Impact of Riverine Liquid Material (RLM) on Estuarine Primary Productivity: A Modeling Study

The simulation of the control accurately replicated primary productivity, with the simulated global ocean's annual primary production (PP) reaching 52.0 PgC/yr, falling within the range of the estimated global ocean PP (38 to 65 PgC/yr) from the Erik2013 database. Here, PP refers to the total integrated photosynthetic carbon from 0 to 100m. While the total annual POC export of the estuarine regions increased with RLM inputs, it had a modest negative impact on the total PP within the euoptic zone of the estuarine regions (Table 3) when compared to the control. The effect on total PP in the euoptic zone of the estuarine regions was limited when RLM was only added to the estuarine regions (sensitive experiments of Type 1), with percentage reductions of approximately 1% under low-concentration forcing (LF) and 2% under high-concentration forcing (HF) respectively (Table 3). When RLM diffused seaward at the surface ocean (sensitive experiments of Type 2), the decrease in PP in the estuarine regions was similar to the results when RLM was only added to the estuarine regions (sensitive experiments of Type 1), under the condition that RLM had the same concentration in the estuarine grid cells (i.e., LF and LF-SD-SurfaceForcing).