GACP Projects
Development and Validation of Multiple-Satellite Data Sets for Global Aerosol Radiative Forcing
Philip A. Durkee
Abstract: Aerosol properties can be derived from numerous satellite data sets. Most aerosol retrieval schemes utilize a single sensor system such as NOAA AVHRR, CZCS, or Meteosat. This study proposes to combine the benefits of individual satellite sensors into a "composite" retrieval scheme. In particular retrievals with NOAA AVHRR nominally provide two daytime views per day. Although AVHRR provides high spatial resolution (1 km) and multi-wavelength observations, the temporal resolution is weak. The GOES Imager provides single-wavelength retrievals with similar spatial resolution to AVHRR but with lower signal-to-noise ratio (less accuracy). However, GOES provides observations as often as four times per hour. The first focus of this study will be to develop combined AVHRR-GOES retrievals that exploit the advantages of each system. In addition, collaboration with TNO Netherlands will investigate composite retrievals using AVHRR, GOES and the ERS-2 ATSR. ATSR adds multiple view angles to the mix of tools for retrieval of aerosol properties. ATSR data is available through TNO and this collaboration will make this data set available to the Science Team formed through this NRA.
The second focus of this study will be to advocate the preparation of comprehensive data sets for validation of retrievals prepared by the Science Team. Comparison of retrieval schemes as well as validation of an aerosol climatology will require intercomparison with common in situ, radiation and satellite data sets. Aircraft, surface (including ship), and satellite data will be used to test not only the absolute result of a retrieval (such as aerosol optical depth), but also the individual assumptions imbedded in the retrieval methods (such as aerosol model size distribution, scattering phase function parameterization, surface reflectance, etc.). These data sets would become standard, community data sets that all algorithms could be validated against.
