Objectives: This proposal will be for the continuation and extension of current activities within the NPP Science Team which involve oversight of the aspects of VIIRS instrument design and testing that have impact on the ability of the NPP/NPOESS satellite series to continue the time series of global SSTs derived by infrared radiometer. The experience we bring to the project is based on current and past activities with AVHRR Pathfinder, MODIS Science Team, AIRS validation Team, NPP Science Team and the GHRSST Science Team. The project would leverage activities supported through Remote Sensing Science to study effects of anomalous conditions (aerosols, high water vapor loading, low water vapor loading, large air-sea temperature differences) scheduled to start in January 2007, and the MODIS SST algorithm maintenance activities, which are the subjects of companion proposals.
Method: We will build on the MODIS SST experience, matching MODIS algorithms and data sets to VIIRS infrared channel selection. This will include analyses of MODIS data sets in aerosol-laden atmospheres and other situations where the globally-optimized atmospheric correction algorithms are known to lead to significant bias errors. The proposed research will involve numerical radiative transfer simulations to study the behavior of the SST retrieval uncertainties as a result of deviations from standard distributions of atmospheric properties, and of instrumental artifacts.
We will evaluate results of pre-launch testing and characterization, and of contractor decisions resulting to the instrument design, construction, testing, and operation insofar these impinge on the SST retrievals. Furthermore we will support NGST activities by a) evaluation of the operational algorithms and operational procedures, b) continuing to provide VIIRS test-bed data sets based on MODIS data and ship- and buoy-based measurements, c) continuing to provide information and advice on MODIS uncertainty characteristics. We would also participate in Technical Interchange Meetings, periodic VOAT meetings and the NASA NPP Science Team conference calls. We would collaborate with the SST and Atmospheres PEATEs. We will also work with the IPO and NGST on validation strategies for VIIRS SST, pre-launch validation planning, and, depending on the eventual launch date, the initial post-launch validation.
Significance: SST is a critical climate variable that can best be measured on a global basis by satellites; this proposed project will help ensure the authenticity of the future extension using VIIRS of the SST "climate record" that now spans two decades and several spacecraft sensors. It targets NASA ROSES Earth System Science Research Using Data and Products from Terra, Aqua, and ACRIMSAT Satellites Announcement (A.15) objective 4.2 "EOS Algorithm Refinement and Cal/Val for ESDRs" by "continuing the evaluation of NPP/NPOESS Environmental Data Records (EDRs) and to demonstrate the suitability of these data sets for use as Earth system and/or climate data records" with the focus on Sea-Surface Temperature.
