2011 Progress Report: 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 Madison
EPA Project Officer: Hunt, Sherri
Project Period: March 1, 2007 through February 28, 2011 (Extended to February 28, 2013)
Project Period Covered by this Report: March 1, 2011 through February 28,2012
Project Amount: $900,000
RFA: Consequences of Global Change For Air Quality (2006) RFA Text |  Recipients Lists
Research Category: Climate Change , Air , Global Climate Change

Objective:

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.

Progress Summary:

The SO-WRF-CHEM6D model has been enhanced so that it conserves two moments (number and mass) to enable realistic calculations of particle activation and aerosol-cloud interactions.

The source-oriented particles within the SO-WRF-CHEM6D framework have been interfaced with an enhanced version of the Lin microphysics scheme to enable calculations of the direct and indirect effects of aerosols on meteorology. Particle activation is based on the chemical composition of each source-oriented particle combined with Kohler theory. Tests conducted for a Tule Fog episode in January 2011 yield encouraging results. 

SO-WRF-CHEM6D simulations using Large Eddy Simulation (LES) have incorporated plume-rise calculations for ships in the vicinity of the Port of Oakland. The time series of PM composition measurements at the community of Oakland have been analyzed using Positive Matrix Factorization (PMF) to provide a PM2.5 source-contribution dataset that can be compared to SO-WRF-CHEM6D model predictions. 

Three manuscripts have been published on the results of tests that examine the effects of fuel and environmental conditions on emissions from compression ignition and spark ignition vehicles. The first study examined the effects of fuel additives on emissions from diesel engines. The second and third studies examined how the blending of petroleum diesel and biodiesel affects the composition of the particles emitted from diesel engines.

A draft manuscript has been prepared for a study to examine the effect of changes in ambient temperature and fuel type in fine particle emissions from light-duty vehicles, including a gasoline-electric hybrid vehicle, a CNG-gasoline dual fuel vehicle, an ethanol-gasoline blends flex fuel vehicle and a CNG powered vehicle. These vehicles were tested in a chassis dynamometer under controlled conditions of ambient temperature following three back-to-back LA92 Unified driving cycles under hot start. Although an increase in ambient temperature results in decreases of about 30% in total particle emissions throughout a whole test, particle number concentrations as a function of time, and particle number size distributions showed that for all tested vehicles, there is no clear effect of ambient temperature in fine particle emissions at the selected ambient temperature range. Results from the flex fuel vehicle tests operating with E0, E6, E35, E65 and E85 fuel blends showed a clear decreasing trend in fine particle emissions when increasing the ethanol content in the fuel blend.

A draft manuscript has been completed for a study to examine the implications of changes in black carbon emissions through the strategic use of biodiesel blends. The results indicate that blending biodiesel with traditional diesel produces important reductions in BC emissions from an agricultural tractor. Comparisons to projections of global and North American CO2 and BC emissions leads to the conclusion that the strategic use of biodiesel blends in diesel-powered vehicles could produce an immediate reduction in global warming rates.

A draft manuscript has been completed for a study to examine how the amount of dilution air used during emissions testing affects the apparent EC absorption efficiency for a diesel engine. These results demonstrate how estimating emissions, based on BC measurements of emissions, can be biased and underscores the importance of establishing a consistent framework for accounting for light absorbing carbon from sources to atmospheric impacts.

Future Activities:

Three additional manuscripts are still in progress with submission planned during summer and fall of 2012:

1) Magara-Gomez, K.T., Olson, M.R. and Schauer, J.J. Sensitivity of PM particle distributions from emissions of light-duty gasoline-powered vehicles to temperature and fuel. To be submitted to Atmospheric Environment (In preparation).

2) Magara-Gomez, K.T., Olson, M.R. and Schauer, J.J. Reduction in black carbon emissions through the strategic use of biodiesel. To be submitted to Environmental Research Letter (In preparation).

3) Magara-Gomez, K.T., Olson, M.R. and Schauer, J.J. Development of black carbon emissions inventory: Biases to BC measurement from sources. To be submitted to Atmospheric Environment (In preparation).

During the coming reporting period we will fully link the source-oriented variables and the cloud chemistry models in the WRF-CHEM calculations. Simulations will be conducted for the state of California during the years 2000 and 2050. Results will be compared to simulations using the WRF model coupled (offline) with the UCD source-oriented air quality model. 


Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other project views: All 6 publications 6 publications in selected types All 6 journal articles
Type Citation Project Document Sources
Journal Article Magara-Gomez KT, Olson MR, Okuda T, Walz KA, Schauer JJ. Sensitivity of hazardous air pollutant emissions to the combustion of blends of petroleum diesel and biodiesel fuel. Atmospheric Environment 2012;50:307-313. R833372 (2011)
R833372 (Final)
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  • Journal Article Magara-Gomez KT, Olson MR, Okuda T, Walz KA, Schauer JJ. Sensitivity of diesel particulate material emissions and composition to blends of petroleum diesel and biodiesel fuel. Aerosol Science and Technology 2012;46(10):1109-1118. R833372 (2011)
    R833372 (Final)
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  • Journal Article Okuda T, Schauer JJ, Olson MR, Shafer MM, Rutter AP, Walz KA, Morschauser PA. Effects of a platinum-cerium bimetallic fuel additive on the chemical composition of diesel engine exhaust particles. Energy & Fuels 2009;23(10):4974-4980. R833372 (2008)
    R833372 (2009)
    R833372 (2010)
    R833372 (2011)
    R833372 (Final)
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  • Journal Article Zhang H, Magara-Gomez KT, Olson MR, Okuda T, Walz KA, Schauer JJ, Kleeman MJ. Atmospheric impacts of black carbon emission reductions through the strategic use of biodiesel in California. Science of the Total Environment 2015;538:412-422. R833372 (2011)
    R833372 (Final)
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  • Supplemental Keywords:

    SO-WRF-CHEM6D, 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

    Relevant Websites:

    UC Davis: Professor Michael Kleeman Exit

    Progress and Final Reports:

    Original Abstract
  • 2007 Progress Report
  • 2008 Progress Report
  • 2009 Progress Report
  • 2010 Progress Report
  • Final Report