Relationships between spectral optical properties and optically active substances in a clear oligotrophic lake

摘要: [1] The absorption and scattering coefficients in the euphotic zone of oligotrophic Lake Taupo, New Zealand, were measured at 19 stations across 620 km2 lake late fall during period mixed layer deepening development annual phytoplankton maximum. These subsequently related to water content colored dissolved organic matter (CDOM), phytoplankton, nonalgal particles via measurements spectra these optically active substances chlorophyll a suspended particle concentrations. Measurements spectral diffuse attenuation coefficient for downwelling irradiance (Kd) reflectance (Lu/Ed) revealed that clear blue waters Taupo had minimum Kd 0.09 m−1 500 nm maximum 490 nm. The Lu/Ed well described by modeled computed using radiative transfer model (Hydrolight) assuming relatively low values backscattering ratio (0.008–0.014). relationships established here between optical properties consistent with previous observations case 2 marine waters, they will provide basis prediction eutrophication, climate, other environmental effects on blueness transparency large lakes.