Download or read book Secondary Marine Aerosol written by Kathryn J. Mayer and published by . This book was released on 2021 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol-cloud interactions are one of the largest sources of uncertainty in our understanding of the Earth's climate system. In order to develop better predictive models and understand how the climate will respond to future changes in atmospheric composition, we must determine the sources and nature of aerosols which serve as cloud condensation nuclei (CCN), thus influencing the properties of clouds. Oceans cover 70% of the Earth's surface and represent a major source of atmospheric aerosols. Sea spray aerosol (SSA) is formed by the action of breaking waves, whereas secondary marine aerosols (SMA) are formed from the oxidation products of gases emitted from the oceans. Biological activity in seawater (i.e. the life, death, and interactions of marine phytoplankton, bacteria, and viruses) can significantly affect the chemical composition of SSA through processing of dissolved organic matter and SMA through the emission of volatile gases. This dissertation investigates the cloud-relevant properties of SSA and SMA generated using ocean-atmosphere simulators in the laboratory, with a specific emphasis on the influence of biological activity in seawater on the properties of these aerosols. For the first time, SMA was produced from the oxidation of the headspace gases of a phytoplankton bloom grown in natural seawater, enabling measurements of its chemical composition and CCN activity. Overall, these studies show that the formation and properties of SMA are much more sensitive to biological activity in seawater than SSA. In addition, the chemical composition of SMA is highly dependent on the extent of photochemical oxidation, with a distinct shift from organic-rich to sulfate-rich composition in response to increased atmospheric aging. This change in SMA composition leads to a significant change in its hygroscopicity. These results suggest that the properties of SMA evolve temporally in the atmosphere, which has implications for CCN concentrations and cloud properties over the oceans.

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 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 Chemistry of the Upper and Lower Atmosphere written by Barbara J. Finlayson-Pitts and published by Elsevier. This book was released on 1999-11-17 with total page 993 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here is the most comprehensive and up-to-date treatment of one of the hottest areas of chemical research. The treatment of fundamental kinetics and photochemistry will be highly useful to chemistry students and their instructors at the graduate level, as well as postdoctoral fellows entering this new, exciting, and well-funded field with a Ph.D. in a related discipline (e.g., analytical, organic, or physical chemistry, chemical physics, etc.). Chemistry of the Upper and Lower Atmosphere provides postgraduate researchers and teachers with a uniquely detailed, comprehensive, and authoritative resource. The text bridges the "gap" between the fundamental chemistry of the earth's atmosphere and "real world" examples of its application to the development of sound scientific risk assessments and associated risk management control strategies for both tropospheric and stratospheric pollutants. - Serves as a graduate textbook and "must have" reference for all atmospheric scientists - Provides more than 5000 references to the literature through the end of 1998 - Presents tables of new actinic flux data for the troposphere and stratospher (0-40km) - Summarizes kinetic and photochemical date for the troposphere and stratosphere - Features problems at the end of most chapters to enhance the book's use in teaching - Includes applications of the OZIPR box model with comprehensive chemistry for student use

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 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 Marine Organic Aerosols and Their Implication to Air Quality written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The global marine sources of organic carbon (OC) are estimated here using a physically-based parameterization for the emission of marine isoprene and primary organic matter. The emission model developed in this study allowed us, for the first time, to explore the relative contributions of sub- and super-micron organic matter and phytoplankton-produced secondary organic aerosol (SOA) to the total OC fraction of marine aerosol. New laboratory measurements of isoprene production by several abundant phytoplankton species under a range of environmental conditions were scaled up, with the help of satellite products, to infer the total annual mean ocean isoprene emissions of 0.92 Tg C yr-1. The sensitivity studies using different schemes for the euphotic zone depth and ocean phytoplankton speciation produced the upper and the lower range of marine-isoprene emissions of 0.31 to 1.09 Tg C yr-1, respectively. Empirical relationships between emissions of water soluble (WSOM) and water insoluble (WIOM) organic matter (OM) and chlorophyll a concentration were used to estimate the total primary sources of oceanic sub- and super-micron OC of 1.26 and 19.01 Tg C yr-1, respectively. Using a fixed 3% mass yield for the conversion of isoprene to SOA, our emission simulations show minor (less than 0.2%) contribution of ocean produced isoprene to the total marine source of OC. However, our model calculations also indicate that over the tropical waters, marine isoprene-derived SOA could contribute over 40% of the total monthly-averaged sub-micron OC fraction of marine aerosol. The estimated contribution of ocean-isoprene SOA to hourly averaged sub-micron marine OC fluxes is even higher, reaching 100% over the vast regions of the oceans during the midday hours. As it is widely believed that sub-micron OC has the potential to influence the cloud droplet activation of marine aerosols, our findings suggest that marine sources of SOA could play critical role in modulating properties of shallo.

