Update "What's New in CTSM 5.3" #2789
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| # What's new in CTSM 5.3 (tag `ctsm5.3.0`) | ||
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| ## Purpose and description of changes since CTSM 5.2 (tag `ctsm5.2.005`) | ||
| - Adds CN Matrix method to speed up spinup for the BGC model. | ||
| - Updates surface datasets. | ||
| - Brings in new Leung 2023 dust emissions. | ||
| - Adds explicit air conditioning for the urban model. | ||
| - Updates crop calendars. | ||
| - Updates fire model with various improvements, including default parameterization against climate reanalysis from CRU-JRA instead of GSWP. | ||
| - FATES compsets can now be run with transient land use. | ||
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| These changes were needed ahead of the CESM3 capability/functionality "chill". For `clm6_0` physics these options are now turned on by default, in addition to Sturm snow and excess ice. | ||
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| ## Changes to CTSM infrastructure | ||
| - `manage_externals` removed and replaced by `git-fleximod` | ||
| - Ability to handle CAM7 in `LND_TUNING_MODE` | ||
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| ## Changes to CTSM answers | ||
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| Changes to defaults for `clm6_0` physics: | ||
| - Urban explicit A/C turned on | ||
| - Snow thermal conductivity method is now `Sturm_1997` | ||
| - New initial conditions file for f09 ("1-degree") 1850, with more in progress | ||
| - New crop calendars | ||
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There was a problem hiding this comment. “with more in progress”—yes? |
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| - Dust emissions method is now `Leung_2023` | ||
| - Excess ice is turned on | ||
| - Updates to MEGAN for BVOCs | ||
| - Updates to BGC fire method | ||
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| Changes for all physics versions: | ||
| - Parameter files updated | ||
| - FATES parameter file updated | ||
| - Glacier region 1 is now undefined | ||
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There was a problem hiding this comment. "Glacier region 1 is now undefined": What does this mean in terms of answer changes? Why should users care? There was a problem hiding this comment. This is something I need to look at more carefully to describe accurately. We also might want to get Bill to help make sure we are accurate. |
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| - Update in FATES transient land use | ||
| - Pass active glacier (CISM) runoff directly to river model (MOSART) | ||
| - Add the option for using Matrix CN method for Carbon/Nitrogen BGC spinup | ||
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There was a problem hiding this comment. Since CN Matrix is an option, does it really fit in the “answer changes” section? There was a problem hiding this comment. Good point, it only changes answers when turned on, which normally is just for spinup. |
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| ## New surface datasets | ||
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There was a problem hiding this comment. Should this section title also mention land-use timeseries files? There was a problem hiding this comment. Yes. I think of "surface datasets" describing both, but for clarity you could spell out both fsurdat and flanduse_timeseries files. |
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| - With new surface datasets the following GLC fields have region "1" set to UNSET: glacier_region_behavior, glacier_region_melt_behavior, glacier_region_ice_runoff_behavior | ||
| - Updates to allow creating transient landuse timeseries files going back to 1700. | ||
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There was a problem hiding this comment. "With new surface datasets the following GLC fields...": What does this mean in terms of answer changes? Why should users care? There was a problem hiding this comment. Same as above. This is a good way to frame it by the way "why should users care"?. That's a good way to handle everything here. |
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There was a problem hiding this comment. So There was a problem hiding this comment. We did make 1700 for f09. I'm pretty sure we have them in the namelist defaults. Although I'd have to check. |
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| - Fix an important bug on soil fields that was there since `ctsm5.2.0`. This has the side effect of `mksurfdata_esmf` now giving identical answers with a change in number of processors, as it should. | ||
| - Surface datasets now provided for the `ne0np4.POLARCAP.ne30x4` grid. | ||
| - Surface datasets now have their version number embedded to prevent mismatch of surface dataset and CTSM version. | ||
| - Remove the `--hires_pft` option from `mksurfdata_esmf` as we don't have the datasets for it. | ||
| - Remove `VIC` fields from surface datasets. | ||
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There was a problem hiding this comment. Is There was a problem hiding this comment. Good question. I thought it worth mentioning for users of mksurfdata_esmf because it was a user visible option that we took away. Hence, it's good to explain why. The point is it was an option that wasn't functional so we removed it, and we'll return it when it is functional. |
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| - Updates to input datasets in PFT/LAI/soil-color raw datasets (now from the TRENDY2024 timeseries that ends in 2023), as well as two fire datasets (crop fire peak month, peatland fraction), and the glacier behavior dataset. | ||
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There was a problem hiding this comment. What are (were) VIC fields? There was a problem hiding this comment. VIC is an alternative hydrological parameterization that you could turn on, that we are deprecating. It required a few fields on the surface datasets to be used. This added complexity to both surface datasets as well as testing for it. So removing it simplifies a bunch of things all around. We could look for what fields were added to the surface datasets, but I think just saying they ware removed is sufficient here. |
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This section should mention new surface datasets and land-use timeseries files. Are those only used in
clm6_0physics or all physics versions?There was a problem hiding this comment.
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All physics versions.