As part of the campaign POLARCAT France, which took place north of Sweden in April 2008, several observations of aerosol plumes were analyzed. The study of aerosol plumes was based on measurements of a backscatter lidar emitting at 355, 532 and 1064 nm with a channel to measure the depolarization at 355 nm. Three optical parameters (the scattering ratio, the pseudo color ratio (CR *), and depolarization) provide information on the optical thickness, the relationship between fine fraction and coarse fraction and the presence of mineral aerosols. A climatology of the optical properties of the aerosol was constructed to establish the gradients, temporal evolution during the campaign and their relation with the origin of air masses. The spatial lidar CALIOP calculates the same optical parameters as the airborne lidar. The intercomparison between the two instruments showed a significant difference in the absolute values of CR *. However, variations of optical parameters remain consistent. To identify the sources of aerosols, a study was conducted with Lagrangian transport model simulations using FLEXPART, combined with data from CALIOP. This analysis shows that the aerosol is a mixture of 223 three sources : pollution from north-east Asia and Europe, forest fires and agricultural Siberian and central Asian desert dust. Finally, a study on the optical properties of the aerosol was focusing on into fires during summer 2010 in Russia and included a comparison of the impact of this episode with the observations collected in 2008.
Optical properties analysis of aerosols observed in the Arctic region during the spring API/POLARCAT campaign