Spring 2024: Mondays 3-4 PM
Robert Harley is a Professor of Civil and Environmental Engineering at UC Berkeley. Harley's research focuses on air quality and sustainable transportation. Harley is the inaugural holder of the Carl W. Johnson Endowed Chair in Civil and Environmental Engineering at Berkeley, awarded in recognition of his record of scholarship and university and professional service.
Ph.D., Environmental Engineering Science, California Institute of Technology, 1993
M.S., Environmental Engineering Science, California Institute of Technology, 1988
B.A.Sc. (with honors), Engineering Science, Chemical Option, University of Toronto, 1987
The atmosphere carries a heavy burden of air pollution, with large contributions to the problem coming from the combustion of fossil fuels. As a society, we need to evolve towards a more sustainable, environmentally benign approach to meeting growing demands for energy. Harley’s research group uses mathematical models and data from field experiments to help understand air pollution problems and related issues in atmospheric chemistry, climate change, and emission source characterization and control. Here are a few of the research projects Harley is currently working on:
Air Quality Modeling - Some air pollutants are formed in situ from other precursor emissions by photochemical reactions in the atmosphere. Air pollution problems of this type, including tropospheric ozone and many of the major components of airborne fine particulate matter or PM2.5, have complex relationships to precursor emissions. Harley’s research group uses mathematical models to synthesize an understanding of precursor emissions and relevant processes that take place in the atmosphere.
- "Fuel-based" Approach to Estimating Vehicle Emissions - Harley has led development of a fuel-based approach to estimating motor vehicle emissions in which vehicle activity is measured by fuel consumption, and emission rates are expressed per unit of fuel burned rather than per km traveled or per unit of time. Emission rates for many pollutants (e.g., CO, NOx, as well as CO2, of course) vary less over wide ranges of vehicle weight and driving conditions when normalized to fuel consumption. This line of research has contributed to policy-relevant revisions in national and state-level emission inventories.
National Science Foundation CAREER Award, 1996
Appointment to Carl W. Johnson Endowed Chair in Civil Engineering, 2014
Editors' Choice Award for Preble et al. (ES&T 2019) research paper in a journal published by the American Chemistry Society, 2019
Courses I have taught at Berkeley include
- E 7 (lower-division undergraduate level), Introduction to Computer Programming for Scientists and Engineers.
Elements of procedural and object-oriented programming. Induction, iteration, and recursion. Real functions and floating-point computations for engineering analysis. Introduction to data structures. Representative examples are drawn from mathematics, science, and engineering. The course uses the MATLAB programming language. - CEE 11 (lower-division undergraduate level), Engineered Systems and Sustainability.
An introduction to key engineered systems (e.g., energy, water supply, buildings, transportation) and their environmental impacts. Basic principles of environmental science needed to understand natural processes as they are influenced by human activities. Overview of concepts and methods of sustainability analysis. Critical evaluation of engineering approaches to address sustainability. - CEE 218A (graduate level), Air Quality Engineering.
Quantitative overview of the characterization and control of air pollution problems. Summary of fundamental chemical and physical processes governing pollutant behavior. Analysis of key elements of the air pollution system: sources and control techniques, atmospheric transformation, atmospheric transport, modeling, and air quality management.
Completed Ph.D. Dissertations
- Tom Kirchstetter (B.S. in Atmospheric Science and Math, SUNY Albany; UC Berkeley Ph.D. 1998). Impact of reformulated fuels on motor vehicle emissions
- Brett Singer (B.S. in Mechanical Engineering, Temple University; UC Berkeley Ph.D. 1998). A fuel-based approach to estimating motor vehicle exhaust emissions
- Doug Black (B.S. in Electrical Engineering, University of Michigan; UC Berkeley Ph.D. 2000). Development and application of a sensor for real-time microenvironmental and personal ozone measurements
- Linsey Marr (B.S. in Engineering Science, Harvard; UC Berkeley Ph.D. 2002). Changes in ozone sensitivity to precursor emissions on diurnal, weekly, and decadal time scales
- Andrew Kean (B.S. in Mechanical Engineering, Cooper Union; UC Berkeley Ph.D. 2002). Effects of vehicle speed and engine load on emissions from in-use light-duty vehicles
- Phil Martien (B.A. in Physics, UC Santa Cruz; B.S. in Environmental Engineering, Humboldt State; UC Berkeley Ph.D. 2004). Forward and adjoint sensitivity analysis in Eulerian photochemical air quality models
- George Ban-Weiss (B.S. in Mechanical Engineering, UC Berkeley; UC Berkeley Ph.D. 2008). Characterization of gas- and particle-phase emissions from on-road motor vehicles
- Ling Jin (B.S. in Physical Geography, Peking University; UC Berkeley Ph.D. 2008). A seasonal perspective on regional air quality in central California (co-advised with Nancy Brown)
- Dev Millstein (B.S. in Economics, Vassar College; UC Berkeley Ph.D. 2009). Air quality responses to changes in black carbon and nitrogen oxide emissions
- Tim Dallmann (B.S. in Civil and Environmental Engineering, University of Wisconsin; UC Berkeley Ph.D. 2013). Evaluation of mobile source emissions and trends.
