The specific heat of sea water

Abstract

There are many calculations in oceanography which involve the specific heat of sea water; this had not until now been determined to the precision desirable, and the temperature coefficient of C p had not been measured. An electrically heated calorimeter has been used to determine the specific heat of sea water over approximately the ranges of temperature and salinity occurring in nature. The results are considered accurate to 0.05%; previously accepted values are shown to be seriously in error. The temperature coefficient of C p is shown to be positive for ocean water, while over the same range it is negative for pure water. An expression has been derived from which C p can be computed over the ranges of 0 to 40 g/kg of salt and — 2 to 30°C, and tabulated values are given. In testing the calorimeter the specific heat of ethanol was redetermined. Although incidental, the results are included as they are thought to be more reliable over the range of temperature covered than those previously published.