An ozone pollution episode typically at the mesoscale is studied for the pe
riod 17-20 July 1996 in the northern half of France. This episode has been
documented through extra stations supplementing the regular French network
in the southwest of the Paris region at large: the ozone threshold value of
90 ppb has been observed to be exceeded only at downwind rural stations at
distances ranging between 25 and 110 km from downtown Paris. This episode
has been simulated with the mesoscale model Meso-NH-C in which the meteorol
ogical model Meso-NH is coupled on-line with a chemistry module. Various as
sumptions are presented which must be made in order to run Meso-NH-C: e.g.
reduction of the chemical scheme to reduce the computational costs or defin
ition of procedures to fill in the lack of emission inventory data. Meso-NH
appears to realistically simulate the position, extent, average and peak o
zone values within the pollution plume. Sensitivity analyses emphasize, in
particular, the need for accurate simulation of the wind field to capture c
orrect characteristics of this plume. (C) 1999 Elsevier Science Ltd. All ri
ghts reserved.