Hi Roland,

Thank you again for your reply, for the explanation and the paper. I was not aware of the use of buffer points related to time integration substeps.

> > then level 1 extends up to 28.5, which is 9 points away from x=24.

> If you look at HDF5 output and ask to not have ghosts output then you
> may be missing 3 points from the output file.

I am looking at HDF5 output, and I have the default "yes" for IOHDF5::output_ghost_zones. I tried to change it to "no" but this did not change this feature of the output. 

> Please let me know if the above is sufficient.

I think it is, thank you! I'm still a bit puzzled by the fact that I don't get 4*ghost_size points as you explained, but for now, I think it is enough for me to understand where these "extra" points come from.

Best,

Jordan