CDO

Hello,

I have a NetCDF file (oldfile.nc) containing one year's worth of monthly data. It has dimensions (from ncdump)
dimensions:
lev = 19 ;
bnds = 2 ;
lat = 36 ;
lon = 72 ;
time = UNLIMITED ; // (12 currently)

I want to create an equivalent file with only the data for June so I issue the command

cdo selmon,6 oldfile.nc newfile.nc

But now newfile.nc has dimensions
dimensions:
gsize = 2 ;
lon = 72 ;
nv = 2 ;
lat = 36 ;
lev = 19 ;
time = UNLIMITED ; // (1 currently)

I don't understand why `bnds' disappears and `gsize' and `nv' appear. Is there anyway to create newfile.nc with the same dimensions as oldfile, but only with time changing from 12 to 1?

Ian