Nonmethane hydrocarbons (NMHC) in the Greater Munich Area Germany

During several field campaigns in the years 1993-1997 quasi-continuous meas urements of NMHC data were obtained at various locations (urban/suburban/ru ral) within the Greater Munich Area (GMA) by means of on-line gaschromatogr aphic methods. Though limited to NMHC between C-6 and C-9 it comprises the first comprehensive data base for this region that features high temporal r esolution. The results for the downtown area show relatively low NMHC value s compared to other cities worldwide. Propene-equivalent 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 co mpounds 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 trans ition zone where VOC-limitation of ozone formation can be expected. (C) 199 9 Elsevier Science Ltd. All rights reserved.