Study of Aerosol Properties North of Svalbard from Autumn 2014 to Spring 2015 Using Combined V4 CALIOP Data, Ice-based IAOOS Lidar Observations and Trajectory Analyses.
Résumé
Properties of aerosol have been analyzed at the regional scale over the high Arctic north of Svalbard between October 2014 and June 2015 using the new version 4 (V4) CALIPSO (Cloud and Aerosol Lidar and Infrared Pathfinder Satellite Observations) data. Systematic trajectories have been performed for all identified aerosol layers. Results have been compared with lidar observations from IAOOS (Ice-Atmosphere-Ocean Observing System) drifting platforms. Space‒borne observations indicate a maximum in aerosol occurrence at the end of winter attributed to low‒level (0-2 km) and mid‒tropospheric (2-5 km) particles mostly identified by the CALIPSO Lidar CALIOP (Cloud and Aerosol Lidar with Orthogonal Polarization) as highly depolarizing. Another maximum was observed in October‒December due to clean marine particles below 2 km as well as smoke and depolarizing particles above. The 532 nm aerosol extinction was a factor 2 lower compared to average values previously reported using CALIOP V3 dataset. Aerosols originated mostly in Russia/Europe at all altitudes, and also North America above 2 km. CALIOP aerosol subtype classification is discussed from case studies allowing to identify aerosols close to IAOOS platforms and follow their transport. Adjustments of the aerosol classification involving arctic diamond dust are proposed. Cloudy parts of trajectories are identified for further aerosol-cloud interaction analyses.