ESCOMP
Change some of our grids to use the MOM land/ocean mask at t232?
CESM3 has removed the POP ocean model, and now only has the MOM ocean model with the t232 grid. To be consistent with this change we should change our mizuRoute grid that use the t13 land/ocean mask to the t232 mask. However, there are some caveats here:
- The t232 grid is at a course resolution there may be science reasons to have a higher resolution land/ocean mask
- We'll have to add these new grids to ccs_config
- We'll need to update the tests to use the new grids
Since, this entails a bit of work to do, I'm not sure we should do it now for the CESM3 release. But, as we eventually want to couple mizuRoute to MOM -- we will need to do this eventually.
The grids that would need to change are:
hcru_hcru_rMERIT_mt13 hcru_hcru_rHDMA_mt13 hcru_hcru_rHDMAlk_mt13 f09_f09_rMERIT_mt13 f09_f09_rHDMA_mt13 f09_f09_rHDMAlk_mt13 f19_f19_rMERIT_mt13 f19_f19_rHDMA_mt13 f19_f19_rHDMAlk_mt13
to:
hcru_hcru_rMERIT_mt232 hcru_hcru_rHDMA_mt232 hcru_hcru_rHDMAlk_mt232 f09_f09_rMERIT_mt232 f09_f09_rHDMA_mt232 f09_f09_rHDMAlk_mt232 f19_f19_rMERIT_mt232 f19_f19_rHDMA_mt232 f19_f19_rHDMAlk_mt232
Definition of done:
- [ ] ESMCI/ccs_config_cesm#209
- [ ] Change tests to use _mt232
- [ ] Remove the _mt13 aliases from ccs_config
However, it does look like there is a t025 (quarter degree grid) for MOM. So perhaps that's what the change should go to?
We can hold off on this because _mt13 is being planned to stay around because it's needed in CAM. So won't be removed by the release. And this doesn't need to be a priority for mizuRoute for the release as well.
@nmizukami and I also noted that currently the ocean mask and ocean fraction has NO impact on mizuRoute. So the only impact for mizuRoute is how it will effect the coastlines for CTSM. And since we are running CTSM at course resolutions (with half degree the finest one) we needn't use anything higher than _mt232.
And going further our mapping doesn't take into account the ocean/mask. So we don't need to worry about this. So this is easier to do. We should just be able to change the grids in ccs_config, and start using them in our testing. Without having to change the mapping.
Mike Levy had this to say about grids:
We just had a CESM+MOM6 developer meeting, and I brought up the need for additional MOM6 grids (or at least masks) in CESM 3.0. The following seem pertinent following our meeting last week:
- The existing t025 grid is the GFDL 1/4° grid; Fred and others are working on a different 1/4° grid using a reproducible workflow that will also produce a 1/12° grid.
- Alper, Gustavo, and I will work on adding the 2°, 1/4°, and 1/12° grids in an upcoming tag -- our goal is to finalize the location of the grid cells / land mask for each resolution, though we will likely update the bathymetry at some point. I don't have a clear ETA for when this will be done, I think there are some updates coming for the 2° grid to make sure the dimensions are more amenable to decomposing across Derecho nodes and we want to bring in all three grids at once rather than repeating the process three times... but I think O(weeks), not months (or days).
I would recommend holding off on changing grids from the POP 0.1° grid to the t025 grid; once we introduce the new grids you can compare runs using the updated 1/4° and the 1/12° masks to see what you want to use.
So we should continue to hold off on updating grids. And I think that means we likely will do this after the cesm3_0 release.