HR: 1400h
AN: A33A-05    [Abstracts]
TI: Measurements of Methylglyoxal and Aromatic Hydrocarbons during 06 MILAGRO Campaign
AU: Fortner, E
AF: Department of Atmospheric Sciences, Texas A&M University, 3150 TAMU, College Station, TX 77843-3150, United States
AU: * Zheng, J
EM: junzheng@ariel.met.tamu.edu
AF: Department of Atmospheric Sciences, Texas A&M University, 3150 TAMU, College Station, TX 77843-3150, United States
AU: Zhang, R
EM: zhang@ariel.met.tamu.edu
AF: Department of Atmospheric Sciences, Texas A&M University, 3150 TAMU, College Station, TX 77843-3150, United States
AU: Molina, L
AF: Molina Center for Energy & the Environment, 3262 Holiday Ct. Suite 201, La Jolla, CA 92037, United States
AB: Methylglyoxal (CH3COCHO) is produced in the atmosphere from photochemical oxidation of volatile organic compounds (VOCs). Oxidation of anthropogenic aromatics (toluene, xylenes, or trimethylbenzenes) and biogenic isoprene leads to a significant production of methylglyoxal in the urban and regional atmospheres. For example, the molar molecular yield of methylglyoxal is about 0.9 from 1,3,5-trimethylbenzene oxidation and 0.4 to 0.16 for toluene oxidation. In the gas-phase, photolysis or reaction with the OH radical has been identified as the major loss process for methylglyoxal, with the lifetimes of about 1-3 h during the daytime. Recently, it has been suggested that aerosol-phase reactions of methylglyoxal contribute to secondary organic aerosol (SOA) formation, by forming low-vapor pressure oligomers in the aerosols. Measurements of methylglyoxal and aromatic hydrocarbons using proton transfer-reaction mass spectrometer (PTR-MS) during the MILAGRO field campaign will be presented. The implications of the results on SOA formation will be discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly