Problem
You downloaded data from the ECMWF data server or another ECMWF repository in NetCDF format.
Then you are trying to read the data with the NCAR Command Language (NCL) , GrADS or Ferret, but get an error message, for example for NCL:
Cause
NCL, GrADS and Ferret do not support dots in variable names.
Solution for NCL
Enclose the variable name in double quotes and Dollar signs:
Workaround
Rename the variable so the name contains only allowed characters.
Rename with CDO (exactly your case): https://code.mpimet.mpg.de/boards/2/topics/4057
Rename with NCO: http://research.jisao.washington.edu/data_sets/nco/#example
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