An Assessment of the Ocean Black Pixel Assumption for the MODIS SWIR Bands
Shi
Wei, NOAA/NESDIS/STAR, wei.1.shi@noaa.gov
(Presenting)
Menghua
Wang, NOAA/NESDIS/STAR, menghua.wang@noaa.gov
Recent studies show that the shortwave infrared (SWIR) atmospheric correction algorithm improves ocean color retrievals in the coast turbid waters. In this poster, the black pixel assumption over ocean for MODIS SWIR bands at 1240 nm, 1640 nm and 2130 nm are assessed over various coastal regions. The black pixel assumption is found to be valid with MODIS SWIR bands centered at 1640 nm and 2130 nm even for the most turbid waters. Ocean water-leaving radiance contribution at 1240 nm is generally negligible in the mildly turbid waters such as along the US coast region, while some slight water-leaving radiance contributions are observed in the extremely turbid waters (e.g., some regions along the China east coast). Particularly, in Hangzhou Bay along the China east coastal region, the water-leaving radiance contribution at 1240 nm results in an overcorrection of atmospheric and surface effects, leading to errors of the MODIS-derived normalized water-radiance at the blue to reach ~0.4-0.5 mW/cm2 μm sr.
NASA Carbon Cycle & Ecosystems Active Awards Represented by this Poster: