b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas (coupled mpas configuration)

[adamrher]

Purpose:
Demonstrate mpasa atmosphere coupled run for mgmt. Will require tuning.

---

Description:
Modify sandbox to include coupled mpas grid alias in sandbox/ccs_config/modelgrid_aliases_nuopc.xml

  <model_grid alias="mpasa120_t232">
    <grid name="atm">mpasa120</grid>
    <grid name="lnd">mpasa120</grid>
    <grid name="ocnice">tx2_3v2</grid>
    <grid name="wav">wgx3v7</grid>
    <mask>tx2_3v2</mask>
  </model_grid>

Not sure on the baseline, however I think it should be initialized from a G-case ocean, rather than a prior ne30pg3 B-case. Perhaps run 287.

Tuning namelists based on prior coupled mpasa120 work with @HingOng, which used the cesm3_0_alpha07g tag with the latest dust mods SourceMod'd in. If we run with a more recent tag we will also need to make tuning adjustments due to the hygroscopicity bug fix that came in after alpha07g. Our best tunings come from the mpas.006 run:

cldfrc_dp1           = 0.1
cldfrc_sh1           =  0.04D0 <-- pretty sure this isn't used in CAM7
clubb_c14            =  1.6D0
frontgfc             = 3.00D-15
taubgnd              = 1.25D-3
micro_mg_dcs         = 600.D-6
zmconv_ke            =  5.0E-6
clubb_c8             =  4.5
dust_emis_fact       = 4.0
seasalt_emis_scale   = 1.5

We will run with CMIP7 emissions on the f09 grid. Note I created this entry by copying similarly named directories and filenames from 271, but in the f09 folder. These need to be double checked and plotted.

srf_emis_specifier             = 'bc_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/bc_a4-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
bc_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/bc_a4_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
pom_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/pom_a4-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
pom_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/pom_a4_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
num_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_bc_a4-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
num_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/num_bc_a4_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
num_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_pom_a4-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
num_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/num_pom_a4_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
num_a1-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_so4_a1_ag-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
num_a1-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_so4_a1_ship_slv-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
num_a2-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_so4_a2_res_trs-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
so4_a1-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/so4_a1_ag_ship_slv-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
so4_a2-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/so4_a2_res_trs-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
so4_a1-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/SO4_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
num_a1-> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/num_SO4_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SO2 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/SO2-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
SO2 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/SO2_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 0.5954D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/ISOP_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 2.5592D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/BENZENE_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 2.5592D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/BENZENE-VOC-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18-supplemental_gn_175001-202312_c20251124.nc',
SOAE -> 8.5371D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/IVOC_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 8.5371D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/IVOC-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
SOAE -> 16.650D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/SVOC_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 16.650D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/SVOC-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
SOAE -> 8.2367D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/TOLUENE_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 8.2367D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/TOLUENE-VOC-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18-supplemental_gn_175001-202312_c20251124.nc',
SOAE -> 6.5013D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/XYLENES_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',
SOAE -> 6.5013D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/XYLENES-VOC-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18-supplemental_gn_175001-202312_c20251124.nc',
SOAE -> 5.1004D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/MTERP_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc'

ext_frc_specifier              = 'bc_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/bc_a4-em-AIR-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251129.nc',
num_a4 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_bc_a4-em-AIR-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251129.nc',
SO2 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/SO2-em-AIR-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251129.nc',
so4_a1 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/so4_a1_ene_vertical-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
num_a1 -> /glade/campaign/acom/MUSICA/emis/cmip7/f09/CEDS-CMIP-2025-04-18_20251124/num_so4_a1_ene_vertical-em-anthro_input4MIPs_emissions_CMIP_CEDS-CMIP-2025-04-18_gn_175001-202312_c20251124.nc',
num_a1 -> /glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_a1_so4_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
num_a2 -> /glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_a2_so4_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
so4_a1 -> /glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a1_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
so4_a2 -> /glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a2_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
SO2 -> /glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_SO2_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc'