Download or read book Atmospheric Multiphase Chemistry written by Hajime Akimoto and published by John Wiley & Sons. This book was released on 2020-03-27 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important guide that highlights the multiphase chemical processes for students and professionals who want to learn more about aerosol chemistry Atmospheric Multiphase Reaction Chemistry provides the information and knowledge of multiphase chemical processes and offers a review of the fundamentals on gas-liquid equilibrium, gas phase reactions, bulk aqueous phase reactions, and gas-particle interface reactions related to formation of secondary aerosols. The authors—noted experts on the topic—also describe new particle formation, and cloud condensation nuclei activity. In addition, the text includes descriptions of field observations on secondary aerosols and PM2.5. Atmospheric aerosols play a critical role in air quality and climate change. There is growing evidence that the multiphase reactions involving heterogeneous reactions on the air-particle interface and the reactions in the bulk liquid phase of wet aerosol and cloud/fog droplets are important processes forming secondary aerosols in addition to gas-phase oxidation reactions to form low-volatile compounds. Comprehensive in scope, the book offers an understanding of the topic by providing a historical overview of secondary aerosols, the fundamentals of multiphase reactions, gas-phase reactions of volatile organic compounds, aqueous phase and air-particle interface reactions of organic compound. This important text: Provides knowledge on multiphase chemical processes for graduate students and research scientists Includes fundamentals on gas-liquid equilibrium, gas phase reactions, bulk aqueous phase reactions, and gas-particle interface reactions related to formation of secondary aerosols Covers in detail reaction chemistry of secondary organic aerosols Written for students and research scientists in atmospheric chemistry and aerosol science of environmental engineering, Atmospheric Multiphase Reaction Chemistry offers an essential guide to the fundamentals of multiphase chemical processes.

Download or read book Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this DOE project the improvements to parameterization of marine primary organic matter (POM) emissions, hygroscopic properties of marine POM, marine isoprene derived secondary organic aerosol (SOA) emissions, surfactant effects, new cloud droplet activation parameterization have been implemented into Community Atmosphere Model (CAM 5.0), with a seven mode aerosol module from the Pacific Northwest National Laboratory (PNNL)'s Modal Aerosol Model (MAM7). The effects of marine aerosols derived from sea spray and ocean emitted biogenic volatile organic compounds (BVOCs) on microphysical properties of clouds were explored by conducting 10 year CAM5.0-MAM7 model simulations at a grid resolution 1.9° by 2.5° with 30 vertical layers. Model-predicted relationship between ocean physical and biological systems and the abundance of CCN in remote marine atmosphere was compared to data from the A-Train satellites (MODIS, CALIPSO, AMSR-E). Model simulations show that on average, primary and secondary organic aerosol emissions from the ocean can yield up to 20% increase in Cloud Condensation Nuclei (CCN) at 0.2% Supersaturation, and up to 5% increases in droplet number concentration of global maritime shallow clouds. Marine organics were treated as internally or externally mixed with sea salt. Changes associated with cloud properties reduced (absolute value) the model-predicted short wave cloud forcing from -1.35 Wm-2 to -0.25 Wm-2. By using different emission scenarios, and droplet activation parameterizations, this study suggests that addition of marine primary aerosols and biologically generated reactive gases makes an important difference in radiative forcing assessments. All baseline and sensitivity simulations for 2001 and 2050 using global-through-urban WRF/Chem (GU-WRF) were completed. The main objective of these simulations was to evaluate the capability of GU-WRF for an accurate representation of the global atmosphere by exploring the most accurate configuration of physics options in GWRF for global scale modeling in 2001 at a horizontal grid resolution of 1° x 1°. GU-WRF model output was evaluated using observational datasets from a variety of sources including surface based observations (NCDC and BSRN), model reanalysis (NCEP/ NCAR Reanalysis and CMAP), and remotely-sensed data (TRMM) to evaluate the ability of GU-WRF to simulate atmospheric variables at the surface as well as aloft. Explicit treatment of nanoparticles produced from new particle formation in GU-WRF/Chem-MADRID was achieved by expanding particle size sections from 8 to 12 to cover particles with the size range of 1.16 nm to 11.6m. Simulations with two different nucleation parameterizations were conducted for August 2002 over a global domain at a 4ð by 5ð horizontal resolution. The results are evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as satellite and reanalysis data. We have also explored the relationship between clean marine aerosol optical properties and ocean surface wind speed using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses were carried out over 15 regions selected to be representative of different areas of the global ocean for the time period from June 2006 to April 2011. We show that for very low (less than 4 m s-1) and very high (more than 12 m s-1) wind speed conditions the mean CALIPSO-derived aerosol optical depth (AOD) has little dependency on the surface wind speed. For an intermediate (between 4 and 12 m s-1) marine AOD was linearly correlated with the surface wind speed values, with a slope of 0.0062 s m-1. Results of our study suggest that considerable improvements to both optical properties of marine aerosols and their production mechanisms can be ach ...

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.

