Identifying sources of dust based on CALIPSO, MODIS satellite data and backward trajectory model

The total suspended particulate matter, total dust and PM10 mass concentrations and visibility data were measured using large flow total suspended particle (inhalable particles) sampler (KC-1000), dust storm sampler (SC-1) and visibility meter in Lanzhou, China. Furthermore, the dust origins of the event occurred during 9–14 March 2013 were accurately identified in this study using HYSPLIT (Hybrid-Single Particle Lagrangian Integrated Trajectory) trajectory model and multiple satellite data, including AOD (Aerosol Optical Depth) data from MODIS (Moderate Resolution Imaging Spectroradiometer), and vertical profiles of atmospheric aerosol properties from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations). It is found that the total suspended particulate matter mass concentration larger than 8 000 µg m-3 on 9 March was the highest among seven dust days with the visibility lower than 500 m. The dust at low levels (500 and 1 000 m AGL) mainly originated from the Hexi (River West) Corridor and Western and Central Inner Mongolia Plateau, which moved very slowly and circulated around the desert regions in Western and Central Inner Mongolia before arriving at Lanzhou. While the air masses at higher altitudes (2 000 and 3 000 m AGL) were transported from the Taklamakan Desert and the Qaidam basin, and arrived at Lanzhou. Most interesting, the air masses from Badain Jaran and Tengger Deserts and their outer edges brought dust particles on the transport pathways into atmosphere led to increase of particle pollutant concentrations due to tightly adherent ground movement of air masses.