Ensemble forecast file formats
Added by Ștefan Săftescu 10 months 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 10 months 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