Combined effects of organic reactivity and NMHC/NOx ratio on photochemical oxidant formation—a modeling study

Characteristics of 1 year of observational data of VOCs, NO<sub><i>x</i></sub> and O<sub>3</sub> at a suburban site in Guangzhou, China

“…The MIR j was estimated by selecting the specific MIR value for each of the VOCs from published studies which were conducted based on modeled scenarios for Los Angeles in the 1980s (Dodge, 1984;Carter, 1994). The OH reaction rate constants and estimated MIR coefficients, as well as their concentrations, for each VOC species are shown in Table 4.…”

Seasonal and spatial variations in biogenic hydrocarbon emissions from southern African savannas and woodlands

“…BVOCs react with the hydroxyl radical (OH), ozone (O 3 ) and nitrate (NO 3 ) leading to the formation of carbon monoxide, secondary chemicals, organic acids and ultimately secondary organic aerosols (Andreae and Crutzen, 1997;Atkinson, 2000;Calogirou et al, 1999;Fehsenfeld et al, 1992). The production or consumption of ozone depends on the ratio between VOCs and NO x (Dodge, 1984;Liu et al, 1987;Bowman and Seinfeld, 1994;Diem, 2000) and regional ozone models have been shown to be very sensitive to isoprene emissions (Pierce et al, 1998).…”

Nonmethane Organic Compound to Nitrogen Oxide Ratios and Organic Composition in Cities and Rural Areas

“…Alkenes, such as propene and trans-2-butene, have been shown to efficiently produce O3 at low ratios to NO X . 9 ' 10 Alkanes, such as propane and n-butane, are much less efficient at producing O3 at low ratios to NO X . 1>9 ' 10 As ratios of organic compounds to NO X increase, the efficiencies of O3 generation uniformly decrease but do so more rapidly for those organic compounds which are more efficient at lower ratios.…”

“…9 ' 10 Alkanes, such as propane and n-butane, are much less efficient at producing O3 at low ratios to NO X . 1>9 ' 10 As ratios of organic compounds to NO X increase, the efficiencies of O3 generation uniformly decrease but do so more rapidly for those organic compounds which are more efficient at lower ratios. At higher NMOC to NO X ratios the O3-generating efficiencies tend to be similar, irrespective of organic composition.…”

“…At higher NMOC to NO X ratios the O3-generating efficiencies tend to be similar, irrespective of organic composition. 9 - 10 An additional complexity is that those organic compounds that react so as to remove radicals and/or nitrogen dioxide have negative 03-producing efficiencies at higher NMOC to NO X ratios. 8 -10 These early environmental chamber studies also indicated that decreasing nitrogen oxide concentrations did result in reducing nitrogen dioxide dosages.…”