The origin of the reflectance peak near 700 nm in chlorophyll-a laden waters-an experiment

This study presents an experiment to determine the major origin of the reflectance peak near 700 nm that can be observed in all chlorophyll-a laden waters. For simulation of chlorophyll-a within an increasing water mass, mountain maple leaves have been fixed on a plate, gradually lowered into the water, and spectrally measured at different water depths. The more water influences the spectra the more the red edge of vegetation is being reduced to the reflectance peak as known from algae laden waters. To make the crosscheck, also a white panel is being lowered and spectrally measured in the same steps. The white panel spectra have been normalised to retrieve pure water reflectance with increasing absorption along with depth. Again normalising the spectra of leaves covered with water by the increasing water absorption, common vegetation spectra are being provided. Therefore the reflectance maximum near 700 nm is mainly due to increasing water absorption that reduces the red edge of plants