Changeset 138 for palm/trunk/DOC/app/chapter_4.1.html

Timestamp:

Nov 28, 2007 10:03:58 AM (17 years ago)

Author:

letzel

Message:

Plant canopy model of Watanabe (2004,BLM 112,307-341) added.

File:

• palm/trunk/DOC/app/chapter_4.1.html (modified) (5 diffs)

palm/trunk/DOC/app/chapter_4.1.html

@@ -2100 +2100 @@
 
 
- <tr>
+ <tr><td><a name="canopy_mode"></a><span style="font-weight: bold;">canopy_mode</span></td><td>C * 20</td><td><span style="font-style: italic;">'block'</span></td><td>Canopy mode.<br><br><font color="#000000">
+Besides using the default value, that will create a horizontally
+homogeneous plant canopy that extends over the total horizontal
+extension of the model domain, the user may add code to the user
+interface subroutine <a href="chapter_3.5.1.html#user_init_plant_canopy">user_init_plant_canopy</a>
+to allow further canopy&nbsp;modes. <br><br>The setting of <a href="#canopy_mode">canopy_mode</a> becomes only active, if&nbsp;<a href="#plant_canopy">plant_canopy</a> has been set <span style="font-style: italic;">.T.</span> and a non-zero <a href="#drag_coefficient">drag_coefficient</a> has been defined.</font></td></tr><tr>
 
 
@@ -2621 +2626 @@
 
 
-    <tr>
+    <tr><td><a name="drag_coefficient"></a><span style="font-weight: bold;">drag_coefficient</span></td><td>R</td><td><span style="font-style: italic;">0.0</span></td><td>Drag coefficient used in the plant canopy model.<br><br>This parameter has to be non-zero, if the parameter <a href="#plant_canopy">plant_canopy</a> is set <span style="font-style: italic;">.T.</span>.</td></tr><tr>
 
 
@@ -4695 +4700 @@
 
 
- <tr>
+ <tr><td><a name="lad_surface"></a><span style="font-weight: bold;">lad_surface</span></td><td>R</td><td><span style="font-style: italic;">0.0</span></td><td>Surface value of the leaf area density (in m<sup>2</sup>/m<sup>3</sup>).<br><br>This
+parameter assigns the value of the leaf area density <span style="font-weight: bold;">lad</span> at the surface (k=0)<b>.</b> Starting from this value,
+the leaf area density profile is constructed with <a href="chapter_4.1.html#lad_vertical_gradient">lad_vertical_gradient</a>
+and <a href="chapter_4.1.html#lad_vertical_gradient_level">lad_vertical_gradient_level
+      </a>.</td></tr><tr><td><a name="lad_vertical_gradient"></a><span style="font-weight: bold;">lad_vertical_gradient</span></td><td>R (10)</td><td><span style="font-style: italic;">10 * 0.0</span></td><td>Gradient(s) of the leaf area density (in&nbsp;m<sup>2</sup>/m<sup>4</sup>).<br><br><p>This leaf area density gradient
+holds starting from the height&nbsp;
+level defined by <a href="chapter_4.1.html#lad_vertical_gradient_level">lad_vertical_gradient_level</a>
+(precisely: for all uv levels k where zu(k) &gt; lad_vertical_gradient_level, lad(k) is set: lad(k) = lad(k-1) + dzu(k) * <b>lad_vertical_gradient</b>)
+up to the level defined by <a href="#pch_index">pch_index</a>. Above that level lad(k) will automatically set to 0.0. A total of 10 different gradients for 11 height intervals (10 intervals
+if <a href="chapter_4.1.html#lad_vertical_gradient_level">lad_vertical_gradient_level</a>(1)
+= <i>0.0</i>) can be assigned. The leaf area density at the surface is
+assigned via <a href="chapter_4.1.html#lad_surface">lad_surface</a>.&nbsp;
+      </p></td></tr><tr><td><a name="lad_vertical_gradient_level"></a><span style="font-weight: bold;">lad_vertical_gradient_level</span></td><td>R (10)</td><td><span style="font-style: italic;">10 * 0.0</span></td><td>Height level from which on the&nbsp;gradient
+of the leaf area density defined by <a href="chapter_4.1.html#lad_vertical_gradient">lad_vertical_gradient_level</a>
+is effective (in m).<br><br>The height levels have to be assigned in ascending order. The
+default values result in a leaf area density that is constant with height uup to the top of the plant canopy layer defined by <a href="#pch_index">pch_index</a>. For the piecewise construction of temperature profiles see <a href="chapter_4.1.html#lad_vertical_gradient">lad_vertical_gradient</a>.</td></tr><tr>
 
 
@@ -7095 +7115 @@
 
 
- <tr>
+ <tr><td><a name="pch_index"></a><span style="font-weight: bold;">pch_index</span></td><td>I</td><td><span style="font-style: italic;">0</span></td><td>Grid point index (scalar) of the upper boundary of the plant canopy layer.<br><br>Above <span style="font-weight: bold;">pch_index</span> the arrays of leaf area density and drag_coeffient are automatically set to zero in case of <a href="#plant_canopy">plant_canopy</a> = .T.. Up to <span style="font-weight: bold;">pch_index</span> a leaf area density profile can be prescribed by using the parameters <a href="#lad_surface">lad_surface</a>, <a href="#lad_vertical_gradient">lad_vertical_gradient</a> and <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>.</td></tr><tr>
 
 
@@ -7162 +7182 @@
 
 
- <tr>
+ <tr><td><a name="plant_canopy"></a><span style="font-weight: bold;">plant_canopy</span></td><td>L</td><td><span style="font-style: italic;">.F.</span></td><td>Switch for the plant_canopy_model.<br><br>If <span style="font-weight: bold;">plant_canopy</span> is set <span style="font-style: italic;">.T.</span>, the plant canopy model of Watanabe (2004, BLM 112, 307-341) is used. <br>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 <a href="#drag_coefficient">drag_coefficient</a>) and the leaf area density (see <a href="#lad_surface">lad_surface</a>, <a href="#lad_vertical_gradient">lad_vertical_gradient</a>, <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>). <br>By default, a horizontally homogeneous plant canopy is prescribed, if&nbsp; <span style="font-weight: bold;">plant_canopy</span> is set <span style="font-style: italic;">.T.</span>. However, the user can define other types of plant canopies (see <a href="#canopy_mode">canopy_mode</a>).<br><br><span style="font-weight: bold;">plant_canopy</span> = <span style="font-style: italic;">.T. </span>is only allowed together with a non-zero <a href="#drag_coefficient">drag_coefficient</a>.</td></tr><tr>