Monoterpenes, atmosphere

Armstrong, D. A., W. L. Waltz and A. Rauk (2006) Carbonate radical anion - thermochemistry. Canadian Journal of Chemistry 84, 1614-1619 Arneth, A., R. K. Monson, G. Schurges, (j. Niinemets and P. I. Palmer (2009) Why are estimates of global terrestrial isoprene emissions so similar (and why is this not so for monoterpenes) Atmospheric Chemistry and Physics 8, 4605-4620 Arnts, R. R., W. B. Petersen, R. L. Seila and B. W. Gay Jr. (1982) Estimates of alpha-pinene emissions from a loblolly pine forest using an atmospheric diffusion model. Atmospheric Environment 16, 2127-2137... 

One consequence of the shift from grassland to shrubland is the potential for significant increases in volatile hydrocarbons added to the atmosphere. The leaves of creosotebush, Larrea tridentata, yielded 0.1 to 0.2 percent of a complex mixture of volatile compounds. That mixture contains several hundred compounds of which 100 accounted for more than 90% of the total volatiles (23). The volatiles that were identified included four monoterpene hydrocarbons, four oxygenated monoterpenes, six sesquiterpene hydrocarbons, eight aromatics like benzyl acetate and ethyl benzoate, plus... 

Atkinson R, SM Aschmann, AM Winer, JN Pitts (1985a) Kinetics and atmospheric implications of the gas-phase reactions of NOj radicals with a series of monoterpenes and related organics at 294 2 K. Environ Sci Technol 19 159-163. 

Grimsrud, E. P., H. H. Westberg, and R. A. Rasmussen. Atmospheric reactivity of monoterpene hydrocarbons, NOs photooxidation and ozonolysis. Int. J. Chem. Kinet. Symp. 1 (Chemical Kinetics Data for the Lower and Upper Atmosphere) 183-195, 1975. 

Pio, C. A., and A. A. Valente, Atmospheric Fluxes and Concentrations of Monoterpenes in Resin-Tapped Pine Forests, Atmos. Enriron., 32, 683-691 (1998). 

Balsam turpentine oil is obtained from the resins of living trees of suitable Pinus species by distillation at atmospheric pressure and temperatures up to 180°C, or by other fractionation methods, which do not change the terpene composition of the resins. Wood turpentine oils, on the other hand, are generally obtained by steam distillation of chopped tree trunks, dead wood, or of resin extracted from this wood. Sulfate turpentine oil is produced as waste in the manufacture of cellulose by the sulfate process and is also a wood turpentine. Pine oil is another wood turpentine oil that is obtained by dry distillation of suitable pine and fir trees, followed by fractionation. However, the term pine oil is nowadays used for a product which is manufactured by hydration of turpentine oil (a-pinene). The resulting product is a mixture of monoterpenes containing o-terpineol as the main component. In addition to many other technical purposes, it is used to a large extent in cheap perfumes for technical applications. 

Fick, J., Pommer, L., Asttand, A., Ostin, R., Nilsson, C. and Andersson, B. (2005) Ozonolysis of monoterpenes in mechanical ventilation systems. Atmospheric Environment, 39, 6315-25. 

As Barr et al. (2003) pointed out, the importance of such emissions is determined mainly by their impact on the three processes taking place in the atmosphere. The first consists in that such NMHCs as isoprene form in the course of carboxylization in plants and contribute much thereby to the formation of biospheric carbon cycle. The second process is connected with NMHCs exhibiting high chemical activity with respect to such main oxidants as hydroxyl radicals (OH), ozone (03), and nitrate radicals (N03). Reactions with the participation of such components result in the formation of radicals of alkylperoxides (R02), which favor efficient transformation of nitrogen monoxide (NO) into nitrogen dioxide (N02), which favors an increase of ozone concentration in the ABL. Finally, NMHC oxidation leads to the formation of such carbonyl compounds as formaldehyde (HCHO), which stimulates the processes of 03 formation. Finally, the oxidation of monoterpenes and sesquiterpenes results in the intensive formation of fine carbon aerosol with a particle diameter of <0.4 pm... 

Barr et al. (2003) performed an analysis of the impact of phytogenic aerosol (PhA) which is defined as forming mainly due to monoterpene oxidation (primarily, a- and /3-pinenes), on the radiative regime of the ABL over the forest in the eastern part of Canada. In the forest ecosystem the level of emissions to the atmosphere of biogenic hydrocarbons is moderate, with the concentration of a- and /3-pinenes constituting about 1.6 ppb. NMHC oxidation resulted in the formation of PhA at a number density of particles of about 5 108 cm 3. For a given concentration and size distribution of aerosol, its impact on the short-wave radiation transfer in the ABL was assessed. 

The reactions observed in the photochemical smog, especially those concerning decomposition and oxidation of volatile organic substances, are accelerated by atmospheric aerosols, eg oxidation of some halogenated hydrocarbons, isoprene, monoterpenes, and aromatic hydrocarbons is enhanced by the surfaces of metal oxides, desert sand, volcanic ash, and sea salt [8],... 

Boyle, J.M., 1976. Atmospheric Reactions of Sulfur Dioxide and Monoterpenes. M.Sc. Thesis, The University of Calgary, Calgary, Canada, 97 pp. 

Fig. 6-2. Skeletal structures of several monoterpenes that have been identified in the atmosphere.

Yokouchi, Y., M. Okaniwa, Y. Ambe, and K. Fuwa (1983). Seasonal variation of monoterpenes in the atmosphere of a pine forest. Atmos. Environ. 17, 743-750. 

Mixing ratios of the individual NMHCs vary greatly, from several parts per trillion by volume (pptv) to several parts per billion by volume (ppbv). Variations in the reactivities of NMHCs are also substantial for example, isoprene (2-methyl butadiene), which is emitted by deciduous vegetation, has an atmospheric lifetime with respect to oxidation by OH of about 20 min in polluted air ([OH] = 10 radicals cm ). Monoterpenes (CiqHis), which are emitted from coniferous trees, react extremely rapidly with OH and O3 and have lifetimes of minutes. The atmospheric lifetimes of 2-methylpropene, 2-methylbutane, and the xylenes, which are found in vehicle emissions, are approximately 30 min, 7 h, and 1.5 h, respectively. Oxidation of the terpenes... 

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