CDO ensemble mean
Added by Mika Rantanen about 4 years ago
Hi,
I have data file which contains ensemble forecast with 50 members. The different ensemble members are as a dimension called "number"
Is it possible to calculate the ensemble mean over these members without extracting the members into their own files?
I found the "ensmean" command but it only takes input as files, not dimension, if I've understood correctly?
Mika
Replies (4)
RE: CDO ensemble mean - Added by Karin Meier-Fleischer about 4 years ago
Hi Mika,
without the input file I can only guess.
You can split a variable, e.g. siconc, into separate files (ensemble numbers) and then compute the ensemble mean.
cdo -splitlevel -selname,siconc infile.nc siconc_ens_ cdo -ensmean siconc_ens_* siconc_ensmean.nc
-Karin
RE: CDO ensemble mean - Added by Mika Rantanen about 4 years ago
Thanks, that actually does the trick.
It seems that even "cdo -vertmean -selvar,t2m ens_finland_20190103.nc out.nc" calculates the mean over the "number"-dimension without splitting first the members into single files.
This is ok, as long as I have 2-dimensional surface data which doesn't have the actual vertical dimension.
Is there a way to calculate the average (or any other statistical values) over non-conventional dimension, such as "number" in this case?
Mika
RE: CDO ensemble mean - Added by Karin Meier-Fleischer about 4 years ago
Only with the trick mentioned above. CDO is following the CF-convention and your files are not CF conform.
RE: CDO ensemble mean - Added by Mika Rantanen about 4 years ago
Ok, thanks for the quick responses!
Mika