[ferret_users] Unable to write to the next vertical level

[sray@xxxxxxxxxxxxxx]

Hi Ferreters,

   I have been trying to work with 8 ensemble outputs, which I have only at the surface level.
I added a z-axis to the data using a pseudo-dataset which has existing vertical levels.
Now my problem is though the vertical axis is created andI couldi write at k=1, but 
I could not write data from k=2:8. 
   I am attaching my script. Does any of you have some suggestions?

use Ensemble_1.cdf  ! Ensemble run 1
use test.cdf        ! A dataset which has z-axis (znum)

! Now add the z-axis (znum) to the existing grid

def grid/x=I/y=J263_289/z=znum/t=TIME tgrid  ! I, J263_289,TIME are axes names in Ensemble_1.cdf

!Create a new variable having a zaxis

let sst = temp[d=1,g=tgrid]+0*z[gz=znum,z=1]
set var/title="Ensembles"/units=ensemble sst

!save the new variable as k=1 in a file having 8 vertical levels
save/file=Outfile.cdf/KLIMITS=1:8/k=1/clobber sst
cancel data/all

! Similarly with the 2nd ensemble member
use Ensemble_2.cdf
let sst = temp[g=tgrid]+0*z[gz=znum,z=2]
save/append/file=Outfile.cdf/k=2 sst

!Though the Outfile.cdf has 8 vertical levels yet it has data only in k=1,
!but do not write the data of Ensemble_2.cdf in k=2

Thanking you,
Sulagna
Graduate student
Department of Oceanography
Physical Oceanography
Texas A&M University