Verification for the Satellite Remote Sensing Products of Aerosol Optical Depth in Taklimakan Desert Area

Using groundbased Aerosol Optical Depth (AOD) data at Tazhong, Taklimakan desert area, four sets of satellite aerosol data, from the Multiangle Imaging Spectrometer (MISR), the Moderate Resolution Imaging Spectrometer (MODIS), and the Ozone Monitoring Instrument (OMI) from 2007 to 2008 were validated. The results show that satellite aerosol retrievals are significantly correlated with the groundbased ones. The correlation coefficient for MODIS/AOD is the largest (0.91), followed by OMI/AOD (0.87), MISR/AOD (0.84), and OMI/UVAI (0.51). MISR/AOD rootmeansquare error (0.14) and the average deviation (-0.06) are the lowest in the four products. MISR/AOD and MODIS/AOD is relatively less than the groundbased AOD, however, OMI/AOD and OMI/UVAI exceeds the groundbased ones. Under the same conditions (groundbased AOD is limited to less than 2.0), the rootmeansquare error and the standard deviation of MISR is the lowest. Seasonal variation of aerosol is captured by satellite data. AOD is relatively larger in spring and summer and is relatively lower in autumn and winter. The result of ngstrm wavelength exponent shows that the spring has the minimum(0.11), followed by summer and autumn, and winter has the maximum(0.61), which shows that the aerosol particle is larger in spring and summer while it is smaller in autumn and winter. Besides, Taklimakan desert area belongs to the sand source where aerosol type is single. In summary, the annual variability tendency of AOD from 2000 to 2010 is not obvious. The result of the retrieval shows that there is the maximal aerosol content in 2003 during the decade and the annual average is up to 0.32, while there is the minimal aerosol content in 2005 and the annual average is 0.28.