HR: 1340h
AN: A33D-1543    [Abstracts]
TI: PANs measurements on board theNOAA P-3 during TexAQS-II
AU: * Zheng, W
EM: wengang@ucar.edu
AF: National center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305, United States
AU: Flocke, F M
EM: ffl@ucar.edu
AF: National center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305, United States
AU: Ryerson, T B
EM: Thomas.B.Ryerson@noaa.gov
AF: National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80303, United States
AU: Trainer, M K
EM: Michael.K.Trainer@noaa.gov
AF: National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80303, United States
AU: Atlas, E L
EM: eatlas@rsmas.miami.edu
AF: RSMAS - University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Schauffler, S
EM: sues@ucar.edu
AF: National center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305, United States
AU: Donnelly, S
EM: sdonnell@fhsu.edu
AF: Fort Hays State University, 600 Park St # 1, Hays, KS 67601, United States
AU: Holloway, J S
EM: John.S.Holloway@noaa.gov
AF: National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80303, United States
AB: Measurements of peroxycarboxylic nitric anhydrides (PANs, i.e. PAN, PPN, PiBN, APAN, MPAN, and MoPAN) were made using the NCAR PAN-CIGARette chemical ionization mass spectrometer on board the NOAA P-3 aircraft during the 2006 Texas Air Quality Study II (TexAQS-II). In this poster, we present the PANs measurements made during the flight on September 27th as a case study. Two separate plumes from Downtown Houston and the Houston Ship Channel were transported in parallel to the north on that day. The flight track crossed these plumes 8 times at increasing distances downwind, and according to the CO distribution, dilution with surrounding air masses was very slow. These conditions make this very nice case for a pollutant transport and chemistry study. The PAN/PPN ratio increased about 18% as the air mass moved away from the pollution source to the furthest leg which is about 130 km north of downtown Houston. As the photolysis rates for PAN and PPN are similar to each other and the thermal decomposition of PAN is faster than PPN, this ratio change is most likely owing to the difference in the chemistry of the source hydrocarbons for these two PAN species, and indicates a faster depletion of PPN precursors (mainly propanal and 1-butene) as the air masses get older. Also, the relative production of ozone and PANs for the Houston city plume and the ship channel plume are analyzed and compared for this flight, demonstrating the difference in the photochemical processes for urban pollution vs. petroleum industry emissions.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting