Monthly mean sea surface Chlorophyll-a concentration (in mg.m^-3 (log10) at 9km resolution) derived from the VIIRS sensor (Visible Infrared Imaging Radiometer Suite): Chlorophyll is a photosynthetic pigment commonly present in all phytoplankton species. It is used as a proxy for phytoplankton biomass. Chlorophyll concentration is a standard product from satellite-based optical sensors, usually retrieved from empirical algorithms using reflectance ratios at two or more wavebands.
- Frederic Melin
How to cite
Melin, Frederic (2018): GMIS - VIIRS Monthly climatology sea surface Chlorophyll-a concentration (9km) in mg.m^-3. European Commission, Joint Research Centre (JRC) [Dataset] PID: http://data.europa.eu/89h/1b971032-d2af-4e75-bf61-ba1678827284
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General information: Monthly mean sea surface Chlorophyll-a concentration in mg.m^-3 (log10 scalling) derived from the VIIRS sensor. Processing information: Chlorophyll-a data is processed using NASA SeaDAS 7.4 software and the standard OC3M algorithm for chla. Temporal characteristics: This product consists of standard monthly mean sea surface chlorophyll-a concentrations (L3 product) at 9km resolution (projection: Equidistant cylindrical Grid mapping: equirectangular). Description of observation methods/instruments: The remote sensing of 'Ocean Color' represents a measure of the spectral variations in the light leaving the water surface, subsequently interpreted in terms of concentrations of optically-significant constituents in the water. After removing the atmospheric contribution, the water leaving radiance recorded at a given time and wavelength by the satellite reflects the optical properties of the water which, in turn, mirrors a specific structure and biogeochemical composition of the marine waters. Accordingly, the satellite-derived reflectance at the air-sea interface can be related to the concentration of an optically-significant constituent (e.g. chlorophyll). The retrieval of chlorophyll from VIIRS for case 1 waters (optically dominated by phytoplankton and associated products) uses a 4th order polynomial algorithm (O'Reilly et al. 2000). Quality/accuracy/calibration information: The 'standard' algorithm proposed by space agencies to process data from their sensors has a nominal accuracy of ~35% in the retrieval of surface chlorophyll in case 1 waters. References: J. E. O'Reilly and co-authors, SeaWiFS Postlaunch Calibration and Validation Analyses, Part 3. NASA Tech. Memo. 2000-206892, Vol. 11, S.B. Hooker and E.R. Firestone, Eds., NASA Goddard Space Flight Center, Greenbelt, Maryland, 9-23. Other contextual information: The product is stored in NetCDF data and available for download.