text: The spiciness can be calculated in several programming languages with the Gibbs SeaWater (GSW) toolbox. It is used to derive thermodynamic seawater properties and is adopted by the Intergovernmental Oceanographic Commission (IOC), International Association for the Physical Sciences of the Oceans (IAPSO) and the Scientific Committee on Oceanic Research (SCOR). They use the definition of spiciness (gsw_spiciness0(), gsw_spiciness1(), gsw_spiciness2() at respectively 0, 1000 and 2000 dbar) provided by. These isobars are chosen because they correspond to commonly used potential density surfaces. Areas with constant density but different spiciness have a net water flow of heat and salinity due to diffusion.