Desert dust observation from space - Application of measured mineral component infrared extinction spectra

Measured extinction spectra of six different components of desert dust have been used as input for a mineral dust retrieval algorithm for the Infrared Atmospheric Sounding Interferometer IASI based on Singular Vector Decomposition. The use of measured dust component extinction spectra rather than dust sample-based optical properties widely used in thermal infrared applications improves retrieval results significantly. Correlation between IASI derived dust optical depth (at 0.5 μm) and AERONET sun-photometer observations from six months over Northern Africa, the Arabian Peninsula and Asia improved from formerly 0.623 to now 0.757 while the root-mean-square difference decreased from 0.322 to now 0.174 and the bias decreased (in terms of its absolute value) from −0.181 to 0.003. The dynamically adjusted e−1 envelope of the deviation histogram between AERONET and IASI dust AOD at 0.5 μm is at 0.160 while 80% of all IASI observations are within AOD0.5 μm ± 0.2 of respective AERONET values.