HR: 0800h
AN: A31C-0063    [Abstracts]
TI: Chemical Analysis of Aerosols for Characterization of Long-Range Transport at Mt. Lassen, CA
AU: * Harada, Y
EM: yharada@ucdavis.edu
AF: University of California, Department of Chemistry, Davis, Ca 95616 United States
AU: Waddell, J A
EM: jawaddell@ucdavis.edu
AF: University of California, Department of Chemistry, Davis, Ca 95616 United States
AU: Cliff, S S
EM: sscliff@ucdavis.edu
AF: University of California, Department of Applied Science, Davis, CA 95616 United States
AU: Perry, K D
EM: perry@met.utah.edu
AF: University of Utah, Department of Meteorology, Salt Lake City, UT 84112-0110 United States
AU: Kelly, P B
EM: pbkelly@ucdavis.edu
AF: University of California, Department of Chemistry, Davis, Ca 95616 United States
AB: Effective regional air pollution regulation requires an understanding of long-range aerosol transport and natural aerosol chemistry. Sample collection was performed at the Interagency Monitoring of Protected Visual Environments (IMPROVE) sampling site on Mt. Lassen in the Sierra Nevada range at 1755 m elevation. The site is in Northern California at Longitude 121ø 34' 40", Latitude 40ø 32' 25". Size segregated and time resolved aerosol samples were collected with an 8 DRUM sampler from April 15th to May 24th 2002 as part of the NOAA Intercontinental Transport and Chemical Transformation Experiment (ITCT). The samples were analyzed with Synchrotron X-Ray Fluorescence (S-XRF) and Time of Flight mass spectroscopy (TOFMS). The total aerosol concentration exhibits a clear daily cycling of total mass, due to a nighttime down-slope air circulation from the free troposphere. The sulfate peaked in concentration during the night. Elemental data is suggestive of dust transport from continental Asia. The micron size ranges were dominated by nitrate, while the sub-micron size ranges had high levels of sulfate. Chemical analysis shows oceanic influence through strong correlations between methyl sulfonic acid (MSA), iodine, and oxalate. The appearance of the oceanic biogenic tracers in the sub-micron fraction is most likely a result of vertical mixing over the Pacific Ocean. MSA follows a diurnal pattern similar to sulfate, however the differences suggest both an oceanic and continental source for sulfate. The carbon particulate signal did not show any diurnal pattern during the measurement period.
DE: 0320 Cloud physics and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting