Quantum yield of photosynthesis in the Baltic: a new mathematical expression for remote sensing applications

Statistical relationships between the quantum yield of photosynthesis Φ and selected environmental factors in the Baltic have been established on the basis of a large quantity of empirical data. The model formula is the product of the theoretical maximum quantum yield ΦMAX =0.125 atomC quantum−1 and five dimensionless factors fi taking values from 0 do 1: Φ = ΦMAXfa fΔ fc(Ca(0)) fc(PARinh) fE, t. To a sufficiently good approximation, each of these factors fi appears to be dependent on one or at most two environmental factors, such as temperature, underwater irradiance, surface concentration of chlorophyll a, absorption properties of phytoplankton and optical depth. These dependences have been determined for Baltic Case 2 waters. The quantum yield Φ, calculated from known values of these environmental factors, is then applicable in the model algorithm for the remote sensing of Baltic primary production. The statistical error of the approximate quantum yields Φ is 62%.