- Sharon Shearer (B.S. in Civil and Environmental Engineering, University of Texas at Austin; UC Berkeley Ph.D. 2013). An improved chemical mechanism for photochemical air quality modeling
- Brian McDonald (B.S. in Civil and Environmental Engineering, Virginia Tech; UC Berkeley Ph.D. 2014). High-resolution mapping and long term trends for motor vehicle emissions
- Ivy Tao (B.S. in Physics, Bryn Mawr/Haverford College; UC Berkeley Ph.D., 2016). Changes in mobile source emissions and ambient air quality in California
- Lucas Bastien (B.S. in Energy and Environmental Engineering, Institut National des Sciences Appliquees, Lyon, France; UC Berkeley Ph.D., 2016). Adjoint sensitivity analysis of air pollution problems (co-advised with Nancy Brown)
- Chelsea Preble (B.S. in Environmental Science, UC Berkeley; UC Berkeley Ph.D., 2017). Effects of advanced after-treatment control technologies on heavy-duty diesel truck emissions (co-advised with Tom Kirchstetter)
- Matthew Vannucci (B.S. in Physics, Rutgers University; UC Berkeley Ph.D., 2018). Human-centric indoor air quality
- Regan Patterson (B.S. in Chemical Engineering, UCLA; UC Berkeley Ph.D., 2019). Effects of diesel emission control measures and truck routing on air quality, environmental equity and justice
- Sofia Hamilton (B.S. in Civil Engineering, UC Berkeley; UC Berkeley Ph.D. 2022). High-resolution modeling and apportionment of diesel-related contributions to black carbon concentrations
Wang, Y.; Bastien, L.A.J.; Jin, L.; Harley. R.A. (2022). Responses of Photochemical Air Pollution in California's San Joaquin Valley to Spatially and Temporally Resolved Changes in Precursor Emissions. Environmental Science & Technology 56, doi: 10.1021/acs.est.1c07011.
Hamilton, S.D.; Harley, R.A. (2021). High-Resolution Modeling and Apportionment of Diesel-Related Contributions to Black Carbon Concentrations. Environmental Science & Technology 55, 12250-12260, doi: 10.1021/acs.est.1c03913.
Patterson, R.F.; Harley, R.A. (2021). Effects of Diesel Engine Emission Controls on Environmental Equity and Justice. Environmental Justice 14, 360-371, doi: 10.1019/env.2020.0078.
Yu, K.A.; McDonald, B.C.; Harley, R.A. (2021). Evaluation of Nitrogen Oxide Emission Inventories and Trends for On-Road Gasoline and Diesel Vehicles. Environmental Science & Technology 55, 6655-6664, doi: 10.1021/acs.est.1c00586.
Preble, C.V.; Harley, R.A.; Kirchstetter, T.W. (2019). Control Technology-Driven Changes to In-Use Heavy-Duty Diesel Truck Emissions of Nitrogenous Species and Related Environmental Impacts. Environmental Science & Technology 53, 14568-14576, doi: 10.1021/acs.est.9b04763. Paper received American Chemistry Society Editors' Choice Award
Patterson, R.F.; Harley, R.A. (2019). Effects of Freeway Rerouting and Boulevard Replacement on Air Pollution Exposure and Neighborhood Attributes. International Journal of Environmental Research and Public Health 16, 4072, doi: 10.3390/ijerph16214072.
Bastien, L.A.J.; Brown, N.J.; Harley, R.A. (2019). Contributions to Local and Regional-Scale Formaldehyde Concentrations. Atmospheric Chemistry and Physics 19, 8363-8381.
Patterson, R.F.; Harley, R.A. (2019). Evaluating Near-Roadway Concentrations of Diesel-Related Air Pollution Using RLINE. Atmospheric Environment 199, 244-251, doi: 10.1016/j.atmosenv.2018.11.016.
Preble, C.V.; Cados, T.E.; Harley, R.A.; Kirchstetter, T.W. (2018). In-Use Performance and Durability of Particle Filters on Heavy-Duty Diesel Trucks. Environmental Science & Technology 52, 11913-11921, doi: 10.1021/acs.est.8b02977.
McDonald, B.C. et al. (2018). Volatile Chemical Products Emerging as Largest Petrochemical Source of Urban Organic Emissions. Science 359, 760-764, doi: 10.1126/science.aaq0524.
