Grantee Research Project Results

2012 Progress Report: Improving Emission Inventories Using Direct Flux Measurements and Modeling

EPA Grant Number: R834556
Title: Improving Emission Inventories Using Direct Flux Measurements and Modeling
Investigators: Schade, Gunnar W. , Collins, Don , Ying, Qi
Institution: Texas A & M University
EPA Project Officer: Chung, Serena
Project Period: April 1, 2010 through March 31, 2014
Project Period Covered by this Report: April 1, 2012 through March 31,2014
Project Amount: $499,992
RFA: Novel Approaches to Improving Air Pollution Emissions Information (2009) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air

Objective:

Measure VOC and criteria air pollutant fluxes from the Yellow Cab tower on a semi-continuous basis.
Extend the current measurements by a novel particulate matter (PM) number density flux technique based on REA.
Carry out flux footprint modeling and subsequent overlays with various GIS data sets to determine flux contributions from the surrounding urban areas.
Create bottom-up emission fluxes from onsite roadways using detailed traffic surveys and MOBILE6 and MOVES modeling. Compare predicted to measured fluxes.
Use comparisons to identify inventory shortfalls and create modified inventories used in alternative scenarios of air quality modeling on larger scales.

Progress Summary:

Measurements of energy, CO₂, and selected criteria pollutant fluxes were operational throughout 2012. Volatile hydrocarbon and aerosol fluxes were operational during selected periods in 2012. Traffic counts to support data interpretation and modeling were conducted once during the third year, June/July 2012. Data processing and analysis is ongoing.

Data analysis shows expected results for criteria pollutants: Variability is high but monthly averages are highly significant. Diurnal, seasonal, and directional dependencies are observed. Traffic dominates CO and NOx emissions at this site, which have, however, been dropping since 2008 when first measured at this site. NMHC fluxes have also been dropping (by 10-15%/yr) since first measured in 2008. Submicron particle fluxes were identified, and found to be highest during early to mid-afternoon periods, possibly a result of intense atmospheric chemistry. Evaluation of earlier flux data using multivariate modeling is near complete and can be submitted for publication soon. Results show a lack of improvement of the new MOVES model over MOBILE6 for CO and NOx emissions, and significant contributions to measured VOC fluxes from a non-reporting source.

Future Activities:

Continue data analysis and modeling. Use traffic counts to develop half-hourly emission data for local conditions; compare bottom-up emissions using footprint overlays with measured flux data.

Journal Articles:

No journal articles submitted with this report: View all 10 publications for this project

Supplemental Keywords:

Mobile sources, pollutant exposure, human health, particulates, solvents, carbon monoxide, nitrogen oxides, BTEX public policy, decision making meteorology, monitoring, remote sensing, DMA, CPC, GIS, CMB, PMF south central, EPA Region 6

Relevant Websites:

Energy and trace gas flux measurements from a tall lattice tower near downtown Houston, Texas Exit

Progress and Final Reports:

Original Abstract

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.