On the Importance of a Band at 709 Nm

We present examples of spectra and image data from ocean and coastal waters observed with MERIS, which demonstrate the importance of a spectral band near 709 nm for interpreting water-leaving spectral radiance. We hope that the evidence presented here will convince planners that it is important to include this band in all future ocean colour sensors (assuming related bands, for example near 665, 680 and 750 nm are already present). For MERIS the 709 nm band has been shown to improve detection and study of a variety of intense, surface plankton blooms and was also instrumental in making the first satellite detection of pelagic Sargassum. This paper also shows how the band provides data important for detection and study of a variety of types of plankton bloom, including those occurring in the high sediment concentrations characteristic of river plumes and in ice. The band also gives important information on coastal vegetation and coral reefs.