SeaWiFS Ocean Reprocessing #5
The Ocean Biology Processing Group (OBPG) has recently completed MODIS/Aqua Reprocessing #1. The primary motivation for reprocessing of SeaWiFS at this time is to maintain consistency with MODIS/Aqua. The proposed changes include minor enhancements to the atmospheric algorithms, adoption of the Thuillier solar irradiance model, and modifications to the definition of normalized water leaving radiance (nLw). In addition, the SeaWiFS instrument calibration will be updated to reflect the most complete information to date on SeaWiFS temporal degradation, and a new vicarious calibration based on a revised set of MOBY measurements will be applied.
The OBPG makes use of a number of standard methods to evaluate the quality of ocean color products and assess the impact of calibration and algorithm changes. A description of the analysis techniques and procedures is available here.
Status of Current Operational Products
The current SeaWiFS operational products are based on reprocessing 4.1. The products available from the 4.1 reprocessing show excellent self consistency, and good agreement with in situ match-ups. The purpose of this reprocessing is to make the correction algorithms and radiance normalization fully consistent with MODIS/Aqua Reprocessing #1.
Proposed Changes
- Updated instrument calibration
- Enhanced Rayleigh pressure corrections
- Normalization of Lw for reflection/refraction effects on solar irradiance
- Normalization of Lw for nonisotropic upwelling radiance (f/Q)
- Change reference spectrum from Neckel & Labs to Thuillier 2003.
Evaluation of Proposed Reprocessing Configuration
For a quick overview of results:
For more details: