Impact/Purpose:

To use the tools of radiocarbon (14C) and gas chromatographic (GC) analysis combined with various receptor models to determine the contributions of sources to ambient VOC, and indirectly their contribution to tropospheric ozone via their role as sources of ozone precursors.

Description:

Source apportionment (receptor) models are mathematical procedures for identifying and quantifying the sources of ambient air pollutants and their effects at a site (the receptor), primarily on the basis of species concentration measurements at the receptor, and generally without need of emissions and meteorological data. NERL's ozone source apportionment program covers both measurements and modeling and includes (1) radiocarbon (14C) determination of biogenic content of volatile organic compounds (VOC); (2) receptor model applications; and (3) VOC source profile/flux measurement and analysis.

Record Details:

Record Type:PROJECT

Start Date:10/01/1999

Completion Date:09/01/2001

Record ID: 56180

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Project Information:

Progress :During FY00 -- GC analyses of gasoline samples collected during Nashville99 have been completed. Ambient samples for VOC radiocarbon measurements, and gasoline and tunnel samples, have been collected during the Texas 2000 Air Quality Study. Similar samples have been collected in the Milwaukee-Chicago area.

NERL/HEASD

ABSTRACT/ORAL

Date Cleared - Citation

08-DEC-99 - Lewis, C.W. VOC radiocarbon measurements during SCOS97 and emissions inventory validation. Abstract presented at: CARB Biogenic Hydrocarbons Symposium, Sacramento, CA, December 9-10, 1999.

SYMPOSIUM/CONFERENCE

Date Cleared - Citation

24-JAN-00 - Klouda, G.A., Lewis, C.W., Rasmussen, R.A., Stiles, D.C., Ellenson, W.D., and Marolf, J.L. Isotopic (14C) and chemical composition of atmospheric volatile organic compound fractions - precursors to ozone formation. Proceedings of the Third International Conference on Isotopes, Vancouver, BC, September 6 - 10, 1999.

Relevance :This task supports GPRA Goal 1 (Clean Air) through the related APG and APM listed below. Radiocarbon measurements on VOC ambient samples carried out under this task are intended to provide definitive answers to the longstanding question of how important are VOC biogenic emissions to the formation of tropospheric ozone. The answers are critical to formulating an effective ozone abatement strategy. The source apportionment modeling activities under this task are intended to demonstrate the viability of recent receptor models (e.g., UNMIX) to provide quantitative estimates of the contributions that source emissions make to measured concentrations of ambient VOC. Such models are required to meet the objectives of EPA's nationwide Photochemical Assessment Monitoring Stations (PAMS) network.

Clients :NARSTO, SOS

Project IDs:

ID Code :5670

Project type :OMIS