diff --git a/sorc/ncep_post.fd/INITPOST_GFS_NEMS_MPIIO.f b/sorc/ncep_post.fd/INITPOST_GFS_NEMS_MPIIO.f
index 1bfc8b7f5d..29ab5f09be 100644
--- a/sorc/ncep_post.fd/INITPOST_GFS_NEMS_MPIIO.f
+++ b/sorc/ncep_post.fd/INITPOST_GFS_NEMS_MPIIO.f
@@ -929,13 +929,14 @@ SUBROUTINE INITPOST_GFS_NEMS_MPIIO(iostatusAER)
         call getrecn(recname,reclevtyp,reclev,nrec,varname,VcoordName,l,recn)
         if(recn /= 0) then
           fldst = (recn-1)*fldsize
+! make sure delz is positive.
 !$omp parallel do private(i,j,js)
           do j=jsta,jend
             js = fldst + (j-jsta)*im
             do i=1,im
-              zint(i,j,ll)=zint(i,j,ll+1)+tmp(i+js)
+              zint(i,j,ll)=zint(i,j,ll+1)+abs(tmp(i+js))
               if(recn_dpres /= -9999)pmid(i,j,ll)=rgas*dpres(i,j,ll)* &
-                      t(i,j,ll)*(q(i,j,ll)*fv+1.0)/grav/tmp(i+js) 
+                      t(i,j,ll)*(q(i,j,ll)*fv+1.0)/grav/abs(tmp(i+js)) 
             enddo
           enddo
           if(debugprint)print*,'sample l ',VarName,' = ',ll, &
@@ -945,7 +946,7 @@ SUBROUTINE INITPOST_GFS_NEMS_MPIIO(iostatusAER)
             do j=jsta,jend
               js = fldst + (j-jsta)*im
               do i=1,im
-                omga(i,j,ll)=(-1.)*wh(i,j,ll)*dpres(i,j,ll)/tmp(i+js) 
+                omga(i,j,ll)=(-1.)*wh(i,j,ll)*dpres(i,j,ll)/abs(tmp(i+js)) 
               end do
             end do
             if(debugprint)print*,'sample l omga for FV3',ll, &
diff --git a/sorc/ncep_post.fd/INITPOST_NETCDF.f b/sorc/ncep_post.fd/INITPOST_NETCDF.f
index 783a4dd641..28595d7f43 100644
--- a/sorc/ncep_post.fd/INITPOST_NETCDF.f
+++ b/sorc/ncep_post.fd/INITPOST_NETCDF.f
@@ -702,16 +702,17 @@ SUBROUTINE INITPOST_NETCDF(ncid3d)
             cwm(i,j,l)=spval
 !           zint(i,j,l)=zint(i,j,l+1)+buf(i,j)
 !           if(abs(dpres(i,j,l))>1.0e5)print*,'bad dpres ',i,j,dpres(i,j,l)
+!make sure delz is positive
            if(dpres(i,j,l)/=spval .and. t(i,j,l)/=spval .and. &
            q(i,j,l)/=spval .and. buf3d(i,j,l)/=spval)then
             pmid(i,j,l)=rgas*dpres(i,j,l)* &
-                t(i,j,l)*(q(i,j,l)*fv+1.0)/grav/buf3d(i,j,l)
+                t(i,j,l)*(q(i,j,l)*fv+1.0)/grav/abs(buf3d(i,j,l))
            else
             pmid(i,j,l)=spval
            end if
 ! dong add missing value
            if (wh(i,j,l) < spval) then
-            omga(i,j,l)=(-1.)*wh(i,j,l)*dpres(i,j,l)/buf3d(i,j,l)
+            omga(i,j,l)=(-1.)*wh(i,j,l)*dpres(i,j,l)/abs(buf3d(i,j,l))
            else
             omga(i,j,l) = spval
            end if
@@ -858,7 +859,8 @@ SUBROUTINE INITPOST_NETCDF(ncid3d)
         do j=jsta,jend
           do i=1,im
             if(zint(i,j,l+1)/=spval .and. buf3d(i,j,l)/=spval)then
-             zint(i,j,l)=zint(i,j,l+1)+buf3d(i,j,l)
+!make sure delz is positive
+             zint(i,j,l)=zint(i,j,l+1)+abs(buf3d(i,j,l))
 !             if(zint(i,j,l)>1.0E6)print*,'bad H ',i,j,l,zint(i,j,l)
             else
              zint(i,j,l)=spval
diff --git a/ush/fv3gfs_downstream_nems.sh b/ush/fv3gfs_downstream_nems.sh
index 707f77a05b..4449c964c7 100755
--- a/ush/fv3gfs_downstream_nems.sh
+++ b/ush/fv3gfs_downstream_nems.sh
@@ -25,6 +25,8 @@ set -x
 #-Wen Meng, January 2018, add flag PGB1F for turning on/ogg grib1 pgb data at 1.00 deg. generation.
 #-Wen Meng, Feburary 2018
 #  1. Add flag PGBS for turning on/off pgb data at 1.0 and 0.5 deg. generation frequency of FHOUT_PGB defined.
+#-Wen Meng, October
+#  1. Use bilinear interpolation for LAND. It can trancate land-sea mask as 1 or 0.
 #-----------------------------------------------------------------------
 
 
@@ -47,7 +49,7 @@ export PGBS=${PGBS:-"NO"} #YES-- generate 1.00 and 0.50 deg pgb data
 #--wgrib2 regrid parameters
 export option1=' -set_grib_type same -new_grid_winds earth '
 export option21=' -new_grid_interpolation bilinear  -if '
-export option22=":(LAND|CRAIN|CICEP|CFRZR|CSNOW|ICSEV):"
+export option22=":(CRAIN|CICEP|CFRZR|CSNOW|ICSEV):"
 export option23=' -new_grid_interpolation neighbor -fi '
 export option24=' -set_bitmap 1 -set_grib_max_bits 16 -if '
 export option25=":(APCP|ACPCP|PRATE|CPRAT):"
diff --git a/ush/fv3gfs_dwn_nems.sh b/ush/fv3gfs_dwn_nems.sh
index c7611e3453..133d62d886 100755
--- a/ush/fv3gfs_dwn_nems.sh
+++ b/ush/fv3gfs_dwn_nems.sh
@@ -9,6 +9,7 @@ set -x
 # Wen Meng 12/2017: add trim_rh.sh for triming RH values larger than 100.
 # Wen Meng 01/2018: add flag PGB1F for turning on/off wgrib1 pgb data at 1.00 deg. generation.
 # Wen Meng 02/2018: add flag PGBS for turning on/off pgb data at 1.0 and 0.5 deg. generation.
+# Wen Meng 10/2019: Use bilinear interpolation for LAND, It can trancate land-sea mask as 0 or 1.
 
 export tmpfile=$1
 export fhr3=$2
@@ -22,7 +23,7 @@ export TRIMRH=${TRIMRH:-$USHgfs/trim_rh.sh}
 
 export opt1=' -set_grib_type same -new_grid_winds earth '
 export opt21=' -new_grid_interpolation bilinear  -if '
-export opt22=":(LAND|CSNOW|CRAIN|CFRZR|CICEP|ICSEV):"
+export opt22=":(CSNOW|CRAIN|CFRZR|CICEP|ICSEV):"
 export opt23=' -new_grid_interpolation neighbor -fi '
 export opt24=' -set_bitmap 1 -set_grib_max_bits 16 -if '
 export opt25=":(APCP|ACPCP|PRATE|CPRAT):"