ARB Research Seminar

This page updated May 26, 2015

Evaluation of Regional Isoprene Emission Estimates in California Based on Direct Airborne Flux Measurements

Photo of Allen Goldstein

Allen Goldstein

Photo of Pawel Misztal

Pawel Misztal

Allen H. Goldstein, Ph.D., Department of Civil and Environmental Engineering and Department of Environmental Science, Policy, and Management; Pawel K. Misztal, Ph.D., Department of Environmental Science, Policy, and Management, University of California, Berkeley

June 12, 2015
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


Accurately modeled Biogenic Volatile Organic Compound (BVOC) emissions are an essential input to atmospheric chemistry simulations of ozone and particle formation. BVOC emission models originate from leaf and branch level measurements with scaling to regional or larger spatial levels based on vegetation landcover data derived Basal Emission Factors (BEFs), but they generally lack validation by regional scale measurements. We directly assess isoprene emission-factor databases for BVOC emission models by deriving BEFs from direct airborne fluxes aggregated at 2 km resolution and averaged spatially over ecoregions covering ~10,000 km of California. Ecoregion averaged BEFs from the landcover used by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) v. 2.1 BVOC emission model agreed within 10% (r²=0.82) with measured BEFs, with few discrepancies (either overestimation or underestimation). Independently, we found the BVOC emission model from the California Air Resources Board averaged for the same flight times and averaged for the same flux footprints as actual measured area emissions agreed on average within 20% (r²=0.96). We show that the choice of model landcover input data has the most critical influence on model-measurement agreement and the uncertainty in meteorology inputs has a lesser impact at scales relevant to regional air quality modeling.

Speaker Biography

Allen H. Goldstein, Ph.D., is currently a Professor in the Department of Civil and Environmental Engineering and in the Department of Environmental Science, Policy, and Management, at the University of California, Berkeley where he served as department chair from 2007-2010. Professor Goldstein is also currently the co-Chair of the International Global Atmospheric Chemistry Program (IGAC). Dr. Goldstein's research program encompasses anthropogenic air pollution, biosphere-atmosphere exchange of radiatively and chemically active trace gases, and development and application of novel instrumentation to investigate the organic chemistry of earth's atmosphere. He engages in field measurement campaigns, controlled laboratory experiments, and modeling activities covering urban, rural, regional, intercontinental, and global scale studies of ozone, aerosols, and their gas phase precursors.

Dr. Goldstein's comprehensive research questions include: What controls atmospheric concentrations of greenhouse gases, photochemical oxidants, and aerosols? How do terrestrial ecosystems interact chemically and physically with earth's atmosphere? Professor Goldstein has published more than 250 peer-reviewed articles and holds a patent (with Susanne Hering) for On-Line Gas Chromatographic Analysis of Airborne Particles. His honors include being elected a fellow of the American Geophysical Union (2011), selected as a Miller Foundation Researcher Professor (2010-11), and a Fulbright Senior Scholar in Australia (2005).

Professor Goldstein received his BA and BS degrees from the University of California at Santa Cruz in politics and chemistry, and his MA and PhD degrees in chemistry from Harvard University.

Pawel K. Misztal, Ph.D., is currently a postdoctoral research scholar in the Department of Environmental Science, Policy, and Management, at the University of California, Berkeley. His research focuses on biosphere-atmosphere flux measurements of Volatile Organic Compounds (VOC) and the processes controlling their emission and deposition.

Dr. Misztal has published more than 20 peer reviewed papers including research on ground based direct fluxes from tropical oil palm plantations and rainforest ecosystems in Borneo and developed methodologies for enhanced detection of structural isomers for proton transfer reaction mass spectrometry. Dr. Misztal was responsible for planning, executing and processing of the CABERNET airborne VOC flux campaign and collaborating with CARB modelers. In his recent papers he has demonstrated how isoprene emissions are distributed in California and demonstrated CARB's biogenic emission models accurately simulate these emissions in California. Dr Misztal has been active in growing the airborne flux measurement community through contributing to research projects at NASA, NCAR, NOAA, PNNL and globally.

Dr. Misztal received his BSc and MSc degrees in Chemistry and Physics from Maria Curie-Sklodowska University in Poland, and PhD in Environmental Chemistry from the University of Edinburgh in the United Kingdom.

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