Download or read book Biogenic Sulfur in the Environment written by Eric S. Saltzman and published by . This book was released on 1989 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Features state-of-the-art research on the fate and origin of natural (as opposed to pollutant) sulfur compounds, specifically, the cycling of biologically produced sulfur throughout the environment. Covers terrestrial and freshwater systems: emissions and transformations, oceans: distributions, biological transformations, and chemical transformations, and atmosphere: distribution, gas-phase transformations, and aqueous-phase transformations. Analytical techniques and up-to-date bibliographies are included as well as new research results never before published.

Download or read book The Role of Air Sea Exchange in Geochemical Cycling written by Patrick Buat-Ménard and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book arises from a NATO-sponsored Advanced Study Institute on 'The Role of Air-Sea Exchange in Geochemical Cycling' held at Bombann@§. near Bordeaux, France. from 16 to 27 September 1985. The chapters of the book are the written versions of the lectures given at the Institute. The aim of the book is to give a comprehensive up-to-date coverage of the subject. presented in a teaching mode. The chapters contain much recent research material and attempt to give the reader an understanding of how the role of air-sea exchange in geochemical cycling can be quantitatively assessed. In the last decade, major advances in the fields of marine and atmospheric chemistry have underlined the role of physical, chemical and biological processes at and near the air-sea interface in a number of geochemical cycles (C. S, N, metals etc ... ). Further, there is strong concern over the anthropogenic perturbation of these cycles on both regional and global scales. The first part of the book (Chapters 1 to 8) provides a review of topics fundamental to such studies. These topics include concepts in geochemical modelling, assessment of atmospheric transport from sources to the oceans. description of mixing and transport processes within the ocean for both dissolved and particulate materials, quantification of air-sea fluxes for both gases and particles, photochemical transformations in the atmospheric and oceanic boundary layers.

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.

Download or read book Characterization of Secondary Organic Aerosols in the Atmosphere by Using Mass Spectrometric Approaches written by Farhat Yasmeen and published by . This book was released on 2010 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol. The chemical composition of SOA is highly uncertain as it depends on different ongoing chemical and physical processes of biogenic volatile organic compounds (BVOC) and anthropogenic volatile organic compounds in the atmosphere. The research performed within the frame of this doctoral thesis is focused on the characterization of SOA produced from BVOC under a variety of atmospheric reactions resorting to mass spectrometric approaches. In a first study, the aqueous-phase oligomer formation of a major atmospheric photooxidation product, i.e., methylglyoxal, has been investigated to explore an additional pathway producing SOA through cloud processes during night-time. A second study deals with the chemical characterization (sulfate and organic matter) of marine aerosols. methanesulfonic acid was the dominating organic compound in in the fine size fraction of aerosol. A third study concerns the structural characterization of a dimeric [alpha]- and [beta]-pinene SOA product. It is proposed that diaterpenylic acid is a key monomeric unit for dimers of the ester type. A fourth study deals with the chemical characterization by fragmentation of major terpenoic acids in ambient fine aerosols from a rural site. Emphasis is given to the mass spectrometric differentiation of isobaric terpenoic acids that occur in fine forest aerosol. This thesis presents results on aerosol characterization from a wide range of parent organic compounds under a variety of atmospheric conditions.

Download or read book Ocean Atmosphere Interactions of Gases and Particles written by Peter S. Liss and published by Springer. This book was released on 2013-12-18 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans and atmosphere interact through various processes, including the transfer of momentum, heat, gases and particles. In this book leading international experts come together to provide a state-of-the-art account of these exchanges and their role in the Earth-system, with particular focus on gases and particles. Chapters in the book cover: i) the ocean-atmosphere exchange of short-lived trace gases; ii) mechanisms and models of interfacial exchange (including transfer velocity parameterisations); iii) ocean-atmosphere exchange of the greenhouse gases carbon dioxide, methane and nitrous oxide; iv) ocean atmosphere exchange of particles and v) current and future data collection and synthesis efforts. The scope of the book extends to the biogeochemical responses to emitted / deposited material and interactions and feedbacks in the wider Earth-system context. This work constitutes a highly detailed synthesis and reference; of interest to higher-level university students (Masters, PhD) and researchers in ocean-atmosphere interactions and related fields (Earth-system science, marine / atmospheric biogeochemistry / climate). Production of this book was supported and funded by the EU COST Action 735 and coordinated by the International SOLAS (Surface Ocean- Lower Atmosphere Study) project office.

Download or read book Atmospheric Aerosols written by Rekha Kale and published by Scitus Academics LLC. This book was released on 2015-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric Aerosols is a vital problem in current environmental research due to its importance in atmospheric optics, energetics, radiative transfer studies, chemistry, climate, biology and public health. Aerosols can influence the energy balance of the terrestrial atmosphere, the hydrological cycle, atmospheric dynamics and monsoon circulations. Because of the heterogeneous aerosol field with large spatial and temporal variability and reduction in uncertainties in aerosol quantification is a challenging task in atmospheric sciences. Keeping this in view the present study aims to assess the impact of aerosols on coastal Indian station Visakhapatnam and the adjoining Bay of Bengal. An aerosol is a colloid of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or not. Examples of natural aerosols are fog, forest exudates and geyser steam.

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.