diff --git a/src/ecwam/userin.F90 b/src/ecwam/userin.F90
index a9bed51b..15a5f905 100644
--- a/src/ecwam/userin.F90
+++ b/src/ecwam/userin.F90
@@ -1590,6 +1590,18 @@ SUBROUTINE USERIN (IFORCA, LWCUR)
             WRITE(IU06,*) '+ PROGRAM WILL IGNORE THIS OUTPUT TIME +'
             WRITE(IU06,*) '+                                      +'
             WRITE(IU06,*) '++++++++++++++++++++++++++++++++++++++++'
+          ELSE IF (MOD(ISHIFT,IDELT) /= 0 .AND. LLSOURCE ) THEN
+            WRITE(IU06,*) '++++++++++++++++++++++++++++++++++++++++'
+            WRITE(IU06,*) '+                                      +'
+            WRITE(IU06,*) '+    WARNING ERROR IN SUB. USERIN      +'
+            WRITE(IU06,*) '+    ============================      +'
+            WRITE(IU06,*) '+ OUTPUT DATE IS NOT AT THE END OF A   +'
+            WRITE(IU06,*) '+ SOURCE TERM TIMESTEP IDELT= ', IDELT
+            WRITE(IU06,*) '+ DATE IS : ', COUTT(J)
+            WRITE(IU06,*) '+ PROGRAM WILL ABORT '
+            WRITE(IU06,*) '+                                       +'
+            WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
+            LERROR = .TRUE.
           ENDIF
         ENDDO
       ELSE
@@ -1611,7 +1623,7 @@ SUBROUTINE USERIN (IFORCA, LWCUR)
           WRITE(IU06,*) '*                                         *'
           WRITE(IU06,*) '*    FATAL ERROR IN SUB. USERIN           *'
           WRITE(IU06,*) '*    ==========================           *'
-          WRITE(IU06,*) '* OUTPUT OF INTEGRATED DATA (TOTAL SEA)   *'
+          WRITE(IU06,*) '* OUTPUT OF INTEGRATED DATA               *'
           WRITE(IU06,*) '* IS REQUESTED.                           *'
           WRITE(IU06,*) '* OUTPUT TIME STEP HAS TO BE A MULTIPLE   *'
           WRITE(IU06,*) '* OF THE PROPAGATION TIME STEP.           *'
@@ -1621,6 +1633,23 @@ SUBROUTINE USERIN (IFORCA, LWCUR)
           WRITE(IU06,*) '*******************************************'
           LERROR = .TRUE.
         ENDIF
+        IF (LLSOURCE) THEN
+          IF ((FFLAG20 .OR. GFLAG20) .AND. MOD(IDELINT,IDELT) /= 0) THEN
+            WRITE(IU06,*) '*******************************************'
+            WRITE(IU06,*) '*                                         *'
+            WRITE(IU06,*) '*    FATAL ERROR IN SUB. USERIN           *'
+            WRITE(IU06,*) '*    ==========================           *'
+            WRITE(IU06,*) '* OUTPUT OF INTEGRATED DATA               *'
+            WRITE(IU06,*) '* IS REQUESTED.                           *'
+            WRITE(IU06,*) '* OUTPUT TIME STEP HAS TO BE A MULTIPLE   *'
+            WRITE(IU06,*) '* OF THE SOURCE TERM TIME STEP.           *'
+            WRITE(IU06,*) '* OUTPUT TIME STEP IS      IDELINT = ', IDELINT
+            WRITE(IU06,*) '* SOURCE TERM TIME STEP IS IDELT = ', IDELT 
+            WRITE(IU06,*) '*                                         *'
+            WRITE(IU06,*) '*******************************************'
+            LERROR = .TRUE.
+          ENDIF
+        ENDIF
       ENDIF
 
