Impact of Riverine Lithogenic Material on Estuarine Primary Productivity: A Modeling Study

The HF-LD-SurfaceForcing experiment showed that riverine lithogenic material (RLMs) had the greatest impact on primary productivity (PP) in the euphotic zone of estuarine regions, resulting in an annual decrease of 2.2% compared to the Control. However, when RLMs diffuse seaward along the bottom of the continental shelf and slope, the annual PP decrease in estuarine regions is significantly smaller than that observed in the other two sensitive experiments (Type1 and Type2), despite the fact that the concentration of lithogenic material added to the estuarine grid cells is the same. For instance, in comparison to the Control, the annual PP reductions in the high-forcing HF-SD-LateralForcing-FuncI and HF-SD-LateralForcing-FuncII experiments are approximately 1.6%, which is less than the 2.1% observed in the HF and HF-SD-SurfaceForcing experiments. The annual PP changes in the low-forcing LF-SD-LateralForcing-FuncI and LF-SD-LateralForcing-FuncII experiments are close to zero, and the simulation results of the former even show a slight increase.