In 271 we had a bad IVOC file, and so we need to determine whether the corresponding entry here needs to be changed as well. The file in question is:

'SOAE -> 8.5371D0*/glade/campaign/acom/MUSICA/emis/cmip7/f09/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251102/IVOC_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251102.nc',

It has the same date stamp c20251102 as the bad ne30pg3 file. The corrected ne30pg3 file has a date stamp of c20251118, and is located here:

'SOAE -> 8.5371D0*/glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/cmip7/ne30/DRES-CMIP-BB4CMIP7-2-0_smoothed_20251118/IVOC_smoothed_input4MIPs_emissions_CMIP_DRES-CMIP-BB4CMIP7-2-0_gn_175001-202112_c20251118.nc',

I don't see a similarly dated directory DRES-CMIP-BB4CMIP7-2-0_smoothed_20251118 in the f09 folder so if the f09 file above is bad, then a corrected version may not exist.

---

Case directory:

• Locally (if still available):
  /glade/campaign/cesm/cesmdata/cseg/runs/cesm2_0/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas

• On github:
  https://github.com/NCAR/cesm_dev/tree/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas

---

Sandbox:

• Locally (if still available): /glade/work/hannay/cesm_tags/cesm3_0_alpha07g_mpas

---

Diagnostics:

• Diags (if available):
  https://webext.cgd.ucar.edu/BLT1850/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas/

---

Output:

• Raw output on derecho (if still available): /glade/derecho/scratch/hannay/archive/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas/
• CAM Climos: /glade/campaign/cgd/amp/amwg/climo/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas

---

Contacts:
@cecilehannay @dlawrenncar @PeterHjortLauritzen @islasimpson @gunterl

---

Extra details:

[HingOng]

To add a bit more context to our "mpas.006" run @adamrher mentioned, the namelist of mpas.006 switches on the deep-atmosphere option of MPAS-A:
mpas_deep_atmosphere = .true.
Before tuning, we ran a pair of coupled simulations with that option set to true and false. Switching it true significantly improves the tropical precipitation distribution and mitigates the double-ITCZ bias. The following poster shows more information:
https://hingong.github.io/files/HingOng_AGU_NCT_ITCZ.pdf

[cecilehannay]

As I was setting this case, I noticed that 287 is not starting from a G case. It is starting from another spunup case: b.e30_alpha07c_cesm.B1850C_LTso.ne30_t232_wgx3.247. So if we want to start from a G case, 287 is not good.
I might try to start that run from 308 to make it we can run it and then we can decide on another setting.

[cecilehannay]

Summary of comments (#257 (comment))

• from Cecile:
  Assuming we want to start from a G case: I talked to Gustavo and and he confirmed that he has not created condition for recent configurations. The latest configuration starting from a G case is 284.

Gustavo: could you confirm this configuration is viable. If not, which configuration starting from a G case would you recommend.

• From Gustavo:
  This configuration is viable. Just keep in mind that Bonder is not turned off in the Lab Sea. If Lab Sea freezes, we can turn it off.

If you want to turn off Bonder in the Lab Sea, remove the following from user_nl_mom:

MLE%
USE_CR_GRID = False
CR = 0.005 ! Low value to improve Salinity cycle in Southern Ocean, especially Atlantic DMB
%MLE
MLE_DENSITY_DIFF = 0.03

• From Adam:
  I think we should turn off Bodner for the MPAS experiment.

• From Cecile:
  The experience the lab sea to freeze in cases starting from a G case even if BOdner is off in lab sea. It will "de-freeze" after spinup.

