Insight into the climatology of different sand-dust aerosol types over the Taklimakan Desert based on the observations from radiosonde and A-train satellites

The vertical distributions of sand-dust aerosols (SDAs) over the Taklimakan Desert (TD; 37 degrees N-41 degrees N, 78 degrees E-88 degrees E) that occurred during the spring are essential for both long-range transport and climate effects, apart from the living environment and health. In this study, we investigated the optical properties of SDAs and evaluated the correlation between optical properties and meteorological factors over the TD area located in the northwest of China. For this, we have utilized the A-train multiple-satellite remote sensing data provided quasi-synchronized observations by the Cloud-aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), CloudSat, and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments for the study period during 2007-2010. Besides, we have verified the meteorological factors observed from the CALIPSO to know the applicability and reliability with the Radiosonde sounding data. We found that the cloud-aerosol discrimination (CAD) algorithm can accurately identify clouds and SDAs over the TD area, especially during blowing dust/floating dust (BD/FD). Overall, it is revealed that the total depolarization ratio of SDAs is below 0.5. Besides, the temperature (T) and pressure (P) of CALIPSO satellite products data are in excellent agreement with the radiosonde sounding measured data over the TD area. Further, most data points during the DS (BD/FD) event spread towards lower (higher) relative humidity (RH) ranged between 0.0386 and 0.6306 (0.1079 and 1.00). Our analysis provides the observational evidence from the CALIOP that the optical properties of vertical dust particles and meteorological elements over the TD have distinct variability below and above 4 km height for DS and BD/FD events. The results obtained will provide not only reliable reference values for the improvement of the CAD algorithm used in the CALIPSO but also provide critical information for model evaluation and enhancement of CALIPSO products.