Switched on optimization again.

Seemingly the -fp-model fast=2 was the origin for the NANs.
To remove tracebacks finally.

build_hlrng.sh

@@ -43,9 +43,11 @@ else
 	# compiler flags
 	export IOW_ESM_CPPDEFS="-DOASIS_IOW_ESM"
 	
-	export IOW_ESM_FFLAGS="-O3 -r8 -no-prec-div -fp-model fast=2 -xHost -I${IOW_ESM_NETCDF_INCLUDE}/"
-	export IOW_ESM_CFLAGS="-O3 -r8 -no-prec-div -fp-model fast=2 -xHost -I${IOW_ESM_NETCDF_INCLUDE}/"
-	export IOW_ESM_LDFLAGS="-L${IOW_ESM_NETCDF_LIBRARY} -lnetcdf -lnetcdff -Wl,-rpath,${IOW_ESM_NETCDF_LIBRARY}"
+	#export IOW_ESM_FFLAGS="-fpp -fpe0 -r8 -O0 -traceback -g -I${IOW_ESM_NETCDF_INCLUDE}/"
+	#export IOW_ESM_CFLAGS="-O0 -traceback -g -I${IOW_ESM_NETCDF_INCLUDE}/"
+    export IOW_ESM_FFLAGS="-fpp -fpe0 -r8 -O3 -fp-model precise -xHost -traceback -g -I${IOW_ESM_NETCDF_INCLUDE}/"
+    export IOW_ESM_CFLAGS="-O3 -traceback -g -I${IOW_ESM_NETCDF_INCLUDE}/"
+    export IOW_ESM_LDFLAGS="-g -traceback -L${IOW_ESM_NETCDF_LIBRARY} -lnetcdf -lnetcdff -Wl,-rpath,${IOW_ESM_NETCDF_LIBRARY}"
 fi
 
 # MAKE CLEAN

src/coupler/surface_flux.F90

@@ -461,12 +461,21 @@ subroutine surface_flux_1d (                                           &
          w_gust = gust
        end where
      endif  
-           
+
      where(avail) 
         w_atm = sqrt(u_dif*u_dif + v_dif*v_dif + w_gust*w_gust)
+#IFDEF OASIS_IOW_ESM        
+     endwhere
+     where(avail .AND. w_atm > 1.0E-15 ) ! avoid dividing by zero
+#ENDIF
         ! derivatives of surface wind w.r.t. atm. wind components
         dw_atmdu = u_dif/w_atm
         dw_atmdv = v_dif/w_atm
+#IFDEF OASIS_IOW_ESM
+     elsewhere
+        dw_atmdu = 0.0
+        dw_atmdv = 0.0
+#ENDIF
      endwhere
   endif
 
@@ -498,6 +507,8 @@ subroutine surface_flux_1d (                                           &
      q_star     = 0.0
      q_surf     = 0.0
      w_atm      = 0.0
+     dtaudu_atm = 0.0
+     dtaudv_atm = 0.0
   ELSEIF (TRIM(type_atmos) == 'none') THEN
 #ENDIF
   where (avail)
@@ -563,9 +574,7 @@ subroutine surface_flux_1d (                                           &
      q_surf     = 0.0
      w_atm      = 0.0
   endwhere
-#IFDEF OASIS_IOW_ESM
-  ENDIF
-#ENDIF
+
   ! calculate d(stress component)/d(atmos wind component)
   dtaudu_atm = 0.0
   dtaudv_atm = 0.0
@@ -581,6 +590,10 @@ subroutine surface_flux_1d (                                           &
      endwhere
   endif
 
+#IFDEF OASIS_IOW_ESM
+ENDIF
+#ENDIF  
+
 end subroutine surface_flux_1d
 ! </SUBROUTINE>