HR: 0800h
AN: A21A-0829    [Abstracts]
TI: Hydrocarbon Measurements Aboard the Ron Brown During NEAQS 2004: Chemical Time Scales and Evidence of Chlorine Chemistry in the Marine Boundary Layer
AU: * Goldan, P D
EM: Paul.D.Goldan@noaa.gov
AF: NOAA Aeronomy Laboratory, 325 Braodway, Boulder, CO 80305 United States
AU: Kuster, W C
EM: William.C.Kuster@noaa.gov
AF: NOAA Aeronomy Laboratory, 325 Braodway, Boulder, CO 80305 United States
AU: Shao, M
EM: mshao@pku.edu.cn
AF: Peiking University, College of Environmental Sciences, Beijing, 100871 China
AU: Fehsenfeld, F C
EM: Fred.C.Fehsenfeld@noaa.gov
AF: NOAA Aeronomy Laboratory, 325 Braodway, Boulder, CO 80305 United States
AU: Fehsenfeld, F C
EM: Fred.C.Fehsenfeld@noaa.gov
AF: CIRES, University of Colorado, Boulder, CO 80309 United States
AB: Ratios of the observed concentrations of Non-Methane Hydrocarbons (NMHCs) have frequently been used to gain insight into the loss mechanisms of those NMHCs. By choosing NMHCs with substantially different rates of reactions with a major reaction partner such as OH, together with an estimate of the OH mean concentration, a "chemical age" may be calculated for the air mass sampled. The ratio of toluene to benzene, for example, has been frequently invoked to calculate such a "chemical age". A different NMHC ratio, resulting in a substantially different calculated "chemical age", may be taken as evidence of more than one significant loss mechanism. Examples of such substantial disagreement will be presented using NMHCs that undergo rapid reaction with Cl radicals. The reconciliation of such disagreements yields an estimate of the marine boundary layer Cl concentration. This estimate will be compared to other reported indirect estimates of maritime Cl contentrations.
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: Fall Meeting 2005