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60-10 Km model integration

pouwereou Nimon

New member
Dear all,
I am running MPAS variable resolution of 60-10 km and getting this issue:

ERROR: MPAS IO Error: Bad return value from PIO
ERROR: Error writing one or more output streams. Attached are my streams files.

I don't have any idea on how to solve the issue. Could you please help me on that. thanks!



  • streams.atmosphere.txt
    1.5 KB · Views: 8
  • streams.init_atmosphere.txt
    1.5 KB · Views: 4
Could you clarify whether the 60-10 km mesh you are using is the one from the mesh download page with 999426 horizontal grid cells? Your streams files reference files with the prefix "x6.23061988", which by our naming convention would suggest a mesh that refines by a factor of six, but with 23061988 horizontal grid cells.

In any case, the errors
ERROR: MPAS IO Error: Bad return value from PIO
ERROR: Error writing one or more output streams. Attached are my streams files.
may be a result of trying to write >4 GB to a single variable or record in a file format that doesn't support large variables. The following note from the mesh download page may apply:
The 3-d fields that exist in the model at higher resolution can easily exceed the 4 GB limit imposed by the classic netCDF format. When creating atmospheric initial conditions (i.e., the "" file), and when writing output streams from the model with 3-d fields, it is necessary to use an "io_type" that supports large variables, such as "pnetcdf,cdf5" or "netcdf4". For more information on selecting the "io_type" of a stream, refer to Chapter 5 in the Users' Guide.
Dear mgduda,
thank you very much for your response. I downloaded the mesh file from the mesh download page. I have just renamed the file to "" as I am simulating the June 23 1988.
I will work on it and give you a feedback. Thanks
Thanks for the clarification on the filenames -- I was wondering whether you might have created your own mesh through some means, and with 23M grid cells, using something like io_type="pnetcdf,cdf5" would be necessary. But, for the 60-10 km mesh from our download page with < 1M grid cells, my initial guess would be that no special settings for the output file format would be needed, unless, for example, you have a very large number of vertical levels.

It may also be worth checking the &io namelist record in your namelist.atmosphere file to verify that you're using multiple I/O tasks, as I think there can be some issues if any individual output task tries to write more than 2 GB at a time.