Changeset 3196 for palm/trunk/SOURCE

Timestamp:

Aug 13, 2018 12:26:14 PM (6 years ago)

Author:

maronga

Message:

set maximum value for aerodynamic resistance over horiztonal surfaces

Location:

palm/trunk/SOURCE

Files:

• land_surface_model_mod.f90 (modified) (2 diffs)
• urban_surface_mod.f90 (modified) (4 diffs)

palm/trunk/SOURCE/land_surface_model_mod.f90

@@ -25 +25 @@
 ! -----------------
 ! $Id$
+! Added maximum aerodynamic resistance of 300.
+! 
+! 3161 2018-07-23 09:30:10Z maronga
 ! Increased roughness of asphalt surfaces to account for turbulence production
 ! by traffic and other obstacles
@@ -1915 +1918 @@
 !
 !--    Make sure that the resistance does not drop to zero for neutral 
-!--    stratification. 
-       IF ( surf%r_a(m) < 1.0_wp )  surf%r_a(m) = 1.0_wp
+!--    stratification. Also, set a maximum resistance to avoid the breakdown of
+!--    MOST for locations with zero wind speed
+       IF ( surf%r_a(m) <   1.0_wp )  surf%r_a(m) =   1.0_wp
+       IF ( surf%r_a(m) > 300.0_wp )  surf%r_a(m) = 300.0_wp       
 !
 !--    Second step: calculate canopy resistance r_canopy

palm/trunk/SOURCE/urban_surface_mod.f90

@@ -28 +28 @@
 ! -----------------
 ! $Id$
+! Added maximum aerodynamic resistance of 300 for horiztonal surfaces.
+! 
+! 3176 2018-07-26 17:12:48Z suehring
 ! Bugfix, update virtual potential surface temparture, else heat fluxes on 
 ! roofs might become unphysical
@@ -7373 +7376 @@
 !                  ( surf_usm_h%ts(m) * surf_usm_h%us(m) + 1.0E-20_wp )
                 
-!--        make sure that the resistance does not drop to zero
+!--        Make sure that the resistance does not drop to zero
            IF ( surf_usm_h%r_a(m)        < 1.0_wp )                            &
                surf_usm_h%r_a(m)        = 1.0_wp
@@ -7380 +7383 @@
            IF ( surf_usm_h%r_a_window(m) < 1.0_wp )                            &
                surf_usm_h%r_a_window(m) = 1.0_wp
+              
+!
+!--        Make sure that the resistacne does not exceed a maxmium value in case
+!--        of zero velocities
+           IF ( surf_usm_h%r_a(m)        > 300.0_wp )                          &
+               surf_usm_h%r_a(m)        = 300.0_wp
+           IF ( surf_usm_h%r_a_green(m)  > 300.0_wp )                          &
+               surf_usm_h%r_a_green(m) = 300.0_wp
+           IF ( surf_usm_h%r_a_window(m) > 300.0_wp )                          &
+               surf_usm_h%r_a_window(m) = 300.0_wp                
+                
                 
 !--        factor for shf_eb
@@ -7579 +7593 @@
 !
 !--          Limit aerodynamic resistance
-             IF ( surf_usm_v(l)%r_a(m) < 1.0_wp )                              &
-                surf_usm_v(l)%r_a(m)        = 1.0_wp          
+             IF ( surf_usm_v(l)%r_a(m) < 1.0_wp )  surf_usm_v(l)%r_a(m) = 1.0_wp   
+             
                            
              f_shf         = rho_cp / surf_usm_v(l)%r_a(m)