Sensitivity of CTM simulations to meteorological input

The objective of this work is to investigate the sensitivity of an Eulerian Chemical Tranport Model to the reconstruction of the wind field. In the framework of City-Delta exercise, three 14-day simulations have been performed, using the same model (CAMx) and different meteorological inputs; these were built combining large-scale analysis, local observations and the output of a high resolution meteorological model (Aladin). When Aladin output is used, stronger surface winds lead to enhanced nighttime mixing, resulting in higher ozone and lower PM10 concentrations in urban areas; on the other hand, the stronger advection associated with Aladin wind seems to help the model reproduce high ozone concentrations during day. The use of local wind observations appears beneficial to model performance.