A Simulation of Bomb Tritium Entry into the Atlantic Ocean

Abstract

Abstract Tritium is used in a model calibration study that is aimed at developing three-dimensional ocean circulation and mixing models for climate and geochemical simulations. The North Atlantic tritium distribution is modeled using a three-dimensional advective field predicted by a primitive equation ocean circulation model. The effect of wintertime convection is parameterized by homogenizing the tracer to the observed March mixed-layer depth. Mixing is parameterized by horizontal and vertical Fickian diffusivities of 5 × 10−6 cm2 s−1 and 0.5 cm2 s−1, respectively. The spreading of tritium in the model is dominated by advection in the horizontal, and by wintertime convection and advection in the vertical. The horizontal and vertical mixing provided by the model have negligible effect. A comparison of the model tracer fields with observations shows that most of the basic patterns of the tritium field are reproduced. The model's mean vertical penetration of 543 m in 1972 is comparable to the 592 m penetra...