Abstract: This tutorial is the first of two that introduce the broad field of aerosol science. We begin with the behavior of individual particles to understand how they behave in the environment, and the physical principles on which most aerosol measurements are based. The drag forces that act on a particle determine its settling velocity and whether it is able to follow the flow of a gas. Several different models describe the drag forces: Stokes law applies for spherical particles moving at modest velocities, though a slip correction must be introduced to account for non-continuum effects for particles small compared to the mean-free-path of the gas molecules. Other corrections are required if the velocity becomes large enough the fluid inertia affects the motion. Knowledge of these scaling principles makes it possible to relate particle behavior in seemingly disparate systems, and make it possible to determine particle size. The drag forces also determine Brownian motion, and, hence, affect their deposition and losses in the respiratory tract, in sampling systems, and in filters, causing aerosol filtration to be more effective than filtration of particles from liquid media. We will briefly look at how this aerodynamic behavior is employed in determining particle size in a wide range of instruments, including the migration of charged particles in mobility analyzers.

Bio: Richard C. Flagan is the Irma and Ross McCollum/William H. Corcoran Professor of Chemical Engineering and Environmental Science and Engineering at the California Institute of Technology. He has served as president of AAAR and editor-in-chief of Aerosol Science and Technology. His research spans the field of aerosol science, including atmospheric aerosols, aerosol instrumentation, aerosol synthesis of nanoparticles and other materials, and bioaerosols. His many contributions to the field of aerosol science have been acknowledged with the Sinclair Award of the AAAR and the Fuchs Award. He is a member of the National Academy of Engineering.

Abstract: Chemical transport models (CTMs) are numerical simulations representing the interplay of emissions, chemistry, transport, microphysics, and deposition that determine the behavior of atmospheric aerosols. As research tools, they play several important roles: assessing the significance of newly discovered or hypothesized processes in an atmospheric context, testing our knowledge of aerosol behavior against ambient observations, and predicting the impacts of policy decisions. Conceptually, they are simple mass and population balances. Complexity arises from several factors: the chemical and physical interactions of many dozen species; transport across a three-dimensional grid representing an urban airshed, a geographic region or even the entire globe; and the numerical approximations required to solve the resulting equations efficiently. This tutorial will provide an overview of the essential components of CTMs, surveying the major algorithms for representing aerosol emissions, chemistry, microphysics, phase partitioning, transport, and deposition. Special focus will be paid to numerical algorithms for representing aerosol size distributions and their evolution via the microphysical processes of condensation, coagulation, and nucleation.

Bio: Peter J. Adams is a professor at Carnegie Mellon University with a joint appointment between the Department of Civil and Environmental Engineering and the Department of Engineering and Public Policy. He earned his bachelor's degree in chemical engineering from Cornell University, followed by a master's and then PhD in chemical engineering at the California Institute of Technology. His research interests include aerosol-climate interactions, global and regional aerosol modeling and the development of aerosol microphysical simulations in climate models. Dr. Adams received the Sheldon K. Friedlander Award in 2004 from AAAR.

Abstract: From an aerosols standpoint, the goal of inhalation toxicology studies and other studies involving environmental chambers is to create a stable aerosol over time in terms of both a desired concentration level and size distribution. This tutorial will provide a detailed overview of aerosol generation and sampling methods, as well as chamber design, for inhalation toxicology and other chamber studies involving the production and measurement of an aerosol. Both the favorable and unfavorable attributes of a variety of aerosol generation techniques for inorganic, organic, and fibrous particles will be described. A special emphasis will be placed on recent devices designed specifically to produce nanoparticle aerosols. Different chamber designs will be discussed in terms of their capabilities to provide spatially homogenous aerosol concentrations. Entire chamber systems for producing and measuring an aerosol will also be described to emphasize airflow considerations and the application of feedback control to stabilize aerosol concentrations.

