Multi-Sensor Ocean Color Data Fusion and Applications

In this paper, we provide an overview of the progress on producing accurate global ocean color products from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) and NOAA-20 satellites. VIIRS global ocean color products include normalized water-leaving radiance spectra nL w (l) at VIIRS five spectral bands, chlorophyll-a (Chl-a) concentration, water diffuse attenuation coefficients at 490 nm, K d (490), and at the domain of photosynthetically available radiation (PAR), K d (PAR). However, VIIRS-derived daily ocean color images on either SNPP or NOAA-20 have some limitations in ocean coverage due to its swath width, high sensor-zenith angle, sun glint, and cloud, etc. Merging VIIRS ocean color products derived from the SNPP and NOAA-20 significantly increases the spatial coverage of daily data images. The two VIIRS sensors on SNPP and NOAA-20 have similar sensor characteristics, and ocean color products are derived using the same Multi-Sensor Level-1 to Level2 (MSL12) ocean color data processing system. Therefore, the merged VIIRS ocean color data from the two sensors have high data quality with consistent statistical property and accuracy globally. We describe an approach to remove data gaps of missing pixels from the SNPP and NOAA-20 merged global ocean color data. Some applications using the new complete global data coverage of daily ocean color product are also presented and discussed.