Combined use of space-borne observations of NO2 and regional CTM model for air quality monitoring in Northern Italy

In this paper SCIAMACHY observations of earth radiance are used to retrieve nitrogen dioxide (NO2) tropospheric column by DOAS spectrometric technique and radiative transfer modelling for AMF computation. These satellite column measurements are then merged with TCAM model simulations, to improve the model output at the ground level. The method used is a weighted resealing of the model column in the troposphere according to the SCIAMACHY observations where the weights are the measurement errors and the model column variances within the satellite ground pixel, respectively. A comparison with ground level measurements shows good agreement mainly where well-horizontal mixing is present.