Changes between Version 80 and Version 81 of doc/app/initialization_parameters

Timestamp:

Sep 15, 2010 9:03:20 AM (14 years ago)

Author:

kanani

Comment:

--

doc/app/initialization_parameters

@@ -1712 +1712 @@
 |----------------
 {{{#!td style="vertical-align:top"
-[=#<insert_parameter_name> '''<insert_parameter_name>''']
-}}}
-{{{#!td style="vertical-align:top"
-<insert type>
-}}}
-{{{#!td style="vertical-align:top"
-<insert value>
-}}}
-{{{#!td
-<insert explanation>
+[=#plant_canopy '''plant_canopy''']
+}}}
+{{{#!td style="vertical-align:top"
+L
+}}}
+{{{#!td style="vertical-align:top"
+.F.
+}}}
+{{{#!td
+Switch for the plant_canopy_model.\\\\
+If '''plant_canopy''' is set ''.T.'', the plant canopy model of Watanabe (2004, BLM 112, 307-341) is used.\\
+The impact of a plant canopy on a turbulent flow is considered by an additional drag term in the momentum equations and an additional sink term in the prognostic equation for the subgrid-scale TKE. These additional terms are dependent on the leaf drag coefficient (see [#drag_coefficient drag_coefficient]) and the leaf area density (see [#lad_surface lad_surface], [#lad_vertical_gradient lad_vertical_gradient], [#lad_vertical_gradient_level lad_vertical_gradient_level). The top boundary of the plant canopy is determined by the parameter [#pch_index pch_index]. For all heights equal to or larger than zw(k=pch_index) the leaf area density is 0 (i.e. there is no canopy at these heights!).\\
+By default, a horizontally homogeneous plant canopy is prescribed, if  '''plant_canopy''' is set ''.T.''. However, the user can define other types of plant canopies (see [#canopy_mode canopy_mode]).\\\\
+If '''plant_canopy''' and  [#passive_scalar passive_scalar] are set ''.T.'', the canopy acts as an additional source or sink, respectively, of scalar concentration. The source/sink strength is dependent on the scalar concentration at the leaf surface, which is generally constant with time in PALM and which can be specified by specifying the parameter [#leaf_surface_concentration leaf_surface_concentration].\\\\
+Additional heating of the air by the plant canopy is taken into account, when the default value of the parameter [#cthf cthf] is altered in the parameter file. In that case the value of [#surface_heatflux surface_heatflux] specified in the parameter file is not used in the model. Instead the near-surface heat flux is derived from an exponential function that is dependent on the cumulative leaf area index.\\\\
+'''plant_canopy''' = ''.T.'' is only allowed together with a non-zero [#drag_coefficient drag_coefficient].
 }}}
 |----------------