Intercomparison of satellite retrieved aerosol optical depth over ocean during the period September 1997 to December 2000

[摘要] Monthly mean aerosol optical depth (AOD) over ocean is compared from a totalof 9 aerosol retrievals during a 40 months period. Comparisons of AOD havebeen made both for the entire period and sub periods. We identify regionswhere there is large disagreement and good agreement between the aerosolsatellite retrievals. Significant differences in AOD have been identified inmost of the oceanic regions. Several analyses are performed includingspatial correlation between the retrievals as well as comparison withAERONET data. During the 40 months period studied there have been severalmajor aerosol field campaigns as well as events of high aerosol content. Itis studied how the aerosol retrievals compare during such circumstances. Thedifferences found in this study are larger than found in a previous studywhere 5 aerosol retrievals over an 8 months period were compared. Part ofthe differences can be explained by limitations and deficiencies in some ofthe aerosol retrievals. In particular, results in coastal regions arepromising especially for aerosol retrievals from satellite instrumentsparticularly suited for aerosol research. In depth analyses explaining thedifferences between AOD obtained in different retrievals are clearly needed.We limit this study to identifying differences and similarities andindicating possible sources that affect the quality of the retrievals. Thisis a necessary first step towards understanding the differences andimproving the retrievals.

[学科分类] 大气科学