Investigation Of Distributions Of Atmospheric Particles Based On Ship-borne Lidar

In order to understand regional haze better,a dual-wavelength elastic polarization lidar was loaded on a ship to measure aerosol distribution along the Yangtze River during the Yangtze River Campaign conducted from November 21 to December 4,2015.The ship was launched from Shanghai,arrived in Wuhan,and returned to Shanghai.Many other scientific instruments were loaded on the ship,and this study used data of some gaseous pollutants measured by online instruments,as well as visibility data.Using these observation data,this study identified large-scale coverings of dust aerosols and biomass-burning aerosols.Results show that in early December there could be large-scale dust aerosol transport in Central and East China,which can reach Yangtze River.The impact area of these dust aerosols was very large,since the section of the transport path had a width more than 130 kilometer.These dust aerosols not only affected the area on their transport path,but also were affected by sources along the transport path.These sources emitted aerosols into dust,mixed with the dust and then changed some of its optical properties.As for biomass-burning aerosols,results show that the plumes generated by biomass burning could reach as far as 100 kilometers away,and near the ground these aerosols could cover more than 200 kilometers along Yangtze River.This study also observed two directly emitted aerosol plumes.These plumes were small,and limited both in time and in space,with a low height.Another small plume was observed,which probably experienced gas-particle conversion.Because this plume ap-peared at night,it may help us understand some aspects of secondary processes,though gas-particle conversion did not necessarily imply secondary chemical processes.All the plumes observed in this study are important in themselves.Besides,because these plumes had different sizes,and were linked by the Yangtze River Campaign,they can help us understand aerosol pollutions from different level simultaneously and provide us a possible 'background" for studying regional haze.