= Land surface model =

== Overview ==
Since r1551 a full land surface model (LSM) is available in PALM. It consists of a four layer soil model, predicting soil temperature and moisture content, and a solver for the energy balance of the skin surface layer. Moreover, a liquid water reservoir accounts for the presence of liquid water on plants and soil due to precipitation. The implementation is based on the ECMWF-IFS land surface parametrization (H-TESSEL) and its adaptation in the DALES model (Heus et al. 2010).

Note that the use of the LSM requires using a [wiki:doc/tec/radiation radiation model] to provide radiative fluxes at the surface.

== Energy balance solver ==
The energy balance of the Earth's surface reads
{{{
#!Latex
\begin{equation}
   C_0 \dfrac{dT_0}{dt} = R_\mathrm{n} - H - LE - G
\end{equation}
}}}
where ''C'',,0,, and ''T'',,0,, are the heat capacity and radiative temperature of the surface skin layer, respectively. ''R'',,n,,, ''H'', ''LE'', and ''G'' are the net radiation, sensible heat flux, latent heat flux, and ground (soil) heat flux at the surface, respectively. ''H'' is calculated as
{{{
#!Latex
\begin{equation}
  H = - \rho\ c_\mathrm{p}\ \dfrac{1}{r_\mathrm{a}} ( \theta_1 - \theta_0 )
\end{equation}
}}}
where ''ρ'' is the density of the air, ''c'',,p,, = 1005 J kg^-1^ K^-1^$ is the specific heat at constant pressure, ''r'',,a,, is the aerodynamic resistance, and ''θ'',,0,, and ''θ'',,1,, are the potential temperature at the surface and at the first grid level above the surface, respectively. ''r'',,a,, is calculated via Monin-Obukhov similarity theory, based on roughness lengths for heat and momentum and the assumption of a constant flux layer between the surface and the first grid level.

== Soil model ==

== Usage ==

== References ==