Gentner, D.R. et al. (2017). Review of Urban Secondary Organic Aerosol Formation from Gasoline and Diesel Motor Vehicle Emissions. Environmental Science & Technology 51, 1074-1093, doi: 10.1021/acs.est.6b04509.
Turner, A.J.; Shusterman, A.A. ; McDonald, B.C.; Teige, V.; Harley, R.A.; Cohen, R.C. (2016). Network Design for Quantifying Urban CO2 Emissions: Assessing Trade-offs Between Precision and Network Density. Atmospheric Chemistry and Physics 16, 13465-13475, doi:10.5194/acp-16-13465-2016.
Kim, S.-W. et al. (2016). Modeling the Weekly Cycle of NOx and CO Emissions and Their Impacts on O3 in the Los Angeles-South Coast Air Basin during the CalNex 2010 Field Campaign. Journal of Geophysical Research 121, 1340-1360, doi: 10.1002/2015JD024292.
Preble, C.V.; Dallmann, T.R.; Kreisberg, N.M.; Hering, S.V.; Harley, R.A.; Kirchstetter, T.W. (2015). Effects of Particle Filters and Selective Catalytic Reduction on Heavy-Duty Diesel Drayage Truck Emissions at the Port of Oakland. Environmental Science & Technology 49, 8864-8871.
Bastien, L.A.J.; McDonald, B.C.; Brown, N.J.; Harley, R.A. (2015) High-Resolution Mapping of Sources Contributing to Urban Air Pollution Using Adjoint Sensitivity Analysis: Benzene and Diesel Black Carbon. Environmental Science & Technology 49, 7276-7284.
McDonald, B.C.; Goldstein, A.H.; Harley, R.A. (2015). Long-Term Trends in California Mobile Source Emissions and Ambient Concentrations of Black Carbon and Organic Aerosol. Environmental Science & Technology 49, 5178-5188.
Wood, E.C.; Knighton, W.; Fortner, E.; Herndon, S.; Onasch, T.; Franklin, J.; Worsnop, D.; Dallmann, T.R.; Gentner, D.R.; Goldstein, A.H.; Harley, R.A. (2015). Ethylene Glycol Emissions from On-Road Vehicles. Environmental Science & Technology 49, 3322-3329.
Maness, H.; Thurlow, M.; McDonald, B.C.; Harley, R.A. (2015). Estimates of CO2 Traffic Emissions from Mobile Concentration Measurements. Journal of Geophysical Research, 120, doi: 10.1002/2014JD022876.
Tao, L.; Harley, R.A. (2014). Changes in Fine Particulate Matter Measurement Methods and Ambient Concentrations in California. Atmospheric Environment 98, 676-684.
Dallmann, T.R.; Onasch, T.B.; Kirchstetter, T.W.; Worton, D.R.; Fortner, E.C.; Herndon, S.C.; Wood, E.C.; Franklin, J.P.; Worsnop, D.R.; Goldstein, A.H.; Harley, R.A. (2014). Characterization of Particulate Matter Emissions from On-Road Gasoline and Diesel Vehicles using a Soot Particle Aerosol Mass Spectrometer. Atmospheric Chemistry and Physics 14, 7585-7599.
Gentner, D.R. et al. (2014). Emissions of Organic Carbon and Methane from Petroleum and Dairy Operations in California's San Joaquin Valley. Atmospheric Chemistry and Physics 14, 4955-4978.
McDonald, B.C.; McBride, Z.C.; Martin, E.W.; Harley, R.A. (2014). High-Resolution Mapping of Motor Vehicle Carbon Dioxide Emissions. Journal of Geophysical Research 119, 5283-5298, doi: 10.1002/2013JD021219.
Worton, D.R.; Isaacman, G.; Gentner, D.R.; Dallmann, T.R.; Chan, A.W.H.; Ruehl, C.; Kirchstetter, T.W.; Wilson, K.R.; Harley, R.A.; Goldstein, A.H. (2014). Lubricating Oil Dominates Primary Organic Aerosol from Motor Vehicles. Environmental Science & Technology 48, 3968-3706.
Joe, D.K.; Zhang, H.; DeNero, S.P.; Lee, H.H.; Chen, S.; McDonald, B.C.; Harley, R.A.; Kleeman, M.J. (2014). Implementation of a High-Resolution WRF/Chem Model at the Port of Oakland. Atmospheric Environment 82, 351-363.
Dallmann, T.R.; Kirchstetter, T.W.; DeMartini, S.J.; Harley, R.A. (2013). Quantifying On-Road Emissions from Gasoline-Powered Motor Vehicles: Accounting for the Presence of Medium- and Heavy-Duty Diesel Trucks. Environmental Science & Technology 47, 13873-13881.
