HR: 0800h
AN: A11B-0874    [Abstracts]
TI: Nitrogen Isotopes: Tracers of Origin and Processes Affecting PM10 in the Atmosphere of Paris
AU: * WIDORY, D
EM: d.widory@brgm.fr
AF: BRGM, 3 ave Claude GUILLEMIN, Orleans, 45060 France
AB: Nitrogen in atmospheric particles in an urban environment is the result of complex primary and secondary processes, which renders identifying its origin somewhat complicated. Using the example of PM10 in the atmosphere of Paris (France), we show that the use of stable nitrogen-isotope compositions (d15N) alleviates this difficulty and provides clear information on the sources of both primary and secondary nitrogen. Characterisation of emissions of the different types of emitters in the city (road traffic, waste incinerators and heating sources) shows that these are clearly discriminated by specific isotope signatures. The characterisation of PM10 during summer and winter campaigns demonstrate that d15N is particularly useful in showing that a substantial portion of the nitrogen is the result of secondary reactions. The reactions involved are different in summer and winter, as are the corresponding pollution sources. Depending on future study of the nitrogen isotope fractionations associated degradation of gaseous NOx in the atmosphere, d15N of PM10 could be shown to be directly linked to those of their parent NOx. Results presented here would thus indicate that, while it is unclear what the winter source of primary nitrogen is, road traffic appear to be its secondary source, as well as the source of primary nitrogen in summer (with heating as the secondary source during this period).
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005