VIIRS Ocean Color Products over Turbid Coastal and Inland Waters

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP), which has 22 spectral bands similar to the Moderate Resolution Imaging Spectroradiometer (MODIS), is a multi-disciplinary sensor providing observations for the Earth’s atmosphere, land, and ocean properties. In this presentation, we provide some extensive evaluations and assessments of VIIRS ocean color data products, including normalized water-leaving radiance spectra nL_w(l) at VIIRS five spectral bands, chlorophyll-a concentration, and diffuse attenuation coefficient at 490 nm K_d(490) (and at the photosynthetically available radiation (PAR), K_d(PAR)), over global open oceans and particularly turbid coastal and inland waters. Specifically, VIIRS ocean color products derived from the NOAA Multi-Sensor Level-1 to Level-2 (MSL12) ocean color data processing system, which is the NOAA official data processing system, are evaluated and compared with those from in situ measurements, as well as ocean color data derived from MODIS-Aqua. Specifically, we show evaluation results using the near-infrared (NIR)-based, shortwave infrared (SWIR)-based, and NIR-SWIR combined ocean color data processing approaches. Furthermore, to meet requirements from broad users (e.g., operational, research, modeling, etc.), we propose to routinely produce two VIIRS ocean color data streams, i.e., the near-real-time and science quality ocean color product data. The implementation details for the two data streams will be discussed. Our results show that VIIRS is capable of providing high-quality global ocean color products in support of the science researches and operational applications. Our efforts on instrument calibration using both solar and lunar calibration approaches for VIIRS Level-1B data, as well as the system vicarious calibration for improving ocean color products will also be discussed.