Changeset 4194 for palm/trunk/SOURCE

Timestamp:

Aug 28, 2019 8:09:44 AM (5 years ago)

Author:

suehring

Message:

In case z0 exceeds the surface-layer height at water surfaces, apply more strict limitation of z0, in order to avoid instabilities when friction velocity is almost zero.

File:

• palm/trunk/SOURCE/land_surface_model_mod.f90 (modified) (4 diffs)

palm/trunk/SOURCE/land_surface_model_mod.f90

@@ -25 +25 @@
 ! -----------------
 ! $Id$
+! Apply more strict limitation of z0 over water surfaces in case it exceeds the 
+! surface-layer height, in order to avoid instabilities. 
+! 
+! 4188 2019-08-26 14:15:47Z suehring
 ! Minor adjustment in error numbers, typos corrected
 ! 
@@ -6979 +6983 @@
 
   
-             IF ( surf_lsm_h%z0(m) >= surf_lsm_h%z_mo(m) )  THEN
+             IF ( surf_lsm_h%z0(m) > 0.1_wp * surf_lsm_h%z_mo(m) )  THEN
   
-                surf_lsm_h%z0(m) = 0.9_wp * surf_lsm_h%z_mo(m)
+                surf_lsm_h%z0(m) = 0.1_wp * surf_lsm_h%z_mo(m)
              
                 WRITE( message_string, * ) 'z0 exceeds surface-layer height' //&
@@ -6991 +6995 @@
              ENDIF
   
-             IF ( surf_lsm_h%z0h(m) >= surf_lsm_h%z_mo(m) )  THEN
+             IF ( surf_lsm_h%z0h(m) >= 0.1_wp * surf_lsm_h%z_mo(m) )  THEN
   
-                surf_lsm_h%z0h(m) = 0.9_wp * surf_lsm_h%z_mo(m)
+                surf_lsm_h%z0h(m) = 0.1_wp * surf_lsm_h%z_mo(m)
              
                 WRITE( message_string, * ) 'z0h exceeds surface-layer height'//&
@@ -7003 +7007 @@
              ENDIF
              
-             IF ( surf_lsm_h%z0q(m) >= surf_lsm_h%z_mo(m) )  THEN
+             IF ( surf_lsm_h%z0q(m) >= 0.1_wp * surf_lsm_h%z_mo(m) )  THEN
   
-                surf_lsm_h%z0q(m) = 0.9_wp * surf_lsm_h%z_mo(m)
+                surf_lsm_h%z0q(m) = 0.1_wp * surf_lsm_h%z_mo(m)
              
                 WRITE( message_string, * ) 'z0q exceeds surface-layer height'//&