Gentner, D.R.; Worton, D.R.; Isaacman, G.; Davis, L.C.; Dallmann, T.R.; Wood, E.C.; Herndon, S.C.; Goldstein, A.H.; Harley, R.A. (2013). Chemical Composition of Gas-Phase Organic Carbon Emissions from Motor Vehicles and Implications for Ozone Production. Environmental Science & Technology 47, 11837-11848.
Tao, I.; Fairley, D.; Kleeman, M.J.; Harley, R.A. (2013). Effects of Switching to Lower Sulfur Marine Fuel on Air Quality in the San Francisco Bay Area.Environmental Science & Technology 47, 10171-10178.
McDonald, B.C.; Gentner, D.R.; Goldstein, A.H.; Harley, R.A. (2013). Long-Term Trends in Motor Vehicle Emissions in U.S. Urban Areas. Environmental Science & Technology 47, 10022-10031.
Chan, A.W.H. et al. (2013). Detailed Chemical Characterization of Unresolved Complex Mixtures in Atmospheric Organics: Insights into Emission Sources, Atmospheric Processing, and Secondary Organic Aerosol Formation. Journal of Geophysical Research 118, doi: 10.1002/jgrd.50533.
Warneke, C. et al. (2013). Photochemical Aging of Volatile Organic Compounds in the Los Angeles Basin: Weekday-Weekend Effect. Journal of Geophysical Research 118, doi: 10.1002/jgrd.50423.
Peischl, J. et al. (2013). Quantifying Sources of Methane and Light Alkanes in the Los Angeles Basin, California. Journal of Geophysical Research 118, doi: 10.1002/jgrd.50413.
Kuwayama, T.; Schwartz, J.R.; Harley, R.A.; Kleeman, M.J. (2013). Particulate Matter Emissions Reductions Due to Adoption of Clean Diesel Technology at a Major Shipping Port. Aerosol Science & Technology 47, 29-36.
Gentner, D.R.; Isaacman, G.; Worton, D.R.; Chan, A.W.H.; Dallmann, T.R.; Davis, L.; Liu, S.; Day, D.A.; Russell, L.M.; Wilson, K.R.; Weber, R.; Guha, A.; Harley, R.A.; Goldstein, A.H. (2012). Elucidating Secondary Organic Aerosol from Diesel and Gasoline Vehicles Through Detailed Characterization of Organic Carbon Emissions. Proceedings of the National Academy of Sciences 109, 18318-18323.
McDonald, B.C.; Dallmann, T.R.; Martin, E.W.; Harley, R.A. (2012). Long-Term Trends in Nitrogen Oxide Emissions from Motor Vehicles at National, State, and Air Basin Scales. Journal of Geophysical Research 117, D00V18, doi: 10.1029/2012JD018304.
de Gouw, J.A. et al. (2012). Increasing Atmospheric Burden of Ethanol in the United States. Geophysical Research Letters 39, L15803, doi: 10.1029/2012GL052109.
Dallmann, T.R.; DeMartini, S.J.; Kirchstetter, T.W.; Herndon, S.C.; Onasch, T.B.; Wood, E.C.; Harley, R.A. (2012). On-Road Measurement of Gas and Particle Phase Pollutant Emission Factors for Individual Heavy-Duty Diesel Trucks. Environmental Science & Technology 46, 8511–8518.
Shearer, S.N.; Harley, R.A.; Jin, L.; Brown, N.J. (2012). Comparison of SAPRC99 and SAPRC07 Mechanisms in Photochemical Modeling for Central California. Atmospheric Environment 46, 205-216.
Dallmann, T.R.; Harley, R.A.; Kirchstetter, T.W. (2011). Effects of Diesel Particle Filter Retrofits and Accelerated Fleet Turnover on Drayage Truck Emissions at the Port of Oakland. Environmental Science & Technology 45, 10773-10779.
Jin, L.; Harley, R.A.; Brown, N.J. (2011). Ozone Pollution Regimes Modeled for a Summer Season in California's San Joaquin Valley: A Cluster Analysis.Atmospheric Environment 45, 4707-4718.
Mollner, A.K.; Valluvadasan, S.; Feng, L.; Sprague, M.K.; Okumura, M.; Milligan, D.B.; Bloss, W.J.; Sander, S.P.; Martien, P.T.; Harley, R.A.; McCoy, A.B.; Carter, W.P.L. (2010). Rate of Gas Phase Association of Hydroxyl Radical and Nitrogen Dioxide. Science 330, 646-649.
Dallmann, T.R.; Harley, R.A. (2010). Evaluation of Mobile Source Emission Trends in the United States. Journal of Geophysical Research 115, D14305, doi: 10.1029/2010JD013862.
Millstein, D.E.; Harley, R.A. (2010). Effects of Retrofitting Emission Control Systems on In-Use Heavy Diesel Vehicles. Environmental Science & Technology 44, 5042-5048.
