CDO

Hello,
i am trying to find new ways of optimizing my workflow and found distgrid and collgrid.
When trying to use ncdata centered around a pole the collgrid command doesn't collect the grids correctly.

This is my minimal example code:

#!/bin/bash

cdo shifttime,1year -addc,10 tas_2011_01.nc tas_2012_01.nc

cdo distgrid,4,4 tas_2011_01.nc dist_ &
cdo distgrid,4,4 tas_2012_01.nc dist10_ &
wait

for i in `seq -f '%05g' 0 15`
do
(
cdo mergetime dist*_${i}.nc fullstripe_${i}.nc
cdo timpctl,50 fullstripe_${i}.nc -timmin fullstripe_${i}.nc -timmax fullstripe_${i}.nc median${i}.nc
) &
done
wait
cdo collgrid median*.nc Final.nc ######
Looking at Final.nc in Ncview the data is not correctly put together.

Attached is tas_2011_01 which is just the first month of tas_ARC-44_ECMWF-ERAINT_evaluation_r1i1p1_DMI-HIRHAM5_v1_mon_201101-201512.nc from esgf-dkrz node
and screenshot from ncview final.nc

CDO-Version
Climate Data Operators version 1.9.3 (http://mpimet.mpg.de/cdo)
CXX Compiler: g++ -g -O2 -fdebug-prefix-map=/build/cdo-g3Qjnd/cdo-1.9.3+dfsg.1=. -fstack-protector-strong -Wformat -Werror=format-security -fopenmp
CXX version : g++ (Ubuntu 7.3.0-1ubuntu1) 7.3.0
C Compiler: gcc -g -O2 -fdebug-prefix-map=/build/cdo-g3Qjnd/cdo-1.9.3+dfsg.1=. -fstack-protector-strong -Wformat -Werror=format-security -Wall -pedantic -fPIC -fopenmp
C version : gcc (Ubuntu 7.3.0-1ubuntu1) 7.3.0
F77 Compiler: f77 -g -O2 -fdebug-prefix-map=/build/cdo-g3Qjnd/cdo-1.9.3+dfsg.1=. -fstack-protector-strong
F77 version : unknown
Features: 251GB C++14 Fortran DATA PTHREADS OpenMP45 HDF5 NC4/HDF5/threadsafe OPeNDAP SZ UDUNITS2 PROJ.4 MAGICS CURL FFTW3 SSE2
Libraries: HDF5/1.10.0 proj/4.93 curl/7.58.0
Filetypes: srv ext ieg grb1 grb2 nc1 nc2 nc4 nc4c nc5
CDI library version : 1.9.3
GRIB_API library version : 2.6.0
NetCDF library version : 4.6.0 of Feb 9 2018 19:21:24 $
HDF5 library version : library undefined
EXSE library version : 1.4.0
FILE library version : 1.8.3

Greetings
Lukas Schefczyk