ROMS users attempting to use perturb_single_instance can compile and run the executable and it generates multiple identical copies of the input restart file.
Is your feature request related to a problem?
Yes, if a particular model_mod uses default_model_mod::pert_model_copies which interf_provided = .false. then perturb_single_instance will produce identical copies of the input restart file.
Describe your preferred solution
Add a pert_model_copies subroutine to the ROMS model_mod.
Describe any alternatives you have considered
I tried to copy the pert_model_copies subroutine from the POP model_mod but it requires an additional subroutine that determines whether a variable is a QTY_DRY_LAND.
Perturbing all non-land fields may be necessary for POP users because the standard POP configuration with ~1.0° horizontal resolution exhibits higher viscosity and includes the Gent and McWilliams (1990) 1 eddy parameterization (which is highly dissipative) when compared to ROMS. ROMS is usually run at much higher resolution than POP and explicitly does not include an eddy parameterization.
Thus the pert_model_copies subroutine in ROMS only perturbs QTY_TEMPERATURE and QTY_SALINITY because we expect perturbations to grow readily in this higher resolution.
hkershaw-brown
commented
2 years ago
Use case
ROMS users attempting to use
perturb_single_instancecan compile and run the executable and it generates multiple identical copies of the input restart file.Is your feature request related to a problem?
Yes, if a particular
model_modusesdefault_model_mod::pert_model_copieswhichinterf_provided = .false.thenperturb_single_instancewill produce identical copies of the input restart file.Describe your preferred solution
Add a
pert_model_copiessubroutine to the ROMSmodel_mod.Describe any alternatives you have considered
I tried to copy the
pert_model_copiessubroutine from the POPmodel_modbut it requires an additional subroutine that determines whether a variable is aQTY_DRY_LAND.Perturbing all non-land fields may be necessary for POP users because the standard POP configuration with ~1.0° horizontal resolution exhibits higher viscosity and includes the Gent and McWilliams (1990) 1 eddy parameterization (which is highly dissipative) when compared to ROMS. ROMS is usually run at much higher resolution than POP and explicitly does not include an eddy parameterization.
Thus the
pert_model_copiessubroutine in ROMS only perturbsQTY_TEMPERATUREandQTY_SALINITYbecause we expect perturbations to grow readily in this higher resolution.References
1 Gent, P. R., and J. C. McWilliams, 1990: Isopycnal Mixing in Ocean Circulation Models. J. Phys. Oceanogr., 20, 150–155, doi.org/10.1175/1520-0485(1990)020<0150:IMIOCM>2.0.CO;2.