Distribution and Estimation of Total Dissolved Inorganic Carbon Dioxide below the Upper Layer of the World Oceans

抄録

Compared with historically accumulated hydrographic and nutrients measurements taken at sea, total inorganic carbon dioxide (TCO2) data are far from enough to produce a gridded map ping of high resolution on a global scale, which is crucial to evaluate the carbon budget in the oceans and provide initial values to constrain the biochemical models. In order to get a better understanding of TCO2in the oceans and contribute the large historical database to TCO2estima tion, TCO2 properties and its relation with nutrients in the world oceans are presented and dis cussed using ship data from several international programs, especially recent WOCE cruises dur ing which the accuracy of TCO2 measurements are believed to have been significantly improved. Based on these, a new parameterization method is proposed and tested to estimate TCO2 below the upper oceans (＞ 400 m) where its seasonal variations are comparatively small. Compared with the ship data which have not been involved in the parameterization procedure, the mean bias and standard deviation are 0.8 u.mol/kg and 7.0 u.mol/kg respectively for Pacific Ocean, while they are 0.5 u.mol/kg and 5.4 u.mol/kg respectively for Atlantic Ocean. Calculated TCO2 in the global oceans can be obtained at Levitus grid point (1°x1°) from 400 m down to the depth of 5,500 m, including vast ocean areas where field investigations ofTCO2 have never been performed.