VIIRS OCEAN COLOR PRODUCTS
In this paper, we provide an overview of the progress on the evaluations of the Visible Infrared Imaging Radiometer Suite (VIIRS) ocean color products with long-term time series and more in situ data for matchup analysis. Specifically, VIIRS ocean color products include normalized water-leaving radiance spectra nLw(λ) at VIIRS five spectral bands, chlorophyll-a concentration (Chl-a), water diffuse attenuation coefficients at the wavelength of 490 nm, Kd(490), and at the domain of photosynthetically available radiation (PAR), Kd(PAR). VIIRS ocean color products derived from the NOAA Multi-Sensor Level-1 to Level-2 (MSL12) ocean color data processing system are evaluated and compared with in situ data from the Marine Optical Buoy (MOBY) and measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS). In order to meet requirements from all users, we propose to routinely produce two ocean color data streams, i.e., the near-real-time (NRT) data and delayed science quality data. The NRT ocean color data stream has the advantage of quick data turn around with data latency ~12-24 hours, while the science quality data stream has highly consistence (with the mission-long data reprocessing) and accuracy of ocean color products. In addition, we have significantly improved sensor calibration by combining the lunar calibration into the current solar calibration method. Our results show that VIIRS is capable of providing high-quality global ocean color products in support of the scientific research and operational applications.