latent_heat_flux#

hydrometlib.evapotranspiration.latent_heat_flux(rn, g, h)[source]#

Latent heat flux (LE) as the residual of the surface energy balance [W m-2]

\[LE = R_n - G - H\]

where \(R_n\) is the net radiation, \(G\) the soil heat flux and \(H\) the sensible heat flux. This rearranges the surface energy balance \(R_n - G - \lambda ET - H = 0\), in which \(\lambda ET\) is the latent heat flux \(LE\).

From FAO-56 Chapter 1: “Only vertical fluxes are considered and the net rate at which energy is being transferred horizontally, by advection, is ignored. Therefore the equation is to be applied to large, extensive surfaces of homogeneous vegetation only … Other energy terms, such as heat stored or released in the plant, or the energy used in metabolic activities, are not considered. These terms account for only a small fraction of the daily net radiation and can be considered negligible when compared with the other four components.”

References

Parameters:

  • rn (Expr) – Net radiation [W m-2]

  • g (Expr) – Soil heat flux [W m-2]

  • h (Expr) – Sensible heat flux [W m-2]

Return type:

Expr

Returns:

Expression or Series computing LE [W m-2]