Ecosystem Predictions with Approximate vs. Exact Light Fields

摘要

The overall goal of this work was to develop an extremely fast but accurate radiative transfer model, called EcoLight, for use in coupled physical- biological-optical ecosystem models, and then to demonstrate the computational feasibility of including accurate light field predictions in coupled physical- biological-optical ecosystem models. Currently available ecosystem models often use fairly sophisticated treatments of the physics (e.g., advection and upper- ocean thermodynamics and mixing) and biology (e.g., primary production, nutrient utilization, and grazing) but use grossly oversimplified treatments of the optics. The optics component of coupled ecosystem models is sometimes just a single equation parameterizing the scalar irradiance in terms of the chlorophyll concentration and a few parameters such as the solar zenith angle. Such simple models often fail even in Case 1 waters, and they can be wrong by orders of magnitude in Case 2 or optically shallow waters. The objective of this work was develop a radiative transfer model that can be used in coupled models to bring the optics component up to the level of accuracy and sophistication needed for ecosystem models that are being applied to any water body, including Case 2 and optically shallow waters.