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The chemistry of the hydroxyl radical in the troposphere

Published online by Cambridge University Press:  05 December 2011

D. H. Ehhalt ,
H.-P. Dorn  and
D. Poppe
D. H. Ehhalt
Affiliation:
Institut für Atmosphärische Chemie, Forschungszentrum Jülich GmbH, Postfach 1913, D-5170 Jülich, Germany
H.-P. Dorn
Affiliation:
Institut für Atmosphärische Chemie, Forschungszentrum Jülich GmbH, Postfach 1913, D-5170 Jülich, Germany
D. Poppe
Affiliation:
Institut für Atmosphärische Chemie, Forschungszentrum Jülich GmbH, Postfach 1913, D-5170 Jülich, Germany
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Synopsis

Like oxidation in a flame, oxidation in the atmosphere is mediated by free radicals. By far the most important radical in the troposphere is the hydroxyl radical, OH. It is generated photochemically, and reacts with most atmospheric trace gases, in many instances as the first, and rate-determining, step in the reaction chains leading to their oxidation. Usually these chains regenerate OH thus maintaining OH at relatively large day-time concentrations of the order of 106 cm−3.

The most important reactions controlling local concentrations of OH form the framework of a photochemical reaction model, the results of which are compared to OH concentrations measured in the field at locations with different concentrations of pollutant attributable to the activities of man. The model-predicted OH concentrations are based on the simultaneously measured concentrations and photolysis rates of those trace gases that dominate OH chemistry at the local level.

Predicted and measured OH concentrations correlate reasonably well where concentrations of atmospheric pollutants are small but not where they are large. Explanations are being sought.

Type
Research Article
Information
Proceedings of the Royal Society of Edinburgh, Section B: Biological Sciences , Volume 97: Acidic Deposition: Its Nature and Impacts , 1990 , pp. 17 - 34
Copyright
Copyright © Royal Society of Edinburgh 1990

