CDO warning when CDORemapper is used

It is a long-term issue that when CDORemapper() is used, there are several warnings coming from CDO:

• Progress: 0%Warning (find_time_vars): Time variable >time< not found! Warning (find_time_vars): Time variable >time< not found! Warning (find_time_vars): Time variable >time< not found! Warning (find_time_vars): Time variable >time< not found!

or

Warning (cdfScanVarAttr): NetCDF: Variable not found - lon_bnds

The results are correct so it is not a critical problem. According to this discussion https://code.mpimet.mpg.de/boards/1/topics/221, the warning might come from the lack of time variable. But our esarchive data always has time variable. It may be a problem in the temporal .nc file created by startR. This problem seems to happen when we changed to use CDO_1.9.8.