We propose the use of EOS and NPOESS satellite information in an integrated science data analysis for the development of a record on aerosol absorption. It is now generally accepted that aerosol absorption plays a very important role in the overall radiation budget of the Earth-Atmosphere System. Aerosols absorb a fraction of the incoming solar radiation and, by doing so, the potential cooling effect of aerosols, associated with the process of scattering, is reduced. On the other hand, the fraction of energy absorbed by the aerosols warms the atmosphere, modifies the heating rates and triggers a series of thermo-dynamical effects that may affect atmospheric circulation patterns. Aerosol absorption has also recently been linked to inhibition of cloud formation and suppression of precipitation. In spite of the crucial role of aerosol absorption on the radiation balance and the potentially important effect on hydrological cycle, the global quantification of aerosol absorption remains a challenge to the aerosol sensing community. The characterization of aerosol scattering and absorption properties requires the fusion of observations from different sensors since no single aerosol-sensing instrument has the required sensitivity to both processes. The MODIS instrument, covering a broad spectral range from the visible to the near-IR, is ideally suited to measure the scattering properties of aerosols. Its spectral coverage provides the necessary sensitivity to both small and very large aerosol particles. OMI near-UV observations, on the other hand, are sensitive to aerosol absorption. With its limited spectral coverage and spatial resolution the characterization of scattering properties is a difficult task. The availability of the MODIS and OMI sensors on the A-train, therefore, offer a unique opportunity to combine their retrieved products to obtain a more complete characterization of the atmospheric aerosol load.
We propose the combined analysis of Aura-OMI aerosol absorption measurements with the Aqua-MODIS aerosol optical depth product to create a data set on visible single scattering albedo and absorption optical depth. This data fusion application using A-train sensors will lay the ground for the continuation of the aerosol absorption record during the NPOESS era with the combination of aerosol absorption measurements from the OMPS sensor and optical depth observations from the VIIRS (Visible/Infrared Imager Radiometer Suite) instrument on the NPP and NPOESS platforms. The application of the proposed data fusion analysis to the NPP-NPOESS requires the development of an algorithm to derive aerosol properties from OMPS observations. The work proposed here fits within NASA�s �mission to measurements� concept to develop long-term data sets that include both EOS and NPOESS sensors.
