Heat capacity properties are often prefixed with the term "specific". International standards now recommend that specific heat capacity always refer to division by mass. The units for the specific heat capacity are formula_7. In chemistry, heat capacity is often specified relative to one mole, the unit of amount of substance, and is called the molar heat capacity. It has the unit formula_8. For some considerations it is useful to specify the volume-specific heat capacity, commonly called volumetric heat capacity, which is the heat capacity per unit volume and has SI units formula_9. This is used almost exclusively for liquids and solids, since
Dobson unit Dobson unit should eventually be replaced by an appropriate SI unit and that the unit mmol m-2 was the most convenient and least cumbersome option. It expressed the hope that this unit would eventually supplant the Dobson Unit. However, as of March 2017, there is little evidence that this has occurred; for example the Dobson unit is still used by NASA and by the World Ozone and Ultraviolet Radiation Data Center in their reporting of total ozone amount. NASA uses a baseline value of 220 DU for ozone. This was chosen as the starting point for observations of the Antarctic