HR: 1340h
AN: A33A-0813    [Abstracts]
TI: Measurements of Extensive Aerosol Optical Properties During TexAQS II: Implications for PM Compliance and Planning
AU: * Wright, M E
EM: wrightm@pdx.edu
AF: Portland State University, Department of Chemistry Post Office Box 751, Portland, OR 97207-0751, United States
AU: Atkinson, D B
EM: atkinsond@pdx.edu
AF: Portland State University, Department of Chemistry Post Office Box 751, Portland, OR 97207-0751, United States
AU: Luke, W T
EM: Winston.Luke@noaa.gov
AF: NOAA/Air Resources Laboratory, SSMC3, Rm. 3316 1315 East West Hwy., Silver Spring, MD 20910, United States
AB: In 2000, the Houston-Galveston Area (HGA) was designated as a non-attainment area for several criteria air pollutants by the US EPA. In order to meet the requirements of the federal Clean Air Act, the Second Texas Air Quality Study (TexAQS II) was designed to update the State Implementation Plan (SIP) by providing scientific air quality data over 18 months from June 2005 to October 2006. The data presented here was collected as part of the Texas Radical and Aerosol Measurement Program (TRAMP), a substudy of TexAQS II. Bulk aerosol optical properties were measured for six weeks atop the 60 m high Southwest Moody Tower on the University of Houston campus. The measurements were collected using a cavity ring-down transmissometer/nephelometer (CRDT/N) and consisted of the extensive aerosol coefficients: extinction (b_ext) at 532 and 1064 nm and scattering (b_scat) at 530nm. In addition to daily and whole study averages and calculated mass values, positive correlations between the 1064 nm extinction and 532 nm absorption (b_abs = b_ext - b_scat) values are displayed for this study period for the first time. Correlation between the particle scattering coefficient and the sum of AMS measured (UNH – PI: R. Griffin) sulfate and organic particle mass concentrations as well as covariance between optical properties and O₃, CO and NO_x values (ARL/NOAA – PI: W. Luke) are also examined. No correlation is expected between coarse particles (PM₁₀), which are typically primary biogenic suspended soil minerals or windblown dust, and high ozone concentrations. Ozone levels are highest during periods of low wind when coarse particulate is likely to be at a minimum. On the other hand, secondary particles and O₃ should be correlated on short time scales because both species tend to have the same precursors, NO_x and VOC's, and formation of particles is favored during stagnant conditions. Fine particles (PM_2.5) should also correlate with CO since both species have a common emission source. Wind roses are compared with pollution roses for each week of the study period, allowing for cluster analysis. Overall, the optical properties appear to be an effective measure of air quality when compared to other measurement techniques. Implications for aerosol effects on regional climate from long-range transport and synoptic scale recirculation are discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 1600 GLOBAL CHANGE
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting