HR: 0800h
AN: A51A-0037 [Abstracts]
TI: Aerosol Monosaccharide Anhydrides as Tracer Species for Identifying Wildfire Smoke Transport to California's Central Valley in August 2002
AU: * Abhyankar, M S
EM: meenal_naik@hotmail.com
AF: Chemistry Dept.
Sacramento State University, 6000 J St, Sacramento, CA 95819-6057, United States
AU: Dixon, R W
EM: rdixon@csus.edu
AF: Chemistry Dept.
Sacramento State University, 6000 J St, Sacramento, CA 95819-6057, United States
AB:
The Biscuit fire burned close to 2,000 km2 of forested land in southwestern Oregon in July and August,
2002. August, 2002 also was a time in which PM2.5 concentrations were higher than typical in California
Central Valley cities located several hundred kilometers to the southeast. The concentrations of two
monosaccharide anhydrides, levoglucosan and mannosan, were measured in aerosol samples collected at four
California Air Resource Board sites in Central Valley cities for the purpose of determining how the wildfire smoke
affected air quality. Levoglucosan concentrations ranged from the detection limit of 18 ng m-3 to about 400
ng m-3. While days with high levoglucosan concentrations generally had above average to high PM2.5
concentrations, there were also days with high PM2.5 concentrations with low levoglucosan concentrations.
Although mannosan was only detected in a small number of samples, the levoglucosan to mannosan ratios in
these samples were consistent with smoke from softwood combustion. A wildfire source levoglucosan to
PM2.5 concentration ratio was used to estimate the PM2.5 concentration originating from smoke.
From this method, smoke was found to be a significant (greater than 10% of the total PM2.5 concentration)
on occassions. The estimated smoke PM2.5 concentration always remained less than 10 μg m-3
and contributed to less than a third of the total PM2.5 concentration. Because the PM2.5
concentrations were higher than typical August values, either there were other factors leading to high PM2.5
concentrations in August 2002, or the smoke estimation method underestimated the smoke concentration.
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 Fall Meeting