Using chemical tracers to assess ocean models

Abstract. Chemical tracers can be used to assess the simulated circulation in ocean models. Tracers that have been used in this context include tritium, chlorofluoro-carbons, natural and bomb-produced radiocarbon, and to a lesser extent, oxygen, silicate, phosphate, isotopes of organic and inorganic carbon compounds, and certain noble gases (e.g., helium and argon). This paper reviews the use of chemical tracers in assessing the circulation and flow patterns in global and regional ocean models. It will be shown that crucial information can be derived from chemcial tracers that cannot be obtained from temperature-salinity (T-S) alone. In fact, it turns out that a model with a good representation of T-S can have significant errors in simulated circulation, so checking a model’s ability to capture chemical tracer patterns i