European Seas, including NE Atlantic, NW Africa, North Sea and Baltic Sea, Mediterranean Sea and Black Sea, Caspian Sea and Aral Sea, Red Sea and N Indian Ocean

Ocean colour and earth-leaving visible waveband spectral radiation

The Sea-viewing Wide-Field-of-view Sensor (SeaWiFS) European Archive was developed to support a number of activities, among which the JRC Institutional Project 'Coastal Monitoring and Management' (COAST), the EC FP IV Programme Environment and Climate (EC-ENV, and in particular the projects CleanSeas, ISOLE), the EC FP IV Programme Marine Science and Technology (EC-MAST 3, and in particular the project COLORS), and various JRC Third Party Work Projects (among which PRISMA, MAT). The Archive contains virtually every image (1 per day, in general) with acceptable cloud cover collected by the SeaWiFS over the European Seas and adjacent ocean basins, since the sensor started operations in September 1997. The Archive includes images at level 1 (original top-of-the-atmosphere radiances), at level 2 (surface reflectances and derived geophysical parameters) and at level 3 (remapped, composited statistical products). A dedicated set of processing algorithms was developed by the Marine Environment Unit, SAI, JRC EC, for processing SeaWiFS data from the NASA-provided level 1A to level 2 and 3. The data received by the main European HRPT receiving stations are received from the NASA/GSFC DAAC and are processed to level 2 with a combined land-sea algorithm. Standard products such as water-leaving radiance (6 wavelengths), aerosol radiance and optical thickness at 865 nm, chlorophyll-a and total suspended matter concentrations, diffuse attenuation coefficient, are retrieved over marine surfaces. A separate Northern Adriatic Sea (NAS) time series is also being processed as a reference product for calibration and validation purposes (in situ optical and bio-optical data are being collected continuously on a offshore platform in the NAS, in the framework of a parallel activity). Products for terrestrial applications result from an Optimized Vegetation Index algorithm developed at the Global Vegetation Monitoring Unit, SAI JRC EC. Each individual scene is re-mapped onto a standard 2 km pixel geographical grid for a number of marine basins (NE Atlantic, NW Africa, North Sea & Baltic Sea, Mediterranean Sea, Black Sea, Caspian Sea and Aral Sea, Red Sea and N Indian Ocean) for each available day. The daily images are then averaged on a pixel by pixel basis, to generate monthly and annual composites. It is intended to continue the processing of SeaWiFS high-resolution LAC data (as well as of low-resolution GAC data, in the near future) for the whole duration of the mission.

Bulgarelli B. and F. Melin (2000) SeaWiFS data processing code REMBRANDT version 1.0. Code Elements., COAST Annual Report, 2000.; Gobron N., B. Pinty, M. Verstraete and F. Melin (1999) Development of a vegetation index optimized for the SeaWiFS instrument. Algorithm Theoretical Basis Document., JRC Publication, No. EUR 18976 EN.; Melin, F., B. Bulgarelli, N. Gobron, B. Pinty, and R. Tacchi (2000) An integrated tool for SeaWiFS operational processing., JRC Publication, No. EUR 19576 EN.

Joint Research Centre
Space Application Institute Marine Environment Via E. Fermi 2749
ISPRA (VA)

I-21027
Italy