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1990
Conference Paper
Titel
Temporal variations of formaldehyde in continental air masses
Alternative
Zeitliche Variation von Formaldehyd in kontinentalen Luftmassen
Abstract
Concentrations of formaldehyde were determined in ambient air during 10 short measuring periods between January and September 1981 at the measuring site of the Umweltbundesamt at Deuselbach, FRG (480 m elevation, 49.8 degree N, 1.2 degree E). HCHO levels were measured using the DNPH-method. Concurrent mixing ratios of SO2, CO2, CO, and O3 were measured and compared with the temporal variations of the HCHO mixing ratio. Solar radiation, wind direction and speed, temperature, precipitation etc. were also obtained routinely at the station. The HCHO mixing ratios ranged between 0.09 and 4.13 ppbv. The highest HCHO mixing ratios were observed in polluted atmospheres, e.g. in January and February, indicating the influence of direct HCHO emissions by anthropogenic sources. Extremely low HCHO values below 0.10 ppbv were observed in clean marine air during winter conditions. During late spring and summer, the HCHO concentrations showed distinct diurnal variations which correlated well with 03, thus indicating photochemical HCHO production. Under winter conditions, anticorrelations between HCHO and O3 were observed.
Language
English