2008 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: Chung, Serena
Project Period: March 1, 2007 through February 28, 2011 (Extended to February 28, 2013)
Project Period Covered by this Report: March 1, 2008 through February 28,2009
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


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:

After consultation with the WRF developers, support for 5D and 6D arrays was incorporated into WRF by the NCAR/NOAA development team.  These features are needed to support the source-oriented WRF-CHEM model.
A new version of WRF-CHEM (3.1) has been installed on Professor Chen’s computer cluster and is in the process of being installed on Professor Kleeman’s computer cluster.  The new version includes the capability to transport 5D and 6D arrays as well as numerous small bug fixes. 
Thirty five nodes of the Kleeman computer cluster were upgraded to quad core systems with 4GB of memory each to support development of the source-oriented WRF-CHEM model.
A new student has been recruited and trained for development of the source-oriented WRF-CHEM model.  The student will complete all relevant class work needed to support this research by the end of the academic year and will take on primary responsibility for the development of the source-oriented WRF model.  All of the previous development work completed by Professor Kleeman during his sabbatical year has been transferred to the new student.
The chemical analysis and data analysis of the fuel based catalyst (FBC) emissions tests was completed.  A manuscript describing the FBC results that has been submitted for publication in the journal Energy and Fuel
A series of tests addressing the impact of biofuel blends on emissions from off-road diesel engines has been completed.  Data analysis of these results is also finalized.
A series of tests looking at the impact of temperature and fuel on emissions of gasoline engines has been completed.  Data analysis is ongoing.
Research Progress-to-Date:
Objective 1:  Emissions (CO, NOx, SOx, NH3, VOC, and PM) from motor vehicles powered by bio-diesel, ethanol, gasoline-hybrid, and hydrogen will be measured at different temperature and humidity so that the effects of climate change on future air pollution emissions can be calculated correctly.  Full profiles for detailed organic species within the VOC fraction will be developed, along with size and composition profiles for particulate matter emissions. 
Progress:  A series of fuel-based catalyst (FBC), bio-diesel, and gasoline emissions tests were conducted in the second year of the project.  The FBC emissions tests utilize a commercial cerium-platinum additive that has been approved by the EPA for certain applications and has gained considerable interest due to the fact that the additive can improve fuel efficiency and can significantly reduce emissions as a retrofit strategy.  The negative aspect of the FBC is that when operated without a diesel particulate filter, the metal additive is emitted into the environment.  The manuscript generated as part of this project was the first detailed characterization of the impact of FBC on the particulate matter emissions from a diesel engine.  The results demonstrate significant reduction in PM and EC emissions along with the emissions of metals, whose environmental impacts are not well understood.  The results are summarized in the following manuscript:
 T. Okuda, J. J. Schauer, M. R. Olson, M. M. Shafer, A. P. Rutter, K. A. Walz, and P. A. Morschauser.  Effects of a platinum-cerium bimetallic fuel additive on the chemical composition of diesel engine exhaust particles.  Submitted to Energy & Fuel.  (Submitted:  April 2009).
The off-road biodiesel experiments utilized and commercial tractor that was operated on an off-road cycle that operated on a Power-Take Off (PTO) dynamometer that simulated the tractor being used to operate auxiliary machinery.  The tractor was operated with blends of petroleum and biodiesel that included soybean oil and tallow biodiesel at blends consisting of B0, B25, B50, B75, and B100.  Chemical measurements have been completed and data analysis is currently underway.  Several manuscripts are planned that cover these experiments,
A series of gasoline powered vehicle tests were conducted in the California Air Resources Board (CARB) dynamometer facility in El Monte, CA, that were directed at understanding the role of ambient temperature on particulate matter emissions from gasoline powered vehicles and the role of fuel composition emissions.  Fuels that were examined included commercial petroleum gasoline, E10, E85, intermediate blends of E85 and petroleum gasoline, and NG.  The chemical measurements made during these tests are mostly complete and data analysis has started and is expected to be completed this fall. 
Objective 2:  A source-oriented external mixture PM module will be implemented in the Weather Research & Forecasting (WRF) model to study feedbacks between air quality and regional-scale meteorology through the interaction of PM with radiation processes and cloud microphysics. 
Progress:   Before version WRF V3.1, WRF_CHEM could track concentration variables or chemistry species with up to 4 dimensions (x,y,z,species) only, and the advection and some physics effects for pollutants calculation were taken care in the model. Working with the WRF chemistry group and professors Kleeman and Chen at UCD and, John Michalakes, the primary WRF software architecture developer, has implemented the capability of creating variables up to 6 dimensions in the WRF Registry in recently released WRF V3.1. This higher dimension capability can accommodate two extra dimensions for size-resolved and source-oriented concentrations that are required for our project.  However, unlike 4D variables neither the pollutant emission nor the calculations of pollutant advection and physics parameterization associated with those high-dimensional variables were implemented.  Therefore, Kleeman has worked on the higher dimension emission data in NETCDF, which is the standard I/O data format for the WRF model. Chen has also built a preliminary version of WRF model based on V3.1 to include the advection and physics effects for a 6 dimensional tracer with a simple hard coded emission function in the model and the code is still under testing.  Once the code is ready, we will test a real case with real emission data. 
Thirty five nodes of the Kleeman computer cluster were upgraded to quad core systems with 4GB of memory each to support development of the source-oriented WRF-CHEM model.
Objective 3:  Simulations of Global Climate produced by the Parallel Climate Model (PCM) under Business as Usual, SRES B1, and A1FI emissions scenarios will be examined to determine how Global Change affects air quality in California in future years. 
Progress:  A large number of WRF simulations have been carried out for California using the PCM inputs for the period 2000-07 and 2047-53.  Source-oriented WRF-CHEM simulations will commence once objectives 1+2 have been accomplished.

Future Activities:

Future measurement efforts are directly at completing chemical measurement and data analysis for the tests that have already been completed, which will be the basis of several manuscripts.  The specifics of future testing will in part depend on the results of the completed tests but are will be directed at the following questions: 1) Role of ambient temperature of diesel engine emissions, 2) impact of biofuels on current and future on-road diesel engine technologies, and 3) the role of seed aerosol on emissions of particulate matter from gasoline and diesel engines. 

During the coming reporting period we will link the source-oriented netcdf emissions with the 5D and 6D particle composition arrays in WRF to perform source-oriented WRF-CHEM simulations.  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 : 1 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 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)
  • Full-text: ACS-Full Text HTML
  • Abstract: ACS-Abstract
  • Other: ACS-Full Text PDF
  • Supplemental Keywords:

    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:

    http://cee.engr.ucdavis.edu/faculty/kleeman/ Exit

    Progress and Final Reports:

    Original Abstract
  • 2007 Progress Report
  • 2009 Progress Report
  • 2010 Progress Report
  • 2011 Progress Report
  • Final Report