Index: trunk/MESOSCALE/LMD_MM_MARS/SRC/WPS/wps_mars/geogrid/GEOGRID.TBL.ARW_Mars
===================================================================
--- trunk/MESOSCALE/LMD_MM_MARS/SRC/WPS/wps_mars/geogrid/GEOGRID.TBL.ARW_Mars	(revision 1113)
+++ trunk/MESOSCALE/LMD_MM_MARS/SRC/WPS/wps_mars/geogrid/GEOGRID.TBL.ARW_Mars	(revision 1128)
@@ -125,6 +125,5 @@
         priority = 1
         dest_type = continuous
-        ## au-dessus de 4.... probleme de valeurs negatives...
-        smooth_option = 1-2-1; smooth_passes=4
+        smooth_option = 1-2-1; smooth_passes=10
         interp_option =         32ppd:sixteen_pt+four_pt+average_4pt+average_16pt+search
         rel_path=               32ppd:rough_GCM/
@@ -133,5 +132,5 @@
         interp_option =         64ppd:sixteen_pt+four_pt+average_4pt+average_16pt+search
         rel_path=               64ppd:rough_GCM/
-        interp_option =         64ppd_noHRti:sixteen_pt+four_pt+average_4pt+average_16pt+search
+        interp_option =         64ppd_noHRti:nearest_neighbor
         rel_path=               64ppd_noHRti:rough_GCM/
         interp_option =         custom:sixteen_pt+four_pt+average_4pt+average_16pt+search
Index: trunk/MESOSCALE/LMD_MM_MARS/SRC/WRFV2/phys/module_lmd_driver.F
===================================================================
--- trunk/MESOSCALE/LMD_MM_MARS/SRC/WRFV2/phys/module_lmd_driver.F	(revision 1113)
+++ trunk/MESOSCALE/LMD_MM_MARS/SRC/WRFV2/phys/module_lmd_driver.F	(revision 1128)
@@ -981,4 +981,11 @@
    z0_val = 0.01
 ENDIF
+!!!! ADDITIONAL SECURITY. INTERP+SMOOTH IN GEOGRID MIGHT YIELD NEGATIVE Z0 !!!
+IF (z0_val < 0.) THEN
+   PRINT *, 'WELL, z0 is NEGATIVE, this is impossible. better stop here.'
+   PRINT *, 'advice --> correct interpolation / smoothing of z0 in WPS'
+   PRINT *, '           -- or check the constant value set in namelist.input'
+   STOP
+ENDIF
 #endif