Update ChangeLog for cam6_4_126

Author: cacraigucar

doc/ChangeLog

@@ -1,12 +1,96 @@
-One-line Summary: Fix frontogenesis function bug
-Originator(s): Walter Hannah, Jack Chen (,Peter Lauritzen)
+===============================================================
+
+Tag name: cam6_4_126
+Originator(s):  Walter Hannah, Jack Chen, Peter Lauritzen, Cheryl Craig
+Date: Oct 16, 2025
+One-line Summary: Fix frontogenesis function bug and Change CISM2 to SGLC in FCHIST_GC compset
+Github PR URL: https://github.com/ESCOMP/pull/1415 and 1417
 
 Purpose of changes (include the issue number and title text for each relevant GitHub issue):
-   Fix bug in frontogenesis function computation: https://github.com/ESCOMP/CAM/issues/1414
+  - Fix bug in frontogenesis function computation: https://github.com/ESCOMP/CAM/issues/1414
+  - Change CISM2 to SGLC in FCHIST_GC compset: https://github.com/ESCOMP/CAM/issues/1416 and 1412
+
+Describe any changes made to build system: Using SGLC for FCHIST_GC compset
+
+Describe any changes made to the namelist: N/A
+
+List any changes to the defaults for the bound N/Aary datasets:
+
+Describe any substantial timing or memory changes: N/A
+
+Code reviewed by: Peter Lauritzen, Jack Chen, cacraigucar
+
+List all files eliminated:
+D       components/cism
+           - CISM external removed from CAM checkouts
+
+List all files added and what they do: N/A
+
+List all existing files that have been modified, and describe the changes:
+M       .gitmodules
+           - CISM external removed from CAM checkouts
+
+M       cime_config/config_compsets.xml
+           - FCHIST_GC compset now uses data ice
+
+M       src/dynamics/se/gravity_waves_sources.F90
+           - bug fixes for frontogenesis
+
+If there were any failures reported from running test_driver.sh on any test
+platform, and checkin with these failures has been OK'd by the gatekeeper,
+then copy the lines from the td.*.status files for the failed tests to the
+appropriate machine below.  All failed tests must be justified.
+
+derecho/intel/aux_cam:
+  ERC_D_Ln9.ne30pg2_ne30pg2_mt232.QPC7.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  ERC_D_Ln9.ne30pg3_ne30pg3_mt232.F1850C_LTso.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  ERI_D_Ln18.ne30pg3_ne30pg3_mt232.FHISTC_LTso.derecho_intel.cam-outfrq3s_eri (Overall: DIFF) details:
+  ERP_D_Ln9.ne30pg3_ne30pg3_mt232.F1850C_MTso.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  ERP_Ld3.ne16pg3_ne16pg3_mg17.FHISTC_WAt1ma.derecho_intel.cam-reduced_hist1d (Overall: DIFF) details:
+  ERP_Ld3.ne30pg3_ne30pg3_mt232.FHISTC_MTt4s.derecho_intel.cam-outfrq1d_aoa (Overall: DIFF) details:
+  ERP_Ln9.ne30pg3_ne30pg3_mg17.FCnudged.derecho_intel.cam-outfrq9s (Overall: DIFF) details  :
+  ERP_Ln9.ne30pg3_ne30pg3_mg17.FHISTC_WAma.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  ERS_Ln9.ne30pg3_ne30pg3_mg17.FHISTC_WXma.derecho_intel.cam-outfrq9s_ctem (Overall: DIFF) details:
+  SMS_C2_D_Ln9.ne16pg3_ne16pg3_mg17.FHISTC_WXma.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  SMS_D_Ln9.ne16_ne16_mg17.QPX2000.derecho_intel.cam-outfrq9s_amie (Overall: DIFF) details:
+  SMS_D_Ln9.ne30pg3_ne30pg3_mt232.FHISTC_MTso.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  SMS_D_Ln9_P1280x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+  SMS_D_Ln9_P1280x1.ne30pg3_ne30pg3_mt232.FHISTC_MTt1s.derecho_intel.cam-outfrq9s_Leung_dust (Overall: DIFF) details:
+  SMS_Ld1.ne30pg3_ne30pg3_mg17.FC2010climo.derecho_intel.cam-outfrq1d (Overall: DIFF) details:
+  SMS_Ln9.ne30pg3_ne30pg3_mg17.FW2000climo.derecho_intel.cam-outfrq9s_rrtmgp (Overall: DIFF) details:
+    - All CAM7 and WACCM tests with SE dycore should have answer changes.
+
+  SMS_Ld1.f09_f09_mg17.FCHIST_GC.derecho_intel.cam-outfrq1d (Overall: DIFF) details:
+    - Answer and namelist changes due to changing CISM to be data ice
+
+derecho/nvhpc/aux_cam:
+  ERS_Ln9.ne30pg3_ne30pg3_mt232.FHISTC_LTso.derecho_nvhpc.cam-outfrq9s_gpu_default (Overall: DIFF) details:
+    - All CAM7 and WACCM tests with SE dycore should have answer changes.
+
+izumi/nag/aux_cam:
+  SMS_D_Ln3.ne5pg3_ne5pg3_mg37.QPX2000.izumi_nag.cam-outfrq3s (Overall: DIFF) details:
+  SMS_D_Ln6.ne5_ne5_mg37.QPWmaC4.izumi_nag.cam-outfrq3s_physgrid_tem (Overall: DIFF) details:
+    - All CAM7 and WACCM tests with SE dycore should have answer changes.
+
+
+izumi/gnu/aux_cam: all BFB
+
+Summarize any changes to answers, i.e.,
+- what code configurations:
+    - All CAM7 and WACCM tests with SE dycore should have answer changes due to using the frontal scheme
+
+- what platforms/compilers:
+    - all
+
+- nature of change (roundoff; larger than roundoff but same climate; new
+  climate): climate changing
 
-   All CAM7 and WACCM tests with SE dycore should have answer changes.
+If this tag changes climate describe the run(s) done to evaluate the new
+climate in enough detail that it(they) could be reproduced, i.e.,
+    - Answers were scientifically verified by Peter and Julio
 
 ===============================================================
+===============================================================
 
 Tag name: cam6_4_125
 Originator(s): eaton