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The Suomi National Polar-orbiting Partnership (SNPP) was successfully launched on October 28, 2011. The Visible
Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi NPP, which has 22 spectral bands (from visible to
infrared) similar to the NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS), is a multi-disciplinary
sensor providing observations for the Earth’s atmosphere, land, and ocean properties. In this paper, we provide some
evaluations and assessments of VIIRS ocean color data products, or ocean color Environmental Data Records (EDR),
including normalized water-leaving radiance spectra nLw(λ) at VIIRS five spectral bands, chlorophyll-a (Chl-a)
concentration, and water diffuse attenuation coefficient at the wavelength of 490 nm Kd(490). Specifically, VIIRS ocean
color products derived from the NOAA Multi-Sensor Level-1 to Level-2 (NOAA-MSL12) ocean color data processing
system are evaluated and compared with MODIS ocean color products and in situ measurements. MSL12 is now
NOAA’s official ocean color data processing system for VIIRS. In addition, VIIRS Sensor Data Records (SDR or Level-
1B data) have been evaluated. In particular, VIIRS SDR and ocean color EDR have been compared with a series of in
situ data from the Marine Optical Buoy (MOBY) in the waters off Hawaii. A notable discrepancy of global deep water
Chl-a derived from MODIS and VIIRS between 2012 and 2013 is observed. This discrepancy is attributed to the SDR
(or Level-1B data) calibration issue and particularly related to VIIRS green band at 551 nm. To resolve this calibration
issue, we have worked on our own sensor calibration by combining the lunar calibration effect into the current
calibration method. The ocean color products derived from our new calibrated SDR in the South Pacific Gyre show that
the Chl-a differences between 2012 and 2013 are significantly reduced. Although there are still some issues, our results
show that VIIRS is capable of providing high-quality global ocean color products in support of science research and
operational applications. The VIIRS evaluation and monitoring results can be found at the website:
http://www.star.nesdis.noaa.gov/sod/mecb/color/index.html.
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