Why is it so slow to process ERA5 data with cdo after ERA5 update？

Hi!
I recently downloaded a few sets of data from ERA5 and had no problem viewing them with commands such as cdo-infos.

However, data processing commands such as daymean, shifttime, etc. will prompt: "Warning (cdfInqContents): Coordinates variable number can't be assigned! Warning (cdfInqContents): Coordinates variable expver can't be assigned!” .

Although the warning does not stop the process, it is very slow and can take several hours, which is something I have not done with ERA5 data before. I wonder if there is a solution to this problem?

Attached are the two ERA5 data I downloaded without any processing.

best wishes,
Rebecca

Download all files

lai_0.1deg_1994-2023.nc (71.7 MB) lai_0.1deg_1994-2023.nc
pre_0.1deg_1994-2023.nc (101 MB) pre_0.1deg_1994-2023.nc

Replies (7)

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by Uwe Schulzweida 10 days ago

Hi Rebecca,

At least CDO version 2.4.1 is required to read/decompress this data much faster.

Cheers,
Uwe

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by wu yy 9 days ago

Thanks!
I found another way to solve this problem

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by Jiawei Bao 5 days ago

Hi Uwe,

I used the latest cdo/2.4.3-gcc-11.2.0 on Levante. And it is still extremely slow. I took almost 8 hours to remap 1 year of hourly data (2d surface temperature) from original grid (0.25 deg) to 1 deg. Before the ERA5 update, it took around 20 minutes.

Below is the command that I used:
cdo remapbil,grid_target.txt era5_tropical_sp_2020.nc era5_tropical_sp_1x1_2020.nc.

Is there any solution to solve the issue? Thanks in advance.

Best,
Jiawei

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by Uwe Schulzweida 5 days ago

Hi Jiawei,

Could you please send a link to the datafile?

Cheers,
Uwe

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by Jiawei Bao 5 days ago

Hi Uwe,

Thanks for the fast reply.
The data is on levante: /work/mh0066/m300752/OBS/ERA5/hourly/era5_tropical_Td_2020.nc

Cheers,
Jiawei

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by Uwe Schulzweida 5 days ago

Hi Jiawei,

The variable CDI_CHUNK_CACHE=1gb is set in the module environment of cdo/2.4.3-gcc-11.2.0. Unfortunately, this value is not sufficient for this ERA5 data.
If you use "unset CDI_CHUNK_CACHE" before the cdo call, it should run much faster:

unset CDI_CHUNK_CACHE
cdo remapbil,global_1 /work/mh0066/m300752/OBS/ERA5/hourly/era5_tropical_Td_2020.nc result
cdo    remapbil: Processed 3048399360 values from 1 variable over 8784 timesteps [51.60s 1567MB]

Cheers,
Uwe

RE: Why is it so slow to process ERA5 data with cdo after ERA5 update？ - Added by Jiawei Bao 5 days ago

Hi Uwe,

It's working and much faster now. Thanks a lot!

Cheers,
Jiawei

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