The interpretation of temperature and salinity variables in numerical ocean model output and the calculation of heat fluxes and heat content

Abstract. The international Thermodynamic Equation of Seawater 2010 (TEOS-10) defined the enthalpy and entropy seawater, thus enabling global ocean heat content to be calculated as volume integral product in situ density, ?, potential enthalpy, h0 (with reference sea pressure 0 dbar). In terms Conservative Temperature, ?, is ?cp0?, where cp0 a constant “isobaric capacity”. However, many models Coupled Model Intercomparison Project Phase 6 (CMIP6) well all that contributed earlier phases, such CMIP5, CMIP3, CMIP2, CMIP1, used EOS-80 (Equation State – 1980) rather than updated TEOS-10, so question arises how salinity temperature variables these should physically interpreted, with particular focus on comparison TEOS-10-compliant observations. this article we address content, surface fluxes, meridional transport are best using output from quantities compared those corresponding We conclude even though model uses EOS-80, which expects its input temperature, most appropriate interpretation model's variable actually Temperature. This perhaps unexpected needed ensure air–sea flux leaves arrives atmosphere ice same model. also show carried by present TEOS-10-based Preformed Salinity, while EOS-80-based proportional Salinity. These interpretations an update comprehensive Griffies et al. (2016) paper discusses aspects coupled Earth system models.