fresno, California from January 13–February 10, 2013. This data was analyzed for ionic inorganic species, organic acids and amines. Gas-phase species including HNO3 and NH3 were collected with annular denuders and analyzed using ion chromatography. Using the thermodynamic E-AIM model, inorganic particle water mass concentration and pH were calculated for the first time in this area. Organic particle water mass concentration was calculated from [kappa]-Köhler theory. In chapter 3 further analysis of the aerosol- and gas-phase data measured during DISCOVER-AQ was performed to determine the effectiveness of a local residential wood burning curtailment program in improving air quality. Using aerosol speciation and concentration measurements from the 2013 winter DISCOVER-AQ study in Fresno, CA, we investigate the impact of residential wood burning restrictions on fine particulate mass concentration and composition. Key species associated with biomass burning in this region include K+, acetonitrile, black carbon, and biomass burning organic aerosol (BBOA), which represents primary organic aerosol associated with residential wood burning. Reductions in acetonitrile associated with wood burning restrictions even at night were not observed and most likely associated with stagnant conditions during curtailment periods that led to the buildup of this long-lived gas. In chapter 4 we transition to the rural aerosol dataset from the DOE SGP site. We discuss the chemical composition and mass concentration of non-refractory submicron aerosols (NR-PM1) that were measured with an aerosol chemical speciation monitor (ACSM) at the DOE SGP site from November 2010 through June 2012. Positive matrix factorization (PMF) was performed on the measured organic aerosol (OA) mass spectral matrix using a newly developed rolling window technique to derive factors associated with distinct sources, evolution processes, and physiochemical properties. The rolling window approach captured the dynamic variations of the chemical properties of the OA factors over time. Three OA factors were obtained including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a BBOA factor. Sources of NR-PM1 species at the SGP site were determined from back trajectory analyses. NR-PM1 mass concentration was dominated by organics for the majority of the study with the exception of winter, when NH4N33 increased due to transport of precursor species from surrounding urban and agricultural regions and also due to cooler temperatures. Chapter 5 is a continuation of chapter 4, where we will explore the use of the multilinear engine (ME-2) as a factor analysis technique, which is an algorithm used for solving the bilinear model called positive matrix factorization (PMF). The importance of ME-2 and its potential application on the long-term aerosol chemical speciation monitor (ACSM) data collected from the Department of Energy (DOE) Southern Great Plains (SPG) site will be discussed. ME-2 was performed on 19 months of OA mass spectral data obtained from the ACSM at the SGP site. Evaluation of ME-2 results are presented, followed by comparison of ME-2 factor results with corresponding OACOMP factor results reported in chapter 4. We show that ME-2 can determine a biomass burning organic aerosol (BBOA) factor during periods when OACOMP cannot. (Abstract shortened by ProQuest.)

Scientific and Technical Aerospace Reports

Author :
Publisher :
ISBN 13 :
Total Pages : 280 pages
Book Rating : 4.:/5 (3 download)

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Book Synopsis Scientific and Technical Aerospace Reports by :

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Detection and Influence of Biological Aerosols in Marine and Coastal Environments

Author : Brock A. Mitts
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis Detection and Influence of Biological Aerosols in Marine and Coastal Environments by : Brock A. Mitts

Download or read book Detection and Influence of Biological Aerosols in Marine and Coastal Environments written by Brock A. Mitts and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols influence climate by directly scatter radiation and affecting cloud properties and lifetime. Biological aerosols (bioaerosols) act as cloud condensation nuclei and ice nucleating particles (INPs) and can impact human and ecosystem health. Oceans, which cover over 70% of the Earth's surface, comprise an important source of bioaerosols emitted in both primary sea spray aerosol (SSA) particles and formed as secondary organic aerosols (SOA) from biogenic volatile organic compounds (VOCs). However, the influence of marine bioaerosols on clouds and climate remains an area of high uncertainty. In this dissertation, bioaerosols from marine environments were measured in laboratory-based systems and the ambient coastal environment to analyze their impact on cloud formation and on local communities. Studies on the ice nucleating ability of SSA showed supermicron-size SSA particles, rather than submicron, were the predominant source of INPs released from a marine environment. The size of these particles suggests these INPs represented bioaerosols, like marine bacteria, their fragments, or exudates. Bioaerosol emissions in SSA were measured with single-particle fluorescence spectrometry over the course of a mesocosm phytoplankton bloom and showed, for the first time, the fluorescence signature and size distribution of these particles in nascent SSA. To uncover how atmospheric oxidants impact the SSA fluorescence profile, an oxidative flow reactor was used to simulate days of atmospheric aging during a phytoplankton bloom study in an ocean-atmosphere system. This study revealed that aged SSA particles underwent chemical transformations from proteinaceous to humic-like particles, reflected in the loss of protein-like fluorescence and the production of humic-like fluorescence. Applying these online fluorescence methods to aerosols in an urban-coastal environment demonstrated the ability to distinguish and characterize marine and continental air masses. Lastly, we developed a novel system combining a sublimation-condensation flow tube with a matrix-assisted laser desorption ionization matrix and an aerosol time-of-flight mass spectrometer to identify sub-100 nm SOA produced from biogenic VOCs. By improving bioaerosol detection in marine environments and better understanding their ability to seed clouds, the findings from this work enable more accurate representations and parameterizations of marine emissions for global climate models.

