Compute thermal expansion coefficient

INTERFACE:

   REALTYPE function eos_alpha(S,T,p,g,rho_0)

DESCRIPTION:

Computes the thermal expansion coefficient defined by

$$\alpha = - \dfrac{1}{\rho_0} \left( \dfrac{\partial {\rho_{is}}}{... ...dfrac{1}{g} \left( \dfrac{\partial {B_{is}}}{\partial {T}} \right)_S \; , \quad$$ (244)

where $B_{is}$ denotes the in-situ buoyancy. The computation is carried out by a finite difference approximation of (244), requiring two evaluations of the equation of state. Note, that comparing (244) with (243) it follows that $\alpha = -$   dtr0$/\rho_0$.

USES:

   IMPLICIT NONE

INPUT PARAMETERS:

   REALTYPE,intent(in)                 :: S,T,p
   REALTYPE,optional,intent(in)        :: g,rho_0

REVISION HISTORY:

   Original author(s): Lars Umlauf