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References

Atkinson, R., Aschmann, S. M., Winer, A. M. & Pitts, J. N. Jr. 1984. Kinetics of gas phase reactions of NO3 radicals with a series of dialkenes, cycloalkenes, and monoterpenes at 295 ± 1 K. Environment Science and Technology 18, 370–75.CrossRefGoogle Scholar
Callies, J. 1988. Absorptionsspektroskopischer Nachweis von Hydroxyl-Radikalen in der Troposphäre. Dissertation, Universität Köln.Google Scholar
Callies, J., Dorn, H.-P., Poppe, D., Platt, U. & Ehhalt, D. H. 1990. Evaluation of OH concentration measurements in the polluted troposphere, in preparation.Google Scholar
DeMore, W. B., Margitan, J. J., Molina, M. J., Watson, R. T., Golden, D. M., Hampson, R. F., Kurylo, M. J., Howard, C. J. & Ravishankara, A. R. 1985. Chemical kinetics and photochemical data for use in stratospheric modeling, evaluation 7, NASA panel for data evaluation. JPL Publication, 85–37.Google Scholar
Dodge, M. C. 1989. A comparison of three photochemical oxidant mechanisms. Journal of Geophysical Research 94, 5121–36.CrossRefGoogle Scholar
Dorn, H.-P., Callies, J., Platt, U. & Ehhalt, D. H. 1988. Measurements of tropospheric OH concentrations by laser long-path absorption spectroscopy. Tellus 40B, 437–45.CrossRefGoogle Scholar
Ehhalt, D. H. 1974. The atmospheric cycle of methane. Tellus 26, 58–70.CrossRefGoogle Scholar
Ehhalt, D. H. 1989. Measurements of OH; an experiment designed to test theories of tropospheric gas phase chemistry. Plenary Lecture, Int. Conf. on the generation of oxidants on regional and global scales, Norwich, England, 3.-7. July 1989.Google Scholar
Ehhalt, D. H. & Drummond, J. W. 1982. The tropospheric cycle of NOx. In Chemistry of the Polluted and Unpolluted Troposphere, pp. 219–51, eds Georgii, H. W. & Jaeschke, W. Dordrecht/NL: D. Reidel Publishing Company.CrossRefGoogle Scholar
Ehhalt, D. H. & Rudolph, J. 1984. On the importance of light hydrocarbons in multiphase atmospheric systems. Berichte der Kernforschungsanlage Jülich GmbH, JÜL-1942.Google Scholar
Hofzumahaus, A.. Rohrer, F., Schiller, C. & Gerhardt, Ph. 1990. Photolysis frequency measurements by photoelectric detectors, in preparation.Google Scholar
Hough, A. M. 1988. An intercomparison of mechanisms for the production of photochemical oxidants. Journal of Geophysical Research 93, 3789–812.CrossRefGoogle Scholar
Hubler, G., Perner, D., Platt, U., Toenissen, A. & Ehhalt, D. H. 1984. Ground level OH radical concentration: New measurements by optical absorption. Journal of Geophysical Research 89, 1309–19.CrossRefGoogle Scholar
Janßen-Schmidt, Th., Röth, E. P., Varhelyi, G. & Gravenhorst, G. 1981. Anthropogene Anteile am atmosphärischen Schwefel- und Stickstoffkreislauf und mögliche globale Auswirkungen auf chemische Umsetzungen in der Atmosphäre. Berichte der Kernforschungsanlage Jülich GmbH, JÜL-1722.Google Scholar
Junkermann, W., Platt, U. & Volz-Thomas, A. 1989. A photoelectric detector for the measurement of photolysis frequencies of ozone and other atmospheric molecules. Journal of Atmospheric Chemistry 8, 203–27.CrossRefGoogle Scholar
Logan, J. A. 1983. Nitrogen oxides in the troposphere: Global and regional budgets. Journal of Geophysical Research 88, 10.785–10.807.CrossRefGoogle Scholar
Mozurkewich, M., McMurry, P. H., Gupta, A. & Calvert, J. G. 1987. Mass accommodation coefficient for NO2 radicals on aqueous particles. Journal of Geophysical Research 92, 4163–70.CrossRefGoogle Scholar
National Academy Press 1984. Global Tropospheric Chemistry, A Plan for Action. Washington, D.C.Google Scholar
Perner, D., Platt, U.. Trainer, M., Hübler, G., Drummond, J., Junkermann, W., Rudolph, J., Schubert, B., Volz, A. & Ehhalt, D. H. 1987. Measurements of tropospheric OH concentrations: A comparison of field data with model predictions. Journal of Atmospheric Chemistry 5, 185–216.CrossRefGoogle Scholar
Platt, U., Rateike, M., Junkermann, W., Rudolph, J. & Ehhalt, D. H. 1988. New tropospheric OH measurements. Journal of Geophysical Research 93, 5159–66.CrossRefGoogle Scholar
Poppe, D., Zimmermann, J. & Ehhalt, D. H. 1990. A comparison of measured OH concentrations with model calculations. In preparation.Google Scholar
Spiegel, M. R., 1975. Probability and Statistics. New York: McGraw Hill.Google Scholar
Stockwell, W. R., Middleton, R., Chang, J. S. & Tang, X. 1990. The RADM II chemical mechanism for regional air quality modeling. Journal of Geophysical Research 95 (D-10), 16343–67.CrossRefGoogle Scholar
Volz, A., Ehhalt, D. H. & Derwent, R. G. 1981. Seasonal and latitudinal variations of 14CO and the tropospheric concentration of OH radicals. Journal of Geophysical Research 86, 5163–71.CrossRefGoogle Scholar
Zimmermann, P. R., Chatfield, Fishmann J., Crutzen, P. J. & Hanst, P. L. 1978. Estimates of the production of CO and H2 from the oxidation of hydrocarbon emissions from vegetation. Geophysical Research Letters 5, 679–82.CrossRefGoogle Scholar