Deep Ocean Circulation Governs Sedimentary CaCO3 Accumulation in the Northeast Pacific Ocean

The meridional overturning circulation influences the deep-sea carbon reservoir, global carbon cycle, and climate change on century to millennium time scales. However, the influence of deep-sea circulation on sedimentary carbonate accumulation and thus deep-sea carbonate system in the North Pacific Ocean is difficult to quantify owing to the complicated geometry of deep ocean ventilation attributed to its topographic complexity. In this study, we reanalyzed the distribution patterns of sedimentary calcium carbonate contents (wtCaCO3%) in the deep Northeast Pacific in a quantitative manner. Our results in conjunction with data from the Northwest Pacific Ocean, suggest that the deep ocean circulation plays a critical role in elucidating the basin-scale features of sedimentary CaCO3 distribution in the North Pacific Ocean, despite elevated non-carbonate dilution exerted by detritus from active geological processes on the topographic structure. Moreover, enhanced carbonate dissolution in the Guatemala and Panama Basins, controlled by higher flow rates of deep currents, influences the depth-profiles of sedimentary wtCaCO3% in that region. These findings suggest a novel avenue to reconstruct past changes in ocean circulation and carbon cycling in the Northeast Pacific Ocean based on the wtCaCO3% records in sediments.