CDO

I am trying to compute zonal anomalies (deviations from the zonal mean) with 4-d (time, lev, lat, lon) data that includes missing values over topography at lower vertical levels (see tmp.nc attached).

When I use this command on the full global field I get an error:
cdo sub tmp.nc -enlarge,tmp.nc -zonmean tmp.nc tmp2.nc

cdo sub: Started child process "enlarge,tmp.nc -zonmean tmp.nc (pipe1.1)".
cdo(2) enlarge: Started child process "zonmean tmp.nc (pipe2.1)".
cdo(2) enlarge (Abort): Missing values unsupported for this operator!

However, when I select a subset of latitudes that does not contain Antarctica the operation works correctly:
cdo sellonlatbox,0,360,-50,90 tmp.nc tmp2.nc
cdo sub tmp2.nc -enlarge,tmp2.nc -zonmean tmp2.nc tmp3.nc

cdo sub: Started child process "enlarge,tmp2.nc -zonmean tmp2.nc (pipe1.1)".
cdo(2) enlarge: Started child process "zonmean tmp2.nc (pipe2.1)".
cdo(2) enlarge: Enlarge zonal
cdo(3) zonmean: Processed 171360 values from 1 variable over 1 timestep. ( 0.00s )
cdo(2) enlarge: Processed 1190 values from 1 variable over 1 timestep. ( 0.00s )
cdo sub: Processed 342720 values from 2 variables over 2 timesteps. ( 0.00s )

So, the problem appears to be with latitude circles that are missing at all longitudes (i.e. there is no valid data to enlarge to). But is there a way to force enlarge to just return a missing value in this case to prevent the command failing? Or perhaps there is another solution so that I can compute zonal anomalies using the full global field?

BTW: I receive the same error with multiple CDO versions on different hardware (1.5.3 -- 1.5.8).

Thanks in advance
Chris