2017 meeting notes

July 12, 2017

We talked about what the next steps in MARBL development should be. After bringing runtime configurability to PFT counts in to MARBL (currently in progress), it will probably be a good time to work on MARBL setting up its own namelist, and it would be useful to have better control over diagnostic output before bringing abio tracers into MARBL. So the recommended path forward is

1. Finish runtime-configurable PFT
2. MARBL building its own namelist
3. More flexibility in marbl_domain_type
4. Better control over what diagnostics are returned to GCM

For the namelist generation, we compiled a list of options the namelist generation tool should support

• --output-file-format: default will be Fortran namelist, but also support MPAS and MOM parameter file formats
• --default-file: XML file containing general defaults
• --non-default-files: a way to have MARBL provide multiple XML files that build on each other (e.g. turning CISO on)
• --user-specified-file: a way for the user to specify changes from the default settings
• --user-specified-file-format: XML file? something like CESM's user_nl text files? Something MPAS or MOM specific? etc etc.

For better control of diagnostics, what if MARBL did not allocate field_2d or field_3d but instead left that up to the GCM? Instead of compute_now we could just look to see if memory was allocated. (Maybe make them pointers, then check if associated?) This led to the follow up question about whether there are other parts of the interface that could be updated in this manner (state, forcings, fluxes, tendencies, etc). Conclusion was that it probably doesn't make sense to determine which tracer tendencies are returned in this manner, it's easier to think of tracers in natural groupings than as individual quantities).