The Conference Committee is proud to have four distinguished speakers for plenary sessions. Each speaker will offer a stimulating and insightful presentation on topics of current and emerging interest to aerosol scientists.

Since aerosols generally do not remain in the atmosphere long enough for global mixing, and many respond to changes in relative humidity and other factors, their properties and amounts vary on many space and time scales. However, aerosols contribute to direct radiative forcing, and indirectly by affecting cloud properties, to a degree that must be considered when modeling climate on global, and especially on regional scales. They are also significant players in regional pollution and long-distance material transport.

Compared to in situ measurements, space-borne detectors are relatively blunt instruments for studying atmospheric aerosols. Until recently, only column-averaged aerosol optical depth over dark water, derived from assumed aerosol microphysical properties, could be retrieved routinely from space. But the enormous range of space and time scales presented by aerosol phenomena of interest creates opportunities for satellites to contribute. Recent advances in spacecraft measuring capabilities, such as those represented by NASA’s Earth Observing System MISR and MODIS instruments, are beginning to reliably retrieve particle column amounts over land and water, and to constrain column average particle size and shape along with spectral optical depth. Polarization, UV, and lidar techniques promise to contribute added sensitivity to particle composition and verticaldistribution. Taken together, these new data products are improving our ability to identify and track aerosol air mass types over regional and larger scales, giving added value and context to detailed particle micro physical properties that can be measured in situ at selected points during the life history of an air mass. This talk will review the strengths and limitations of current space-based aerosol products, and will suggest how they may fit with in situ and surface measurements, to advance our global picture of atmospheric aerosols.

Biography: Ralph Kahn is a principal scientist at NASA’s Jet Propulsion Laboratory. He received his PhD in applied physics from Harvard University, concentrating in atmospheric physics and radiative transfer. His research interests include the climate and climate history of Mars and Earth. As a student, he was an experimenter on the Viking Lander Imaging team, and was responsible for imaging the sunset of Mars. Kahn is currently the aerosol scientist for the Multiangle Imaging SpectroRadiometer (MISR; www.misr.jpl.nasa.gov), which flies aboard the Earth Observing System’s Terra satellite. His role in this experiment is to learn as much as possible about dust, smoke, and pollution particles in Earth’s atmosphere from MISR’s unique observations. Kahn has lectured on global change and atmospheric physics at UCLA and Caltech, and is editor and founder of PUMAS, the online journal of science and math examples for pre-college education (http://pumas.jpl.nasa.gov).

The last decade has seen the accumulation of a large and ever-convincing database that ambient particulate matter can have adverse impacts on health. These impacts range from hospitalization, worsening of pre-existing health impairments, loss of work and school, to mortality. The growing evidence points to certain population subgroups, typically the aged with cardiopulmonary deficiencies, impairments, or genetic predisposition, or children with asthma, are at unusual risk of adverse effect. Life-threatening risk appears to involve cardiac mechanisms not heretofore appreciated as an impact of air pollution. However, what it is about particulate matter that impacts health remains speculative, although there is evidence that certain attributes related to size and combustion origin are involved. PM-associated contaminants such as metal and organic compounds may impart their effects via oxidant mechanisms or distort neural or humoral balances in the body. Linking health effects to the contaminants most associated with specific source or transformation processes may allow for more effective regulatory control. Linking sources to hazardous components to health outcomes remains a challenge to the air pollution science community.

Biography: Dan Costa, ScD, is currently National Program Director for Air Research in the Office of Research & Development/EPA. He is responsible for the Air Research Program across the EPA Labs and Centers. For 18 years prior, he served as chief of the Pulmonary Toxicology Branch of the National Health and Environmental Research Laboratory, where he led an active group investigating the health effects of particulate matter and other air pollutants. He is still personally engaged in some of this work while functioning as director. Dr. Costa earned a BS (1970) in biology at Providence College, RI, a MS (1973) in environmental sciences at Rutgers University, NJ, and a MS (1973) and ScD (1977) in physiology/toxicology at the Harvard School of Public Health under the mentorship of the late Dr. Mary Amdur. He is a diplomat and past-president of the American Board of Toxicology (1994) and is past-president of the Inhalation Specialty Section of the Society of Toxicology (1996). Dr. Costa’s personal research interests include the assessment of potential acute and chronic effects of air pollutants on the heart and lung, most recently with focus on mechanisms airway irritant mediation of cardiac dysfunction in compromised animal models.

