Using a mobile laboratory to characterize gas and particle emissions during the study of Houston area radical precursors SHARP-2009

The formation of ozone and secondary aerosol is driven by atmospheric chemical reaction cycles that involve radicals. Major radical sources include photolysis of ozone, formaldehyde and nitrous acid. Direct emissions of radical precursors, such as formaldehyde can accelerate the production of secondary pollutants. Several compounds emitted from petrochemical refining and chemical production facilities are highly reactive volatile organic compounds (HR-VOC). The measurements undertaken during the Study of Houston Area Radical Precursors (SHARP) were designed to improve inventory assessments of industrial HR-VOC emissions as well as understand the near field plume evolution from unique partial combustion point sources such as industrial flares. The measurements were conducted using a mobile laboratory equipped with real-time, in-situ sampling instrumentation for several of the top HR-VOC compounds and other combustion tracer compounds. The mobile laboratory was maneuvered downwind from several industrial facilities during the campaign. These measurements have been evaluated using a state of the art dispersion model. The sampling method, plume characteristics, and model comparison will be discussed. The measurement effort was coordinated with other approaches, including open path techniques and airborne sampling methods. The preliminary comparison of source strengths will be discussed. Where these results fit within the objectives of SHARP will be detailed.