Bio: Patrick O'Shaughnessy is Professor in the department of Occupational & Environmental Health at the University of Iowa where he also holds a joint appointment with the department of Civil & Environmental Engineering. He has taught a range of courses including air pollution control technology, environmental health, and statistics for experimenters. He has been a member of the AAAR since 1999 where he has served as chair of the Health Related Aerosols committee. His research has involved over twenty years of experience collaborating on inhalation toxicology studies involving asbestos, silica, organic aerosols and nanoparticles, as well as supervising studies involving exposure assessments of aerosols in occupational settings and ambient environments.

Abstract: Studying the microphysics and chemistry of atmospheric aerosols at the single particle level allows for physical parameters to be found with high accuracy and precision. This tutorial will discuss methods for determining the size and refractive index of single aerosol droplets using (i) whispering gallery modes (WGMs) and (ii) angular light scattering (phase functions). After reviewing the relevant aspects of Mie theory, the fitting of WGMs measured in various experiments will be discussed. We will proceed through the entire fitting process and examine some of the common difficulties, limitations, and pitfalls. Several data sets from the literature will be fitted. The Fortran code used for the fitting is freely available so attendees can repeat all of the examples in this section. For the analysis of phase functions, the focus will be on droplets whose composition changes with size and the optimal fitting process for such a system. The effect of beam-shape on phase function fitting will also be briefly discussed.

Bio: Thomas Preston is an Assistant Professor in the Department of Chemistry and the Department of Atmospheric and Oceanic Sciences at McGill University. He received a PhD from the University of British Columbia and completed a NSERC Postdoctoral Fellowship at the University of Bristol. His research focuses on the optical trapping and spectroscopy of single aerosol particles.

Abstract: This tutorial continues the basic introduction to aerosol science. In this session we focus on developing the tools to describe the dynamics of aerosol populations. An aerosol is an ensemble of particles in a gas, and the particles are distributed over a range of sizes. Therefore, they must be represented by a particle size distribution. We will discuss the representation of aerosol populations as size distributions, their graphical representation, and models such as the log normal-distribution. Condensation and evaporation of volatile species onto particles determines their growth in the atmosphere, and efficient counting of particles too small to detect optically in condensation particle counters. Both continuum and non-continuum effects must again be considered, as must the surface tension which governs particle activation, initial activation, and the possibility of nucleating new particles from the vapor phase. These processes also alter the shape of the size distribution. Particle-particle collisions lead to coagulation, which further alters the size distribution. We will examine how these diverse processes are combined to describe the population dynamics for aerosol systems.

Bio: Richard C. Flagan is the Irma and Ross McCollum/William H. Corcoran Professor of Chemical Engineering and Environmental Science and Engineering at the California Institute of Technology. He has served as president of AAAR and editor-in-chief of Aerosol Science and Technology. His research spans the field of aerosol science, including atmospheric aerosols, aerosol instrumentation, aerosol synthesis of nanoparticles and other materials, and bioaerosols. His many contributions to the field of aerosol science have been acknowledged with the Sinclair Award of the AAAR and the Fuchs Award. He is a member of the National Academy of Engineering.

Abstract: Since the mid-1980s, airborne and ground measurements have been widely used to provide comprehensive characterization of atmospheric composition and processes. Field campaigns have generated a wealth of in-situ data and have grown considerably over the years in terms of both the number of measured parameters and the data volume. This can largely be attributed to the rapid advances in instrument development and computing power. The users of field data may face a number of challenges spanning data access, understanding, and proper use in scientific analysis. This tutorial is designed to provide an introduction to using data sets, with a focus on airborne measurements, for atmospheric research. The first part of the tutorial provides an overview of airborne measurements and data discovery. This will be followed by a discussion on the understanding of airborne data files. An actual data file will be used to illustrate how data are reported, including the use of data flags to indicate missing data and limits of detection. Retrieving information from the file header will be discussed, which is essential to properly interpreting the data. Field measurements are typically reported as a function of sampling time, but different instruments often have different sampling intervals. To create a combined data set, the data merge process (interpolation of all data to a common time base) will be discussed in terms of the algorithm, data merge products available from airborne studies, and their application in research. Statistical treatment of missing data and data flagged for limit of detection will also be covered in this section. These basic data processing techniques are applicable to both airborne and ground-based observational data sets. Finally, the recently developed Toolsets for Airborne Data (TAD) will be introduced. TAD (tad.larc.nasa.gov) is an airborne data portal offering tools to create user defined merged data products with the capability to provide descriptive statistics and the option to treat measurement uncertainty.

