# Info

P as a function of S,T(P = 0 db) P as a function of P,T(S = 35)

P as a function of S,T(P = 0 db) P as a function of P,T(S = 35)

Fig. 2.8 Haline contraction coefficient (10 4/psu): a as a function of (S,T); b as a function of (P,T).

2.4.4 Specific heat capacity

Specific heat capacity differentiates in two different cases. First, if heating/cooling takes place under a constant pressure, we have cp=( £)„ = T( £)„ (175)

which is the specific heat capacity under constant pressure. Second, if heating/cooling takes place with a constant volume, we have c-=( i) „ - t(£) ,„ <2-76»

which is the specific heat capacity with constant volume. These two types of specific heat are related through the following relation

T a2

P\ dP / T,s is the isothermal compressibility of the fluid. Although seawater is almost incompressible, nevertheless its density can change, and therefore maintaining a constant specific volume is not a good assumption. As a result, the specific heat capacity under constant pressure is most commonly used.