A SIMULATION OF CO₂ UPTAKE IN A THREE DIMENSIONAL OCEAN CARBON CYCLE MODEL^*

A three-dimensional ocean carbon cycle model which is a general circulation model coupled with simple biogeochemical processes is used to simulate CO2 uptake by the ocean.The OGCM used is a modified version of the Geophysical Fluid Dynamics Laboratory modular ocean model(MOM2).The ocean chemistry and a simple ocean biota model are included.Principal variablesare total CO2,alkalinity and phosphate.The vertical profile of POC flux observed by sediment traps is adopted,the rain ratio,a ratio of production rate of calcite against that of POC,and the bio-production efficiency should be 0.06 and 2 per year,separately.The uptake of anthropogenic CO2 by the ocean is studied.Calculated oceanic uptake of anthropogenic CO2 during the 1980s is 2.05×1015g(Pg)per year.The regional distributions of global oceanic CO2 are discussed.