Sathaye, N.; Harley, R.A.; Madanat, S. (2010). Unintended Environmental Impacts of Nighttime Freight Logistics Activities. Transportation Research Part A: Policy and Practice 44, 642-659.
Jin, L.; Brown, N.J.; Harley, R.A.; Bao, J.; Michelson, S.A.; Wilczak, J.M. (2010). Seasonal versus Episodic Performance Evaluation for an Eulerian Photochemical Air Quality Model. Journal of Geophysical Research 115, D09302, doi: 10.1029/2009JD012680.
Strawa, A.W.; Kirchstetter, T.W.; Hallar, A.G.; Ban-Weiss, G.A.; McLaughlin, J.P.; Harley, R.A.; Lunden, M.M. (2010). Optical and Physical Properties of Primary On-Road Vehicle Particle Emissions and Their Implications for Climate Change. Journal of Aerosol Science 41, 36-50.
Ban-Weiss, G.A.; Lunden, M.M.; Kirchstetter, T.W.; Harley, R.A. (2010). Size-Resolved Particle Number and Volume Emission Factors for On-Road Gasoline and Diesel Motor Vehicles. Journal of Aerosol Science 41, 5-12.
Millstein, D.E.; Harley, R.A. (2009). Revised Estimates of Construction Activity and Emissions: Effects on Ozone and Elemental Carbon Concentrations in Southern California. Atmospheric Environment 43, 6328-6335.
Weaver, C.P. et al. (2009). A Preliminary Synthesis of Modeled Climate Change Impacts on U.S. Regional Ozone Concentrations. Bulletin of the American Meteorological Society 90, 1843-1863.
Millstein, D.E.; Harley, R.A. (2009). Impact of Climate Change on Photochemical Air Pollution in Southern California. Atmospheric Chemistry and Physics 9, 3745-3754.
Gentner, D.R.; Harley, R.A.; Miller, A.M.; Goldstein, A.H. (2009). Diurnal and Seasonal Variability of Gasoline-Related Volatile Organic Compound Emissions in Riverside, California. Environmental Science & Technology 43, 4247-4252.
Gilman, J.B. et al. (2009). Measurements of Volatile Organic Compounds during the 2006 TexAQS/GoMACCS Campaign: Industrial Influences, Regional Characteristics, and Diurnal Dependencies of the OH Reactivity. Journal of Geophysical Research 114, D00F06, doi: 10.1029/2008JD011525.
Ban-Weiss, G.A.; Lunden, M.M.; Kirchstetter, T.W.; Harley, R.A. (2009). Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks. Environmental Science & Technology 43, 1419-1424.
Kean, A.J.; Ban-Weiss, G.A.; Harley, R.A.; Kirchstetter, T.W.; Lunden, M.M. (2009). Trends in On-Road Vehicle Emissions of Ammonia. Atmospheric Environment 43, 1565-1570.
Tonse, S.; Brown, N.J.; Jin, L.; Harley, R.A. (2008). A Process-Analysis Based Study of the Ozone Weekend Effect. Atmospheric Environment 42, 7728-7736.
Ban-Weiss, G.A.; McLaughlin, J.P.; Harley, R.A.; Kean, A.J.; Grosjean, E.; Grosjean, D. (2008). Carbonyl and Nitrogen Dioxide Emissions from Gasoline- and Diesel-Powered Motor Vehicles. Environmental Science & Technology 42, 3944-3950.
Jin, L.; Tonse, S.; Cohan, D.; Mao, X.; Harley, R.A.; Brown, N.J. (2008). Sensitivity Analysis of Ozone Formation and Transport for a Central California Air Pollution Episode. Environmental Science & Technology 42, 3683-3689.
Steiner, A.L.; Cohen, R.C.; Harley, R.A.; Tonse, S.; Goldstein, A.H.; Millet, D.; Schade, G. (2008). VOC Reactivity in Central California: Comparing an Air Quality Model to Ground-Based Measurements. Atmospheric Chemistry and Physics 8, 351-368.
Millstein, D.E.; Harley, R.A.; Hering, S.V. (2008). Weekly Cycles in Fine Particulate Nitrate. Atmospheric Environment 42, 632-641.
Ban-Weiss, G.A.; McLaughlin, J.P.; Harley, R.A.; Lunden, M.M.; Kirchstetter, T.W.; Kean, A.J.; Strawa, A.W.; Stevenson, E.D.; Kendall, G.R. (2008). Long-Term Changes in Emissions of Nitrogen Oxides and Particulate Matter from On-Road Gasoline and Diesel Vehicles. Atmospheric Environment 42, 220-232.
Steiner, A.L.; Tonse, S.; Cohen, R.C.; Goldstein, A.H.; Harley, R.A. (2007). Biogenic 2-Methyl-3-Buten-2-ol Increases Regional Ozone and HOx Sources.Geophysical Research Letters 34, L15806, doi: 10.1029/2007GL030802.