       IF (NOUTS > 0) THEN
@@ -1639,6 +1668,24 @@ SUBROUTINE USERIN (IFORCA, LWCUR)
             WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
           ENDIF
         ENDDO
+        IF (LLSOURCE) THEN
+          DO J=1,NOUTS
+            CALL DIFDATE (CDATEA, COUTS(J), ISHIFT)
+            IF (ISHIFT <= 0 .OR. MOD(ISHIFT,IDELT) /= 0) THEN
+              WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
+              WRITE(IU06,*) '+                                       +'
+              WRITE(IU06,*) '+    WARNING ERROR IN SUB. USERIN       +'
+              WRITE(IU06,*) '+    ============================       +'
+              WRITE(IU06,*) '+ SPECTRA OUTPUT DATE IS NOT AT THE END +'
+              WRITE(IU06,*) '+ OF A SOURCE TERM TIMESTEP IDELT= ', IDELT
+              WRITE(IU06,*) '+ DATE IS : ', COUTS(J)
+              WRITE(IU06,*) '+ PROGRAM WILL ABORT '
+              WRITE(IU06,*) '+                                       +'
+              WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
+              LERROR = .TRUE.
+            ENDIF
+          ENDDO
+        ENDIF
       ENDIF
 
       IF (NASS > 0 .AND. IASSI == 1) THEN
@@ -1655,7 +1702,23 @@ SUBROUTINE USERIN (IFORCA, LWCUR)
             WRITE(IU06,*) '+ PROGRAM WILL ABORT '
             WRITE(IU06,*) '+                                       +'
             WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
-            CALL WAM_ABORT(__FILENAME__,__LINE__)
+            LERROR = .TRUE.
+          ENDIF
+        ENDDO
+        DO J=1,NASS
+          CALL DIFDATE (CDATEA, CASS(J), ISHIFT)
+          IF (ISHIFT <= 0 .OR. MOD(ISHIFT,IDELT) /= 0) THEN
+            WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
+            WRITE(IU06,*) '+                                       +'
+            WRITE(IU06,*) '+    WARNING ERROR IN SUB. USERIN       +'
+            WRITE(IU06,*) '+    ============================       +'
+            WRITE(IU06,*) '+ ASSIMILATION DATE IS NOT AT THE END   +'
+            WRITE(IU06,*) '+ OF A SOURCE TERM TIMESTEP IDELT= ', IDELT
+            WRITE(IU06,*) '+ DATE IS : ', CASS(J)
+            WRITE(IU06,*) '+ PROGRAM WILL ABORT '
+            WRITE(IU06,*) '+                                       +'
+            WRITE(IU06,*) '+++++++++++++++++++++++++++++++++++++++++'
+            LERROR = .TRUE.
           ENDIF
         ENDDO
       ENDIF
@@ -1677,6 +1740,10 @@ SUBROUTINE USERIN (IFORCA, LWCUR)
         WRITE(IU06,*) '* PROGRAM ABORTS.   PROGRAM ABORTS.       *'
         WRITE(IU06,*) '* ---------------   --------------        *'
         WRITE(IU06,*) '*******************************************'
+        WRITE(NULERR,*) '*******************************************'
+        WRITE(NULERR,*) '*    FATAL ERROR(S) IN SUB. USERIN        *'
+        WRITE(NULERR,*) '*    SEE LOGFILE        *'
+        WRITE(NULERR,*) '*******************************************'
         CALL WAM_ABORT(__FILENAME__,__LINE__)
       ELSE
 
diff --git a/src/ecwam/wamintgr.F90 b/src/ecwam/wamintgr.F90
index 6d429226..8fd4b2af 100644
--- a/src/ecwam/wamintgr.F90
+++ b/src/ecwam/wamintgr.F90
@@ -172,6 +172,14 @@ SUBROUTINE WAMINTGR (CDTPRA, CDATE, CDATEWH, CDTIMP, CDTIMPNEXT,  &
   CDTIMP=CDTIMPNEXT
   CALL INCDATE(CDTIMPNEXT, IDELT)
 
+ELSE
+!   NO SOURCE TERM CONTRIBUTION
+!$OMP PARALLEL DO SCHEDULE(STATIC) PRIVATE(ICHNK)
+    DO ICHNK = 1, NCHNK
+      MIJ(:,ICHNK) = NFRE
+      XLLWS(:,:,:,ICHNK) = 0.0_JWRB
+    ENDDO
+!$OMP END PARALLEL DO
 ENDIF
 
 IF (LHOOK) CALL DR_HOOK('WAMINTGR',1,ZHOOK_HANDLE)