Nonmethane hydrocarbons (NMHC) in the Greater Munich Area/Germany

During several field campaigns in the years 1993–1997 quasi-continuous measurements of NMHC data were obtained at various locations (urban/suburban/rural) within the Greater Munich Area (GMA) by means of on-line gaschromatographic methods. Though limited to NMHC between C6 and C9 it comprises the first comprehensive data base for this region that features high temporal resolution. The results for the downtown area show relatively low NMHC values compared to other cities worldwide. Propene-eqivalent analysis suggests that aromatic compounds such as toluene and m & p-xylenes play a major role in the formation of urban photochemical smog in the GMA. Since aromatic compounds were found to be ubiquitous at all measurement sites (altogether 8 sites) the pattern of these NMHC were investigated thoroughly. The results suggest that aromatic compounds are most effective in the urban/rural transition zone where VOC-limitation of ozone formation can be expected.