HR: 1340h
AN: A43C-0062 [Abstracts]
TI: Chemical age of air Masses Determined From Ambient Volatile Organic Compound Measurements During NEAQS
2004
AU: * Goldan, P D
EM: Paul.D.Goldan@noaa.gov
AF: Aeronomy Laboratory, NOAA
U.S. Dept of Commerce
325 Broadway, Boulder, CO 80305
United States
AU: Shao, M
EM: mshao@pku.edu.cn
AF: CIRES, University of Colorado, Boulder, CO 80302
United States
AU: Shao, M
EM: mshao@pku.edu.cn
AF: College of Environmental Sciences, Peking University, Beijing, 100871
China
AU: Kuster, W C
EM: William.C.Kuster@noaa.gov
AF: Aeronomy Laboratory, NOAA
U.S. Dept of Commerce
325 Broadway, Boulder, CO 80305
United States
AU: Fehsenfeld, F C
EM: Fred.C.Fehsenfeld@noaa.gov
AF: Aeronomy Laboratory, NOAA
U.S. Dept of Commerce
325 Broadway, Boulder, CO 80305
United States
AU: Fehsenfeld, F C
EM: Fred.C.Fehsenfeld@noaa.gov
AF: CIRES, University of Colorado, Boulder, CO 80302
United States
AB:
During July and August of 2004, as part of the New England Air Quality Study (NEAQS 2004), volatile organic compounds (VOCs)
including hydrocarbons, oxygenated hydrocarbons and alkyl nitrates were measured aboard the NOAA research vessel Ronald H.
Brown. Samples were acquired at half hourly intervals without storage and analyzed immediately by an automated GC-FID and
GC-MS system.
The observed ratios of VOC species with different photochemical loss rates, or the ratios of oxidation products and their
precursors, can be employed as indicators for chemical age of air masses encountered. Several of these ratios have been
compared to those expected from OH photochemistry and photolysis. Time scales inferred are shown to be in reasonably good
agreement with transport times obtained from backward trajectory calculations. The choice of appropriate ratios for the
estimation of air mass chemical age (from hours to days) is discussed. The influence of regional backgrounds of relevant VOC
species, and nighttime chemistry are also pointed out.
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting