Research Of Global Aerosol Optical Properties Based On Spaceborne Lidar

Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is a spacebornelidar onboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation(CALIPSO), which can provide global measurements of aerosols and clouds withhigh-precision, high-resolution vertical classified information. Based on the classifiedaerosol data from CALIOP, the optical properties and spatial distributions of the sixkinds of aerosols (including dust, polluted dust, smoke, marine, clean continential,polluted continental) are studied. And then, combined with the ability of the OzoneMonitoring Instrument (OMI) onboard Aura for finding absorbing aerosols in theUltraviolet, the absorptive aerosols are tried to be identified just using CALIOP data.The CALIOP Level25km Aerosol Layer products from2007to2010areapplied to the global statistical analysis for the global six aerosols, including theprobability of the aerosol appears, aerosol layer depth, volume depolarization ratio,attenuated color ratio, attenuated backscatter coefficient and aerosol optical depth.The results show that, the volume depolarization ratio of dust is the biggest of all, themain distribution areas of the dust is the north of Africa, Arabia, Iran and TaklimakanDesert of China, and the aerosol layer depth is bigger in these areas, about more than1.6km. The polluted dust aerosols widely distribute in the continents of the world,except for Antarctica. Both dust and polluted dust aerosol optical depth shows a trendof decreasing gradually since from the December2008. The smoke aerosols originatefrom the African traditional agriculture. The aerosol layer altitudes become higherover the ocean, because of the sea surface wind. The high attenuated color ratio valueof marine aerosols mainly distribute in the ocean between30°N and30°S. Theclean continental and polluted continental aerosol backscatter coefficient is thesmallest, mainly distributed in the North and South poles. The volume depolarizationratio (VDR) values are almost zero in winter and autumn because of the Perpetualday. Based on the statistical analysis of the global optical properties of six kinds ofaerosols, the threshold values for identifying dust aerosols are concluded, VDR isbetween0.075and0.3, ACR is between0.4and0.8. Combined with the ability of theOMI for finding absorbing aerosol and the results of CALIOP aerosol subtype, theresearch result shows that the threshold values for identifying dust aerosols workswell. This method is applied to the Level1B single-shot data, and the identifyingresult is almost consistent with that from algorithms of CALIOP. In addition, theresult shows that some dust aerosols are mistaken for the smoke or sulfate aerosolwith the algorithms of OMI.