海水状态方程式亦称海水的P—V—T性质,它是描述海水的状态参数之间关系的数学表达式。最常用的是海水的比容(或密度)同温度(T)、盐度(S)及压力(P)之间关系的数学表达式,因为海水的密度(或比容)的测定目前还多限于实验室条件之下,要在海洋现场进行精密地测定是比较困难的,而有了海水状态方程式就可以很方便地从海洋现场调查中容易得到的温度、盐度和压力等观测资料,计算出海水的密度或比容。海水的密度或比容的精密资料不仅可直接用于动力高度等海洋学计算之中,而且还可用来计算作为温度、盐度和压力函 The sea state equation, also known as the P-V-T property of seawater, is a mathematical expression that describes the relationship between the state parameters of seawater. The most commonly used is the mathematical expression of the relationship between seawater specific volume (or density) and temperature (T), salinity (S) and pressure (P) since the density (or specific volume) Confined to laboratory conditions, it is difficult to accurately measure at the ocean site, and with the sea state equation, it is easy to calculate from observations such as temperature, salinity and pressure that are readily available from marine field surveys The density or specific volume of seawater. Precision data on the density or specific volume of seawater can be used not only directly in oceanographic calculations such as power heights, but also as an indicator of temperature, salinity and stress