There are 4 products for each scene (this may eventually be 7 products for some scenes):

1. RGB - a true color image using level 1 (i.e. at-satellite) radiance values at 665nm, 560 nm and 443 nm.

2. FLH - the fluorescence line height indicating level 1 radiance at 681 nm relative to a baseline derived by linear interpolation between level 1 radiance values at 665nm and 709nm.

3. MCI - the maximum chlorophyll index indicating level 1 radiance at 709 nm relative to a baseline derived by linear interpolation between level 1 radiance values at 681 nm and 735 nm.

4. Algal1 - the case 1 chlorophyll product derived from level 2 (i.e. corrected to sea surface by computing atmospheric effects) reflectance values.

The FLH and MCI products are masked to black using a suitable radiance threshold from band 13 radiance values. The images are not rectified. The spatial resolution is 1200m for the reduced resolution products and 300m for the full resolution products. FLH images are sometimes affected by a sudden colour change at one of the boundaries between the 5 cameras of MERIS. In some cases a correction has been applied. The letters "cbCorr" are then included in the file name.

The enhancement is not the same between dates. For FLH, MCI and Algal 1, blue represents low chlorophyll concentrations and red/white represents high chlorophyll concentrations ( palette shown above). FLH and MCI both have a linear enhancement. Algal 1 has a logarithmic enhancement. The FLH enhancement is generally comparable to extracted chlorophyll concentrations of 1 to above 10 mg/m³. The Algal 1 enhancement is generally from 0.3 to 50 mg/m³ (2002-May 2006) or 0.1 to 30 mg/m³ (May 2006 to present).