[cecilehannay]

I created a case:
/glade/campaign/cesm/cesmdata/cseg/runs/cesm2_0/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas

If we want to match the tuning from 284, we would need to add:

seasalt_emis_scale		= 1.25
micro_mg_dcs		= 500.D-6
micro_mg_vtrmi_factor		= 1.2
zmconv_c0_lnd		= 0.0035D0

[HingOng]

I created a case: /glade/campaign/cesm/cesmdata/cseg/runs/cesm2_0/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas

If we want to match the tuning from 284, we would need to add:

seasalt_emis_scale		= 1.25
micro_mg_dcs		= 500.D-6
micro_mg_vtrmi_factor		= 1.2
zmconv_c0_lnd		= 0.0035D0

@adamrher How does this .284 case compare to our mpas.006 case?

[adamrher]

Hi @cecilehannay

If we want to match the tuning from 284, we would need to add:

Don't add those to user_nl_cam. Just use the namelists listed at the top of this thread.

Hi @HingOng

How does this .284 case compare to our mpas.006 case?

The ocean configuration is slightly different. A taper was added to the Leith-E backscatter to reduce excessively deep mixing in the equatorial regions.

This run will also be initialized from a G-case using the OMIP protocol (JRA data atmosphere with the ocean initialized from Levitus World Ocean Atlas), whereas our runs were initialized from the end of a long ne30pg3 BHIST_LTso run. I think this was creating large initial adjustments in our previous mpas runs since the ocean was equilibrated to a different atm dycore. The G-case initialization will likely also cause large initial adjustments, but it's a cleaner approach.

[cecilehannay]

I am getting an error:

Grid: mpas_cell, ID =  101, lat coord  = latCell, lon coord  = lonCell, unstruct   =  T, block_ind  =  F, zonal_grid =  F
Attribute: area_cell, long name = 'mpas cell areas'
           dimname = nCells
Attribute: area_weight_mpas, long name = 'mpas area weight'
           dimname = nCells
Grid: cam_cell, ID =  104, lat coord  = lat, lon coord  = lon, unstruct   =  T, block_ind  =  F, zonal_grid =  F
Grid: mpas_edge, ID =  102, lat coord  = latEdge, lon coord  = lonEdge, unstruct   =  T, block_ind  =  F, zonal_grid =  F
Grid: mpas_vertex, ID =  103, lat coord  = latVertex, lon coord  = lonVertex, unstruct   =  T, block_ind  =  F, zonal_grid =  F
Grid: physgrid, ID =  100, lat coord  = lat, lon coord  = lon, unstruct   =  T, block_ind  =  T, zonal_grid =  F
Attribute: area, long name = 'physics column areas'
           dimname = ncol
Attribute: areawt, long name = 'physics column area weight'
           dimname = ncol

DOes it look familiar?

[adamrher]

I've checked that's normal output -- not an error. The issue seems to be the zonal averaging fincl tape, in the cesm.log:

dec1927.hsn.de.hpc.ucar.edu 2432:  ZonalAverage init ERROR: jlat not in range
dec0625.hsn.de.hpc.ucar.edu 55:  ZonalAverage init ERROR: jlat not in range
dec1927.hsn.de.hpc.ucar.edu 2432: Image              PC                Routine            Line        Source
dec1927.hsn.de.hpc.ucar.edu 2432: cesm.exe           0000000003D11392  shr_abort_mod_mp_         110  shr_abort_mod.F90
dec1927.hsn.de.hpc.ucar.edu 2432: cesm.exe           000000000097625C  zonal_mean_mod_mp        1130  zonal_mean_mod.F90
dec1927.hsn.de.hpc.ucar.edu 2432: cesm.exe           00000000006B0CA4  phys_grid_ctem_mp         174  phys_grid_ctem.F90
dec1927.hsn.de.hpc.ucar.edu 2432: cesm.exe           00000000005A6CB4  cam_comp_mp_cam_i         167  cam_comp.F90

Can you remove these entries from user_nl_cam?

fincl5 = 'Uzm','Vzm','Wzm','THzm', 'VTHzm','WTHzm','UVzm','UWzm'
phys_grid_ctem_nfreq=-6
phys_grid_ctem_zm_nbas=120
phys_grid_ctem_za_nlat=90

[cecilehannay]

thanks @adamrher. I confirm it is running fine now. It just completed the first year.

