During a photosmog period in summer 1993, several ozone plumes (enrichment of O3 of 10--45 ppb over levels of surrounding air masses) were observed in the southern part of eastern Germany. Analyses of the plumes for other species reveal that SO2, NoY, CO, and photochemically formed CH2O were enriched synchronously with O3. The measured enhancement factors SO2/CO and NOy/CO agree well with emission factors of local emission inquiries. The O3 production potential in the plumes must have originated from emissions from furnaces burning sulfur rich lignite coal under non-optimum conditions such as old power plants, industrial plants, and domestic water heating systems. The co-emission of VOC's with SO2 lead to the formation of O3 and CH2O. Most of the plumes seem to be less than one day old. ¿ American Geophysical Union 1995