Bio: Gao Chen is a physical scientist at the NASA Langley Research Center in Hampton Virginia. Dr. Chen has 20+ years of experience in interpretive analysis of the in situ observations from both airborne and ground-based field studies. He served as the data manager for several NASA tropospheric chemistry field campaigns, including ARCTAS, DC3, DISCOVER-AQ and SEAC4RS.

Abstract: The thermodynamic properties of the mixture of electrolytes and organic compounds present in soluble aerosol particles dictate the particles' water uptake, gas-particle equilibrium, and any intraparticle liquid-liquid or liquid-solid partitioning, as functions of temperature and relative humidity. In this course, we will first cover fundamental thermodynamic properties used to describe atmospheric aerosol particles, including density, surface tension, hygroscopicity, particle partitioning, and activity coefficients. We will also observe water uptake effects with a hands-on cloud demonstration. Bulk and single particle thermodynamic measurement techniques will be reviewed, including isopiestic measurement techniques, electrodynamic balances, optical tweezers, and hydrodynamic traps. Attention will be given to typical sources of error and uncertainty in the measurements, in order to improve the user's understanding and interpretation of thermodynamic properties. Available modeling approaches and predictive calculators for thermodynamic properties of activity, surface tension, density, phase partitioning, and mixing state will be discussed. The tutorial will end with practical discussions of methods for determining thermodynamic property effects on measurements, from density effects on aerodynamic diameter to diffusivity effects on mobility equivalent diameter.

Bio: Cari Dutcher is a Benjamin Mayhugh Assistant Professor of Mechanical Engineering at the University of Minnesota, Twin Cities, with a graduate faculty appointment in the Department of Chemical Engineering and Materials Science. Her research interests are in dynamics of soft matter and multiphase flows, and she has recently received the 3M Nontenure Faculty Award. Prior to joining the University of Minnesota in 2013, Cari was an NSF-AGS Postdoctoral Research Fellow in the Air Quality Research Center at the University of California, Davis. Cari received her B.S from Illinois Institute of Technology (2004) and her Ph.D. from the University of California, Berkeley (2009), both in Chemical Engineering. While at UC Berkeley, Cari was supported by an NSF Graduate Research Fellowship and an American Association of University Women Fellowship.

Abstract: This tutorial will focus on synthesis of micron sized and nano-sized aerosols with controlled composition and morphology for materials processing applications as well as environmental health and safety studies. Precursor selection, droplet generation or gas phase delivery methods, choice of reaction environment, and powder collection technologies will be reviewed. Aerosol dynamics involved in gas-to-particle conversion and droplet-to-particle conversion will be described. Upon completion of this tutorial, participants will be able to design a lab scale micro or nanoparticle synthesis process.

Bio: Sheryl Ehrman received her BS in chemical engineering from the University of California at Santa Barbara, and her doctorate from UCLA. Since August of 1998 she has been a faculty member in the Chemical and Biomolecular Engineering Department at the University of Maryland, College Park, where she is presently professor and chair of the department. Her current research interests include aerosol synthesis routes to micro and nanostructured materials, interactions between nanoparticles and biological materials, and the formation, characterization and minimization of air pollutants. Prof. Ehrman has been an active member of the American Association for Aerosol Research for over 20 years.