Ambient Submicron Particles in North America

Author : Richard Edward Peltier
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (252 download)

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Book Synopsis Ambient Submicron Particles in North America by : Richard Edward Peltier

Download or read book Ambient Submicron Particles in North America written by Richard Edward Peltier and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis improves the understanding of the fate and transport of aerosols in North America. Aerosols play an important role climate modification, visibility, human health, and regulatory compliance. Through multiple aircraft-based and ground-based field campaigns, in situ ambient bulk aerosol concentrations will be determined across geographically diverse regions of the United States. By examining aerosol composition - specifically, inorganic ions and water-soluble organic carbon - as they are transported across the Pacific Ocean, we can observe background concentrations that may contribute to aerosol loading observed in many US communities. Furthermore, the aerosol continues to be modified by anthropogenic and biogenic emissions, dry and wet deposition, and secondary formation and transformation as it is transported across the continent. To capture some of these dynamic changes, aerosol will be extensively measured near the east coast of the US and Canada, and results may show significant anthopogenic, biogenic, and secondary transformation. Many results from the Northeastern United States and Southeastern Canada will be presented, and a special case study discussing acid-catalyzed formation of secondary organic aerosol in the region of northern Georgia, US is discussed. Lastly, through laboratory- and field-based instrument development, a commonly-deployed instrument is modified for improved measurement of organic carbon and results are presented herein.

Direct Measurements of Marine Aerosols to Examine the Influence of Biological Activity, Anthropogenic Emissions, and Secondary Processing on Particle Chemistry

Download Direct Measurements of Marine Aerosols to Examine the Influence of Biological Activity, Anthropogenic Emissions, and Secondary Processing on Particle Chemistry PDF Online Free

Author : Cassandra Jayne Gaston
Publisher :
ISBN 13 : 9781267468598
Total Pages : 294 pages
Book Rating : 4.4/5 (685 download)

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Book Synopsis Direct Measurements of Marine Aerosols to Examine the Influence of Biological Activity, Anthropogenic Emissions, and Secondary Processing on Particle Chemistry by : Cassandra Jayne Gaston

Download or read book Direct Measurements of Marine Aerosols to Examine the Influence of Biological Activity, Anthropogenic Emissions, and Secondary Processing on Particle Chemistry written by Cassandra Jayne Gaston and published by . This book was released on 2012 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols influence global climate directly by scattering and absorbing incoming solar radiation and indirectly by initiating cloud droplet and ice crystal formation; both particle size and chemical composition play a role in these impacts. Particle size and composition constantly evolve due to atmospheric processing. The physicochemical properties of marine aerosols, including sea spray and anthropogenic emissions, are of particular interest since oceans cover over 70% of the Earth's surface. This dissertation aims to probe the role of oceanic biological activity, anthropogenic emissions, and subsequent atmospheric processing on marine particle chemistry by measuring the size-resolved chemistry of individual ambient marine aerosols and laboratory-generated particles using aerosol time-of-flight mass spectrometry (ATOFMS). The impact of biological activity on the mixing-state of sea spray particles was examined by adding biologically-derived organic material and/or phytoplankton cells to seawater then generating particles through bubble bursting. Unique particles characterized by organics, Mg2 and/or Ca2 were detected during these experiments as well as in the ambient atmosphere during periods of elevated biological activity. Additionally, elemental sulfur ions were also detected in ambient marine particles in regions of elevated biological activity at night. These particles were successfully reproduced from bubble bursting experiments suggesting that these particles are directly ejected from the ocean. In addition to sea spray aerosol, the particle chemistry of marine aerosols from anthropogenic sources was also examined during shipboard measurements made during CalNex along the California coast. Soot was dominant in Southern California while organics characterized the particle chemistry in the Sacramento area highlighting regional differences in anthropogenic emissions in California. Further, measurements made at the Port of Los Angeles and those made on the Scripps Pier showed a decline in emissions from ships combusting residual fuel compared to earlier measurements; these results are in compliance with recent regulations requiring ships to combust low sulfur fuel when approaching the California coast. Finally, during the Study of Organic Aerosols in Riverside, CA (SOAR), the dimethyl sulfide (DMS) oxidation product methanesulfonic acid (MSA) was detected in anthropogenic particle types, and was elevated in vanadium-containing emissions characteristic of residual fuel combustion suggesting that anthropogenic particles can enhance the atmospheric processing of marine biogenic emissions.

