Carbonate Chemistry of the North Pacific Ocean

摘要

Data collected along two longitudinal cruises serve as the main data sources, and supplementary data sets in the literature are selected for delineating the distribution of physical and chemical properties in a wide area of the North Pacific Ocean. Oxygen, pH, alkalinity, total CO sub 2 , and nutrients are interrelated parameters. Along our two longitudinal sections they all show a core structure underlying the salinity minimum layer. From these oxidation-related parameters we conclude that the subsurface water of the eastern North Pacific Ocean is older than that of the western North Pacific Ocean. Calcium and alkalinity data indicate a CaCO sub 3 dissolution rate of 0.060 and 0.053 mu mol/kg/yr, respectively, referenced to the Weddell Sea Deep Water for waters deeper than 2000 m. The organic carbon decomposition rate is 0.107 mu mol/kg/yr and the oxygen consumption rate is 0.13 mu mol/kg/yr, also for waters below 2000 m. Our analysis of carbonate data shows that about 25% of the increase in total inorganic CO sub 2 in deep water. Selected cross-sections show that a large volume of the North Pacific is undersaturated with respect to CaCO sub 3 . Our calculations on the excess CO sub 2 show that its penetration depth is strongly related to circulation. Overall the North Pacific contains 14.7 +- 4 x 10 sup 15 g excess carbon. (ERA citation 12:001774)