Tuesday, 24 January 2012: 1:45 PM
First-Look Diagnosis of Satellite Aerosol Optical Depth Retrievals Using a Data Assimilation System
Room 257 (New Orleans Convention Center )
For satellite retrievals of aerosol optical depth, the gold standard is comparison to Sun Photometer data from the extremely well-calibrated instruments in the Aerosol Robotic Network (AERONET). However, the AERONET network is sparse and can require long time series to acquire sufficient data volume for statistical analysis of satellite products. Satellite products can be evaluated by comparison with other products with established error characteristics, but the spatial and temporal overlap of products may be very limited. In the case of new sensors, or field campaigns oriented toward satellite product validation, it is desirable to have a source of information to quickly identify times and places where satellite products give different information on atmospheric aerosol. The Naval Research Laboratory, in preparation for new data from the Visible and Infrared Radiometer System (VIIRS) on board the NASA NPP satellite, has developed a system based on the Navy Variational Data Assimilation System for Aerosol Optical Depth (NAVDAS-AOD) which will permit rapid diagnosis of VIIRS AOD starting from first light. This system assimilates AOD from the Moderate Resolution Imaging Spectroradiometer (MODIS) to provide a global analysis of AOD with characterized uncertainty for comparison to VIIRS AOD, and can automatically evaluate the impact of assimilation of new data on the accuracy of aerosol forecasts from the Navy Aerosol Analysis and Prediction System (NAAPS). We will describe the design of this system, and demonstrate a prototype using AOD products from MODIS and from the NOAA Advanced Very High Resolution Radiometer (AVHRR). We will show how this system identifies areas of potential retrieval problems and facilitates rapid evaluation of satellite data post-processing methods.