How do we run with hybrid vs isopycnic BLOM i NorESM2.5?

[adagj]

Hi,
Can someone please explain how we activate the hybrid version of BLOM (I'm assuming isopycnic still is the default option, but I might be wrong - then please correct me :) in NorESM2.5? @matsbn @oyvindseland @mvertens

[matsbn]

BLOM isopycnic is still default. To activate hybrid vertical coordinate one needs to execute

./xmlchange BLOM_VCOORD=cntiso_hybrid,BLOM_TURBULENT_CLOSURE=

before case.setup (I suggest to make this selectable in the compset definition, so that e.g. BLOM%HYB will set these options NorESMhub/BLOM#361).

With BLOM hybrid and the tnx1v4 grid, I recommend the following consistent initial conditions for CICE and BLOM:

In user_nl_cice, set

ice_ic = "/cluster/work/users/matsbn/archive/NOIIAJRAOC20TR_TL319_tn14_ppm_notz_20240115/rest/1775-01-01-00000/NOIIAJRAOC20TR_TL319_tn14_ppm_notz_20240115.cice.r.1775-01-01-00000.nc”

In user_nl_blom, set

ICFILE = "/cluster/work/users/matsbn/archive/NOIIAJRAOC20TR_TL319_tn14_ppm_notz_20240115/rest/1775-01-01-00000/NOIIAJRAOC20TR_TL319_tn14_ppm_notz_20240115.blom.r.1775-01-01-00000.nc”

With BLOM isopycnic, I recommend the following initial conditions for CICE and BLOM, that has a similar spinup procedure as above for BLOM hybrid:

In user_nl_cice, set

ice_ic="/cluster/work/users/matsbn/archive/NOIIAJRAOC20TR_TL319_tn14_20190710/rest/1775-01-01-00000/NOIIAJRAOC20TR_TL319_tn14_20190710.cice.r.1775-01-01-00000.nc"

In user_nl_blom, set

ICFILE   = "/cluster/work/users/matsbn/archive/NOIIAJRAOC20TR_TL319_tn14_20190710/rest/1775-01-01-00000/NOIIAJRAOC20TR_TL319_tn14_20190710.micom.r.1775-01-01-00000.nc"