Analysis and applications of measurements of source dominated hydrocarbon concentrations from the PUMA campaigns in June/July 1999 and January/February 2000 at an urban background site in Birmingham, UK

Abstract: Approximately, hourly C2–C7 hydrocarbon concentrations from gas chromatographic measurements are reported for an urban background site in Birmingham, UK, from summer 1999 and winter 1999–2000. Comparison with another measurement site suggests that the observed behaviour is typical of the urban background in the whole conurbation. The lack of any correlation between seasonal variation and OH rate coefficient shows that hydrocarbon concentrations are dominated by local sources. Chemical mass balance techniques have been applied and indicate the main sources are vehicle emissions (exhaust and fugitive) and natural gas leakage. Winter concentrations of isoprene correlate well with butadiene concentrations suggesting an automotive related source. This correlation disappears during the summer when isoprene displays a high correlation with radiation. During a period of the summer campaign ethane and propane concentrations displayed a regular diurnal behaviour, which has been utilized to estimate the ratios of the day/night boundary layer height and natural gas emission rates for the West Midlands conurbation. [Copyright &y& Elsevier]