DEVELOPMENT, VALIDATION, AND POTENTIAL ENHANCEMENTS TO THE 2ND-GENERATION OPERATIONAL AEROSOL PRODUCT AT THE NATIONAL ENVIRONMENTAL SATELLITE, DATA, AND INFORMATION-SERVICE OF THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

A revised (phase 2) single-channel algorithm for aerosol optical thick ness, tau(SAT)(A), retrieval over oceans from radiances in channel 1 ( 0.63 mu m) of the advanced very high resolution radiometer (AVHRR) has been implemented at the National Oceanic and Atmospheric Administrati on's National Environmental Satellite Data and Information Service for the NOAA 14 satellite launched December 30, 1994. It is based on care ful validation of its operational predecessor (phase 1 algorithm), imp lemented for NOAA 11 in 1989. Both algorithms scale the upward satelli te radiances in cloud-free conditions to aerosol optical thickness usi ng an updated radiative transfer model of the ocean and atmosphere. Ap plication of the phase 2 algorithm to three matchup Sun-photometer and satellite data sets, one with NOAA 9 in 1988 and two with NOAA 11 in 1989 and 1991, respectively, show systematic error is less than 10%, w ith a random error of sigma(tau) approximate to 0.04. First results of tau(SAT)(A) retrievals from NOAA 14 using the phase 2 algorithm, and from checking its internal consistency, are presented. The potential t wo-channel (phase 3) algorithm for the retrieval of an aerosol size pa rameter, such as the Junge size distribution exponent, by adding eithe r channel 2 (0.83 mu m) from the current AVHRR instrument, or a 1.6-mu m channel to be available on the Tropical Rainfall Measurement Missio n and the NOAA-KLM satellites by 1997 is under investigation. The poss ibility of using this additional information in the retrieval of a mor e accurate estimate of aerosol optical thickness is being explored.