Steiner, A.L.; Tonse, S.; Cohen, R.C.; Goldstein, A.H.; Harley, R.A. (2006). Influence of Future Climate and Emissions on Regional Air Quality in California.Journal of Geophysical Research 111, D18303, doi:10.1029/2005JD006935.
Harley, R.A.; Hooper, D.S.; Kean, A.J.; Kirchstetter, T.W.; Hesson, J.M.; Balberan, N.T.; Stevenson, E.D.; Kendall, G.R. (2006). Effects of Reformulated Gasoline and Motor Vehicle Fleet Turnover on Emissions and Ambient Concentrations of Benzene. Environmental Science & Technology 40, 5084-5088.
Martien, P.T.; Harley, R.A. (2006). Adjoint Sensitivity Analysis for a Three-Dimensional Photochemical Model: Application to Southern California. Environmental Science & Technology 40, 4200-4210.
Martien, P.T.; Harley, R.A.; Cacuci, D.G. (2006). Adjoint Sensitivity Analysis for a Three-Dimensional Photochemical Model: Implementation and Method Comparison. Environmental Science & Technology 40, 2663-2670.
Rubin, J.I.; Kean, A.J.; Harley, R.A.; Millet, D.B.; Goldstein, A.H. (2006). Temperature Dependence of Volatile Organic Compound Evaporative Emissions from Motor Vehicles. Journal of Geophysical Research 111, D03305, doi: 10.1029/2005JD006458.
Harley, R.A.; Marr, L.C.; Lehner, J.K.; Giddings, S.N. (2005). Changes in Motor Vehicle Emissions on Diurnal to Decadal Time Scales and Effects on Atmospheric Composition. Environmental Science & Technology, 39, 5356-5362.
Fortin, T.J.; Howard, B.J.; Parrish, D.D.; Goldan, P.D.; Kuster, W.C.; Atlas, E.L.; Harley, R.A. (2005). Trends in U.S. Benzene Emissions Derived from Atmospheric Measurements. Environmental Science & Technology, 39, 1403-1408.
Andrade, M.F.; Ynoue, R.Y.; Harley, R.; Miguel, A.H. (2004). Air Quality Model Simulating Photochemical Formation of Pollutants: the Sao Paulo Metropolitan Area, Brazil. International Journal of Environment and Pollution 22, 460-475.
McGaughey, G.R.; Desai, N.R.; Allen, D.T.; Seila, R.L.; Lonneman, W.A.; Fraser, M.P.; Harley, R.A; Pollack, A.K.; Ivy, J.M.; Price, J.H. (2004). Analysis of Motor Vehicle Emissions in a Houston Tunnel During the Texas Air Quality Study 2000. Atmospheric Environment 38, 3363-3372.
Hakami, A.; Harley, R.A.; Milford, J.B.; Odman, M.T.; Russell, A.G. (2004). Regional, Three-Dimensional Assessment of the Ozone Formation Potential of Organic Compounds. Atmospheric Environment 38, 121-134.
Fraser, M. P.; Buzcu, B.; Yue, Z. W.; McGaughey, G. R.; Desai, N. R.; Allen, D. T.; Seila, R. L.; Lonneman, W. A.; Harley, R. A. (2003). Separation of Fine Particulate Matter Emitted from Gasoline and Diesel Vehicles Using Chemical Mass Balancing Techniques. Environmental Science & Technology 37, 3904-3909.
Kean, A.J.; Harley, R.A.; Kendall, G.R. (2003). Effects of Vehicle Speed and Engine Load on Motor Vehicle Emissions. Environmental Science & Technology 37, 3739-3746.
Martien, P.T.; Harley, R.A.; Milford, J.B.; Russell, A.G. (2003). Evaluation of Incremental Reactivity and Its Uncertainty in Southern California. Environmental Science & Technology 37, 1598-1608.
Marr, L.C.; Harley, R.A. (2002). Modeling the Effect of Weekday-Weekend Differences in Motor Vehicle Emissions on Photochemical Air Pollution in Central California. Environmental Science & Technology 36, 4099-4106.
Parrish, D.D.; Trainer, M.; Hereid, D.; Williams, E.J.; Olszyna, K.J.; Harley, R.A.; Meagher, J.F.; Fehsenfeld, F.C. (2002). Decadal Change in Carbon Monoxide to Nitrogen Oxide Ratio in U.S. Vehicular Emissions. Journal of Geophysical Research 107(D12), 4140, doi: 10.1029/2001JD000720.
Marr, L.C.; Harley, R.A. (2002). Spectral Analysis of Weekday-Weekend Differences in Ambient Ozone, Nitrogen Oxide, and Non-methane Hydrocarbon Time Series in California. Atmospheric Environment 36, 2327-2335.