[adamrher]

Update on the coupled mpas run. The main takeaway is that (a) RESTOM is too +ve, and (b) there are a lot of interesting differences in the clouds relative to the current workhorse candidates 315 & 316. The main question is whether this is good enough, or if we should stop this run and wait for there to be a G-case with a more recent tag (i.e, based on run 311), and do some add'l tunings to bring RESTOM into balance. I suspect some of the larger cloud changes over the Southern Ocean in this run are at least in part due to using this older configuration, which we know has unrealistic low frequency variability.

[dlawrenncar]

I'd say this is good enough for now. Maybe we try again with the 'final' configuration of CESM3, which we are quite close to and possibly we could spend a small amount of effort to tune. For now, we are mainly looking for a demonstration that this could work which we effectively already knew, but now can show explicitly.

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On Mon, Feb 23, 2026 at 7:47 PM Adam Herrington ***@***.***> wrote: *adamrher* left a comment (NCAR/cesm_dev#295) <#295 (comment)> Update on the coupled mpas run. The main takeaway is that (a) RESTOM is too +ve, and (b) there are a lot of interesting differences in the clouds relative to the current workhorse candidates 315 & 316. The main question is whether this is good enough, or if we should stop this run and wait for there to be a G-case with a more recent tag (i.e, based on run 311), and do some add'l tunings to bring RESTOM into balance. I suspect some of the larger cloud changes over the Southern Ocean in this run are at least in part due to using this older configuration, which we know has unrealistic low frequency variability. Screenshot.2026-02-23.at.7.45.11.PM.png (view on web) <https://github.com/user-attachments/assets/f2fa14c0-2ad3-4913-b1f0-d3e9518f92db> Screenshot.2026-02-23.at.7.45.29.PM.png (view on web) <https://github.com/user-attachments/assets/0b0f1f31-ec35-4965-b182-553f130b5890> Screenshot.2026-02-23.at.7.45.37.PM.png (view on web) <https://github.com/user-attachments/assets/8b06c3f9-2759-42da-8a2b-7a865131b7e9> Screenshot.2026-02-23.at.7.45.44.PM.png (view on web) <https://github.com/user-attachments/assets/43a6585e-75f2-47b0-bd8f-39e86bae62ab> — Reply to this email directly, view it on GitHub <#295 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFABYVEWBFOHM7TCQDZHJQL4NO3VFAVCNFSM6AAAAACVKSQXGKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTSNBYGU4DANJTGU> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[HingOng]

@adamrher I am interested in the differences between the orange (mpas.284) and magenta (mpas.006) curves.
I understand that this #284.mpas case solves the shallow-atmosphere equations while our mpas.006 case solves the deep-atmosphere equations in the mpas dynamical core. I wonder whether the differences originate from the atmospheric governing equations. However, in addition to the governing equations, these two cases use different ocean model settings. To get a cleaner comparison, would you recommend that I clone the #284.mpas case and run it with "mpas_deep_atmosphere = .true."?

[HingOng]

I cloned this case and ran 20 years with "mpas_deep_atmosphere = .true." (i.e., with the nontraditional Coriolis terms [NCTs]). As expected, the NCTs tend to move the ITCZs toward the equator.
The following figure shows the precipitation rate climatology in the second decade. The shading shows the difference between @cecilehannay 's run (shallow) and mine (deep). The green contours show the deep one.

Case directory: /glade/derecho/scratch/hxong/b.e30_alpha07g.B1850C_LTso.ne30_t232_wgx3.284.mpas.deep
Reference: https://hingong.github.io/files/HingOng_AGU_NCT_ITCZ.pdf

[adamrher]

Thanks for this Hing, I'll take a closer look at this run. Can you explain how you cloned the case, given you had to use a different code base than Cecile's?