Abstract: This tutorial will enable participants to get an "under the hood" look at a broad spectrum of currently available aerosol instruments. Whether you are an experimentalist, modeler, or both, this is an opportunity to learn how fundamental aerosol scientific principles are used in actual aerosol measurement technologies. Key capabilities, as well as limitations, of each technique will be described in order to instill a better appreciation of what different instruments can and cannot, do. In each of two separate sessions, six aerosol instrumentation suppliers will present the design, concepts, and engineering choices that led to the successful development of different aerosol instrumentation. The tutorial is not a marketing and sales opportunity for participating vendors; this is an education session with an emphasis entirely on technology and the key physical concepts employed by the instrumentation. A primary goal is that by the end of the tutorial participants no longer consider instrumentation a "black box" but rather have some understanding of the principles and design consideration that went into the development of the various instruments. A secondary goal is that participants will use the information presented on measurement uncertainties and limitations to better avoid over-interpreting measurement results.

Participating Companies - Instrumentation:
Cambustion - Centrifugal Particle Mass Analyzer
Catalytic Instruments – 1.5 L/min catalytic stripper
Dekati – High Resolution and High Temperature ELPI+
Magee Scientific - "Dual Spot" Aethalometer, model AE33
Tisch Environmental – TE-WILBUR
TSI Incorporated – SMPS

Abstract: Numerous epidemiological studies have shown a relationship between ambient particulate pollution and adverse health effects on humans. Nonetheless, our understanding of how particle properties such as particle size, surface area and chemistry affect their toxic properties remains rather limited. In this tutorial we will discuss conventional and state-of-the-art technologies used for the evaluation of toxicological properties of PM. We will first start with traditional particle collection methods, such as filtration, impaction and the use of liquid impinger- BioSampler techniques. Despite their simplicity, we will demonstrate that these methods may suffer from shortcomings related to alterations of the physical and/or chemical characteristics of the sampled aerosol. We will then present state-of-the-art technological improvements of these conventional methods, such as particle concentrators that have been widely used in different aerosol study applications. We will present results from numerous studies showing that these concentrators can effectively preserve the physical, chemical and redox properties of PM during the concentration enrichment process, thereby making them a significant advancement in many aerosol research applications, including enhancement of signal-to-noise ratios of on-line aerosol monitors, uses in molecular/cellular in-vitro toxicity assays and real-time in-vivo exposures, as well as direct PM collection in aqueous solutions for chemical and toxicological analysis. We will then present applications and modifications of these systems for innovative particle-into-liquid collection that can achieve a much better recovery of both soluble and insoluble species of PM compared to conventional filtration/impaction methods, and demonstrate how this increased recovery translates into better and more accurate ways of assessing the toxicological properties of PM. We will finally present major findings from recent health studies utilizing these technologies to expose cells or animals to urban aerosols of various sizes and chemical composition, and discuss how these particle attributes affect the observed health outcomes.

Bio:Dr. Constantinos Sioutas, Sc.D., is the first holder of the Fred Champion Professorship in Civil and Environmental Engineering at the University of Southern California (USC). His research has followed an integrated approach to the problem of the well-publicized and significant effects of particulate air pollution on health and the environment. His research has focused on investigations of the underlying mechanisms that produce the health effects associated with exposure to air pollutants generated by a variety of sources. He has developed many state-of-the-art technologies used by many academic institutions and national laboratories for aerosol sampling and characterization. He has authored 280 peer-reviewed journal publications, 5 book chapters and holds 13 U.S. patents in the development of instrumentation for aerosol measurement and emissions control. He is the recipient of the AAAR David Sinclair award in 2015, the Hagen Smit award of Atmospheric Environment for seminal publications, the 2010 Scientific and Technological Achievement Award by the U.S. Environmental Protection Agency, a Fulbright fellow and a trustee of his undergraduate alma mater, the Aristotle University of Thessaloniki in Greece.

