GMIS - MODIS-AQUA Monthly mean sea surface Chlorophyll-a concentration (9km) in mg.m^-3

Collection: GMIS : Global Marine Information System 


Monthly mean sea surface Chlorophyll-a concentration (in mg.m^-3 (log10) at 9km resolution) derived from the MODIS-AQUA sensor (Satellite remote sensing Ocean color data):

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.


jrc-emis (at)


  • Frederic Melin

How to cite

Melin, Frederic (2013): GMIS - MODIS-AQUA Monthly mean sea surface Chlorophyll-a concentration (9km) in mg.m^-3. European Commission, Joint Research Centre (JRC) [Dataset] PID:


climate change coastal environment GIS digital format marine monitoring ocean color sea water protection satellite observations sea surface Chlorophyll-a concentration marine environment

Data access

GMIS - Download access (GMIS_A_CHLA)
  • Direct NetCDF download

Spatial coverage

Type Value
<gml:Envelope srsName=""><gml:lowerCorner>-180.0 -90.0</gml:lowerCorner><gml:upperCorner>180.0 90.0</gml:upperCorner></gml:Envelope>
POLYGON((-180 90,180 90,180 -90,-180 -90,-180 90))

Temporal coverage

From date To date
2002-07-01 2017-12-31

Lineage information

General information: Monthly mean sea surface Chlorophyll-a concentration in mg.m^-3 (log10 scalling) derived from the MODIS-AQUA sensor. Processing information: Chlorophyll-a data is processed using NASA SeaDAS 6.4 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 MODIS-AQUA 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.

Additional information

Published by
European Commission, Joint Research Centre
Created date
Modified date
Issued date
Landing page 
Data theme(s)
Update frequency