Characterization of the Molecular Composition of Secondary Organic Aerosols Using High Resolution Mass Spectrometry

Author : Rachel Elizabeth Sellon
Publisher :
ISBN 13 :
Total Pages : 274 pages
Book Rating : 4.:/5 (839 download)

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Book Synopsis Characterization of the Molecular Composition of Secondary Organic Aerosols Using High Resolution Mass Spectrometry by : Rachel Elizabeth Sellon

Download or read book Characterization of the Molecular Composition of Secondary Organic Aerosols Using High Resolution Mass Spectrometry written by Rachel Elizabeth Sellon and published by . This book was released on 2012 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols can affect visibility and the Earth's climate by scattering and absorbing light and they also can have adverse effects on human health. The organic portion of atmospheric aerosols is very complex and is a major fraction of fine particulate matter. High molecular weight (high-MW)/oligomeric organic compounds can make up a large part of this organic fraction and the composition, sources, and formation mechanisms for these compounds are not well understood. This knowledge and understanding is necessary to decrease the uncertainty in the climate affects of aerosols and to improve climate models. This dissertation investigates the composition and formation mechanisms for the high-MW/oligomeric fraction of secondary organic aerosols (SOA) collected in Bakersfield, CA and presents a comparative analysis of chamber and ambient SOA, from both Los Angeles (LA) and Bakersfield, to investigate sources at both locations. A novel sampling technique, nanospray-Desorption Electrospray Ionization (nano-DESI), was used with high resolution mass spectrometry (HR-MS) to determine the molecular formulas of the high molecular weight (HMW)/oligomeric fraction of SOA. Nano-DESI involves direct desorption from the sample surface and was used to limit reactions that can take place with extraction and storage in solvent. The samples were collected in Bakersfield and LA during CalNex 2010. Both Bakersfield and LA are out of compliance with EPA standards of ozone and particulate matter and provide opportunities to examine air masses affected by both anthropogenic and biogenic sources. This dissertation has provided the first evidence of observable changes in the composition of high-MW/oligomeric compounds throughout the day. Using positive mode nano-DESI, afternoon increases in the number of compounds that contain carbon, hydrogen and oxygen (CHO) were observed consistent with photochemistry/ozonolysis as a major source for these compounds. Compounds containing reduced nitrogen groups were dominant at night and had precursors consistent with imine formation products from the reaction of carbonyls and ammonia. In the negative mode, organonitrates (CHON) and nitroxy organosulfates (CHONS) had larger numbers of compounds in the night/morning samples consistent with nitrate radical formation reactions. A subset of the CHONS compounds and compounds containing sulfur (CHOS) had the same composition as known biogenic organosulfates and nitroxy organosulfates indicating contributions from both biogenic and anthropogenic sources to the SOA. This dissertation also provides the first analysis of the high-MW/oligomeric fraction in size resolved samples; the majority of the compounds were found in aerosol diameters between 0.18-1.0 micrometers and the CHON were bimodal with size. Finally, this dissertation presents the first comparative analysis of the overlap in the composition of this fraction of SOA between ambient and chamber samples. Samples collected in Pasadena, LA and Bakersfield were compared with samples collected in a smog chamber using diesel and isoprene sources. The results indicate that diesel had the highest overlap at both sites, Bakersfield samples were more oxidized, and LA showed evidence of a SOA plume arriving from downtown LA. The addition of ammonia to the diesel chamber experiment was necessary to form many of the 2N compounds found in Bakersfield. These results increase our understanding of the types of compounds found in urban environments and give evidence for the timescales of formation reactions in an ambient environment. They show that the majority of the high-MW oligomeric compounds are found in submicron size particles and that the composition of this fraction of SOA varies with aerosol size. Results from the chamber comparisons show that both diesel and isoprene are important sources for these compounds and also that there other sources are present. Future work that combines this type of analysis, in other ambient environments, with studies of the optical properties of aerosols could be used to help improve climate models and to start to close the gap in our understanding of the climate effects of atmospheric aerosols.

