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Extramural Research

Impact of Global Change on Urban Air Quality via Changes in Mobile Source Emissions, Background Concentrations, and Regional Scale Meteorological Feedbacks

EPA Grant Number: R833372
Title: Impact of Global Change on Urban Air Quality via Changes in Mobile Source Emissions, Background Concentrations, and Regional Scale Meteorological Feedbacks
Investigators: Kleeman, Michael J. , Chen, Shuhua , Schauer, James J.
Institution: University of California - Davis , University of Wisconsin
EPA Project Officer: Dawson, John P
Project Period: March 1, 2007 through February 28, 2011 (Extended to February 28, 2013)
Project Amount: $900,000
RFA: Consequences of Global Change For Air Quality (2006)
Research Category: Global Climate Change



Ozone (O3) and particulate matter (PM) standards designed to protect public health are routinely violated in California’s South Coast Air Basin (SoCAB) surrounding Los Angeles and the San Joaquin Valley (SJV) in central California. Global change will affect air quality in California through adoption of new technology, altered background concentrations, and evolving meteorological conditions. The magnitude and direction of these effects are unknown, and so the true public health costs of Global Change can not be quantified at this time.


The current project aims to quantitatively assess the consequences of Global Change on California air quality by (1) measuring emissions from mobile sources powered by alternative fuels as a function of temperature and humidity, (2) creating a source-oriented PM module for the Weather Research & Forecasting (WRF) model to quantify feedback between air quality and regional meteorology, and (3) calculating California air quality in the year 2030 during a range of O3 and PM2.5 pollution events.

Emission rates and composition from light duty vehicles powered by gasoline, gasoline-electric hybrid, and ethanol blends will be measured as a function of temperature and humidity. Emissions from heavy duty engines powered by diesel and biodiesel will also be measured as a function of temperature and humidity. These emissions profiles will be used during simulations of future air quality in California in the presence of altered temperature and humidity. Predictions of future climate produced by Global Climate Models will be dynamically downscaled to the regional scale using the Weather Research and Forecasting (WRF) meteorological model. A source-oriented PM module will be integrated into WRF to study the interactions between pollution and local meteorology. The new model will be used to compare current air pollution episodes in California with those that are expected to occur in the year 2030. Multiple episodes (~30) will be studied in current and future periods to understand the distribution of possible events.

Expected Results:

The source profiles measured during the current project will be useful for all future simulations of air pollution in the United States. The specific model predictions created in this project will contribute to the “weight-of-science” evaluation for the effect of Global Change on urban and regional air quality.

Publications and Presentations:

Publications have been submitted on this project: View all 5 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 5 journal articles for this project

Supplemental Keywords:

source-oriented external mixture air quality model, dilution sampling, E85,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Air Quality, Air Pollutants, Chemistry, climate change, Air Pollution Effects, Monitoring/Modeling, Atmospheric Sciences, Environmental Engineering, Atmosphere, ambient aerosol, environmental monitoring, anthropogenic stress, atmospheric dispersion models, aerosol formation, atmospheric particulate matter, meteorology, climatic influence, emissions monitoring, future projections, air quality models, ozone, global change, atmospheric transport, greenhouse gases, climate models, atmospheric aerosol particles, airborne aerosols, environmental stress, regional emissions model, climate model, ecological models, greenhouse gas, aerosols, atmospheric chemistry, climate variability, Global Climate Change, ambient air pollution

Progress and Final Reports:
2007 Progress Report
2008 Progress Report
2009 Progress Report
2010 Progress Report
2011 Progress Report
Final Report

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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