Characterisation of Arctic Aerosols on the basis of Lidar- and Radiometer-Data
In the beginning of March 2018 and during the haze period, Lidar measurements were performed from AWIPEV on Svalbard in the Arctic Ocean in order to analyse Arctic aerosols. Additionally, radiosondes were launched. It was analysed that the backscatter data had significant higher values in a lower altitude, decreasing with height. A detected weak depolarisation indicated mostly spherical shaped particles, a moderate Lidar Ratio showed a rather weak extinction. The analysis of the Colour Ratio revealed smaller particles in lower altitudes; larger particles only appeared in a height above 5 km. As the hygroscopic growth of the aerosols was shown, it became apparent that the hygroscopicity can be well described with a growth parameter introduced by Gassó et.al. (2000). It can be seen that temperature fluctuations appeared on a short time range, otherwise water cloud formations wouldn’t be explainable. Even though high relative humidity values over ice were measured, no ice cloud formation occured. This in the end indicates that the concept of Arctic aerosols acting as ice nuclei is still a complicated matter. 1