Climatology of dust aerosol Observed from 6-year CALIPSO lidar measurements

Abstract:

The Level 3 aerosol profile data derived from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) provide a multiyear global aerosol distribution with high vertical resolution. In this study, we investigate the climatology of global dust associated with dust and polluted dust aerosol types represented by 6-year CALIPSO data. The significant meridional and vertical distributions of dust are observed over most areas during boreal spring and summer. Furthermore, considering changes of dust optical and microphysical properties during long-range transport, layer-mean particulate depolarization ratio of dust, polluted dust and other aerosols are analyzed. Then we define the threshold of layer depolarization ratio of dust aerosol and non-dust aerosols over different regions. Based on these threshold and assumption of dust mass extinction efficiency, observation-based global dust mass flux over all-sky condition is firstly estimated, except for dust below low-level cloud. Finally, the uncertainties of dust mass flux are analyzed in the different conditions.