No anthro options to tools, and all future scenarios in place, plus a few small issue fixes #616
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…as well as lakes and wetlands outside of the landmask with new code: < ! Assume wetland, glacier and/or lake when dataset landmask implies ocean < if (pctgla(n) < 1.e-6_r8) then < pctwet(n) = 100._r8 - pctlak(n) < pctgla(n) = 0._r8 < else < pctwet(n) = 100._r8 - pctgla(n) - pctlak(n) < end if from > ! Assume wetland and/or lake when dataset landmask implies ocean > pctwet(n) = 100._r8 - pctlak(n) > pctgla(n) = 0._r8
Update cime to next version being used in cesm2.1.0 release. And fix the XML for f05 surface dataset for 1850 and non-crop. Test that all six f05 cases work (1850/2000/Hist,crop/non-crop).
…rrecting that now allows each one to work correctly
Option for rain-to-snow to immediately run off in some regions Up until now: When repartition_rain_snow is .true. (which is the default for CLM5), rain that falls when the near-surface temperature is cold is converted to snow. This repartitioning was put in place for two reasons: (1) Downscaling to elevation classes: changing the balance between rain and snow for different elevation classes; (2) Correcting problems in CAM. However, members of the Land Ice Working Group would like to change this behavior so that, when CAM produces cold-temperature rain, this rain immediately runs off rather than being converted to snow. The purpose of this is to reduce the too-high SMB over portions of Greenland in CESM2 coupled runs (which results in part from CAM's generation of liquid precipitation despite very cold temperatures). This new behavior is implemented in a glacier region-specific manner, based on a new namelist flag, glacier_region_rain_to_snow_behavior. It is not at all ideal to make this aspect of the physics differ by region, but this has been requested by members of the Land Ice Working Group in order to address biases over Greenland while having minimal impact on the climate (so that the climate can stay very similar to that of the official CMIP6 runs). Note that, unlike other glacier region-specific behaviors, this one applies to all landunits, not just glaciers. This also seems a bit non-ideal, but we want the physics to be the same for all landunit types in a given region, and we also want this behavior to apply to vegetated columns because they are used for glacial inception (and we want this alternate behavior to apply to glacial inception, too, in order to decrease some instances of inception). The justification for this new physics is: In the case of (1) above: If CAM is generating rain at a given elevation / temperature, that doesn't necessarily imply that an equal water equivalent of snow would be generated at a higher elevation / lower temperature: indeed, in reality, there might not be any precipitation falling at that higher elevation / lower temperature. In the case of (2) above: There seem to be problems with CAM's microphysics that cause it to produce too much rain when temperatures are very cold; it seems (at least to some people) equally justifiable to throw this cold rain away (by sending it to the ocean as runoff) as it is to convert this cold rain to snow. Note: I don't think any changes are needed in BalanceCheck (unfortunately), since BalanceCheck currently uses the post-downscaling precipitation fluxes, and the pre-lnd2atm runoff fluxes (i.e., the new runoff flux isn't included in the terms in BalanceCheck, and it doesn't need to be because BalanceCheck uses the post-downscaling precipitation fluxes). (See also ESCOMP#201 (comment) .) CTSM Master Tag This Corresponds To: N/A At least for now, we are bringing this to the release branch but not to master. Here is an excerpt from the email explaining this rationale: My question is: Should I do this: (1) Just on a branch off of the release-clm5.0 branch, with no plan to bring it back to release-clm5.0 or master (2) On the release-clm5.0 branch, but not bring it back to master (3) On the release-clm5.0 branch and master My inclination right now is towards (2). I don't really like (1) because this change will be wanted for a number of CMIP6-related experiments, and it feels like it could be a pain to keep this branch up-to-date with the evolving release-clm5.0 branch. However, the changes are going to be a bit messy and having this be region-specific isn't really physically justifiable (it's just being done that way to keep the climate as close as possible to the official CMIP6 runs), so I'm not sure we really want this on master. If we did anything on master, I could imagine having a globally-applicable switch controlling this behavior, rather than having it apply to just certain glacier regions. Bette: The main reason I could see for bringing this to master is if you imagine needing to use this new option in isotope-enabled runs, since the isotope-enabled version of CTSM won't be on the release-clm5.0 branch. Do you think it's likely that you'd need to do that, or would the isotope-enabled runs use the standard CMIP6 physics settings in this respect?
…as sim_year for clm4_5
ekluzek
added
type: enhancement
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Description of changes
Brings in PtVg option for sim_year, which can be used for noanthro option for tools.
Bring all future scenarios in place for tools.
Fix some small issues
Specific notes
Contributors other than yourself, if any: lawrencepj1
CTSM Issues Fixed (include github issue #): #553 #533 #547 #545
Are answers expected to change (and if so in what way)? No
only changes tools, brings in wetlands fix so surface datasets are different
Any User Interface Changes (namelist or namelist defaults changes)? sim_year in build-namelist is now char*4 rather than integer
Testing performed, if any: tools testing and namelist testing