Gregg, Watson: NASA GSFC (Project Lead)
Project Funding:
2012 - 2014
NRA: 2010 NASA: NPP Science Team for Climate Data Records
Funded by NASA
Abstract:
Observing long term trends in ocean color data requires consistency among successive missions, since the lifetime of each is finite. NPP/VIIRS is the next global ocean color mission, following the highly successful SeaWiFS and MODIS-Aqua sensors. Like all preceding ocean color sensors (except perhaps MODIS-Terra, which should be discounted because of inadequate capability), VIIRS has a different design and orbit than any other global sensor. Rectifying the differences among different sensors and producing consistent ocean color observations is crucial to our understanding of global ocean biology variability and trends.
We propose to investigate the ability of an established approach to improve the consistency of VIIRS ocean color data. This approach utilizes completely processed and gridded ocean color data (Level-3 Environmental Data Records), applies in situ data for an a posteriori correction, and then applies data assimilation to correct sampling problems. As a post-processing application, the approach meets the requirements of the proposal announcement, i.e., that it does not resort to lower level data (i.e., RDRs, SDRs or intermediate products). As such, it is responsive to the specification for Section 2.2: Development of New Approaches to Extend Critical Earth System Data Records that Cannot be Produced by NPP.
Our approach has been applied to the circa 2007 data sets of SeaWiFS and MODIS- Aqua and has dramatically increased the consistency of these sensor data sets globally and in all major oceanographic basins. In addition to improving the consistency of disparate ocean color data sets, the approach also conforms more closely to in situ data, producing a unified description of ocean biology from satellites and in situ platforms.
We will test our approach in advance of launch of NPP using circa 2009/2010 processing of SeaWiFS and MODIS-Aqua, and additionally MERIS data. Then after launch and acquisition of in situ chlorophyll data, we will apply our approach to fully processed VIIRS ocean color data. We do not intend to produce or distribute VIIRS ocean chlorophyll data sets, but rather evaluate our approach with VIIRS data.
More details may be found in the following project profile(s):
