1.1.9. Scientific Validation

In this section we go over what has been extensively tested and scientifically validated with CTSM1, and maybe more importantly what has NOT been tested and may NOT be scientifically validated. You can use all features of CLM, but need to realize that some things haven’t been tested extensively or validated scientifically. When you use these features you may run into trouble doing so, and will need to do your own work to make sure the science is reasonable.

1.1.9.1. Standard Configuration and Namelist Options that are Validated

See http://www.cesm.ucar.edu/models/cesm1.2/clm/CLM_configurations_CESM1.2.pdf for an explanation of what configurations are scientifically validated for CTSM1. For CLM4.0 changes to the science of the model are minimal since CESM1.1.1 so we expect answers to be very similar to using it.

In the sections below we go through configuration and/or namelist options or modes that the user should be especially wary of using. You are of course free to use these options, and you may find that they work functionally. Although in some cases you will find issues even with functionality of using them. If so you will need to test, debug and find solutions for these issues on your own. But in every case you will need to go through more extensive work to validate these options from a scientific standpoint. Some of these options are only for CTSM1 while others are for both CLM4.0 AND CTSM1 we explicitly say which they apply to.

1.1.9.2. Configurations that should be used with caution

There are some options in CTSM1 that are available but either not tested extensively, or not scientifically evaluated. These options should be used with caution. And any options that deviate from the scientifically supported configurations can have issues. The IMPORTANT_NODES file goes into more details on this.

The IMPORTANT_NOTES (which can be found in $CTSMROOT/doc) is repeated here.

$CTSMROOT/doc/IMPORTANT_NOTES                                   Apr/19/2024
                                                                            Erik Kluzek

Namelist items that are not regularly tested or used. Some aren't even implemented.

    See

    ../bld/namelist_files/namelist_definition_ctsm.xml -- for definitions

    CN_evergreen_phenology_opt
    CNratio_floating
    all_active
    allowlakeprod
    carbon_resp_opt
    ch4offline
    do_sno_oc
    finundation_method = h2osfc
    no_frozen_nitrif_denitrif
    perchroot
    perchroot_alt
    reduce_dayl_factor
    replenishlakec
    snicar_dust_optics /= sahara
    snicar_numrad_snw /= 5
    snicar_snobc_intmix /= TRUE
    snicar_snodst_intmix /= TRUE
    snicar_snw_shape /= hexagonal_plate
    snicar_solarspec /= mid_latitude_winter
    snicar_use_aerosol /= FALSE
    urban_traffic
    usefrootc
    use_cndv (deprecated)
    use_extralakelayers
    use_soil_moisture_streams
    use_vichydro
    vcmax_opt = 4

    FATES namelist options: FATES is a new experiemental subcomponent where all of it's options are
                            under current development. As such FATES and all of it's options should
                            be considered experimental.

   fates_history_dimlevel
   fates_inventory_ctrl_filename
   fates_parteh_mode
   fates_spitfire_mode
   use_fates
   use_fates_cohort_age_tracking
   use_fates_ed_prescribed_phys
   use_fates_ed_st3
   use_fates_fixed_biogeog
   use_fates_logging
   use_fates_luh
   use_fates_nocomp
   use_fates_planthydro
   use_fates_sp
   use_fates_spitfire
   use_fates_tree_damage
   use_fates_inventory_init