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These commands will generate the remapping weights by computing the intersection mesh through advancing front intersection algorithm in MOAB and then using TempestRemap to generate the weights in parallel. The computed matrix weights are then written out in parallel in the h5m format (specified through option -f).
Note on DoF IDs for SE meshes
Currently, there is no consistent way to generate the global DoF ids for a spectral mesh in parallel, through MOAB. While the actual ID assignments for DoFs are easy in serial, the assignment in parallel could be dependent on the partitions and may not even match the numbering in HOMME. Hence, the generated mapping weights may need a different permutation to be applied before passing it back to HOMME within E3SM. So, the recommended workflow for such a case is to run HOMME to get the resolution of the grid required to generate the mapping file, and then store the DoF IDs as a GLOBAL_DOFS tag in MOAB, before being written to disk. This eliminates the need to get a consistent match when generating the weights in the MOAB mbtempest offline workflow.
Converting parallel h5m file to SCRIP file for E3SM
We are currently working on a Python script to convert the MOAB h5m file to a SCRIP file to be consumed in E3SM directly. As a future task, we will also be investing effort into writing a SCRIP file in parallel through a custom I/O interface using PNetCDF.
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