The lecture will start with an overview of aerosol technology from ancient China and Greece to the current manufacture of fumed silica and alumina, pigmentary titania, optical fibers, carbon black and filamentary nickel commodities. Today production rates of these materials can be up to several tons/hour and corresponding reactors resemble best the space shuttle rockets departing from Cape Kennedy. These reactors, however, were built with valiant Edisonian research making difficult reactor operation for flexible synthesis of other promising materials.Recent major advances in the scientific understanding of aerosol formation and growth allow now optimal aerosol reactor design and inexpensive production of sophisticated nanoparticles with controlled composition, size and morphology leading to exciting new products. For example, noble metal bearing catalysts that were made for eons by multi-step wet impregnation and costly effluent treatment are made now by one-step liquid-fed flame aerosol reactors. Transparent but radioopaque dental nanocomposite materials can be made, for the first time, in these reactors breaking, somehow, the “tyranny” of thermodynamics. These developments bring new challenges to modern aerosol science and engineering. For example, there is a need to distinguish between hard- and soft-agglomerates as the structure of nanomaterials affects their performance as, for example, in a slurry for chemical-mechanical polishing of microelectronics or as a filler in a dental resin. As with every technology that has to survive the “death valley” of scale-up, there is a need for quantitative understanding of the controlling phenomena during interfacing of fluid and particle dynamics for process design that lead to homogeneous multicomponent products of controlled characteristics. Aside from these promising research areas with aerosol-made nanoparticles, there is concern for their health effects. Do the advanced material properties come with adverse health effects? Scattered data imply a rather vague answer. Some are ready to treat this technology as another “GMO” and even impose a moratorium on such research. Clearly, there is a need to place the health effects of aerosol-made nanoparticles on a firm scientific basis to better protect the international investment in this field and guide researchers. Given the current advances in aerosol characterization and the large body of anecdotal data in industry regarding exposure to nanoparticle commodities (carbon black, fumed silica, titania, welding fumes), there is enough knowledge to initiate health effect and, even, epidemiologic research on these materials.

Biography: Sotiris E. Pratsinis has a diploma in chemical engineering from the Aristotle University of Thessaloniki, Greece (1977) and a PhD from the University of California, Los Angeles (1985). He was professor (1985-2000) and interim head (1998) of chemical engineering at the University of Cincinnati, Ohio, USA, until he was elected professor of process engineering atthe Swiss Federal Institute of Technology (ETH Zurich) in 1998. There he teaches Mass Transfer, Particle Technology, Nanoscale Engineering and Combustion Synthesis of Materials. His current research focuses on the fundamentals of aerosol synthesis of metal and ceramic nanoparticles and their applications in catalysis, sensors, solar engineering, and nanocomposites. His results are documented in over 200 refereed articles in scientific journals and book chapters while he has received six U.S. and European patents licensed to Dow Chemical, Hosokawa-Micron Degussa, and FlamePowders AG. He is a recipient of the 1988 Kenneth T. Whitby Award of AAAR and the 1995 Marian Smoluchowski Award of the Gesellschaft für Aerosolforschung (GAeF).

The past decade has seen the emergence of several methods capable of determining the size and chemical composition of aerosol particles in real-time using mass spectrometry, allowing the investigation of aerosol sources, processes, and effects in more detail than was possible before. The Aerodyne Aerosol Mass Spectrometer (AMS) is currently the most widely used instrument of this type. This presentation explores recent applications of the AMS and complementary instrumentation to the analysis of ambient particles at multiple urban, rural, and remote locations. Urban locations include Pittsburgh, Mexico City, New York City, Riverside (California), and Manchester (UK). Rural and remote locations include Storm Peak (Colorado), Jungfraujoch (Switzerland), Trinidad Head (California), Jeju Island (Korea), Okinawa (Japan), and Mace Head (Ireland). Examples include the determination of the composition of growing particles during nucleation events; the characterization of the organic aerosol components based on the entire organic mass, rather than on tracers; and the integration of AMS data with other measurements towards closure of aerosol effects on light scattering and cloud nucleation. The presentation will conclude by summarizing recent improvements to the AMS: high m/z resolution, soft ionization, and light scattering and surrogate morphology measurements.

Biography: Dr. Jose-Luis Jimenez received a double MS in mechanical engineering from the Universities of Zaragoza (Spain) and Compiegne (France) in 1993; and a PhD also in mechanical engineering from MIT in 1998. From 1999 to mid-2002, he was a research scientist, first at Aerodyne Research and MIT, and later at Caltech. He has been heavily involved in the development of the Aerodyne Aerosol Mass Spectrometer (AMS), and led the first field deployment (Atlanta Supersite) and the first aircraft deployment (ACEAsia) of this instrument, among many other field campaigns. In August 2002, he joined the faculty of the Department of Chemistry and CIRES at the University of Colorado-Boulder. His current research interests center on instrument development for organic aerosols and particle shape measurement, and on ground and aircraft field studies of aerosol sources, processes, and effects. He is a co-author on 35 journal papers on aerosol mass spectrometry and its applications.