Use of the 709 Nm Band of Meris to Detect Intense Plankton Blooms and Other Conditions in Coastal Waters

Water-leaving radiance with a strong spectral peak at about 705 nm has been noted as a signature of dense surface phytoplankton in bloom conditions. In shallow water, a peak near this wavelength can also indicate the presence of benthic vegetation. MERIS on Envisat provides a band at 709 nm which can be used to detect this signature. We present images and spectra derived from MERIS image data of coastal waters of Vancouver Island on the west coast of Canada, showing examples of the peak in the productive waters on the continental shelf, where it appears characteristic of small areas of high surface biomass. ESA has accepted an AO proposal in which the spectral bands of MERIS should be changed for a brief period to give continuous coverage of the spectral range 650 to 723.5 nm at about 10 nm resolution, to allow a fuller evaluation of spectral signatures in this region.