Changes between Version 9 and Version 10 of doc/tec/lsm

Timestamp:

Apr 4, 2016 3:59:12 PM (9 years ago)

Author:

maronga

Comment:

--

doc/tec/lsm

@@ -21 +21 @@
 \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.
+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:
+{{{
+#!Latex
+\begin{equation*}
+r_\mathrm{a} = \dfrac{u_*\ \theta_*}{\theta_1 - \theta_0}
+\end{equation*}
+}}}
+where ''u'',,*,, and ''θ'',,*,, are the friction velocity and the characteristic temperature scale according to Monin-Obukhov similarity scaling.
 
 ''G'' is parametrized as (Duynkerke 1999)
@@ -39 +46 @@
 Here, ''l'',,v,, = 2.5 * 10^6^ J kg^-1^ is the latent heat of vaporisation, ''r'',,s,, is the surface resistance, ''q'',,v,1,, is the specific humidity at first grid level, and ''q'',,v,sat,, is the saturation specific humidity at temperature ''T'',,0,,. 
 
-All equations above are solved locally for each surface element of the LES grid. Each element can consist of both patches of bare soil, vegetation, and a liquid water reservoir, which is the interception water stored on plants and soil from precipitation. Therefore, an additional equation is solved for the liquid water reservoir. ''LE'' is then calculated for each of the three components (bare soil, vegetation, liquid water). The resistances are calculated following Jarvis (1976).
-
-''C'',,0,, is set to zero, the energy balance is solved implicitly by linearising ''q'',,v,sat,,.
+All equations above are solved locally for each surface element of the LES grid. Each element can consist of both patches of bare soil, vegetation, and a liquid water reservoir, which is the interception water stored on plants and soil from precipitation. Therefore, an additional equation is solved for the liquid water reservoir. ''LE'' is then calculated for each of the three components (bare soil, vegetation, liquid water). The resistances are calculated separately for bare soil and vegetation following Jarvis (1976). The canopy resistance is calculated as
+{{{
+#!Latex
+\begin{equation*}
+r_\mathrm{c} = \dfrac{r_\mathrm{c,min}}{LAI}\ f_1(R_\mathrm{sw,in})\ f_2(\widetilde m)\ f_3(e_\mathrm{def})
+\end{equation*}
+}}}
+with
+{{{
+#!Latex
+$r_\mathrm{c,min}$: Minimum stomatal resistance\\
+$LAI$: Leaf area index\\
+$f_i$: Correction functions ($f_i \geq 1$)\\
+$R_\mathrm{sw,in}$: Incoming shortwave radiation\\
+$\widetilde m$: Layer-averaged soil moisture\\
+$e_\mathrm{def}$: Water-vapor pressure deficit
+}}}
+The bare soil resistance is given by
+{{{
+#!Latex
+\begin{equation*}
+r_\mathrm{soil} = r_\mathrm{soil,min}\ f_{2b}(m_\mathrm{soil,1})
+\end{equation*}
+}}}
+with
+{{{
+#!Latex
+$r_\mathrm{soil,min}$: Minimum soil resistance\\
+$f_{2b}$:{Correction function} ($f_i \geq 1$)\\
+$m_\mathrm{soil,1}$: Soil moisture of the uppermost layer)
+}}}
 
 == Soil model ==
+The soil model consists of prognostic equations for the soil temperature and the volumetric soil moisture which are solved for multiple layers. By default, the soil model consists of four layers, in which the vertical heat and water transport is modelled using the Fourier law of diffusion and Richards' equation, respectively. Also, root fractions can be assigned to each soil layer to to account for the explicit water withdrawal of plants used for transpiration from the respective soil layer. 
+
+=== Soil heat transport ===
+
+=== Soil moisture transport ===
+
+
+
+For more details, see \citet{viterbo1995} and \citet{balsamo2009}.
+
+
 
 == Technical details ==
@@ -96 +142 @@
 
 == References ==
+* Jarvis PG. 1976. The interpretation of the variations in leaf water potential and stomatal conductance found in canopies in the field. Philos. Trans. Roy. Soc. London 273B: 593–610.
+* Heus T, Van Heerwaarden CC, Jonker HJJ, Siebesma AP, Axelsen S, Dries K, Geoffroy O, Moene AF, Pino D, De Roode SR, Vil`a-Guerau de Arellano J. 2010. Formulation of the dutch atmospheric large-eddy simulation (dales) and overview of its applications. Geosci. Model Dev. 3: 415–444.
+* Duynkerke PG. 1999. Turbulence, radiation and fog in Dutch stable boundary layers. Boundary-Layer Meteorol. 90: 447–477, doi:10.1023/A:1026441904734.
+* Viterbo P, Beljaars ACM. 1995. An Improved Land Surface Parameterization Scheme in the ECMWF Model and Its Validation. J. Climate 8: 2716–2748.
+
+