Mechanism maintaining the primary productivity in the western subarctic North Pacific by tide-induced diapycnal mixing

Research summary

　Iron is an essential nutrient for marine phytoplankton growth, and its deficiency limits the primary productivity in the subarctic North Pacific. This study investigates effects of iron supply to the surface water due to tide-driven diapycnal mixing on the primary productivity in the North Pacific using an eddy-resolving (1/12 degree) marine-biogeochemical cycle model. We successfully simulated high dissolved iron concentrations distributed in the intermediate layer of the North Pacific using an eddy-permitting (1/4 degree) model (Fig. 1). However, the simulated Kuroshio and subarctic front shifted poleward, suggesting that the model does not have enough skill to investigate effects of iron supplied by the diapycnal mixing on the surface productivity. In this study, we ameliorate the deficiency in the ocean physics by increasing the horizontal resolution, and investigate effects of iron supplied by tide-induced mixing on the primary productivity.

Fig. 1 Dissolved iron distribution in the intermediate layer water simulated by an eddy-permitting model developed in the previous study.

研究代表者：

三角 和弘

電力中央研究所 環境科学研究所 主任研究員 海洋物質循環

http://criepi.denken.or.jp/jp/env/index.html