Ocean colour remote sensing allows the study of the optical properties of the oceans and the biology of the marine ecosystems. The right-hand links lead to images of chlorophyll a maps for the European seas and the global ocean, or to the MERSEA Thematic Portal.
The Global Environment
Monitoring Unit is maintaining an archive of ocean colour derived
products for the European seas, over the geographical domain 40W-55E,
10N-80N (see domain on the right). This site shows maps of chlorophyll
a concentration for specific regions covering the European Atlantic
sector from the Arctic to the Cape Verde Islands, the North Sea, Baltic
Sea, Mediterranean Sea, Black Sea and Caspian Sea.
The time series contains daily, 8-day and monthly maps derived from
SeaWiFS and MODIS for the period Sep. 1997 to present. These maps have
an approximate resolution of 2-km and are obtained after processing of
all top-of-atmosphere full resolution imagery available for the domain.
The processor used for the development of the archive is SeaDAS version
The archive contains several categories of products:
The GEM also maintains a global archive of ocean colour derived data sets, based on SeaWiFS and MODIS. Emphasis is given for the study of the global oceans with monthly maps of aerosol optical thickness, normalized water leaving radiances, diffuse attenuation coefficient, chlorophyll a concentration and PAR. Moreover, chlorophyll a and PAR time series are used to compute global primary production with a depth- and wavelength-resolved primary productivity model (see example of annual PP estimate on the right).
As a product of reference
for calibration purposes and for comparison with the outputs of its own
algorithms, the Unit keeps an ocean colour data archive focused on the
Northern Adriatic Sea, where the Acqua Alta Oceanographic Tower
measurement site is located. This web site shows the SeaWiFS series for
this location processed with the SeaDAS software package.
Selected references for validation studies: