diff --git a/doc/ChangeLog b/doc/ChangeLog index d2ef9f1e5d..15c36ca5f5 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,4 +1,149 @@ =============================================================== +Tag name: ctsm5.1.dev098 +Originator(s): swensosc (Sean Swenson) +Date: Fri May 20 18:15:53 MDT 2022 +One-line Summary: Correct perched water table calculation + +Purpose and description of changes +---------------------------------- + +Modifies the calculation of the frost table and perched water table +layers. + +This brings in the answer-changing aspects of the Hillslope Hydrology +branch (https://github.com/ESCOMP/CTSM/pull/1715). + +Specific changes are: + +* PerchedWaterTable + +1) Frost table depth + +a) original frost table determination looped from the top +of the soil column downward to the index of the first layer +whose temperature was <= freezing, and whose neighbor above +had a temperature above freezing. The frost table depth is +then given by the node of that soil layer, i.e. z(k_frz). + +b) in the new method, the same index is found, but the +depth of the frost table is given by the depth of the top +of the frozen layer, i.e. zi(k_frz-1). Note zi(k_frz) would +be the bottom of layer k_frz. + +2) Perched water table depth + +a) in the original formulation, a loop from k_frz to layer 1 +was used to identify the deepest layer in 1:k_frz whose +volumetric soil moisture was greater than a threshold given +by sat_lev (e.g. sat_lev = 0.9). + +b) in the new method, the search is only done if k_frz is +greater than 1. The rationale is that if k_frz = 1, then +zwt_perched has already been initialized to the frost_table +depth (which is equal to the top of the uppermost soil layer), +and therefore no search is required. + +3) Determining perched water table depth within layer +identified by index k_perch in 2) + +a) in the original formulation, the perched water table +depth was calculated by linearly interpolating between layers +k_perch and k_perch+1, with no consideration of their relative +values. In the case where the deeper layer was drier than the +layer above it, this could result in values far outside the +soil layer. + +b) in the new formulation, if the deeper layer is drier than the +layer above it (s1 > s2), then the perched water table depth is +simply given by the depth of the upper surface of layer k_perch, +i.e. zi(c,k_perch-1). + +* PerchedLateralFlow + +1) Removal of icefrac calculation + +a) in the original calculation, the frozen layer was included, +so an ice impedance factor was calculated using icefrac. If +only unfrozen layers are used, no ice impedance factor is needed. + +b) in the new formulation, the icefrac variable and loop are +removed. + +2) Move loop calculating frost and perched water table depths + +a) in the original formulation, the frost and perched water +table depths were calculated in the same loop as the calculation +of the lateral flow from the perched saturated zone. + +b) in preparation for the hillslope hydrology branch, this +calculation is moved into its own loop. + +3) q_perch calculation + +a)in the original formulation, q_perch was calculated by summing +over layers k_perch to k_frost. However, because k_frost is now +identified as the frozen layer, and its depth the top of the frozen +layer, it should not be included in the calculation; only the +unfrozen layers above it should be included. + +b) in the new formulation, the loop is bounded by k_frost-1 instead +of k_frost. + +4) Removal of water from perched saturated zone + +a) the in the original method, the frozen layer (k_frost) +was included in the loop. Also, the drainage was defined to be +negative, which was confusing. + +b) in the new method, the frozen layer is not included in the +loop; water is only removed from the unfrozen layers above k_frost. +Calculate drainage as positive values, which are then subtracted +from the soil moisture in each layer. + +Significant changes to scientifically-supported configurations +-------------------------------------------------------------- + +Does this tag change answers significantly for any of the following physics configurations? +(Details of any changes will be given in the "Answer changes" section below.) + + [Put an [X] in the box for any configuration with significant answer changes.] + +[X] clm5_1 + +[X] clm5_0 + +[X] ctsm5_0-nwp + +[ ] clm4_5 + + +Testing summary: +---------------- + + regular tests (aux_clm: https://github.com/ESCOMP/CTSM/wiki/System-Testing-Guide#pre-merge-system-testing): + + cheyenne ---- OK + izumi ------- OK + +Answer changes +-------------- + +Changes answers relative to baseline: YES + + Summarize any changes to answers, i.e., + - what code configurations: All Clm50 and Clm51 cases + - what platforms/compilers: All + - nature of change (roundoff; larger than roundoff/same climate; new climate): + Larger than roundoff; small changes to surface climate due to + differences originating in soil moisture + +Other details +------------- +Pull Requests that document the changes (include PR ids): +https://github.com/ESCOMP/CTSM/pull/1738 + +=============================================================== +=============================================================== Tag name: ctsm5.1.dev097 Originator(s): sacks (Bill Sacks) Date: Fri May 20 15:30:17 MDT 2022 diff --git a/doc/ChangeSum b/doc/ChangeSum index 1e5c4fb911..cf4df1cb81 100644 --- a/doc/ChangeSum +++ b/doc/ChangeSum @@ -1,5 +1,6 @@ Tag Who Date Summary ============================================================================================================================ + ctsm5.1.dev098 swensosc 05/20/2022 Correct perched water table calculation ctsm5.1.dev097 sacks 05/20/2022 Update ccs_config to fix issue on izumi and maybe elsewhere ctsm5.1.dev096 erik 05/18/2022 Fix a few glitches from the last tag ctsm5.1.dev095 erik 05/09/2022 Turn soil BGC off for FATES-SP mode, externals updates, FatesSP user-mod directory and compset