Biogenic and anthropogenic fluxes of non-methane hydrocarbons over an urban-impacted forest, Frankfurter Stadtwald, Germany

• Published in: Atmospheric environment (1994) Vol. 34; no. 22; pp. 3779 - 3788
• Main Authors: STEINBRECHER, R, KLAUER, M, HAUFF, K, STOCKWELL, W. R, JAESCHKE, W, DIETRICH, T, HERBERT, F
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Science 2000
• Subjects: Applied sciences; Atmospheric pollution; Exact sciences and technology; Germany; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Europe; Germany; Frankfurter Stadtwald, Germany; Natural origin pollution; Atmospheric condition; Forests; Hydrocarbon; Toluene; Carbon dioxide; Ozone; Volatile organic compound; Photochemical reaction; Biogenic factor; Atmospheric chemistry; Flux density; Benzene; Content; Xylene; Monoterpene; Air pollution; Aromatic compound; Mixing ratio; Nitrogen Oxides; Isoprene; Anthropogenic factor
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/S1352-2310(99)00518-X

In the eastern part of the Frankfurter Stadtwald, which is a forest located in the southern part of Frankfurt am Main, Germany, the distribution of anthropogenic and biogenic nonmethane hydrocarbons was investigated. Nonmethane hydrocarbon concentrations were analyzed at two levels of a meteorological tower. The flux-gradient relationship was determined for all vegetation, and a photochemical box model was used to assess chemical degradation in relation to transport or deposition to and from the canopy. The study was conducted in August 1995. Results indicated that the nonmethane hydrocarbon mixing ratios were influenced strongly by traffic, with benzene, toluene, and m-, p-, and o-xylene exhibiting maximum mixing ratios of about 3 ppb during the night. The mixing ratios of the anthropogenic nonmethane hydrocarbons were correlated with the mixing ratios of nitric oxide and nitrogen oxides, which exhibited maxima during the morning and evening rush hours. Ozone mixing ratios peaked on sunny days at about 70 ppb. The observed anthropogenic nonmethane hydrocarbon fluxes were small despite the high load in the air above the forest. The biogenic nonmethane hydrocarbon emissions were dominated by isoprene, with beta -pinene detected in much lower amounts. Isoprene mixing ratios were lowest during the night.