Comparative analyses of Asian and Saharan Dust in source regions and downwind using CALIPSO space lidar data in conjunction with A-Train multi-sensor data and ground-based observations

Northern Africa and East Asia are the two world's largest sources of mineral aerosol (dust). Each year large amounts of mineral dust are emitted into the atmosphere, affecting the regional air quality, environment and climate. This study presents analyses of Saharan and Asian dust events by integrating CALIPSO lidar data with A-Train satellite multi-sensor observations (Ozone Monitoring Instrument, OMI, and Moderate-Resolution Imaging Spectroradiometer, MODIS), as well as ground-based observations. The focus is on dust events that occurred during the spring-summer seasons of 2007-2008. The capability of CALIPSO to detect dust was investigated by analyzing the CALIPSO features against independent observations for selected CALPSO overpasses on a case-by-case basis. The changes in the linear depolarization ratio were analyzed in conjunction with optical modeling, using the T-matrix and the improved geometric optics methods (IGOM) with the focus on the role of the particle nonsphericity and size distribution. The dust properties and vertical distribution in dust sources were analyzed, as well as changes in dust properties during the mid-range transport.

Based on CALIPSO observations, we investigate the importance of the layered vertical distribution of dust on the dust radiative impact. The results of intensive one-dimensional radiative transfer simulations addressing these issues will be presented with the focus on TOA and surface radiative forcing, and heating/cooling rates in differing dust-laden conditions.