Marr, L.C.; Noblet, G.S.; Harley, R.A. (2002). Formation of Photochemical Air Pollution in Central California. 2. Impact of Revised Emissions on Eulerian Model Predictions. Journal of Geophysical Research 107(D6), 4048, doi: 10.1029/2001JD000690.
Marr, L.C.; Black, D.R.; Harley, R.A. (2002). Formation of Photochemical Air Pollution in Central California. 1. Development of a Revised Motor Vehicle Emission Inventory. Journal of Geophysical Research 107(D6), 4047, doi: 10.1029/2001JD000689.
Vuilleumier, L.; Bamer, J.T.; Harley, R.A.; Brown, N.J. (2001). Evaluation of Nitrogen Dioxide Photolysis Rates in an Urban Area Using Data from the Southern California Ozone Study. Atmospheric Environment 35, 6525-6537.
Kean, A.J.; Grosjean, E.; Grosjean, D.; Harley, R.A. (2001). On-Road Measurement of Carbonyls in California Light-duty Vehicle Emissions. Environmental Science & Technology 35, 4198-4204.
Harley, R.A.; McKeen, S.A.; Pearson, J.; Rodgers, M.O.; Lonneman, W.A. (2001). Analysis of Motor Vehicle Emissions During the Nashville/Middle Tennessee Ozone Study. Journal of Geophysical Research 106(D4), 3559-3567.
Vuilleumier, L.; Harley, R.A.; Brown, N.J.; Slusser, J.R.; Kolinski, D.; Bigelow, D.S. (2001). Variability in Ultraviolet Total Optical Depth During the Southern California Ozone Study (SCOS97). Atmospheric Environment 35, 1111-1122.
Kean, A.J.; Sawyer, R.F.; Harley, R.A. (2000). A Fuel-Based Assessment of Off-Road Diesel Engine Emissions. Journal of the Air & Waste Management Association 50, 1929-1939.
Harley, R.A.; Coulter-Burke, S.C.; Yeung, T.S. (2000). Relating Liquid Fuel and Headspace Vapor Composition for California Reformulated Gasoline Samples Containing Ethanol. Environmental Science & Technology 34, 4088-4094.
Kean, A.J.; Harley, R.A.; Littlejohn, D.; Kendall, G.R. (2000). On-Road Measurement of Ammonia and Other Motor Vehicle Exhaust Emissions. Environmental Science & Technology 34, 3535-3539.
Black, D.R.; Harley, R.A.; Hering, S.V.; Stolzenburg, M.R. (2000). A New, Portable, Real-Time Ozone Monitor. Environmental Science & Technology 34, 3031-3040.
Sawyer, R.F.; Harley, R.A.; Cadle, S.H.; Slott, R.; Gorse, R.A.; Norbeck, J.M.; Bravo, H.A. (2000). Mobile Sources Critical Review. Atmospheric Environment 34, 2161-2181.
Singer, B.C.; Harley, R.A. (2000). A Fuel-Based Inventory of Motor Vehicle Exhaust Emissions in the Los Angeles Area During Summer 1997. Atmospheric Environment 34, 1783-1795.
Marr, L.C.; Kirchstetter, T.W.; Harley, R.A.; Miguel, A.H.; Hering, S.V.; Hammond, S.K. (1999). Characterization of Polycyclic Aromatic Hydrocarbons in Motor Vehicle Fuels and Exhaust Emissions. Environmental Science & Technology 33, 3091-3099.
Kirchstetter, T.W.; Harley, R.A.; Kreisberg, N.M.; Stolzenburg, M.R.; Hering, S.V. (1999). On-Road Measurement of Fine Particle and Nitrogen Oxide Emissions from Light- and Heavy-Duty Motor Vehicles. Atmospheric Environment 33, 2955-2968. [See also CORRECTION].
Bergin, M.S.; Noblet, G.S.; Petrini, K.; Dhieux, J.R.; Milford, J.B.; Harley, R.A. (1999). Formal Uncertainty Analysis of a Lagrangian Photochemical Air Pollution Model. Environmental Science & Technology 33, 1116-1126.
Singer, B.C.; Kirchstetter, T.W.; Harley, R.A.; Kendall, G.R.; Hesson, J.M. (1999). A Fuel-Based Approach to Estimating Motor Vehicle Cold Start Emissions. Journal of the Air & Waste Management Association 49, 125-135.
Kirchstetter, T.W.; Singer, B.C.; Harley, R.A.; Kendall, G.R.; Hesson, J.M. (1999). Impact of California Reformulated Gasoline on Motor Vehicle Emissions. 2. Volatile Organic Compound Speciation and Reactivity. Environmental Science & Technology 33, 329-336.
