NASA - National Aeronautics and Space Administration

An integrated method for the simultaneous detection/ separation of mineral dust and clouds for both daytime and nighttime conditions using MODIS thermal infrared window brightness temperature data has been developed. Based on the spectral variability of dust emissivity at 3.75, 8.6, 11 and 12 mm wavelengths, we combine three heritage approaches to identify dust and cirrus. MODIS data for three dust-laden scenes have been analyzed to demonstrate the effectiveness of this detection/separation method. The detected daytime dust and cloud coverage for the Persian Gulf case compares reasonably well to those from the ‘‘Deep Blue’’ algorithm developed at NASA-GSFC. Validation of the nighttime dust and cloud detection method has been carried out by using the cases surrounding Cape Verde and Niger, West Africa, on the basis of the coincident and collocated ground-based micro-pulse lidar measurements.