# Namelist configuration discussion meeting **URL:** https://forum.access-hive.org.au/t/namelist-configuration-discussion-meeting/1917 **Category:** Working Group **Tags:** meeting, access-om3, mom6 **Created:** [13 March 2024 04:06 UTC](https://forum.access-hive.org.au/t/namelist-configuration-discussion-meeting/1917 "2024-03-13T04:06:04Z") **Posts on this page:** 1 **Showing post:** 9
### Author: ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss) #### Post date: [15 March 2024 03:31 UTC](https://forum.access-hive.org.au/t/namelist-configuration-discussion-meeting/1917/9 "2024-03-15T03:31:50Z")
**Meeting notes** (_this is a wiki - please edit!_) existing cosima mom6 came from mom6 examples from om4 0.25° but with some changes Adele: should we get the GFDL OM5 param? Steve says we should use their mixing parameters which they have carefully tuned (see [MOM6 science testing · Issue #96 · COSIMA/access-om3 · GitHub](https://github.com/COSIMA/access-om3/issues/96#issuecomment-1939804701)) - Adele to follow up - [GFDL OM5 parameters are here](https://github.com/COSIMA/access-om3-doc/tree/main/configs/GFDL-OM5). Adele: dttherm:dt ratio was only 2 for regional due to boundary issues but could presumably be increased for global Dougie: WOMBAT has hard-coded 900s timestep for ecology - can be configurable in generic tracers leave HFREEZE set to 10m (default) so we calculate freeze/melt potential MINIMUM\_DEPTH - changes land mask - set to zero so we control minimum depth via topog.nc CHANNEL\_CONFIG set to none nk set to 75 at both 1° and 0.25° to match ACCESS-OM2-01 - use KDS75 z\* - test hybrid adaptive coords later; initial target is something as robust as we can, eg for CMIP7 look in more detail at DTFREEZE\_DP = -7.75E-08 - differs from default 0 and would be redundant if we used TFREEZE\_FORM = “TEOS10” - should we move to TEOS10 for EOS as well? do we want to save diagnostics on a lower resolution horizontal grid? USE\_MEKE: calculates evolution of mesoscale EKE budget and uses it to tune eddy parameterisation - something we should test; until we do that we should leave as-is or turn off - see [1deg\_jra55do\_ryf: Address MOM warnings · Issue #199 · COSIMA/access-om3 · GitHub](https://github.com/COSIMA/MOM6-CICE6/issues/13#issuecomment-1997006493) RESOLN\_SCALED\_KH, KHTH - leave on at both 1° and 0.25° leave KHTH parameters as they are for mow, but needs testing - important to test if they came from NCAR as may not have been tested TIDES - turn off, and all associated parameters Lateral viscosity, smag etc - try using same values as [ACCESS-OM2](https://github.com/COSIMA/access-om3-doc/blob/main/tables/MOM_input/ACCESS-OM2-1-025_nml.md) mixed layer restratification - not very sensitive to these params so use the same as access-om2 for consistency use KPP with existing for now but test EPBL for future configs (ask Wilton - he’s done some testing) use pressure-dependent frazil pen\_sw\_\* - match access-om2 shortwave penetration if we can, and test/compare - may have bearing on WOMBAT - Dougie to do with Pearse - what about WOMBAT-mid shortwave attenuation? is that still planned? - might change use neutral diffusion at both 1° and 0.25° - is this done the same way as in mom5? - to test RESTART\_CONTROL - try using default (1) OCEAN\_SURFACE\_STAGGER = “A” - needed for NUOPC to avoid remapping in mediator LATENT\_HEAT\_FUSION - make sure this matches CICE - add to list of cross-component tests ADJUST\_NET\_SRESTORE\_TO\_ZERO = True - matches access-om2 ADJUST\_NET\_FRESH\_WATER\_TO\_ZERO = True - matches access-om2 ADJUST\_NET\_FRESH\_WATER\_BY\_SCALING - try this out FLUXCONST = 0.11 matches access-om2 piston velocity RESTORE\_SALINITY - to investigate - can we have salinity restoring via salt flux in OM3? I guess we want a water flux in CM3? GUST\_CONST - leave as-is for now MAX\_ENT\_IT and TOLERANCE\_ENT - set to default - see [MOM\_parameter\_doc\_\* incomplete · Issue #121 · COSIMA/access-om3 · GitHub](https://github.com/COSIMA/access-om3/issues/121) HMIX\_MIN - use default (0.0) since we don’t use `REGULARIZE_SURFACE_LAYERS` in our configurations WRITE\_GEOM = 1 RESTART\_CHECKSUMS\_REQUIRED = True - needed for repro testing, leave as default all OBC params irrelevant BOUNDARY\_EXTRAPOLATION\_PRESSURE - delete - use default PRANDTL\_TURB = 1.0 (default) SMAGORINSKY\_AH - turn on SMAGORINSKY\_KH - turn off Jump over EPBL for now leave TIMEUNIT = 8.64E+04 (default) MAXTRUNC = 1000 DIAG\_COORDS - want both zstart and rho2 BAD\_VAL\_SS\*\_MAX/MIN - should work out why it crashes with default values [Sudden crashes with excessive SSH · Issue #55 · COSIMA/access-om3 · GitHub](https://github.com/COSIMA/access-om3/issues/55) **Summary of Tests we should run:** 1. Hybrid and/or Adaptive vertical coordinates (vs default z\*) 2. The Equation of State - switch to Roquet formulation?? 3. Can we output diagnostics at subsampled resolution?? 4. MEKE to tune eddy parameterisation. 5. KHTH & neutral diffusion 6. Smagorinsky lateral viscosity - move towards OM2 values? 7. EPBL vs KPP 8. SW penetration scheme - pen\_sw\_\* 9. RESTART\_CONTROL 10. Salinity restoring fluxconst Note that some of these tests will require longer (10-20 year) simulations. --- _[View the full topic](https://forum.access-hive.org.au/t/namelist-configuration-discussion-meeting/1917)._