Biogeochemistry of Marine Dissolved Organic Matter

Author : Dennis A. Hansell
Publisher : Academic Press
ISBN 13 : 0124071538
Total Pages : 712 pages
Book Rating : 4.1/5 (24 download)

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Book Synopsis Biogeochemistry of Marine Dissolved Organic Matter by : Dennis A. Hansell

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

Composition and Sources of Biogenic Secondary Organic Aerosols in the Southeastern U.S. and Antarctica

Author : Jun Liu
Publisher :
ISBN 13 :
Total Pages : 201 pages
Book Rating : 4.:/5 (14 download)

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Book Synopsis Composition and Sources of Biogenic Secondary Organic Aerosols in the Southeastern U.S. and Antarctica by : Jun Liu

Download or read book Composition and Sources of Biogenic Secondary Organic Aerosols in the Southeastern U.S. and Antarctica written by Jun Liu and published by . This book was released on 2018 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biogenic Secondary Organic Aerosols (bSOA) account for a large fraction of the global aerosols budget, and thus have a significant impact on climate and public health. Observations of bSOA in the southeastern U.S. included Fourier Transform Infrared Spectroscopy (FTIR) and Aerosol Mass Spectrometer (AMS) measurements of submicron mass at Look Rock (LRK), Tennessee, and Centreville (CTR), Alabama. At LRK, Organic mass (OM) sources were apportioned to three factors, including "sulfate-related bSOA" that correlated to sulfate (r=0.72). Single-particle mass spectra also showed three composition types that corresponded to the mass-based factors with spectra cosine similarity of 0.93 and time series correlations of r>0.4. The similarity of the m/z spectra (cosine similarity=0.97) and the time series correlation (r=0.80) of the "sulfate-related bSOA" to the sulfate-containing single-particle type provide evidence for particle composition contributing to selective uptake of isoprene oxidation products onto sulfate particles. NOx had nighttime-to-early-morning peaks 3~10 times higher at CTR than at LRK, but OM sources identified by FTIR had three very similar factors at both sites including Biogenic Organic Aerosols (BOA). The BOA spectrum from FTIR is similar (cosine similarity > 0.6) to that of lab-generated particle mass from isoprene and monoterpene with NOx. NOx was correlated with FTIR-BOA and AMS related biogenic factors for NOx concentrations higher than 1 ppb at both sites, producing 0.5 to 1 [mu]g m-3 additional biogenic OM for each 1 ppb increase of NOx. Submicron organic mass (OM), particle number, and cloud condensation nuclei concentrations were measured at a costal Antarctica site and were found to be highest in summer. Natural sources that included marine sea spray and seabird emissions contributed 56% of OM in austral summer but only 3% in austral winter. Fourier transform infrared spectra showed the natural sources of organic aerosol were characterized by amide group absorption, which may be from seabird populations. Carboxylic acid group contributions from natural sources were correlated to incoming solar radiation, indicating both seasonal sources and likely secondary reactions.

The Chemical Composition of the Atmospheric Aerosol

Author : Kenneth A. Rahn
Publisher :
ISBN 13 :
Total Pages : 296 pages
Book Rating : 4.:/5 (319 download)

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Book Synopsis The Chemical Composition of the Atmospheric Aerosol by : Kenneth A. Rahn

Download or read book The Chemical Composition of the Atmospheric Aerosol written by Kenneth A. Rahn and published by . This book was released on 1976 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Oceanic Whitecaps

Author : E.C. Monahan
Publisher : Springer Science & Business Media
ISBN 13 : 9789027722515
Total Pages : 316 pages
Book Rating : 4.7/5 (225 download)

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Book Synopsis Oceanic Whitecaps by : E.C. Monahan

Download or read book Oceanic Whitecaps written by E.C. Monahan and published by Springer Science & Business Media. This book was released on 1986-04-30 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: While various volumes havepreviously been de bable, answer to this question lies in the obser vation that while whitecaps are some of the voted to such topics as droplets and bubbles, it is our conceit that this is the first volume dedi most apparent features associated with high sea cated to the description of the phenomenon states, they have also pro\'ed to be someofthe of oceanic whitecapping, and to a considera most difficult objects to measure and describe tion of the role these whitecapsplay in satellite quantitatively, and while scientists as a group marine remote sensing, in sea-salt aerosol gene may like to tackle difficult problems, we ration, and in a broad range ofother sea surface should not be accused ofundue modesty when processes. This observation, reOecting in part we observe that as a group we also have a finite the relatively modest attention paid until re tolerance for frustration and ahuman,perhaps cently by the scientific community to white aesthetic, prejudice in favour ofnatural pheno caps, is noteworthy when one considers that mena that are amcnable to detailed description. collectively whitecaps are to thegeneral public It is appropriate to note that Professor Wood one of the most striking features of the sea cock, to whom this volume is dedicated, ap scape.

