CDO

I want to convert multiple nc file to grb2. I used for file in *.nc; do short_name=$(echo "$file" | cut -c 1-22); cdo -f grb2 copy "$file" "${short_name}.grib"; done.

The input nc file has time double time(time=1);
  :units = "Hour since 2021-01-01T00:00:00Z";
  :standard_name = "time";
  :long_name = "GRIB forecast or observation time";
  :calendar = "proleptic_gregorian";

Array is single-valued, with value: 0.0

The output grib has time as In file "amerge.grib"
double time(time=1);
:units = "Hour since 0001-01-01T00:00:00Z";
:standard_name = "time";
:long_name = "GRIB forecast or observation time";
:calendar = "proleptic_gregorian";

Array is single-valued, with value: 0.0

I also tried to use for file in *.nc; do short_name=$(echo "$file" | cut -c 1-22); cdo -f grb copy "$file" "${short_name}.grib"; done.

then my input variable is t(time=1, hybrid_output=42, latitude=181, longitude=360); and output the t(time=1, isobaric=18, lat=181, lon=360); t(time=1, isobaric_surface=21, lat=181, lon=360) is split into two variables. but time dimension is preserved. what can be done