Comparison of aerosol chemistry transport model simulations with lidar and Sun photometer observations at a site near Paris

The comparisons of model aerosols with measurements are carried out over a full year time period between October 2002 and September 2003. The methodology we propose here is new: From the model concentration outputs ( optical properties varying with chemical composition and mass vertical distribution) we simulate the lidar backscattering profiles and compare them with the observed ones.

The comparisons demonstrate the ability of the model to reproduce correctly the aerosol vertical distributions and their temporal variability. However, the aerosol load within the boundary layer is generally underestimated by the model, in particular during the afternoon hours and the summertime period. Several sensitivity tests indicate that this underestimation may have two origins: the lack of secondary organic and, to a lesser extent, mineral aerosols inside the model.