Uptake of Anthropogenic Co2by Lateral Transport Models of the Ocean Based on the Distribution of Bomb-Produced14C

Abstract

The pattern of global water column inventories of bomb-produced 14C suggests that a sizeable portion of bomb 14C that entered the Antarctic, northern Pacific, and tropical oceans has been transported to adjacent temperate regions. Models of lateral transport of surface water in the Atlantic, Indian, and Pacific Oceans are based on this distribution pattern. Upwelling of bomb-14C-free water from below takes place in the Antarctic, northern Pacific, and tropical regions; downwelling of surface water occurs in the temperate oceans and northern Atlantic. Uptake of excess CO2 by these models is calculated using the observed Mauna Loa pCO2 record as an input function. Results indicate that 35% of fossil fuel CO2 is taken up by these model oceans during the period 1958–1980. Considering the observed airborne fraction of 0.55, it appears that ca 10% of the global fossil fuel CO2 is still missing.