def dynamic_enthalpy_CT_exact(SA, CT, p): r"""Calculates the dynamic enthalpy of seawater from Absolute Salinity and Conservative Temperature and pressure. Dynamic enthalpy is defined as enthalpy minus potential enthalpy (Young, 2010). Parameters ---------- SA : array_like Absolute Salinity [g/kg] CT : array_like Conservative Temperature [:math:`^\circ` C (ITS-90)] p : array_like sea pressure [dbar] Returns ------- dynamic_enthalpy_CT_exact : array_like dynamic enthalpy [J/kg] See Also -------- TODO Notes ----- This function uses the full Gibbs function. There is an alternative to calling this function, namely dynamic_enthalpy(SA, CT, p), which uses the computationally efficient 48-term expression for density in terms of SA, CT and p (McDougall et al., 2011). Examples -------- TODO References ---------- .. [1] IOC, SCOR and IAPSO, 2010: The international thermodynamic equation of seawater - 2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, UNESCO (English), 196 pp. See apendix A.30. .. [2] McDougall T.J., P.M. Barker, R. Feistel and D.R. Jackett, 2011: A computationally efficient 48-term expression for the density of seawater in terms of Conservative Temperature, and related properties of seawater. .. [3] Young, W.R., 2010: Dynamic enthalpy, Conservative Temperature, and the seawater Boussinesq approximation. Journal of Physical Oceanography, 40, 394-400. Modifications: 2011-04-05. Trevor McDougall and Paul Barker. """ t = t_from_CT(SA, CT, p) return enthalpy_t_exact(SA, t, p) - cp0 * CT
def enthalpy_diff_CT_exact(SA, CT, p_shallow, p_deep): r"""Calculates the difference of the specific enthalpy of seawater between two different pressures, p_deep (the deeper pressure) and p_shallow (the shallower pressure), at the same values of SA and CT. The output (enthalpy_diff_CT_exact) is the specific enthalpy evaluated at (SA, CT, p_deep) minus the specific enthalpy at (SA,CT,p_shallow). parameters ---------- Parameters ---------- SA : array_like Absolute Salinity [g/kg] CT : array_like Conservative Temperature [:math:`^\circ` C (ITS-90)] p_shallow : array_like lower sea pressure [dbar] p_deep : array-like upper sea pressure [dbar] returns ------- enthalpy_diff_CT_exact : array_like difference of specific enthalpy [J/kg] (deep minus shallow) See Also -------- TODO Notes ----- This function uses the full Gibbs function. There is an alternative to calling this function, namely enthalpy_diff_CT(SA, CT, p), which uses the computationally efficient 48-term expression for density in terms of SA, CT and p (McDougall et al., 2011). Examples -------- TODO References ---------- .. [1] IOC, SCOR and IAPSO, 2010: The international thermodynamic equation of seawater - 2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, UNESCO (English), 196 pp. See Eqns (3.32.2). .. [2] McDougall T.J., P.M. Barker, R. Feistel and D.R. Jackett, 2011: A computationally efficient 48-term expression for the density of seawater in terms of Conservative Temperature, and related properties of seawater. Modifications: 2011-04-06. Trevor McDougall and Paul Barker. """ t_shallow = t_from_CT(SA, CT, p_shallow) t_deep = t_from_CT(SA, CT, p_deep) return (enthalpy_t_exact(SA, t_deep, p_deep) - enthalpy_t_exact(SA, t_shallow, p_shallow))