Advances in Measurements of the Properties of Aerosol Particles

Author : Emma Tackman
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (138 download)

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Book Synopsis Advances in Measurements of the Properties of Aerosol Particles by : Emma Tackman

Download or read book Advances in Measurements of the Properties of Aerosol Particles written by Emma Tackman and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol particles are a diverse class of materials that permeate the atmosphere with implications for global climate and human health. Atmospheric aerosols are released into the environment from many sources and continue to undergo atmospheric processing which introduces further variation into particle populations. This surfeit of sources and atmospheric trajectories leads to a wide variety in the properties in aerosol particles such as composition, shape, size, morphology, and reactivity. The methods measuring properties of aerosol particles is itself an important and developing field of study with direct applications in bettering our understanding of aerosol behaviors and atmospheric chemical systems. This work presents a critical analysis of existing microscopy-based measurements and provides new methods, applications, and recommendations for improving the assessment of aerosol properties. Chemical properties of aerosol particles include aqueous particle acidity and the O:C ratio of organic constituents. A new method for measuring the internal pH of aqueous aerosol microdroplets was developed and presented here using carbon quantum dots as a pH sensitive fluorophore. This technique was validated using a complex organic mixture representing various functional groups found in atmospheric organic material. The influence of organic O:C ratio on phase separation for proxy organic/inorganic mixed aerosol particles was assessed for microdroplets and nanoparticles. For optical microscope experiments, sucrose was added to organic/inorganic mixtures to systematically increase the O:C ratio of the system and was observed to suppress phase separation. Similarly, particles made up of combinations of carboxylic acids at particular O:C ratios and inorganic salts are analyzed using TEM for size dependence of phase separation at the nanoscale. Generally, large particles are able to phase separate while small particles remain homogeneous, or well mixed, and the transition region between the two regimes was examined. TEM is used in several studies to consider aerosol particle spreading and morphology at atmospherically relevant sizes. Inorganic particles were found to spread along the surface of a substrate. Particles with an organic coating also spread on the substrate but additionally lost volume, possibly due to outgassing of residual volatile species in storage or physical deformation during the impaction process. Results were compared to measurements of the same particles suspended in a gas flow and sizing discrepancies between the two methods were found, mostly attributed to the presence of a substrate in microscope assays. Further, the influence of generation parameters on the final morphologies of particles was determined for particles made under low and high relative humidity conditions with wet and dry seed particles. Wet seeds were found to restructure due to humidity cycling and spread less on the surface than dry seeds, while wet and dry coated particles were influenced similarly by the impaction process. Wet seeded organic particles also showed a new textured morphology, emphasizing the utility of microscope measurements of individual aerosol particles.

Advances and Applications of Mass Spectral Techniques for the Characterization of Atmospheric Aerosol Particles

Author : Lindsay Erighn Hatch
Publisher :
ISBN 13 : 9781267646781
Total Pages : 172 pages
Book Rating : 4.6/5 (467 download)

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Book Synopsis Advances and Applications of Mass Spectral Techniques for the Characterization of Atmospheric Aerosol Particles by : Lindsay Erighn Hatch