Kirchstetter, T.W.; Singer, B.C.; Harley, R.A.; Kendall, G.R.; Traverse, M. (1999). Impact of California Reformulated Gasoline on Motor Vehicle Emissions. 1. Mass Emission Rates. Environmental Science & Technology 33, 318-328.
Singer, B.C.; Harley, R.A.; Littlejohn, D.; Ho, J.; Vo, T. (1998). Scaling of Infrared Remote Sensor Hydrocarbon Measurements for Motor Vehicle Emission Inventory Calculations. Environmental Science & Technology 32, 3241-3248.
Marr, L.C.; Morrison, G.C.; Nazaroff, W.W.; Harley, R.A. (1998). Reducing the Risk of Accidental Death Due to Vehicle-Related Carbon Monoxide Poisoning. Journal of the Air & Waste Management Association 48, 899-906.
Dreher, D.B.; Harley, R.A. (1998). A Fuel-Based Inventory for Heavy-Duty Diesel Truck Emissions. Journal of the Air & Waste Management Association 48, 352-358.
Miguel, A.H.; Kirchstetter, T.W.; Harley, R.A.; Hering, S.V. (1998). On-Road Emissions of Particulate Polycyclic Aromatic Hydrocarbons and Black Carbon from Gasoline and Diesel Vehicles. Environmental Science & Technology 32, 450-455.
Harley, R.A.; Sawyer, R.F.; Milford, J.B. (1997). Updated Photochemical Modeling for California's South Coast Air Basin: Comparison of Chemical Mechanisms and Motor Vehicle Emission Inventories. Environmental Science & Technology 31, 2829-2839.
Vuilleumier, L.; Harley, R.A.; Brown, N.J. (1997). First- and Second-Order Sensitivity Analysis of a Photochemically Reactive System (A Green's Function Approach). Environmental Science & Technology 31, 1206-1217.
McNair, L.A.; Harley, R.A.; Russell, A.G. (1996). Spatial Inhomogeneity in Pollutant Concentrations and Implications for Air Quality Model Evaluation. Atmospheric Environment 30, 4291-4301.
Kirchstetter, T.W.; Harley, R.A.; Littlejohn, D. (1996). Measurement of Nitrous Acid Emissions in Motor Vehicle Exhaust. Environmental Science & Technology30, 2843-2849.
Kirchstetter, T.W.; Singer, B.C.; Harley, R.A.; Kendall, G.R.; Chan, W. (1996). Impact of Oxygenated Gasoline Use on California Light-Duty Vehicle Emissions. Environmental Science & Technology 30, 661-670.
Singer, B.C.; Harley, R.A. (1996). A Fuel-Based Motor Vehicle Emission Inventory. Journal of the Air & Waste Management Association 46, 581-593.
Winner, D.A.; Cass, G.R.; Harley, R.A. (1995). The Effect of Alternative Boundary Conditions on Predicted Ozone Control Strategy Performance. Atmospheric Environment 29, 3451-3464.
Harley, R.A.; Cass, G.R. (1995). Modeling the Atmospheric Concentrations of Individual Volatile Organic Compounds. Atmospheric Environment 29, 905-922.
Harley, R.A.; Cass, G.R. (1994). Modeling the Concentrations of Gas-Phase Toxic Organic Air Pollutants: Direct Emissions and Atmospheric Formation.Environmental Science & Technology 28, 88-98.
Russell, A.G.; Winner, D.A.; Harley, R.A.; McCue, K.F.; Cass, G.R. (1993). Mathematical Modeling and Control of the Dry Deposition Flux of Nitrogen-Containing Air Pollutants. Environmental Science & Technology 27, 2772-2782.
Harley, R.A.; Russell, A.G.; Cass, G.R. (1993). Mathematical Modeling of the Concentrations of Volatile Organic Compounds: Model Performance Using a Lumped Chemical Mechanism. Environmental Science & Technology 27, 1638-1649.
Harley, R.A.; Russell, A.G.; McRae, G.J.; Cass, G.R.; Seinfeld, J.H. (1993). Photochemical Modeling of the Southern California Air Quality Study. Environmental Science & Technology 27, 378-388.
Harley, R.A.; Hannigan, M.P.; Cass, G.R. (1992). Respeciation of Organic Gas Emissions and the Detection of Excess Unburned Gasoline in the Atmosphere.Environmental Science & Technology 26, 2395-2408.
Pandis, S.N.; Harley, R.A.; Cass, G.R.; Seinfeld, J.H. (1992). Secondary Organic Aerosol Formation and Transport. Atmospheric Environment 26A, 2269-2282.
Harley, R.A.; Hunts, S.E.; Cass, G.R. (1989). Strategies for the Control of Particulate Air Quality: Least-Cost Solutions Based on Receptor-Oriented Models.Environmental Science & Technology 23, 1007-1014.