konrad.physics.saturation_pressure

konrad.physics.saturation_pressure(temperature)[source]
konrad.physics.saturation_pressure(temperature: numbers.Number)

Return equilibrium pressure of water with respect to the mixed-phase.

The equilibrium pressure over water is taken for temperatures above the triple point \(T_t\) the value over ice is taken for temperatures below \(T_t–23\,\mathrm{K}\). For intermediate temperatures the equilibrium pressure is computed as a combination of the values over water and ice according to the IFS documentation:

\[\begin{split}e_\mathrm{s} = \begin{cases} T > T_t, & e_\mathrm{liq} \\ T < T_t - 23\,\mathrm{K}, & e_\mathrm{ice} \\ else, & e_\mathrm{ice} + (e_\mathrm{liq} - e_\mathrm{ice}) \cdot \left(\frac{T - T_t - 23}{23}\right)^2 \end{cases}\end{split}\]

References

IFS Documentation – Cy45r1, Operational implementation 5 June 2018, Part IV: Physical Processes, Chapter 12, Eq. 12.13, https://www.ecmwf.int/node/18714

Parameters

temperature (float or ndarray) – Temperature [K].

See also

e_eq_ice_mk()

Equilibrium pressure of water over ice.

e_eq_water_mk()

Equilibrium pressure of water over liquid water.

Returns

float or ndarray – Equilibrium pressure [Pa].