Download or read book Advances and Applications of Mass Spectral Techniques for the Characterization of Atmospheric Aerosol Particles written by Lindsay Erighn Hatch and published by . This book was released on 2012 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol particles are ubiquitous in the atmosphere and induce significant impacts on human health and climate that depend on their physical and chemical properties, such as size, composition, and mixing state (chemical associations). Measurements of aerosol composition at the single-particle level are necessary to better understand these effects. Aerosol time-of-flight mass spectrometry (ATOFMS) is able to monitor the size and chemical composition of individual particles in real time. In this doctoral research, ATOFMS analysis was extended to identify new mass spectral markers and improve the potential for quantitative measurements. Development of novel instrumentation was also undertaken. Ion markers indicative of organosulfate compounds were identified in ATOFMS mass spectra collected in Atlanta, GA. In this study, the mixing state and temporal behavior of particulate organosulfate compounds were observed for the first time. Organosulfates were overwhelmingly detected in carbonaceous submicron particles and the temporal trends indicated that they likely formed by the daytime oxidation of isoprene followed by aqueous reaction with sulfate overnight. These results highlight the roles of mixing state and multi-phase reactivity on the formation of secondary organic aerosols. ATOFMS measurements of thermally-conditioned aerosol residuals obtained during the 2005 Study of Organic Aerosols in Riverside, CA were analyzed to determine the impacts of atmospheric aging on the laser desorption/ionization process. Coatings of secondary species suppressed the ionization efficiency, thereby impacting the mass spectral peak areas; however, a novel analysis method was found to correct these artifacts and produced strong agreement with collocated quantitative instrumentation. This new analysis technique was then applied to investigate the mixing-state dependence of aerosol volatility observed in Riverside. It was observed that particulate nitrate evaporated at different temperatures from different particle types (e.g., organic vs. biomass burning), which may influence the regional transport of nitrate species. ATOFMS provides important insights into size-resolved particle sources; however it heavily fragments most organic species, resulting in loss of the molecular information. Therefore, a novel chemical ionization mass spectrometer was developed to better characterize the molecular organic aerosol constituents. In particular, an ion funnel was incorporated into a home-built proton-transfer-reaction mass spectrometer. Initial characterization studies and ion simulations indicated that the ion funnel can provide high-efficiency ion transfer from the ionization region to the mass spectrometer. These results demonstrate the potential for this instrument to ultimately achieve highly sensitive analyses of organic aerosols.

Investigations Into Biological Influences on the Carbon Isotopic Composition (d13C) of Nascent Sea Spray Aerosol and Ocean-Aerosol Transfer of Organic Material

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Author : Daniel Robert Crocker
Publisher :
ISBN 13 :
Total Pages : 163 pages
Book Rating : 4.:/5 (129 download)

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Book Synopsis Investigations Into Biological Influences on the Carbon Isotopic Composition (d13C) of Nascent Sea Spray Aerosol and Ocean-Aerosol Transfer of Organic Material by : Daniel Robert Crocker

Download or read book Investigations Into Biological Influences on the Carbon Isotopic Composition (d13C) of Nascent Sea Spray Aerosol and Ocean-Aerosol Transfer of Organic Material written by Daniel Robert Crocker and published by . This book was released on 2021 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols remain the largest uncertainty in assessments of the anthropogenic influence on Earth's radiative budget. Aerosols affect Earth's radiative budget directly, by reflecting and absorbing incoming solar radiation, and indirectly, by serving as nuclei for water and ice cloud formation. Current estimates of anthropogenic impacts on the direct and indirect aerosol effects are hindered by an inadequate understanding of how naturally produced aerosols contribute to both processes. Sea spray aerosol (SSA), formed by oceanic wave breaking, represents the largest source of natural aerosol to the atmosphere by mass. The climate-relevant properties of SSA, such as hygroscopicity, reflectivity, and ice nucleation ability, are highly dependent on the amount and composition of the organic material transferred from the seawater into these aerosols. The composition of this organic material is strongly influenced by microbial activity in the seawater, highlighting the importance of employing new techniques to examine the impact of oceanic biological activity on the organic material transferred into SSA. Carbon isotopic analysis has been frequently employed to differentiate between anthropogenic and natural sources of aerosol carbon, but has not previously been applied to study ocean-aerosol transfer of organic material. In my dissertation work, I measured carbon isotopic compositions (d13C) of seawater and SSA organic material during two laboratory phytoplankton blooms, identifying an increased contribution of "freshly-produced" carbon to SSA, strongly controlled by the microbial loop. I further demonstrate that not accounting for this biological influence on the d13C value of nascent SSA can lead to significant underestimates in the contribution of anthropogenic aerosol carbon to the marine environment (Chapter 2). Building from this work, I investigated differences between submicron and supermicron SSA during a wave channel mesocosm experiment. The stark differences between these two SSA fractions, with supermicron SSA heavily influenced by biological activity and submicron SSA primarily influenced by surface-active anthropogenic compounds originating from the coastal seawater, reveals the importance of biology and ocean-aerosol transfer processes on SSA organic composition and d13C (Chapter 3). Finally, I explored biologically induced changes in seawater submicron particulates (SMPs) in the bulk seawater and SSML to better understand how seawater biology may influence the transfer of ice nucleating entities into SSA (Chapter 4).