A principal objective of this proposal is to diagnose current performance of MODIS SST algorithms through comparison of AQUA and TERRA SST derived from MODIS observed 4 and 11 �m radiances with in situ SST observations (bulk temperature) and MAERI and ISAR infrared radiometers (skin temperature). This is a continuation of our current MODIS activities, as members of the original MODIS science team and for the past three years, that have focused on comparing time series of satellite and in situ SST retrievals and applying the differences to help diagnose and correct instrument trends that otherwise could be interpreted as SST trends. This proposal addresses section A3.2 of the ROSES 06 NRA as it relates to the Cal/Val activities associated with the maintenance of the SST Earth Science Data Record from MODIS Aqua and Terra sensors with special attention to the climate data record. The proposed work support the MODIS matchup database product (MMDB) currently approved under ATBD 26 and provides the central dataset for both continued instrument characterization and Cal/Val studies, proposed refinements to the algorithm support the SST products approved under ATBD 25. In section A4.2 of the NRA, maintenance and stewardship of the SST ESDR/CDR is identified as a fundamental core systematic variable required to understand and predict climate variability.
Specific objectives are:
- Maintain a consistent SST calibration for MODIS AQUA and TERRA to enable calculation of a seamless climate quality data record independent of sensor variations
- Continue to provide IR instrument characterization and calibration updates to the Aqua and Terra SST calibration tables to enable elimination of mirror-side difference trends and minimization of detector banding in high resolution data products
- Improve global SST coverage by extending the range of satellite zenith angles over which low uncertainty SST can be retrieved
- Refine pixel quality algorithm in high gradient regions to increase the retention of low uncertainty SST retrievals through the use of higher resolution reference maps
- Extend the SST retrieval algorithm by implementation of an absorbing aerosol identification and correction methodology for MODIS SST 4um (nighttime) product.
In addition to direct mission support for AQUA and TERRA the MMDB enables synergistic NASA collaboration across multiple investigations including the Global Ocean Data Assimilation Experiment, an international effort to develop operational ocean analysis and prediction systems for the global ocean. The MMDB also provides a scientific bridge between heritage AVHRR missions and the future NPOESS and NPP VIIRS instruments. The MMDB provides the core observational dataset being utilized by both private sector contractors and university based researchers as a test bed for the VIIRS SST algorithms. Other instrument teams, eg. AMSR, AATSR, have also used the MMDB to understand the SST retrieval uncertainties. Proposed further development of the MMDB, will directly link to improved science and understanding of the NPOESS and NPP SST algorithms, as well as Multi-Sensor SST (MISST) activities.
