In-situ OH kinetics study providing an indicator for ozone formation limitation
Hydroxyl radicals dominate daytime tropospheric chem., responsible for reactive removal of most trace gases (e.g., volatile org. compds.[VOC]), and is an active participant in the NO and NO2 cycle. Pump-and-probe LIDAR was used to examine the OH- chem. in the planetary boundary layer. This method consists of a high OH- concn. prodn. by a first laser beam (pump), including a flash photolysis of O3: O3 + hv (256 nm) -> O(1D) + O2, and the reaction, O(1D) + H2O -> 2OH. Its relaxation is followed by measuring the time evolution of the radical by laser-induced fluorescence (probe beam). A simulation of this expt. showed that in a short delay time, a direct est. of the total hydrocarbon reactivity defined as SVOC was obtained. The pump-and-probe technique allows measurements which can distinguish between locations where O3 formation mainly depends on NOx concns. and those where it mainly depends on VOC concns.
1999
28
317
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Copyright 2003 ACS
CAPLUS
AN 1999:576228
CAN 131:218390
59-2
Air Pollution and Industrial Hygiene
53, 67
EPFL, DGR, LPAS, LIDAR Group,Lausanne,Switz. FIELD URL:
Conference
68CAA6
written in English.
Air pollution; Reaction kinetics (in-situ hydroxyl radical kinetics study providing indicator for atm. ozone formation limitations via pump-and-probe lidar); Volatile organic compounds Role: POL (Pollutant), RCT (Reactant), OCCU (Occurrence), RACT (Reactant or reagent) (in-situ hydroxyl radical kinetics study providing indicator for atm. ozone formation limitations via pump-and-probe lidar); Lidar (pump-and-probe; in-situ hydroxyl radical kinetics study providing indicator for atm. ozone formation limitations via pump-and-probe lidar)
Atkinson, R; J Phys Chem Ref Data 1997, 26, 215|Atkinson, R; J Phys Chem Ref Data 1997|Calpini, B; J Geophys Res submitted 1998|Clappier, A; 17th International Laser Radar Conference 1994|Jeanneret, F; Spectrochimica Acta submitted 1998|Kirchner, F; in preparation
REVIEWED
EPFL