ONE-YEAR MEASUREMENTS OF PAN IN THE PARIS BASIN - EFFECT OF METEOROLOGICAL PARAMETERS

PAN has been measured continuously for 1 year in Creteil, a southeastern suburb of Paris. Correspondence analysis was used to analyse the important PAN database obtained during this period, in relation to associated meteorological parameters and the location of precursors sources. This analysis revealed a complex relation (U-shaped curve) between PAN and temperature, with a minimum in the range of 4-12-degrees-C and an increase in the lower and higher temperatures, arising from the competition between photochemical production and thermal decomposition. Long-range transport of PAN is associated with easterly winds and occurs under anticyclonic conditions in all seasons, particularly in winter. The highest PAN values (maximum 33.6 ppb) are observed in summer. They have a local origin and are associated with northwesterly to southwesterly winds, revealing the net impact, in summer, of nearby sources such as the urban conglomeration of Paris on PAN levels recorded in the surrounding areas.