Energy

Functions involving internal energy, enthalpy, latent heat.

gsw.energy.enthalpy(SA, CT, p)[source]

Calculates specific enthalpy of seawater using the computationally- efficient expression for specific volume in terms of SA, CT and p (Roquet et al., 2015).

Parameters:

SAarray-like: Absolute Salinity, g/kg
CTarray-like: Conservative Temperature (ITS-90), degrees C
parray-like: Sea pressure (absolute pressure minus 10.1325 dbar), dbar

Returns:

enthalpyarray-like, J/kg: specific enthalpy

Notes

Note that the 75-term equation has been fitted in a restricted range of parameter space, and is most accurate inside the “oceanographic funnel” described in McDougall et al. (2003). The GSW library function “gsw_infunnel(SA,CT,p)” is available to be used if one wants to test if some of one’s data lies outside this “funnel”.

References

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. Available from https://www.teos-10.org/ See Eqn. (A.30.6) of this TEOS-10 Manual.

McDougall, T.J., 2003: Potential enthalpy: A conservative oceanic variable for evaluating heat content and heat fluxes. Journal of Physical Oceanography, 33, 945-963. See Eqns. (18) and (22)

McDougall, T.J., D.R. Jackett, D.G. Wright and R. Feistel, 2003: Accurate and computationally efficient algorithms for potential temperature and density of seawater. J. Atmosph. Ocean. Tech., 20, pp. 730-741.

Roquet, F., G. Madec, T.J. McDougall, P.M. Barker, 2015: Accurate polynomial expressions for the density and specific volume of seawater using the TEOS-10 standard. Ocean Modelling., 90, pp. 29-43.

gsw.energy.enthalpy_diff(SA, CT, p_shallow, p_deep)[source]

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. This function uses the computationally-efficient expression for specific volume in terms of SA, CT and p (Roquet et al., 2015). The output (enthalpy_diff) is the specific enthalpy evaluated at (SA,CT,p_deep) minus the specific enthalpy at (SA,CT,p_shallow).

Parameters:

SAarray-like: Absolute Salinity, g/kg
CTarray-like: Conservative Temperature (ITS-90), degrees C
p_shallowarray-like: Upper sea pressure (absolute pressure minus 10.1325 dbar), dbar
p_deeparray-like: Lower sea pressure (absolute pressure minus 10.1325 dbar), dbar

Returns:

enthalpy_diffarray-like, J/kg: difference of specific enthalpy (deep minus shallow)

Notes

Note that the 75-term equation has been fitted in a restricted range of parameter space, and is most accurate inside the “oceanographic funnel” described in McDougall et al. (2003). The GSW library function “gsw_infunnel(SA,CT,p)” is available to be used if one wants to test if some of one’s data lies outside this “funnel”.

References

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. Available from https://www.teos-10.org/ See Eqns. (3.32.2) and (A.30.6) of this TEOS-10 Manual.

McDougall, T.J., 2003: Potential enthalpy: A conservative oceanic variable for evaluating heat content and heat fluxes. Journal of Physical Oceanography, 33, 945-963. See Eqns. (18) and (22)

McDougall, T.J., D.R. Jackett, D.G. Wright and R. Feistel, 2003: Accurate and computationally efficient algorithms for potential temperature and density of seawater. J. Atmosph. Ocean. Tech., 20, pp. 730-741.

Roquet, F., G. Madec, T.J. McDougall, P.M. Barker, 2015: Accurate polynomial expressions for the density and specific volume of seawater using the TEOS-10 standard. Ocean Modelling., 90, pp. 29-43.

gsw.energy.internal_energy(SA, CT, p)[source]

Calculates specific internal energy of seawater using the computationally-efficient expression for specific volume in terms of SA, CT and p (Roquet et al., 2015).

Parameters:

SAarray-like: Absolute Salinity, g/kg
CTarray-like: Conservative Temperature (ITS-90), degrees C
parray-like: Sea pressure (absolute pressure minus 10.1325 dbar), dbar

Returns:

internal_energyarray-like, J/kg: specific internal energy

Notes

Note that the 75-term equation has been fitted in a restricted range of parameter space, and is most accurate inside the “oceanographic funnel” described in McDougall et al. (2003). The GSW library function “gsw_infunnel(SA,CT,p)” is available to be used if one wants to test if some of one’s data lies outside this “funnel”.

References

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. Available from https://www.teos-10.org/

McDougall, T.J., D.R. Jackett, D.G. Wright and R. Feistel, 2003: Accurate and computationally efficient algorithms for potential temperature and density of seawater. J. Atmosph. Ocean. Tech., 20, pp. 730-741.

Roquet, F., G. Madec, T.J. McDougall, P.M. Barker, 2015: Accurate polynomial expressions for the density and specific volume of seawater using the TEOS-10 standard. Ocean Modelling., 90, pp. 29-43.

gsw.energy.latentheat_evap_CT(SA, CT)[source]

Calculates latent heat, or enthalpy, of evaporation at p = 0 (the surface). It is defined as a function of Absolute Salinity, SA, and Conservative Temperature, CT, and is valid in the ranges 0 < SA < 42 g/kg and 0 < CT < 40 deg C. The errors range between -0.4 and 0.6 J/kg.

Parameters:

SAarray-like: Absolute Salinity, g/kg
CTarray-like: Conservative Temperature (ITS-90), degrees C

Returns:

latentheat_evaparray-like, J/kg: latent heat of evaporation

References

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. Available from https://www.teos-10.org/ See section 3.39 of this TEOS-10 Manual.

gsw.energy.latentheat_evap_t(SA, t)[source]

Calculates latent heat, or enthalpy, of evaporation at p = 0 (the surface). It is defined as a function of Absolute Salinity, SA, and in-situ temperature, t, and is valid in the ranges 0 < SA < 40 g/kg and 0 < CT < 42 deg C. The errors range between -0.4 and 0.6 J/kg.

Parameters:

SAarray-like: Absolute Salinity, g/kg
tarray-like: In-situ temperature (ITS-90), degrees C

Returns:

latentheat_evaparray-like, J/kg: latent heat of evaporation

References

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. Available from https://www.teos-10.org/ See section 3.39 of this TEOS-10 Manual.