Salinity and temperature have been used for over a century to study oceanic circulation. However, with the aid of chemical tracers it is possible to gain a more detailed picture and provision of additional information such as the age of the water mass. Chemical tracers are very suitable in particular to evaluate water mass formation and circulation in the Arctic Ocean and the Nordic Seas where the temperature and salinity field show small variations, except for the very top layers of the Arctic Ocean. Also, a number of processes give specific chemical signatures to different water masses. For example, when tracing freshwater sources and distributions in the Polar regions, alkalinity and nitrate-phosphate relationships can be used to distinguish between sea ice melt, river-runoff and pacific water, which is impossible only knowing the salinity and temperature.

The chlorofluorocarbons (CFCs) are tracers used for estimations of the ventilation ages (i.e. the time since the water was last in contact with the atmosphere) of water masses and have in that context been used to estimate the sequestration of anthropogenic carbon dioxide in the deep waters of the Nordic Seas and the Arctic Ocean. They have also been used to study dense water formation occurring in the Greenland Sea, and to characterise water masses and their contributions to the North Atlantic deepwater. In some cases the chemical tracer is deliberately released into a water mass and then the spreading pattern is studied. This was done in the Greenland Sea in 1996 using the tracer SF6 with the intent to follow the spreading of the intermediate waters from the Greenland Sea gyre to the surrounding seas.