g.e23_a16g.GJRAv4.TL319_t232_zstar_N65.2024.021

[gustavo-marques]

Purpose: Twin of 2024.0015, but with the near-infra-red light attenuation coefficient set to half of the original value ( kIR = 0. 5 x 2.86 m−1)

One hypothesis for the warm SST bias in the southeast Equatorial Pacific is the strong near-surface SW absorption.

Running for only one year initially and saving terms needed to compute temperature budget.

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Case directory:

• Locally (if still available): /glade/work/gmarques/cesm.cases/G/g.e23_a16g.GJRAv4.TL319_t232_zstar_N65.2024.021

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Sandbox:

• Locally (if still available): /glade/work/gmarques/cesm.sandboxes/cesm2_3_alpha16g

• On github: https://github.com/ESCOMP/cesm/tree/cesm2_3_alpha16g

MOM6 tag:

dev/ncar_231018

MOM_interface tag: mi_231018

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Diagnostics:

• Diags (if available): TODO

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  Output:

• Raw output on derecho (if still available): /glade/derecho/scratch/gmarques/archive/g.e23_a16g.GJRAv4.TL319_t232_zstar_N65.2024.021/

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  Contacts: @gustavo-marques, @fobryan3

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  Extra details:

--compset 2000_DATM%JRA-1p4-2018_SLND_CICE_MOM6_DROF%JRA-1p4-2018_SGLC_SWAV_SESP --res TL319_t232

The following changes are included in user_nl_mom

INPUTDIR = "INPUT"
STOCH_EOS=True
STANLEY_COEFF=0.5
USE_STANLEY_PGF=True
USE_STANLEY_ML=True
USE_STANLEY_ISO=True
USE_STANLEY_GM=True
USE_NEUTRAL_DIFFUSION = True
NDIFF_TAPERING = True
KHTR_USE_EBT_STRUCT = True
MEKE_KHTR_FAC = 1.0
DO_GEOTHERMAL = True
GEOTHERMAL_SCALE = 1.0
GEOTHERMAL_FILE = "geothermal_davies2013_tx2_3_20231120_cdf5.nc"
GEOTHERMAL_VARNAME = "geothermal_hf"

The following changes are included in SourceMods/src.mom/MOM_opacity.F90

Change this line to

do n=3,nbands ; optics%opacity_band(n,i,j,k) = 0.5 * 2.86*US%Z_to_m ; enddo

[fobryan3]

Only a very small change in the solar absorption profile. I think the NIR is absorbed so quickly that even the factor of 2 change doesn't shift the profile into levels below 5m. Probably not worth extending this one. May need to rethink which coefficients to perturb.