Abstract: The atmosphere is a complex continuum that transforms chemical species during transport. Reactions in the unified atmosphere encompass multiple states of matter. These reactions define the fate and transport of a variety of compounds that impact air quality and climate. This tutorial will introduce the broad field of atmospheric chemistry as it relates to aerosols and apply chemical principals to all relevant physical states. We will connect laboratory, field and modeling methods to understand chemistry in the atmosphere and address strategies to identify which method, or combination of methods, is best suited for a particular science question. We will discuss how detailed chemical mechanisms developed from and optimized for laboratory experiments are parameterized for implementation into atmospheric models. We will discuss field evaluation of such modeling approaches when measured species in the ambient environment are different from the laboratory, and how that impacts interpretation. The tutorial will outline a spectrum of atmospheric chemistry science questions and we will discuss how to develop strategies that employ laboratory, field and/or modeling techniques to answer them.

Bio: Annmarie Carlton is an assistant professor of Environmental Science and Engineering at Rutgers University. She is a lead organizer for the Southern Oxidant and Aerosol Study (SOAS) and serves as a co-editor for Atmospheric Chemistry and Physics. Her research focuses on the chemistry of aerosols and cloud droplets. Her work spans laboratory experiments to field measurements to atmospheric modeling. Annmarie considers AAAR her professional society “home” and has been known to organize her birthday festivities around the annual meeting.

Abstract: Ammonia (NH₃) is recognized as the dominant gas-phase base in the atmosphere, and can strongly influence the formation, growth, and neutralization of secondary particulate matter in the atmosphere. Organic analogues of ammonia, amines (NR3), are emitted from similar sources, especially animal husbandry, though typically at much lower levels. However the properties of many amines result in them having a relatively stronger role in particle formation. In this tutorial, I will review ammonia and amines in the gas and particle phases with respect to 1) commonly employed measurement techniques; 2) ambient observations in various environments; 3) modelling approaches for predicting gas-particle partitioning and contributions to particle growth.

Bio: Professor Jennifer Murphy is an Associate Professor and Associate Chair of Graduate Studies in the Department of Chemistry at the University of Toronto. She received her BSc in Chemistry and Environmental Studies at McGill University and her PhD in Physical Chemistry at UC Berkeley. Her research program in atmospheric chemistry encompasses field measurements, laboratory studies and model comparisons, with a focus on reactive nitrogen compounds. She holds a Canada Research Chair in Atmospheric and Environmental Chemistry, and was awarded an Ontario Early Research Award in 2011 to support her work on particle deposition in forests.

Abstract: This tutorial will enable participants to get an "under the hood" look at a broad spectrum of currently available aerosol instruments. Whether you are an experimentalist, modeler, or both, this is an opportunity to learn how fundamental aerosol scientific principles are used in actual aerosol measurement technologies. Key capabilities, as well as limitations, of each technique will be described in order to instill a better appreciation of what different instruments can and cannot, do. In each of two separate sessions, six aerosol instrumentation suppliers will present the design, concepts, and engineering choices that led to the successful development of different aerosol instrumentation. The tutorial is not a marketing and sales opportunity for participating vendors; this is an education session with an emphasis entirely on technology and the key physical concepts employed by the instrumentation. A primary goal is that by the end of the tutorial participants no longer consider instrumentation a "black box" but rather have some understanding of the principles and design consideration that went into the development of the various instruments. A secondary goal is that participants will use the information presented on measurement uncertainties and limitations to better avoid over-interpreting measurement results.

Participating Companies - Instrumentation:
Aerodyne Research, Inc. – ACSM and CAPSssa
Aethlabs – microAeth® Personal Black Carbon Monitor
Bretchel Manufacturing - Model 2900 Tricolor Absorption Photometer
Kanomax – Aerosol Particle Mass Analyzer and Portable Mobility Spectrometer
Sunset Laboratory, Inc. – Semi-Continuous OCEC
URG Corporation

Abstract: To prevent the spread of undesired airborne agents or to collect valuable products from industrial processes, control of aerosol is essential in determining its fate. The first part of the tutorial will cover principles of control mechanisms, including inertial, electrostatic, thermophoretic, and diffusional mechanisms, as well as biological inactivation. The second part will give an overview of the applications of these mechanisms in industrial processes, individual/collective protection, space exploration and instrumentation. The final part of the tutorial will touch upon emerging control technology for emerging scenarios. The tutorial will use virtual simulators, web calculators and various educational resources to facilitate hands-on experiences.

