Zinc (Zn) is biogeochemically significant due to its crucial role in biological processes. In the global ocean, there is an apparent coupling between the concentrations of zinc and silicon (Si), and there is a consistent ratio between the two. However, this coupling is observed to be disrupted in the North Pacific Ocean. It has been suggested that this disruption is due to Zn that originates on the continental shelf. However, this explanation relied on the particular circulation field used in the model described in the relevant study. The aim of the current study was to use more realistic circulation fields as the basis of a more accurate evaluation of deep circulation and export production in the North Pacific. We also aimed to analyze the impact of uptake parameters, continental-shelf supply, and regeneration of Zn on the observed Zn–Si decoupling in the North Pacific. Sensitivity experiments employing two distinct circulation fields were performed. It was found that the two circulation fields yielded different decoupling influences: continental-shelf supply or regeneration. A comparison between the two circulation fields also revealed discrepancies in the concentration of regenerated Zn. The main factors causing these differences were found to be the age of the water masses in the North Pacific and the magnitude of export production. Greater export production and a more stagnant circulation field in the North Pacific led to more regenerated Zn and a higher probability of decoupling without the need for an input of Zn from the continental shelf.