Air Quality
UC Davis' mass spectrometer used for measuring the size and composition of particles in the atmosphere.
Students in the air quality program at Davis study a wide range of questions regarding the emission, transformation, transport and deposition of air pollutants. Research projects include measurement and modeling of emission, deposition and dispersion on scales ranging from the microscale processes around individual plants to mesoscale flows over an entire state. The study of air quality problems is multi-disciplinary as is reflected by the diversity of training and departmental affiliation of the Graduate Group members associated with this specialty.
Select a faculty member's name below to visit their web page.
For further information, visit the Air Quality Research web site.
Cort Anastasio
explores the chemistry and composition of tropospheric aerosol particles and cloud/fog drops. Reactions in these particles and drops are an important component of the biogeochemical cycles of nutrients and pollutants that can alter atmospheric composition and affect climate and impact human health. Current projects explore both the chemistry of anthropogenic air pollutants as well as the chemistry of the natural "background" atmosphere. These activities include: describing new chemical reactions in sea-salt particles and their effects on the marine atmosphere; characterizing the concentrations and atmospheric reactions of organic and inorganic nitrogen and carbon; examining the atmospheric reactions of particulate chromium and their effects upon particle toxicity; and laboratory and field measurements of Arctic snow photochemistry and its effects on the atmospheric boundary layer.
Lowell Ashbaugh's
interests span a wide range of research, including long-term trends in visibility effects of particulate matter, transport and deposition of particles in the western United States, dry deposition of acidic particles and gases in California, motor vehicle emissions, and PM10 fugitive dust generation, including particulate matter generated by agricultural activities. He has directed research on acidic aerosols throughout California, and participated in the Southern California Air Quality Study. His expertise has contributed to successful airborne particle research studies on Owens Lake and in the Antelope Valley. He has also contributed to the testing and validation of the motor vehicle remote sensor developed at the University of Denver. He currently works as a data analyst for the Interagency Monitoring of Protected Visual Environments (IMPROVE) program. Dr. Ashbaugh served on the Grand Canyon Visibility Transport Commission, created by the 1990 Clean Air Act Amendments to investigate the causes of reduced visibility at the Grand Canyon and other national resources on the Colorado Plateau. He currently serves on the Western Regional Air Partnership, formed to follow up on the recommendations of the Grand Canyon Visibility Transport Commission. He has also served as a peer reviewer for the Environmental Protection Agency and the National Acid Precipitation Assessment Program, as well as for numerous scientific journals.
Chris Cappa
Professor Cappa's research is focused on the study of physical, chemical and optical properties of atmospheric aerosols. We use state-of-the-art analytical techniques in the lab and the field to characterize how and why aerosol properties vary in both time and space.
Steven Cliff
performs research utilizing advanced analytical techniques to better characterize atmospheric aerosols for regional air quality and global climate projects. He is currently PI on a National Oceanic and Atmospheric Administration (NOAA) grant for work on the Intercontinental Transport and Chemical Transformation Experiment (ITCT) and investigator on a Lawrence Livermore National Laboratory Atmospheric Sciences Group through a Laboratory Directed Research and Development (LLNL-LDRD) grant to understand the climatic impact of long-range transport of particulate matter through model calibration and interpretation. In addition, he is looking at the question of air quality as a source of pollution to Lake Tahoe and human health related impacts of aerosols at Fresno.
Ann M. Dillner
conducts research on particulate matter air pollution in the atmosphere. A primary motivation for much of her work is visibility degradation by particulate matter at National Parks in the US and she is a part of the Interagency Monitoring for Protected Visual Environments (IMPROVE) program at UCDavis. Current and recent projects include studying the volatility and reactivity of organic particles after collection and before traditional analysis, developing a method utilizing FTIR to quantify particulate organic compound classes for use at a National Park in Arizona, characterizing and developing improved methods for particulate matter sampling for the IMPROVE network, developing a size distribution cluster technique to determine sources of elemental and trace metal particulate matter, characterizing bioaerosols and fine and ultrafine particles for health effects studies.
Ian Faloona
seeks to develop research spanning the gaps between atmospheric chemistry and turbulent exchange dynamics. He is interested in developing a novel laser spectroscopic technique to measure halogen gases (e.g., HCl) in the atmosphere, yet the ultimate objective is to use the data to learn about both the chemical reactions of the atmosphere as well as the mixing processes which strongly control the ability of compounds to react with one another. Specific current research includes direct eddy-correlation measurements of carbon monoxide (CO) from a coastal marine ecosystem, mixing studies of dimethyl sulfide (DMS) in the stratocumulus topped marine boundary layer, and measurements of formaldehyde (HCHO), an important byproduct of biogenic hydrocarbon oxidation, in a Pine forest in the Sierras.
Robert Flocchini
studies primarily the temporal and spatial distribution of airborne particles in relation to meteorological conditions to identify transport patterns for these pollutants. He has designed particle collection equipment and advanced analysis techniques for determining the elemental composition of the samples collected. His work has focused on documenting particulate concentrations in areas remote from urban sources such as National Parks and wilderness areas. In addition to the National Park work he focuses on evaluating particulate fluxes from agricultural practices.
Michael Kleeman's
research is focused on the study of urban and regional air quality problems with an emphasis on the size and composition of atmospheric particles and gas-to-particle conversion processes. These issues are important because research has found that airborne particles with diameters less than 2.5 microns cause adverse health effects. The size and composition of particles found in the atmosphere also determines much of the visibility reduction observed in large cities.
Debbie Niemeier
studies transportation-air quality estimation and modeling. Her projects include transportation modeling, urban and regional planning, and modeling of mobile emissions. Research focuses on translating micro-scale mobile emission processes to meso-scale simulation and monitoring frameworks.
Kyaw Tha Paw U
studies the microscale processes near the ground and around plant canopies. His interests in air quality are focused on large aerosol physics and gas phase transport, emissions, and sinks, including measurements and modeling. Recent projects include estimating turbulent parameters and dispersion coefficients for a California regional air quality study, and determining by eddy-covariance the carbon exchange between the atmosphere and a 500-year old, 65 m high forest. His research group is measuring carbon dioxide fluxes, and is in collaboration with a group measuring biogenic hydrocarbon emissions from the forest canopy. Past projects have included fast-response eddy-covariance measurements of ozone exchange with grasslands. He and his graduate students have also developed the Advanced Canopy-Atmosphere Simulation Algorithm (ACASA), based on higher-order closure principles for turbulent transport. ACASA has been linked to the regional scale model MM5 and can provide regional scale estimates of carbon, water, other gaseous and particulate emissions, transport, and deposition.