Bio: Professor Chang-Yu Wu is Professor and Department Head of Environmental Engineering Sciences at the University of Florida. He received his BS from Mechanical Engineering Department at National Taiwan University and PhD from the Department of Civil & Environmental Engineering at University of Cincinnati. His teaching and research interests range from air pollution control, aerosol science, environmental nanotechnology, dust control to engineering education. He has published 110+ refereed journal particles and given 50+ invited lectures. His research has resulted in 5 US patents and 5 pending applications. He has received several awards recognizing his accomplishments in education, research and service.

Abstract: Biological aerosols are comprised of particles containing bacteria, fungal spores, hyphae pollen, algae, proteins, viruses, and fragments of the above. They have wide ranging impacts from human disease and allergies, to potential impacts on the water cycle by acting as cloud condensation or ice nuclei. Characterization of these populations is desirable to understand which species are causing these impacts, and via what biological and atmospheric processes. Efforts to characterize these populations of biological particles have used methods such as: culture, characterization of nucleic acids and proteins, as well as real-time methods using spectroscopy and mass spectrometry. All characterization methods have limitations and complications that must be considered. Biological particles in the atmosphere can be changed by atmospheric chemical processes. These processes may affect their measurement by all of the above methods, as well as their viability. This tutorial will focus on techniques to measure, collect and analyze biological particles in the atmosphere, appropriate pairing of collection and analysis techniques, and the limitations to these analyses that should motivate their use in specific measurement and sampling scenarios.

Bio: Dr. Joshua L. Santarpia is a Principal Member of the Technical Staff at Sandia National Laboratories. His current research focuses on examining the role of atmospheric aging processes on microbial aerosols and their properties, in particular those processes affecting detection and measurement of those particles. These studies are intended to inform detection strategies for biological warfare agents and environmental studies of biological aerosols. He also studies microbial communities in the ambient environment (aerosol, soil, and water) and how those communities interact, process nutrients and respond to change, such as natural disasters and new community members, using both traditional microbiology and next generation sequencing. His past research has included urban aerosols and air pollution, biological and chemical aerosol detection, aerosol measurement and sampling techniques, and methods to support these pursuits.

Abstract: This tutorial will have four main sections: a review of both dynamic and equilibrium behavior of organic aerosol; the design, implementation, and potential pitfalls of both chamber and flow-tube experiments; the analysis of SOA formation data; and parameterizations used in various chemical transport models. First we shall discuss what drives organic vapors to condense to particles and how the dynamics and equilibrium change with conditions (composition, water content, temperature, etc). Second, we shall apply those theoretical considerations to experimental design, both for an idealized experiment and for real-world situations. We shall discuss issues including equilibrium timescales and wall losses. Third, we shall discuss methods for interpreting SOA production data, including inversion (fitting) to equilibrium models with either unknown or specified volatility (multi-product models and the volatility basis set) as well as forward comparison between measurements and models using chamber box models. Finally, we shall discuss various parameterizations used to represent SOA formation in chemical transport models, considering the relative advantages and disadvantages of each.

Bio: Neil M. Donahue is the Thomas Lord Professor of Chemistry in the Departments of Chemistry, Chemical Engineering and Engineering and Public Policy at Carnegie Mellon University, where he is also Director of the Steinbrenner Institute for Environmental Education and Research. He has an AB in Physics from Brown University and a PhD in Meteorology from MIT. He has studied the origin, behavior, and fate of atmospheric organic compounds for the past 30 years from many different perspectives. These include in-situ measurement, modeling, theory, and laboratory experiments ranging from elementary gas-phase kinetics and mechanisms to probing the evolution of complex organic mixtures subject to photochemistry. He is the author of more than 180 publications, many of which are highly cited.