Ensemble forecast file formats
Added by Ștefan Săftescu 5 days ago
Hello,
I am working with the DWD ICON model, looking at their global ensemble data. The individual ensemble predictions are all packed inside a dimension number in the DWD Open Data GRIB2 files (see, e.g. https://opendata.dwd.de/weather/nwp/icon-eps/grib/00/t_2m/). If I pack a few variables into a NetCDF file, I get a file that CDO can’t read (attached). Looking at the CF conventions, I am not sure how to represent ensembles in NetCDF files, but it seems like dimensions other than X, Y, Z, T should be fine for CF-conformant files.
Does anyone have any suggestions of how to structure this file so I can do CDO operations on it (specifically remap for regridding from ICON to a regular grid)? I know I could split up the file into one file per ensemble member, but I’d like to try to do it with one file.
Thanks!
Ștefan
Replies (2)
RE: Ensemble forecast file formats - Added by Uwe Schulzweida 4 days ago
Hello Ștefan,
In this case, it is not so easy to automatically recognize which dimension belongs to which axis. If you add the attribute axis="Z" to the ensemble array number, it works without any problems:
ncatted -a axis,number,c,c,"Z" ens.ncCheers,
Uwe